<commit_before>use byteorder::{LittleEndian, WriteBytesExt};
use std::io::{self, Write};

use crate::color;
use crate::error::{ImageError, ImageResult, ParameterError, ParameterErrorKind};
use crate::image::ImageEncoder;

const BITMAPFILEHEADER_SIZE: u32 = 14;
const BITMAPINFOHEADER_SIZE: u32 = 40;
const BITMAPV4HEADER_SIZE: u32 = 108;

/// The representation of a BMP encoder.
pub struct BmpEncoder<'a, W: 'a> {
    writer: &'a mut W,
}

/// BMP Encoder
///
/// An alias of [`BmpEncoder`].
///
/// TODO: remove
///
/// [`BmpEncoder`]: struct.BmpEncoder.html
#[allow(dead_code)]
#[deprecated(note = "Use `BmpEncoder` instead")]
pub type BMPEncoder<'a, W> = BmpEncoder<'a, W>;

impl<'a, W: Write + 'a> BmpEncoder<'a, W> {
    /// Create a new encoder that writes its output to ```w```.
    pub fn new(w: &'a mut W) -> Self {
        BmpEncoder { writer: w }
    }

    /// Encodes the image ```image```
    /// that has dimensions ```width``` and ```height```
    /// and ```ColorType``` ```c```.
    pub fn encode(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        c: color::ColorType,
    ) -> ImageResult<()> {
        let bmp_header_size = BITMAPFILEHEADER_SIZE;

        let (dib_header_size, written_pixel_size, palette_color_count) = get_pixel_info(c)?;
        let row_pad_size = (4 - (width * written_pixel_size) % 4) % 4; // each row must be padded to a multiple of 4 bytes
        let image_size = width
            .checked_mul(height)
            .and_then(|v| v.checked_mul(written_pixel_size))
            .and_then(|v| v.checked_add(height * row_pad_size))
            .ok_or_else(|| {
                ImageError::Parameter(ParameterError::from_kind(
                    ParameterErrorKind::DimensionMismatch,
                ))
            })?;
        let palette_size = palette_color_count * 4; // all palette colors are BGRA
        let file_size = bmp_header_size + dib_header_size + palette_size + image_size;

        // write BMP header
        self.writer.write_u8(b'B')?;
        self.writer.write_u8(b'M')?;
        self.writer.write_u32::<LittleEndian>(file_size)?; // file size
        self.writer.write_u16::<LittleEndian>(0)?; // reserved 1
        self.writer.write_u16::<LittleEndian>(0)?; // reserved 2
        self.writer
            .write_u32::<LittleEndian>(bmp_header_size + dib_header_size + palette_size)?; // image data offset

        // write DIB header
        self.writer.write_u32::<LittleEndian>(dib_header_size)?;
        self.writer.write_i32::<LittleEndian>(width as i32)?;
        self.writer.write_i32::<LittleEndian>(height as i32)?;
        self.writer.write_u16::<LittleEndian>(1)?; // color planes
        self.writer
            .write_u16::<LittleEndian>((written_pixel_size * 8) as u16)?; // bits per pixel
        if dib_header_size >= BITMAPV4HEADER_SIZE {
            // Assume BGRA32
            self.writer.write_u32::<LittleEndian>(3)?; // compression method - bitfields
        } else {
            self.writer.write_u32::<LittleEndian>(0)?; // compression method - no compression
        }
        self.writer.write_u32::<LittleEndian>(image_size)?;
        self.writer.write_i32::<LittleEndian>(0)?; // horizontal ppm
        self.writer.write_i32::<LittleEndian>(0)?; // vertical ppm
        self.writer.write_u32::<LittleEndian>(palette_color_count)?;
        self.writer.write_u32::<LittleEndian>(0)?; // all colors are important
        if dib_header_size >= BITMAPV4HEADER_SIZE {
            // Assume BGRA32
            self.writer.write_u32::<LittleEndian>(0xff << 16)?; // red mask
            self.writer.write_u32::<LittleEndian>(0xff << 8)?; // green mask
            self.writer.write_u32::<LittleEndian>(0xff)?; // blue mask
            self.writer.write_u32::<LittleEndian>(0xff << 24)?; // alpha mask
            self.writer.write_u32::<LittleEndian>(0x73524742)?; // colorspace - sRGB

            // endpoints (3x3) and gamma (3)
            for _ in 0..12 {
                self.writer.write_u32::<LittleEndian>(0)?;
            }
        }

        // write image data
        match c {
            color::ColorType::Rgb8 => {
                self.encode_rgb(image, width, height, row_pad_size, 3)?
            }
            color::ColorType::Rgba8 => {
                self.encode_rgba(image, width, height, row_pad_size, 4)?
            }
            color::ColorType::L8 => {
                self.encode_gray(image, width, height, row_pad_size, 1)?
            }
            color::ColorType::La8 => {
                self.encode_gray(image, width, height, row_pad_size, 2)?
            }
            _ => {
                return Err(ImageError::IoError(io::Error::new(
                    io::ErrorKind::InvalidInput,
                    &get_unsupported_error_message(c)[..],
                )))
            }
        }

        Ok(())
    }

    fn encode_rgb(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
    ) -> io::Result<()> {
        let width = width as usize;
        let height = height as usize;
        let x_stride = bytes_per_pixel as usize;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for px in image[row_start..][..y_stride].chunks_exact(x_stride) {
                let r = px[0];
                let g = px[1];
                let b = px[2];
                // written as BGR
                self.writer.write_all(&[b, g, r])?;
            }
            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn encode_rgba(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
    ) -> io::Result<()> {
        let width = width as usize;
        let height = height as usize;
        let x_stride = bytes_per_pixel as usize;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for px in image[row_start..][..y_stride].chunks_exact(x_stride) {
                let r = px[0];
                let g = px[1];
                let b = px[2];
                let a = px[3];
                // written as BGRA
                self.writer.write_all(&[b, g, r, a])?;
            }
            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn encode_gray(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
    ) -> io::Result<()> {
        // write grayscale palette
        for val in 0u8..=255 {
            // each color is written as BGRA, where A is always 0 and since only grayscale is being written, B = G = R = index
            self.writer.write_all(&[val, val, val, 0])?;
        }

        // write image data
        let x_stride = bytes_per_pixel;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for col in 0..width {
                let pixel_start = (row_start + (col * x_stride)) as usize;
                // color value is equal to the palette index
                self.writer.write_u8(image[pixel_start])?;
                // alpha is never written as it's not widely supported
            }

            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn write_row_pad(&mut self, row_pad_size: u32) -> io::Result<()> {
        for _ in 0..row_pad_size {
            self.writer.write_u8(0)?;
        }

        Ok(())
    }
}

impl<'a, W: Write> ImageEncoder for BmpEncoder<'a, W> {
    fn write_image(
        mut self,
        buf: &[u8],
        width: u32,
        height: u32,
        color_type: color::ColorType,
    ) -> ImageResult<()> {
        self.encode(buf, width, height, color_type)
    }
}

fn get_unsupported_error_message(c: color::ColorType) -> String {
    format!(
        "Unsupported color type {:?}.  Supported types: RGB(8), RGBA(8), Gray(8), GrayA(8).",
        c
    )
}

/// Returns a tuple representing: (dib header size, written pixel size, palette color count).
fn get_pixel_info(c: color::ColorType) -> io::Result<(u32, u32, u32)> {
    let sizes = match c {
        color::ColorType::Rgb8 => (BITMAPINFOHEADER_SIZE, 3, 0),
        color::ColorType::Rgba8 => (BITMAPV4HEADER_SIZE, 4, 0),
        color::ColorType::L8 => (BITMAPINFOHEADER_SIZE, 1, 256),
        color::ColorType::La8 => (BITMAPINFOHEADER_SIZE, 1, 256),
        _ => {
            return Err(io::Error::new(
                io::ErrorKind::InvalidInput,
                &get_unsupported_error_message(c)[..],
            ))
        }
    };

    Ok(sizes)
}

#[cfg(test)]
mod tests {
    use super::super::BmpDecoder;
    use super::BmpEncoder;
    use crate::color::ColorType;
    use crate::image::ImageDecoder;
    use std::io::Cursor;

    fn round_trip_image(image: &[u8], width: u32, height: u32, c: ColorType) -> Vec<u8> {
        let mut encoded_data = Vec::new();
        {
            let mut encoder = BmpEncoder::new(&mut encoded_data);
            encoder
                .encode(&image, width, height, c)
                .expect("could not encode image");
        }

        let decoder = BmpDecoder::new(Cursor::new(&encoded_data)).expect("failed to decode");

        let mut buf = vec![0; decoder.total_bytes() as usize];
        decoder.read_image(&mut buf).expect("failed to decode");
        buf
    }

    #[test]
    fn round_trip_single_pixel_rgb() {
        let image = [255u8, 0, 0]; // single red pixel
        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgb8);
        assert_eq!(3, decoded.len());
        assert_eq!(255, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
    }

    #[test]
    fn huge_files_return_error() {
        let mut encoded_data = Vec::new();
        let image = vec![0u8; 3 * 40_000 * 40_000]; // 40_000x40_000 pixels, 3 bytes per pixel, allocated on the heap
        let mut encoder = BmpEncoder::new(&mut encoded_data);
        let result = encoder.encode(&image, 40_000, 40_000, ColorType::Rgb8);
        assert!(result.is_err());
    }

    #[test]
    fn round_trip_single_pixel_rgba() {
        let image = [1, 2, 3, 4];
        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgba8);
        assert_eq!(&decoded[..], &image[..]);
    }

    #[test]
    fn round_trip_3px_rgb() {
        let image = [0u8; 3 * 3 * 3]; // 3x3 pixels, 3 bytes per pixel
        let _decoded = round_trip_image(&image, 3, 3, ColorType::Rgb8);
    }

    #[test]
    fn round_trip_gray() {
        let image = [0u8, 1, 2]; // 3 pixels
        let decoded = round_trip_image(&image, 3, 1, ColorType::L8);
        // should be read back as 3 RGB pixels
        assert_eq!(9, decoded.len());
        assert_eq!(0, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
        assert_eq!(1, decoded[3]);
        assert_eq!(1, decoded[4]);
        assert_eq!(1, decoded[5]);
        assert_eq!(2, decoded[6]);
        assert_eq!(2, decoded[7]);
        assert_eq!(2, decoded[8]);
    }

    #[test]
    fn round_trip_graya() {
        let image = [0u8, 0, 1, 0, 2, 0]; // 3 pixels, each with an alpha channel
        let decoded = round_trip_image(&image, 1, 3, ColorType::La8);
        // should be read back as 3 RGB pixels
        assert_eq!(9, decoded.len());
        assert_eq!(0, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
        assert_eq!(1, decoded[3]);
        assert_eq!(1, decoded[4]);
        assert_eq!(1, decoded[5]);
        assert_eq!(2, decoded[6]);
        assert_eq!(2, decoded[7]);
        assert_eq!(2, decoded[8]);
    }
}
<commit_msg>support BMP encode with palette (indexed color)<commit_after>use byteorder::{LittleEndian, WriteBytesExt};
use std::io::{self, Write};

use crate::color;
use crate::error::{ImageError, ImageResult, ParameterError, ParameterErrorKind};
use crate::image::ImageEncoder;

const BITMAPFILEHEADER_SIZE: u32 = 14;
const BITMAPINFOHEADER_SIZE: u32 = 40;
const BITMAPV4HEADER_SIZE: u32 = 108;

/// The representation of a BMP encoder.
pub struct BmpEncoder<'a, W: 'a> {
    writer: &'a mut W,
}

/// BMP Encoder
///
/// An alias of [`BmpEncoder`].
///
/// TODO: remove
///
/// [`BmpEncoder`]: struct.BmpEncoder.html
#[allow(dead_code)]
#[deprecated(note = "Use `BmpEncoder` instead")]
pub type BMPEncoder<'a, W> = BmpEncoder<'a, W>;

impl<'a, W: Write + 'a> BmpEncoder<'a, W> {
    /// Create a new encoder that writes its output to ```w```.
    pub fn new(w: &'a mut W) -> Self {
        BmpEncoder { writer: w }
    }

    /// Encodes the image ```image```
    /// that has dimensions ```width``` and ```height```
    /// and ```ColorType``` ```c```.
    pub fn encode(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        c: color::ColorType,
    ) -> ImageResult<()> {
        self.encode_with_palette(image, width, height, c, None)
    }

    /// Same as ```encode```, but allow a palette to be passed in
    pub fn encode_with_palette(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        c: color::ColorType,
        palette: Option<&[(u8, u8, u8)]>,
    ) -> ImageResult<()> {
        let bmp_header_size = BITMAPFILEHEADER_SIZE;

        let (dib_header_size, written_pixel_size, palette_color_count) = get_pixel_info(c, palette)?;
        let row_pad_size = (4 - (width * written_pixel_size) % 4) % 4; // each row must be padded to a multiple of 4 bytes
        let image_size = width
            .checked_mul(height)
            .and_then(|v| v.checked_mul(written_pixel_size))
            .and_then(|v| v.checked_add(height * row_pad_size))
            .ok_or_else(|| {
                ImageError::Parameter(ParameterError::from_kind(
                    ParameterErrorKind::DimensionMismatch,
                ))
            })?;
        let palette_size = palette_color_count * 4; // all palette colors are BGRA
        let file_size = bmp_header_size + dib_header_size + palette_size + image_size;

        // write BMP header
        self.writer.write_u8(b'B')?;
        self.writer.write_u8(b'M')?;
        self.writer.write_u32::<LittleEndian>(file_size)?; // file size
        self.writer.write_u16::<LittleEndian>(0)?; // reserved 1
        self.writer.write_u16::<LittleEndian>(0)?; // reserved 2
        self.writer
            .write_u32::<LittleEndian>(bmp_header_size + dib_header_size + palette_size)?; // image data offset

        // write DIB header
        self.writer.write_u32::<LittleEndian>(dib_header_size)?;
        self.writer.write_i32::<LittleEndian>(width as i32)?;
        self.writer.write_i32::<LittleEndian>(height as i32)?;
        self.writer.write_u16::<LittleEndian>(1)?; // color planes
        self.writer
            .write_u16::<LittleEndian>((written_pixel_size * 8) as u16)?; // bits per pixel
        if dib_header_size >= BITMAPV4HEADER_SIZE {
            // Assume BGRA32
            self.writer.write_u32::<LittleEndian>(3)?; // compression method - bitfields
        } else {
            self.writer.write_u32::<LittleEndian>(0)?; // compression method - no compression
        }
        self.writer.write_u32::<LittleEndian>(image_size)?;
        self.writer.write_i32::<LittleEndian>(0)?; // horizontal ppm
        self.writer.write_i32::<LittleEndian>(0)?; // vertical ppm
        self.writer.write_u32::<LittleEndian>(palette_color_count)?;
        self.writer.write_u32::<LittleEndian>(0)?; // all colors are important
        if dib_header_size >= BITMAPV4HEADER_SIZE {
            // Assume BGRA32
            self.writer.write_u32::<LittleEndian>(0xff << 16)?; // red mask
            self.writer.write_u32::<LittleEndian>(0xff << 8)?; // green mask
            self.writer.write_u32::<LittleEndian>(0xff)?; // blue mask
            self.writer.write_u32::<LittleEndian>(0xff << 24)?; // alpha mask
            self.writer.write_u32::<LittleEndian>(0x73524742)?; // colorspace - sRGB

            // endpoints (3x3) and gamma (3)
            for _ in 0..12 {
                self.writer.write_u32::<LittleEndian>(0)?;
            }
        }

        // write image data
        match c {
            color::ColorType::Rgb8 => {
                self.encode_rgb(image, width, height, row_pad_size, 3)?
            }
            color::ColorType::Rgba8 => {
                self.encode_rgba(image, width, height, row_pad_size, 4)?
            }
            color::ColorType::L8 => {
                self.encode_gray(image, width, height, row_pad_size, 1, palette)?
            }
            color::ColorType::La8 => {
                self.encode_gray(image, width, height, row_pad_size, 2, palette)?
            }
            _ => {
                return Err(ImageError::IoError(io::Error::new(
                    io::ErrorKind::InvalidInput,
                    &get_unsupported_error_message(c)[..],
                )))
            }
        }

        Ok(())
    }

    fn encode_rgb(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
    ) -> io::Result<()> {
        let width = width as usize;
        let height = height as usize;
        let x_stride = bytes_per_pixel as usize;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for px in image[row_start..][..y_stride].chunks_exact(x_stride) {
                let r = px[0];
                let g = px[1];
                let b = px[2];
                // written as BGR
                self.writer.write_all(&[b, g, r])?;
            }
            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn encode_rgba(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
    ) -> io::Result<()> {
        let width = width as usize;
        let height = height as usize;
        let x_stride = bytes_per_pixel as usize;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for px in image[row_start..][..y_stride].chunks_exact(x_stride) {
                let r = px[0];
                let g = px[1];
                let b = px[2];
                let a = px[3];
                // written as BGRA
                self.writer.write_all(&[b, g, r, a])?;
            }
            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn encode_gray(
        &mut self,
        image: &[u8],
        width: u32,
        height: u32,
        row_pad_size: u32,
        bytes_per_pixel: u32,
        palette: Option<&[(u8, u8, u8)]>,
    ) -> io::Result<()> {
        // write grayscale palette
        if let Some(palette) = palette {
            for (r, g, b) in palette {
                // each color is written as BGRA, where A is always 0
                self.writer.write_all(&[*b, *g, *r, 0])?;
            }
        } else {
            for val in 0u8..=255 {
                // each color is written as BGRA, where A is always 0 and since only grayscale is being written, B = G = R = index
                self.writer.write_all(&[val, val, val, 0])?;
            }
        }

        // write image data
        let x_stride = bytes_per_pixel;
        let y_stride = width * x_stride;
        for row in (0..height).rev() {
            // from the bottom up
            let row_start = row * y_stride;
            for col in 0..width {
                let pixel_start = (row_start + (col * x_stride)) as usize;
                // color value is equal to the palette index
                self.writer.write_u8(image[pixel_start])?;
                // alpha is never written as it's not widely supported
            }

            self.write_row_pad(row_pad_size)?;
        }

        Ok(())
    }

    fn write_row_pad(&mut self, row_pad_size: u32) -> io::Result<()> {
        for _ in 0..row_pad_size {
            self.writer.write_u8(0)?;
        }

        Ok(())
    }
}

impl<'a, W: Write> ImageEncoder for BmpEncoder<'a, W> {
    fn write_image(
        mut self,
        buf: &[u8],
        width: u32,
        height: u32,
        color_type: color::ColorType,
    ) -> ImageResult<()> {
        self.encode(buf, width, height, color_type)
    }
}

fn get_unsupported_error_message(c: color::ColorType) -> String {
    format!(
        "Unsupported color type {:?}.  Supported types: RGB(8), RGBA(8), Gray(8), GrayA(8).",
        c
    )
}

/// Returns a tuple representing: (dib header size, written pixel size, palette color count).
fn get_pixel_info(c: color::ColorType, palette: Option<&[(u8, u8, u8)]>) -> io::Result<(u32, u32, u32)> {
    let sizes = match c {
        color::ColorType::Rgb8 => (BITMAPINFOHEADER_SIZE, 3, 0),
        color::ColorType::Rgba8 => (BITMAPV4HEADER_SIZE, 4, 0),
        color::ColorType::L8 => (BITMAPINFOHEADER_SIZE, 1, palette.map(|p| p.len()).unwrap_or(256) as u32),
        color::ColorType::La8 => (BITMAPINFOHEADER_SIZE, 1, palette.map(|p| p.len()).unwrap_or(256) as u32),
        _ => {
            return Err(io::Error::new(
                io::ErrorKind::InvalidInput,
                &get_unsupported_error_message(c)[..],
            ))
        }
    };

    Ok(sizes)
}

#[cfg(test)]
mod tests {
    use super::super::BmpDecoder;
    use super::BmpEncoder;
    use crate::color::ColorType;
    use crate::image::ImageDecoder;
    use std::io::Cursor;

    fn round_trip_image(image: &[u8], width: u32, height: u32, c: ColorType) -> Vec<u8> {
        let mut encoded_data = Vec::new();
        {
            let mut encoder = BmpEncoder::new(&mut encoded_data);
            encoder
                .encode(&image, width, height, c)
                .expect("could not encode image");
        }

        let decoder = BmpDecoder::new(Cursor::new(&encoded_data)).expect("failed to decode");

        let mut buf = vec![0; decoder.total_bytes() as usize];
        decoder.read_image(&mut buf).expect("failed to decode");
        buf
    }

    #[test]
    fn round_trip_single_pixel_rgb() {
        let image = [255u8, 0, 0]; // single red pixel
        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgb8);
        assert_eq!(3, decoded.len());
        assert_eq!(255, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
    }

    #[test]
    fn huge_files_return_error() {
        let mut encoded_data = Vec::new();
        let image = vec![0u8; 3 * 40_000 * 40_000]; // 40_000x40_000 pixels, 3 bytes per pixel, allocated on the heap
        let mut encoder = BmpEncoder::new(&mut encoded_data);
        let result = encoder.encode(&image, 40_000, 40_000, ColorType::Rgb8);
        assert!(result.is_err());
    }

    #[test]
    fn round_trip_single_pixel_rgba() {
        let image = [1, 2, 3, 4];
        let decoded = round_trip_image(&image, 1, 1, ColorType::Rgba8);
        assert_eq!(&decoded[..], &image[..]);
    }

    #[test]
    fn round_trip_3px_rgb() {
        let image = [0u8; 3 * 3 * 3]; // 3x3 pixels, 3 bytes per pixel
        let _decoded = round_trip_image(&image, 3, 3, ColorType::Rgb8);
    }

    #[test]
    fn round_trip_gray() {
        let image = [0u8, 1, 2]; // 3 pixels
        let decoded = round_trip_image(&image, 3, 1, ColorType::L8);
        // should be read back as 3 RGB pixels
        assert_eq!(9, decoded.len());
        assert_eq!(0, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
        assert_eq!(1, decoded[3]);
        assert_eq!(1, decoded[4]);
        assert_eq!(1, decoded[5]);
        assert_eq!(2, decoded[6]);
        assert_eq!(2, decoded[7]);
        assert_eq!(2, decoded[8]);
    }

    #[test]
    fn round_trip_graya() {
        let image = [0u8, 0, 1, 0, 2, 0]; // 3 pixels, each with an alpha channel
        let decoded = round_trip_image(&image, 1, 3, ColorType::La8);
        // should be read back as 3 RGB pixels
        assert_eq!(9, decoded.len());
        assert_eq!(0, decoded[0]);
        assert_eq!(0, decoded[1]);
        assert_eq!(0, decoded[2]);
        assert_eq!(1, decoded[3]);
        assert_eq!(1, decoded[4]);
        assert_eq!(1, decoded[5]);
        assert_eq!(2, decoded[6]);
        assert_eq!(2, decoded[7]);
        assert_eq!(2, decoded[8]);
    }
}
<|endoftext|>


<commit_before>//! Random number generation

export Rng, seed, seeded_rng, Weighted, extensions;
export xorshift, seeded_xorshift;

#[allow(non_camel_case_types)] // runtime type
enum rctx {}

#[abi = "cdecl"]
extern mod rustrt {
    fn rand_seed() -> ~[u8];
    fn rand_new() -> *rctx;
    fn rand_new_seeded(seed: ~[u8]) -> *rctx;
    fn rand_next(c: *rctx) -> u32;
    fn rand_free(c: *rctx);
}

/// A random number generator
trait Rng {
    /// Return the next random integer
    fn next() -> u32;
}

/// A value with a particular weight compared to other values
type Weighted<T> = { weight: uint, item: T };

/// Extension methods for random number generators
impl Rng {

    /// Return a random int
    fn gen_int() -> int {
        self.gen_i64() as int
    }

    /**
     * Return an int randomly chosen from the range [start, end),
     * failing if start >= end
     */
    fn gen_int_range(start: int, end: int) -> int {
        assert start < end;
        start + int::abs(self.gen_int() % (end - start))
    }

    /// Return a random i8
    fn gen_i8() -> i8 {
        self.next() as i8
    }

    /// Return a random i16
    fn gen_i16() -> i16 {
        self.next() as i16
    }

    /// Return a random i32
    fn gen_i32() -> i32 {
        self.next() as i32
    }

    /// Return a random i64
    fn gen_i64() -> i64 {
        (self.next() as i64 << 32) | self.next() as i64
    }

    /// Return a random uint
    fn gen_uint() -> uint {
        self.gen_u64() as uint
    }

    /**
     * Return a uint randomly chosen from the range [start, end),
     * failing if start >= end
     */
    fn gen_uint_range(start: uint, end: uint) -> uint {
        assert start < end;
        start + (self.gen_uint() % (end - start))
    }

    /// Return a random u8
    fn gen_u8() -> u8 {
        self.next() as u8
    }

    /// Return a random u16
    fn gen_u16() -> u16 {
        self.next() as u16
    }

    /// Return a random u32
    fn gen_u32() -> u32 {
        self.next()
    }

    /// Return a random u64
    fn gen_u64() -> u64 {
        (self.next() as u64 << 32) | self.next() as u64
    }

    /// Return a random float in the interval [0,1]
    fn gen_float() -> float {
        self.gen_f64() as float
    }

    /// Return a random f32 in the interval [0,1]
    fn gen_f32() -> f32 {
        self.gen_f64() as f32
    }

    /// Return a random f64 in the interval [0,1]
    fn gen_f64() -> f64 {
        let u1 = self.next() as f64;
        let u2 = self.next() as f64;
        let u3 = self.next() as f64;
        const scale : f64 = (u32::max_value as f64) + 1.0f64;
        return ((u1 / scale + u2) / scale + u3) / scale;
    }

    /// Return a random char
    fn gen_char() -> char {
        self.next() as char
    }

    /**
     * Return a char randomly chosen from chars, failing if chars is empty
     */
    fn gen_char_from(chars: ~str) -> char {
        assert !chars.is_empty();
        self.choose(str::chars(chars))
    }

    /// Return a random bool
    fn gen_bool() -> bool {
        self.next() & 1u32 == 1u32
    }

    /// Return a bool with a 1 in n chance of true
    fn gen_weighted_bool(n: uint) -> bool {
        if n == 0u {
            true
        } else {
            self.gen_uint_range(1u, n + 1u) == 1u
        }
    }

    /**
     * Return a random string of the specified length composed of A-Z,a-z,0-9
     */
    fn gen_str(len: uint) -> ~str {
        let charset = ~"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
                       abcdefghijklmnopqrstuvwxyz\
                       0123456789";
        let mut s = ~"";
        let mut i = 0u;
        while (i < len) {
            s = s + str::from_char(self.gen_char_from(charset));
            i += 1u;
        }
        s
    }

    /// Return a random byte string of the specified length
    fn gen_bytes(len: uint) -> ~[u8] {
        do vec::from_fn(len) |_i| {
            self.gen_u8()
        }
    }

    /// Choose an item randomly, failing if values is empty
    fn choose<T:copy>(values: ~[T]) -> T {
        self.choose_option(values).get()
    }

    /// Choose Some(item) randomly, returning None if values is empty
    fn choose_option<T:copy>(values: ~[T]) -> Option<T> {
        if values.is_empty() {
            None
        } else {
            Some(values[self.gen_uint_range(0u, values.len())])
        }
    }

    /**
     * Choose an item respecting the relative weights, failing if the sum of
     * the weights is 0
     */
    fn choose_weighted<T: copy>(v : ~[Weighted<T>]) -> T {
        self.choose_weighted_option(v).get()
    }

    /**
     * Choose Some(item) respecting the relative weights, returning none if
     * the sum of the weights is 0
     */
    fn choose_weighted_option<T:copy>(v: ~[Weighted<T>]) -> Option<T> {
        let mut total = 0u;
        for v.each |item| {
            total += item.weight;
        }
        if total == 0u {
            return None;
        }
        let chosen = self.gen_uint_range(0u, total);
        let mut so_far = 0u;
        for v.each |item| {
            so_far += item.weight;
            if so_far > chosen {
                return Some(item.item);
            }
        }
        unreachable();
    }

    /**
     * Return a vec containing copies of the items, in order, where
     * the weight of the item determines how many copies there are
     */
    fn weighted_vec<T:copy>(v: ~[Weighted<T>]) -> ~[T] {
        let mut r = ~[];
        for v.each |item| {
            for uint::range(0u, item.weight) |_i| {
                vec::push(r, item.item);
            }
        }
        r
    }

    /// Shuffle a vec
    fn shuffle<T:copy>(values: ~[T]) -> ~[T] {
        let mut m = vec::to_mut(values);
        self.shuffle_mut(m);
        return vec::from_mut(m);
    }

    /// Shuffle a mutable vec in place
    fn shuffle_mut<T>(&&values: ~[mut T]) {
        let mut i = values.len();
        while i >= 2u {
            // invariant: elements with index >= i have been locked in place.
            i -= 1u;
            // lock element i in place.
            vec::swap(values, i, self.gen_uint_range(0u, i + 1u));
        }
    }

}

struct RandRes {
    let c: *rctx;
    new(c: *rctx) { self.c = c; }
    drop { rustrt::rand_free(self.c); }
}

impl @RandRes: Rng {
    fn next() -> u32 { return rustrt::rand_next((*self).c); }
}

/// Create a new random seed for seeded_rng
fn seed() -> ~[u8] {
    rustrt::rand_seed()
}

/// Create a random number generator with a system specified seed
fn Rng() -> Rng {
    @RandRes(rustrt::rand_new()) as Rng
}

/**
 * Create a random number generator using the specified seed. A generator
 * constructed with a given seed will generate the same sequence of values as
 * all other generators constructed with the same seed. The seed may be any
 * length.
 */
fn seeded_rng(seed: ~[u8]) -> Rng {
    @RandRes(rustrt::rand_new_seeded(seed)) as Rng
}

type XorShiftState = {
    mut x: u32,
    mut y: u32,
    mut z: u32,
    mut w: u32
};

impl XorShiftState: Rng {
    fn next() -> u32 {
        let x = self.x;
        let mut t = x ^ (x << 11);
        self.x = self.y;
        self.y = self.z;
        self.z = self.w;
        let w = self.w;
        self.w = w ^ (w >> 19) ^ (t ^ (t >> 8));
        self.w
    }
}

fn xorshift() -> Rng {
    // constants taken from http://en.wikipedia.org/wiki/Xorshift
    seeded_xorshift(123456789u32, 362436069u32, 521288629u32, 88675123u32)
}

fn seeded_xorshift(x: u32, y: u32, z: u32, w: u32) -> Rng {
    {mut x: x, mut y: y, mut z: z, mut w: w} as Rng
}

#[cfg(test)]
mod tests {

    #[test]
    fn rng_seeded() {
        let seed = rand::seed();
        let ra = rand::seeded_rng(seed);
        let rb = rand::seeded_rng(seed);
        assert ra.gen_str(100u) == rb.gen_str(100u);
    }

    #[test]
    fn rng_seeded_custom_seed() {
        // much shorter than generated seeds which are 1024 bytes
        let seed = ~[2u8, 32u8, 4u8, 32u8, 51u8];
        let ra = rand::seeded_rng(seed);
        let rb = rand::seeded_rng(seed);
        assert ra.gen_str(100u) == rb.gen_str(100u);
    }

    #[test]
    fn rng_seeded_custom_seed2() {
        let seed = ~[2u8, 32u8, 4u8, 32u8, 51u8];
        let ra = rand::seeded_rng(seed);
        // Regression test that isaac is actually using the above vector
        let r = ra.next();
        error!("%?", r);
        assert r == 890007737u32 // on x86_64
            || r == 2935188040u32; // on x86
    }

    #[test]
    fn gen_int_range() {
        let r = rand::Rng();
        let a = r.gen_int_range(-3, 42);
        assert a >= -3 && a < 42;
        assert r.gen_int_range(0, 1) == 0;
        assert r.gen_int_range(-12, -11) == -12;
    }

    #[test]
    #[should_fail]
    #[ignore(cfg(windows))]
    fn gen_int_from_fail() {
        rand::Rng().gen_int_range(5, -2);
    }

    #[test]
    fn gen_uint_range() {
        let r = rand::Rng();
        let a = r.gen_uint_range(3u, 42u);
        assert a >= 3u && a < 42u;
        assert r.gen_uint_range(0u, 1u) == 0u;
        assert r.gen_uint_range(12u, 13u) == 12u;
    }

    #[test]
    #[should_fail]
    #[ignore(cfg(windows))]
    fn gen_uint_range_fail() {
        rand::Rng().gen_uint_range(5u, 2u);
    }

    #[test]
    fn gen_float() {
        let r = rand::Rng();
        let a = r.gen_float();
        let b = r.gen_float();
        log(debug, (a, b));
    }

    #[test]
    fn gen_weighted_bool() {
        let r = rand::Rng();
        assert r.gen_weighted_bool(0u) == true;
        assert r.gen_weighted_bool(1u) == true;
    }

    #[test]
    fn gen_str() {
        let r = rand::Rng();
        log(debug, r.gen_str(10u));
        log(debug, r.gen_str(10u));
        log(debug, r.gen_str(10u));
        assert r.gen_str(0u).len() == 0u;
        assert r.gen_str(10u).len() == 10u;
        assert r.gen_str(16u).len() == 16u;
    }

    #[test]
    fn gen_bytes() {
        let r = rand::Rng();
        assert r.gen_bytes(0u).len() == 0u;
        assert r.gen_bytes(10u).len() == 10u;
        assert r.gen_bytes(16u).len() == 16u;
    }

    #[test]
    fn choose() {
        let r = rand::Rng();
        assert r.choose(~[1, 1, 1]) == 1;
    }

    #[test]
    fn choose_option() {
        let r = rand::Rng();
        assert r.choose_option(~[]).is_none();
        assert r.choose_option(~[1, 1, 1]) == Some(1);
    }

    #[test]
    fn choose_weighted() {
        let r = rand::Rng();
        assert r.choose_weighted(~[{weight: 1u, item: 42}]) == 42;
        assert r.choose_weighted(~[
            {weight: 0u, item: 42},
            {weight: 1u, item: 43}
        ]) == 43;
    }

    #[test]
    fn choose_weighted_option() {
        let r = rand::Rng();
        assert r.choose_weighted_option(~[{weight: 1u, item: 42}]) ==
               Some(42);
        assert r.choose_weighted_option(~[
            {weight: 0u, item: 42},
            {weight: 1u, item: 43}
        ]) == Some(43);
        assert r.choose_weighted_option(~[]).is_none();
    }

    #[test]
    fn weighted_vec() {
        let r = rand::Rng();
        let empty: ~[int] = ~[];
        assert r.weighted_vec(~[]) == empty;
        assert r.weighted_vec(~[
            {weight: 0u, item: 3u},
            {weight: 1u, item: 2u},
            {weight: 2u, item: 1u}
        ]) == ~[2u, 1u, 1u];
    }

    #[test]
    fn shuffle() {
        let r = rand::Rng();
        let empty: ~[int] = ~[];
        assert r.shuffle(~[]) == empty;
        assert r.shuffle(~[1, 1, 1]) == ~[1, 1, 1];
    }
}

// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
<commit_msg>make rand code use slices<commit_after>//! Random number generation

export Rng, seed, seeded_rng, Weighted, extensions;
export xorshift, seeded_xorshift;

#[allow(non_camel_case_types)] // runtime type
enum rctx {}

#[abi = "cdecl"]
extern mod rustrt {
    fn rand_seed() -> ~[u8];
    fn rand_new() -> *rctx;
    fn rand_new_seeded(seed: ~[u8]) -> *rctx;
    fn rand_next(c: *rctx) -> u32;
    fn rand_free(c: *rctx);
}

/// A random number generator
trait Rng {
    /// Return the next random integer
    fn next() -> u32;
}

/// A value with a particular weight compared to other values
type Weighted<T> = { weight: uint, item: T };

/// Extension methods for random number generators
impl Rng {

    /// Return a random int
    fn gen_int() -> int {
        self.gen_i64() as int
    }

    /**
     * Return an int randomly chosen from the range [start, end),
     * failing if start >= end
     */
    fn gen_int_range(start: int, end: int) -> int {
        assert start < end;
        start + int::abs(self.gen_int() % (end - start))
    }

    /// Return a random i8
    fn gen_i8() -> i8 {
        self.next() as i8
    }

    /// Return a random i16
    fn gen_i16() -> i16 {
        self.next() as i16
    }

    /// Return a random i32
    fn gen_i32() -> i32 {
        self.next() as i32
    }

    /// Return a random i64
    fn gen_i64() -> i64 {
        (self.next() as i64 << 32) | self.next() as i64
    }

    /// Return a random uint
    fn gen_uint() -> uint {
        self.gen_u64() as uint
    }

    /**
     * Return a uint randomly chosen from the range [start, end),
     * failing if start >= end
     */
    fn gen_uint_range(start: uint, end: uint) -> uint {
        assert start < end;
        start + (self.gen_uint() % (end - start))
    }

    /// Return a random u8
    fn gen_u8() -> u8 {
        self.next() as u8
    }

    /// Return a random u16
    fn gen_u16() -> u16 {
        self.next() as u16
    }

    /// Return a random u32
    fn gen_u32() -> u32 {
        self.next()
    }

    /// Return a random u64
    fn gen_u64() -> u64 {
        (self.next() as u64 << 32) | self.next() as u64
    }

    /// Return a random float in the interval [0,1]
    fn gen_float() -> float {
        self.gen_f64() as float
    }

    /// Return a random f32 in the interval [0,1]
    fn gen_f32() -> f32 {
        self.gen_f64() as f32
    }

    /// Return a random f64 in the interval [0,1]
    fn gen_f64() -> f64 {
        let u1 = self.next() as f64;
        let u2 = self.next() as f64;
        let u3 = self.next() as f64;
        const scale : f64 = (u32::max_value as f64) + 1.0f64;
        return ((u1 / scale + u2) / scale + u3) / scale;
    }

    /// Return a random char
    fn gen_char() -> char {
        self.next() as char
    }

    /**
     * Return a char randomly chosen from chars, failing if chars is empty
     */
    fn gen_char_from(chars: ~str) -> char {
        assert !chars.is_empty();
        self.choose(str::chars(chars))
    }

    /// Return a random bool
    fn gen_bool() -> bool {
        self.next() & 1u32 == 1u32
    }

    /// Return a bool with a 1 in n chance of true
    fn gen_weighted_bool(n: uint) -> bool {
        if n == 0u {
            true
        } else {
            self.gen_uint_range(1u, n + 1u) == 1u
        }
    }

    /**
     * Return a random string of the specified length composed of A-Z,a-z,0-9
     */
    fn gen_str(len: uint) -> ~str {
        let charset = ~"ABCDEFGHIJKLMNOPQRSTUVWXYZ\
                       abcdefghijklmnopqrstuvwxyz\
                       0123456789";
        let mut s = ~"";
        let mut i = 0u;
        while (i < len) {
            s = s + str::from_char(self.gen_char_from(charset));
            i += 1u;
        }
        s
    }

    /// Return a random byte string of the specified length
    fn gen_bytes(len: uint) -> ~[u8] {
        do vec::from_fn(len) |_i| {
            self.gen_u8()
        }
    }

    /// Choose an item randomly, failing if values is empty
    fn choose<T:copy>(values: &[T]) -> T {
        self.choose_option(values).get()
    }

    /// Choose Some(item) randomly, returning None if values is empty
    fn choose_option<T:copy>(values: &[T]) -> Option<T> {
        if values.is_empty() {
            None
        } else {
            Some(values[self.gen_uint_range(0u, values.len())])
        }
    }

    /**
     * Choose an item respecting the relative weights, failing if the sum of
     * the weights is 0
     */
    fn choose_weighted<T: copy>(v : &[Weighted<T>]) -> T {
        self.choose_weighted_option(v).get()
    }

    /**
     * Choose Some(item) respecting the relative weights, returning none if
     * the sum of the weights is 0
     */
    fn choose_weighted_option<T:copy>(v: &[Weighted<T>]) -> Option<T> {
        let mut total = 0u;
        for v.each |item| {
            total += item.weight;
        }
        if total == 0u {
            return None;
        }
        let chosen = self.gen_uint_range(0u, total);
        let mut so_far = 0u;
        for v.each |item| {
            so_far += item.weight;
            if so_far > chosen {
                return Some(item.item);
            }
        }
        unreachable();
    }

    /**
     * Return a vec containing copies of the items, in order, where
     * the weight of the item determines how many copies there are
     */
    fn weighted_vec<T:copy>(v: &[Weighted<T>]) -> ~[T] {
        let mut r = ~[];
        for v.each |item| {
            for uint::range(0u, item.weight) |_i| {
                vec::push(r, item.item);
            }
        }
        r
    }

    /// Shuffle a vec
    fn shuffle<T:copy>(values: &[T]) -> ~[T] {
        let mut m = vec::from_slice(values);
        self.shuffle_mut(m);
        return m;
    }

    /// Shuffle a mutable vec in place
    fn shuffle_mut<T>(values: &[mut T]) {
        let mut i = values.len();
        while i >= 2u {
            // invariant: elements with index >= i have been locked in place.
            i -= 1u;
            // lock element i in place.
            vec::swap(values, i, self.gen_uint_range(0u, i + 1u));
        }
    }

}

struct RandRes {
    let c: *rctx;
    new(c: *rctx) { self.c = c; }
    drop { rustrt::rand_free(self.c); }
}

impl @RandRes: Rng {
    fn next() -> u32 { return rustrt::rand_next((*self).c); }
}

/// Create a new random seed for seeded_rng
fn seed() -> ~[u8] {
    rustrt::rand_seed()
}

/// Create a random number generator with a system specified seed
fn Rng() -> Rng {
    @RandRes(rustrt::rand_new()) as Rng
}

/**
 * Create a random number generator using the specified seed. A generator
 * constructed with a given seed will generate the same sequence of values as
 * all other generators constructed with the same seed. The seed may be any
 * length.
 */
fn seeded_rng(seed: ~[u8]) -> Rng {
    @RandRes(rustrt::rand_new_seeded(seed)) as Rng
}

type XorShiftState = {
    mut x: u32,
    mut y: u32,
    mut z: u32,
    mut w: u32
};

impl XorShiftState: Rng {
    fn next() -> u32 {
        let x = self.x;
        let mut t = x ^ (x << 11);
        self.x = self.y;
        self.y = self.z;
        self.z = self.w;
        let w = self.w;
        self.w = w ^ (w >> 19) ^ (t ^ (t >> 8));
        self.w
    }
}

fn xorshift() -> Rng {
    // constants taken from http://en.wikipedia.org/wiki/Xorshift
    seeded_xorshift(123456789u32, 362436069u32, 521288629u32, 88675123u32)
}

fn seeded_xorshift(x: u32, y: u32, z: u32, w: u32) -> Rng {
    {mut x: x, mut y: y, mut z: z, mut w: w} as Rng
}

#[cfg(test)]
mod tests {

    #[test]
    fn rng_seeded() {
        let seed = rand::seed();
        let ra = rand::seeded_rng(seed);
        let rb = rand::seeded_rng(seed);
        assert ra.gen_str(100u) == rb.gen_str(100u);
    }

    #[test]
    fn rng_seeded_custom_seed() {
        // much shorter than generated seeds which are 1024 bytes
        let seed = ~[2u8, 32u8, 4u8, 32u8, 51u8];
        let ra = rand::seeded_rng(seed);
        let rb = rand::seeded_rng(seed);
        assert ra.gen_str(100u) == rb.gen_str(100u);
    }

    #[test]
    fn rng_seeded_custom_seed2() {
        let seed = ~[2u8, 32u8, 4u8, 32u8, 51u8];
        let ra = rand::seeded_rng(seed);
        // Regression test that isaac is actually using the above vector
        let r = ra.next();
        error!("%?", r);
        assert r == 890007737u32 // on x86_64
            || r == 2935188040u32; // on x86
    }

    #[test]
    fn gen_int_range() {
        let r = rand::Rng();
        let a = r.gen_int_range(-3, 42);
        assert a >= -3 && a < 42;
        assert r.gen_int_range(0, 1) == 0;
        assert r.gen_int_range(-12, -11) == -12;
    }

    #[test]
    #[should_fail]
    #[ignore(cfg(windows))]
    fn gen_int_from_fail() {
        rand::Rng().gen_int_range(5, -2);
    }

    #[test]
    fn gen_uint_range() {
        let r = rand::Rng();
        let a = r.gen_uint_range(3u, 42u);
        assert a >= 3u && a < 42u;
        assert r.gen_uint_range(0u, 1u) == 0u;
        assert r.gen_uint_range(12u, 13u) == 12u;
    }

    #[test]
    #[should_fail]
    #[ignore(cfg(windows))]
    fn gen_uint_range_fail() {
        rand::Rng().gen_uint_range(5u, 2u);
    }

    #[test]
    fn gen_float() {
        let r = rand::Rng();
        let a = r.gen_float();
        let b = r.gen_float();
        log(debug, (a, b));
    }

    #[test]
    fn gen_weighted_bool() {
        let r = rand::Rng();
        assert r.gen_weighted_bool(0u) == true;
        assert r.gen_weighted_bool(1u) == true;
    }

    #[test]
    fn gen_str() {
        let r = rand::Rng();
        log(debug, r.gen_str(10u));
        log(debug, r.gen_str(10u));
        log(debug, r.gen_str(10u));
        assert r.gen_str(0u).len() == 0u;
        assert r.gen_str(10u).len() == 10u;
        assert r.gen_str(16u).len() == 16u;
    }

    #[test]
    fn gen_bytes() {
        let r = rand::Rng();
        assert r.gen_bytes(0u).len() == 0u;
        assert r.gen_bytes(10u).len() == 10u;
        assert r.gen_bytes(16u).len() == 16u;
    }

    #[test]
    fn choose() {
        let r = rand::Rng();
        assert r.choose([1, 1, 1]) == 1;
    }

    #[test]
    fn choose_option() {
        let r = rand::Rng();
        assert r.choose_option::<int>([]).is_none();
        assert r.choose_option([1, 1, 1]) == Some(1);
    }

    #[test]
    fn choose_weighted() {
        let r = rand::Rng();
        assert r.choose_weighted(~[{weight: 1u, item: 42}]) == 42;
        assert r.choose_weighted(~[
            {weight: 0u, item: 42},
            {weight: 1u, item: 43}
        ]) == 43;
    }

    #[test]
    fn choose_weighted_option() {
        let r = rand::Rng();
        assert r.choose_weighted_option(~[{weight: 1u, item: 42}]) ==
               Some(42);
        assert r.choose_weighted_option(~[
            {weight: 0u, item: 42},
            {weight: 1u, item: 43}
        ]) == Some(43);
        assert r.choose_weighted_option::<int>([]).is_none();
    }

    #[test]
    fn weighted_vec() {
        let r = rand::Rng();
        let empty: ~[int] = ~[];
        assert r.weighted_vec(~[]) == empty;
        assert r.weighted_vec(~[
            {weight: 0u, item: 3u},
            {weight: 1u, item: 2u},
            {weight: 2u, item: 1u}
        ]) == ~[2u, 1u, 1u];
    }

    #[test]
    fn shuffle() {
        let r = rand::Rng();
        let empty: ~[int] = ~[];
        assert r.shuffle(~[]) == empty;
        assert r.shuffle(~[1, 1, 1]) == ~[1, 1, 1];
    }
}

// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
<|endoftext|>


<commit_before>/*
 * Copyright (C) 2017 Ryan Huang
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

pub struct Model {
    pub board: Board,
    pub turn: Turn,
    pub white_pieces: u32,
    pub white_hexes: u32,
    pub black_pieces: u32,
    pub black_hexes: u32,
    pub selected_piece: Option<FieldCoord>,
    // If a piece moves off of a hex, and that hex gets removed, the last move will not have a
    // "from" field, only a "to" field
    pub last_move: Option<(Option<FieldCoord>, FieldCoord)>,
    pub available_moves: Option<Vec<FieldCoord>>,
}

impl Model {
    pub fn new() -> Model {
        Model {
            board: Board::new(),
            turn: Turn::White,
            white_pieces: 18,
            white_hexes: 0,
            black_pieces: 18,
            black_hexes: 0,
            selected_piece: None,
            last_move: None,
            available_moves: None,
        }
    }
}

#[derive(PartialEq)]
pub enum Turn {
    White,
    Black,
}

impl Turn {
    pub fn switch_turns(&mut self) {
        *self = match *self {
            Turn::White => Turn::Black,
            Turn::Black => Turn::White,
        }
    }
}

pub struct Board {
    /*
                ____
               /    \
          ____/  +y  \____
         /    \      /    \
        /      \____/  +x  \
        \      /    \      /
         \____/      \____/
         /    \      /    \
        /  -x  \____/      \
        \      /    \      /
         \____/  -y  \____/
              \      /
               \____/

        The hex board uses an axial coordinate system with (0, 0) at the center. The x-axis slopes
        up to the right, and the y-axis goes up and down. The board is stored as a dense 2D array,
        because a ragged array won't work (since each row would have to be a different type).

        See http://www.redblobgames.com/grids/hexagons/#coordinates-axial for more info.
    */
    board: [[Option<Hex>; 5]; 5],
}

// Fields are numbered clockwise from the top. Even indicies are black, odd indicies are white.
type Hex = [Field; 6];

// There's no need to store the color of the piece on this field, since only white pieces can be on
// white fields, and vice versa.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum Field {
    Piece,
    Empty,
}

impl Board {
    #[cfg_attr(rustfmt, rustfmt_skip)]
    /// Create a new board with the "Laurentius" starting position.
    pub fn new() -> Board {
        let mut board = Board {
            board: [[None; 5]; 5]
        };

        // (0, 0) is the only empty hex.
        board.set_hex(&HexCoord::new(0, 0), Some([Field::Empty; 6]));

        // All other hexes have exactly two pieces on them in the starting position.
        let piece_locations = [
            (-2,  2, 0, 4),
            (-2,  1, 0, 3),
            (-2,  0, 3, 5),
            (-1,  2, 1, 4),
            (-1,  1, 0, 4),
            (-1,  0, 3, 5),
            (-1, -1, 2, 5),
            ( 0,  2, 1, 5),
            ( 0,  1, 1, 5),
            ( 0, -1, 2, 4),
            ( 0, -2, 2, 4),
            ( 1,  1, 2, 5),
            ( 1,  0, 0, 2),
            ( 1, -1, 1, 3),
            ( 1, -2, 1, 4),
            ( 2,  0, 0, 2),
            ( 2, -1, 0, 3),
            ( 2, -2, 1, 3),
        ];

        for &(x, y, f1, f2) in &piece_locations {
            let mut hex = [Field::Empty; 6];
            hex[f1] = Field::Piece;
            hex[f2] = Field::Piece;
            board.set_hex(&HexCoord::new(x, y), Some(hex));
        }

        board
    }

    fn get_field(&self, coord: &FieldCoord) -> &Field {
        match *self.get_hex(&coord.to_hex()) {
            Some(ref hex) => &hex[coord.f as usize],
            None => panic!(
                "Cannot get field {} on removed hex at {:?}",
                coord.f,
                coord.to_hex()
            ),
        }
    }
    fn set_field(&mut self, coord: &FieldCoord, field: Field) {
        match *self.get_hex(&coord.to_hex()) {
            Some(mut hex) => {
                hex[coord.f as usize] = field;
                self.set_hex(&coord.to_hex(), Some(hex));
            }
            None => panic!(
                "Cannot set field {} on removed hex at {:?}",
                coord.f,
                coord.to_hex()
            ),
        }
    }
    pub fn is_piece_on_field(&self, coord: &FieldCoord) -> bool {
        self.get_field(coord) == &Field::Piece
    }
    /// Return fields that share an edge with the given field. These fields are always the opposite
    /// color of the given field. If all of a piece's edge neighbors are occupied, that piece might
    /// be capturable.
    pub fn get_field_edge_neighbors(&self, coord: &FieldCoord) -> Vec<FieldCoord> {
        let mut neighbors = vec![
            // There are always two edge neighbors on the same hex as the given field
            FieldCoord::new(coord.x, coord.y, (coord.f + 1) % 6),
            FieldCoord::new(coord.x, coord.y, (coord.f + 5) % 6),
        ];

        match self.get_hex_neighbor(&coord.to_hex(), coord.f) {
            Some(neighbor) => {
                let f = (coord.f + 3) % 6;
                neighbors.push(neighbor.to_field(f));
            }
            None => {}
        }

        neighbors
    }
    /// Return fields that share a vertex with the given field and have the same color as the given
    /// field. Pieces can move to fields that are vertex neighbors of the field they are on.
    pub fn get_field_vertex_neighbors(&self, coord: &FieldCoord) -> Vec<FieldCoord> {
        // A field's vertex neighbors can be defined as the edge neighbors of its edge neighbors
        let mut neighbors = vec![];
        for neighbor in self.get_field_edge_neighbors(coord) {
            neighbors.append(&mut self.get_field_edge_neighbors(&neighbor));
        }
        // A field is not its own neighbor
        neighbors.into_iter().filter(|n| n != coord).collect()
    }
    pub fn can_move_piece(&self, from: &FieldCoord, to: &FieldCoord) -> bool {
        self.is_piece_on_field(from) && !self.is_piece_on_field(to) &&
            self.get_field_vertex_neighbors(from).contains(to)
    }
    pub fn move_piece(&mut self, from: &FieldCoord, to: &FieldCoord) {
        assert!(
            self.can_move_piece(from, to),
            "Can't move {:?} at {:?} to {:?} at {:?}. These fields {} vertex neighbors.",
            self.get_field(from),
            from,
            self.get_field(to),
            to,
            if self.get_field_vertex_neighbors(from).contains(to) {
                "ARE"
            } else {
                "ARE NOT"
            },
        );

        self.set_field(from, Field::Empty);
        self.set_field(to, Field::Piece);
    }
    pub fn remove_piece(&mut self, coord: &FieldCoord) {
        assert_eq!(
            self.get_field(coord),
            &Field::Piece,
            "There is no piece at {:?} to remove",
            coord
        );
        self.set_field(coord, Field::Empty);
    }
    fn get_hex(&self, coord: &HexCoord) -> &Option<Hex> {
        &self.board[(coord.x + 2) as usize][(coord.y + 2) as usize]
    }
    fn set_hex(&mut self, coord: &HexCoord, hex: Option<Hex>) {
        self.board[(coord.x + 2) as usize][(coord.y + 2) as usize] = hex;
    }
    fn is_hex_extant(&self, coord: &HexCoord) -> bool {
        self.get_hex(coord).is_some()
    }
    fn get_hex_neighbor(&self, coord: &HexCoord, direction: u32) -> Option<HexCoord> {
        assert!(direction < 6);

        let neighbors = [
            (coord.x, coord.y + 1),
            (coord.x + 1, coord.y),
            (coord.x + 1, coord.y - 1),
            (coord.x, coord.y - 1),
            (coord.x - 1, coord.y),
            (coord.x - 1, coord.y + 1),
        ];

        let (x, y) = neighbors[direction as usize];
        if HexCoord::is_valid_coord(x, y) {
            let coord = HexCoord::new(x, y);
            if self.is_hex_extant(&coord) {
                return Some(coord);
            }
        }
        None
    }
    /// Return fields that share an edge with the given hex and are outside of the given hex. If a
    /// hex is removed from the board, pieces occupying that hex's field neighbors might be
    /// capturable.
    pub fn get_hex_field_neighbors(&self, coord: &HexCoord) -> Vec<FieldCoord> {
        let mut neighbors = vec![];

        for f in 0..6 {
            if let Some(neighbor) = self.get_hex_neighbor(coord, f) {
                neighbors.push(neighbor.to_field((f + 3) % 6));
            }
        }
        neighbors
    }
    /// A hex is removable (and must be removed) if it is empty and is "attached to the board by 3
    /// or less adjacent sides."
    pub fn is_hex_removable(&self, coord: &HexCoord) -> bool {
        match *self.get_hex(coord) {
            Some(hex) => if hex.iter().any(|&f| f == Field::Piece) {
                return false;
            },
            None => panic!("The hex at {:?} has already been removed", coord),
        }

        let neighbor_indexes: Vec<u32> = vec![0, 1, 2, 3, 4, 5]
            .into_iter()
            .filter(|&f| self.get_hex_neighbor(coord, f).is_some())
            .collect();
        let neighbor_indexes = neighbor_indexes.as_slice();

        match neighbor_indexes.len() {
            0 => panic!("A hex at {:?} is empty and has no neighbors", coord),
            1 => true,
            2 => {
                let valid_idx_combos = [[0, 1], [1, 2], [2, 3], [3, 4], [4, 5], [0, 5]];
                valid_idx_combos.iter().any(|c| c == neighbor_indexes)
            }
            3 => {
                let valid_idx_combos = [
                    [0, 1, 2],
                    [1, 2, 3],
                    [2, 3, 4],
                    [3, 4, 5],
                    [0, 4, 5],
                    [0, 1, 5],
                ];
                valid_idx_combos.iter().any(|c| c == neighbor_indexes)
            }
            _ => false,
        }
    }
    pub fn remove_hex(&mut self, coord: &HexCoord) {
        assert!(
            self.is_hex_removable(coord),
            "Cannot remove the hex at {:?} which is {:?} and has {} neighbors",
            coord,
            self.get_hex(coord),
            [0, 1, 2, 3, 4, 5]
                .into_iter()
                .filter(|&&f| self.get_hex_neighbor(coord, f).is_some())
                .collect::<Vec<_>>()
                .len(),
        );
        self.set_hex(coord, None);
    }
    /// > extant (adj.): Still in existence; not destroyed, lost, or extinct (The Free Dictionary)
    ///
    /// Return the coordinates of the hexes that have not been removed yet.
    pub fn extant_hexes(&self) -> Vec<HexCoord> {
        let mut coords = vec![];

        for x in -2..3 {
            for y in -2..3 {
                if HexCoord::is_valid_coord(x, y) {
                    let coord = HexCoord::new(x, y);
                    if self.is_hex_extant(&coord) {
                        coords.push(coord);
                    }
                }
            }
        }
        coords
    }
}

#[derive(Debug, PartialEq)]
pub struct FieldCoord {
    x: i32,
    y: i32,
    f: u32,
}

#[derive(Clone, Copy, Debug)]
pub struct HexCoord {
    x: i32,
    y: i32,
}

impl FieldCoord {
    pub fn new(x: i32, y: i32, f: u32) -> FieldCoord {
        assert!(Self::is_valid_coord(x, y, f));
        FieldCoord { x, y, f }
    }
    pub fn x(&self) -> i32 {
        self.x
    }
    pub fn y(&self) -> i32 {
        self.y
    }
    pub fn f(&self) -> u32 {
        self.f
    }
    pub fn to_hex(&self) -> HexCoord {
        HexCoord::new(self.x, self.y)
    }
    pub fn is_valid_coord(x: i32, y: i32, f: u32) -> bool {
        (x + y).abs() <= 2 && x.abs() <= 2 && y.abs() <= 2 && f < 6
    }
    pub fn is_white(&self) -> bool {
        self.f % 2 == 1
    }
    pub fn is_black(&self) -> bool {
        self.f % 2 == 0
    }
}

impl HexCoord {
    pub fn new(x: i32, y: i32) -> HexCoord {
        assert!(Self::is_valid_coord(x, y));
        HexCoord { x, y }
    }
    pub fn x(&self) -> i32 {
        self.x
    }
    pub fn y(&self) -> i32 {
        self.y
    }
    pub fn to_field(&self, f: u32) -> FieldCoord {
        FieldCoord::new(self.x, self.y, f)
    }
    pub fn is_valid_coord(x: i32, y: i32) -> bool {
        (x + y).abs() <= 2 && x.abs() <= 2 && y.abs() <= 2
    }
}
<commit_msg>Replace match with if let<commit_after>/*
 * Copyright (C) 2017 Ryan Huang
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

pub struct Model {
    pub board: Board,
    pub turn: Turn,
    pub white_pieces: u32,
    pub white_hexes: u32,
    pub black_pieces: u32,
    pub black_hexes: u32,
    pub selected_piece: Option<FieldCoord>,
    // If a piece moves off of a hex, and that hex gets removed, the last move will not have a
    // "from" field, only a "to" field
    pub last_move: Option<(Option<FieldCoord>, FieldCoord)>,
    pub available_moves: Option<Vec<FieldCoord>>,
}

impl Model {
    pub fn new() -> Model {
        Model {
            board: Board::new(),
            turn: Turn::White,
            white_pieces: 18,
            white_hexes: 0,
            black_pieces: 18,
            black_hexes: 0,
            selected_piece: None,
            last_move: None,
            available_moves: None,
        }
    }
}

#[derive(PartialEq)]
pub enum Turn {
    White,
    Black,
}

impl Turn {
    pub fn switch_turns(&mut self) {
        *self = match *self {
            Turn::White => Turn::Black,
            Turn::Black => Turn::White,
        }
    }
}

pub struct Board {
    /*
                ____
               /    \
          ____/  +y  \____
         /    \      /    \
        /      \____/  +x  \
        \      /    \      /
         \____/      \____/
         /    \      /    \
        /  -x  \____/      \
        \      /    \      /
         \____/  -y  \____/
              \      /
               \____/

        The hex board uses an axial coordinate system with (0, 0) at the center. The x-axis slopes
        up to the right, and the y-axis goes up and down. The board is stored as a dense 2D array,
        because a ragged array won't work (since each row would have to be a different type).

        See http://www.redblobgames.com/grids/hexagons/#coordinates-axial for more info.
    */
    board: [[Option<Hex>; 5]; 5],
}

// Fields are numbered clockwise from the top. Even indicies are black, odd indicies are white.
type Hex = [Field; 6];

// There's no need to store the color of the piece on this field, since only white pieces can be on
// white fields, and vice versa.
#[derive(Clone, Copy, Debug, PartialEq)]
pub enum Field {
    Piece,
    Empty,
}

impl Board {
    #[cfg_attr(rustfmt, rustfmt_skip)]
    /// Create a new board with the "Laurentius" starting position.
    pub fn new() -> Board {
        let mut board = Board {
            board: [[None; 5]; 5]
        };

        // (0, 0) is the only empty hex.
        board.set_hex(&HexCoord::new(0, 0), Some([Field::Empty; 6]));

        // All other hexes have exactly two pieces on them in the starting position.
        let piece_locations = [
            (-2,  2, 0, 4),
            (-2,  1, 0, 3),
            (-2,  0, 3, 5),
            (-1,  2, 1, 4),
            (-1,  1, 0, 4),
            (-1,  0, 3, 5),
            (-1, -1, 2, 5),
            ( 0,  2, 1, 5),
            ( 0,  1, 1, 5),
            ( 0, -1, 2, 4),
            ( 0, -2, 2, 4),
            ( 1,  1, 2, 5),
            ( 1,  0, 0, 2),
            ( 1, -1, 1, 3),
            ( 1, -2, 1, 4),
            ( 2,  0, 0, 2),
            ( 2, -1, 0, 3),
            ( 2, -2, 1, 3),
        ];

        for &(x, y, f1, f2) in &piece_locations {
            let mut hex = [Field::Empty; 6];
            hex[f1] = Field::Piece;
            hex[f2] = Field::Piece;
            board.set_hex(&HexCoord::new(x, y), Some(hex));
        }

        board
    }

    fn get_field(&self, coord: &FieldCoord) -> &Field {
        match *self.get_hex(&coord.to_hex()) {
            Some(ref hex) => &hex[coord.f as usize],
            None => panic!(
                "Cannot get field {} on removed hex at {:?}",
                coord.f,
                coord.to_hex()
            ),
        }
    }
    fn set_field(&mut self, coord: &FieldCoord, field: Field) {
        match *self.get_hex(&coord.to_hex()) {
            Some(mut hex) => {
                hex[coord.f as usize] = field;
                self.set_hex(&coord.to_hex(), Some(hex));
            }
            None => panic!(
                "Cannot set field {} on removed hex at {:?}",
                coord.f,
                coord.to_hex()
            ),
        }
    }
    pub fn is_piece_on_field(&self, coord: &FieldCoord) -> bool {
        self.get_field(coord) == &Field::Piece
    }
    /// Return fields that share an edge with the given field. These fields are always the opposite
    /// color of the given field. If all of a piece's edge neighbors are occupied, that piece might
    /// be capturable.
    pub fn get_field_edge_neighbors(&self, coord: &FieldCoord) -> Vec<FieldCoord> {
        let mut neighbors = vec![
            // There are always two edge neighbors on the same hex as the given field
            FieldCoord::new(coord.x, coord.y, (coord.f + 1) % 6),
            FieldCoord::new(coord.x, coord.y, (coord.f + 5) % 6),
        ];

        if let Some(neighbor) = self.get_hex_neighbor(&coord.to_hex(), coord.f) {
            neighbors.push(neighbor.to_field((coord.f + 3) % 6));
        }

        neighbors
    }
    /// Return fields that share a vertex with the given field and have the same color as the given
    /// field. Pieces can move to fields that are vertex neighbors of the field they are on.
    pub fn get_field_vertex_neighbors(&self, coord: &FieldCoord) -> Vec<FieldCoord> {
        // A field's vertex neighbors can be defined as the edge neighbors of its edge neighbors
        let mut neighbors = vec![];
        for neighbor in self.get_field_edge_neighbors(coord) {
            neighbors.append(&mut self.get_field_edge_neighbors(&neighbor));
        }
        // A field is not its own neighbor
        neighbors.into_iter().filter(|n| n != coord).collect()
    }
    pub fn can_move_piece(&self, from: &FieldCoord, to: &FieldCoord) -> bool {
        self.is_piece_on_field(from) && !self.is_piece_on_field(to) &&
            self.get_field_vertex_neighbors(from).contains(to)
    }
    pub fn move_piece(&mut self, from: &FieldCoord, to: &FieldCoord) {
        assert!(
            self.can_move_piece(from, to),
            "Can't move {:?} at {:?} to {:?} at {:?}. These fields {} vertex neighbors.",
            self.get_field(from),
            from,
            self.get_field(to),
            to,
            if self.get_field_vertex_neighbors(from).contains(to) {
                "ARE"
            } else {
                "ARE NOT"
            },
        );

        self.set_field(from, Field::Empty);
        self.set_field(to, Field::Piece);
    }
    pub fn remove_piece(&mut self, coord: &FieldCoord) {
        assert_eq!(
            self.get_field(coord),
            &Field::Piece,
            "There is no piece at {:?} to remove",
            coord
        );
        self.set_field(coord, Field::Empty);
    }
    fn get_hex(&self, coord: &HexCoord) -> &Option<Hex> {
        &self.board[(coord.x + 2) as usize][(coord.y + 2) as usize]
    }
    fn set_hex(&mut self, coord: &HexCoord, hex: Option<Hex>) {
        self.board[(coord.x + 2) as usize][(coord.y + 2) as usize] = hex;
    }
    fn is_hex_extant(&self, coord: &HexCoord) -> bool {
        self.get_hex(coord).is_some()
    }
    fn get_hex_neighbor(&self, coord: &HexCoord, direction: u32) -> Option<HexCoord> {
        assert!(direction < 6);

        let neighbors = [
            (coord.x, coord.y + 1),
            (coord.x + 1, coord.y),
            (coord.x + 1, coord.y - 1),
            (coord.x, coord.y - 1),
            (coord.x - 1, coord.y),
            (coord.x - 1, coord.y + 1),
        ];

        let (x, y) = neighbors[direction as usize];
        if HexCoord::is_valid_coord(x, y) {
            let coord = HexCoord::new(x, y);
            if self.is_hex_extant(&coord) {
                return Some(coord);
            }
        }
        None
    }
    /// Return fields that share an edge with the given hex and are outside of the given hex. If a
    /// hex is removed from the board, pieces occupying that hex's field neighbors might be
    /// capturable.
    pub fn get_hex_field_neighbors(&self, coord: &HexCoord) -> Vec<FieldCoord> {
        let mut neighbors = vec![];

        for f in 0..6 {
            if let Some(neighbor) = self.get_hex_neighbor(coord, f) {
                neighbors.push(neighbor.to_field((f + 3) % 6));
            }
        }
        neighbors
    }
    /// A hex is removable (and must be removed) if it is empty and is "attached to the board by 3
    /// or less adjacent sides."
    pub fn is_hex_removable(&self, coord: &HexCoord) -> bool {
        match *self.get_hex(coord) {
            Some(hex) => if hex.iter().any(|&f| f == Field::Piece) {
                return false;
            },
            None => panic!("The hex at {:?} has already been removed", coord),
        }

        let neighbor_indexes: Vec<u32> = vec![0, 1, 2, 3, 4, 5]
            .into_iter()
            .filter(|&f| self.get_hex_neighbor(coord, f).is_some())
            .collect();
        let neighbor_indexes = neighbor_indexes.as_slice();

        match neighbor_indexes.len() {
            0 => panic!("A hex at {:?} is empty and has no neighbors", coord),
            1 => true,
            2 => {
                let valid_idx_combos = [[0, 1], [1, 2], [2, 3], [3, 4], [4, 5], [0, 5]];
                valid_idx_combos.iter().any(|c| c == neighbor_indexes)
            }
            3 => {
                let valid_idx_combos = [
                    [0, 1, 2],
                    [1, 2, 3],
                    [2, 3, 4],
                    [3, 4, 5],
                    [0, 4, 5],
                    [0, 1, 5],
                ];
                valid_idx_combos.iter().any(|c| c == neighbor_indexes)
            }
            _ => false,
        }
    }
    pub fn remove_hex(&mut self, coord: &HexCoord) {
        assert!(
            self.is_hex_removable(coord),
            "Cannot remove the hex at {:?} which is {:?} and has {} neighbors",
            coord,
            self.get_hex(coord),
            [0, 1, 2, 3, 4, 5]
                .into_iter()
                .filter(|&&f| self.get_hex_neighbor(coord, f).is_some())
                .collect::<Vec<_>>()
                .len(),
        );
        self.set_hex(coord, None);
    }
    /// > extant (adj.): Still in existence; not destroyed, lost, or extinct (The Free Dictionary)
    ///
    /// Return the coordinates of the hexes that have not been removed yet.
    pub fn extant_hexes(&self) -> Vec<HexCoord> {
        let mut coords = vec![];

        for x in -2..3 {
            for y in -2..3 {
                if HexCoord::is_valid_coord(x, y) {
                    let coord = HexCoord::new(x, y);
                    if self.is_hex_extant(&coord) {
                        coords.push(coord);
                    }
                }
            }
        }
        coords
    }
}

#[derive(Debug, PartialEq)]
pub struct FieldCoord {
    x: i32,
    y: i32,
    f: u32,
}

#[derive(Clone, Copy, Debug)]
pub struct HexCoord {
    x: i32,
    y: i32,
}

impl FieldCoord {
    pub fn new(x: i32, y: i32, f: u32) -> FieldCoord {
        assert!(Self::is_valid_coord(x, y, f));
        FieldCoord { x, y, f }
    }
    pub fn x(&self) -> i32 {
        self.x
    }
    pub fn y(&self) -> i32 {
        self.y
    }
    pub fn f(&self) -> u32 {
        self.f
    }
    pub fn to_hex(&self) -> HexCoord {
        HexCoord::new(self.x, self.y)
    }
    pub fn is_valid_coord(x: i32, y: i32, f: u32) -> bool {
        (x + y).abs() <= 2 && x.abs() <= 2 && y.abs() <= 2 && f < 6
    }
    pub fn is_white(&self) -> bool {
        self.f % 2 == 1
    }
    pub fn is_black(&self) -> bool {
        self.f % 2 == 0
    }
}

impl HexCoord {
    pub fn new(x: i32, y: i32) -> HexCoord {
        assert!(Self::is_valid_coord(x, y));
        HexCoord { x, y }
    }
    pub fn x(&self) -> i32 {
        self.x
    }
    pub fn y(&self) -> i32 {
        self.y
    }
    pub fn to_field(&self, f: u32) -> FieldCoord {
        FieldCoord::new(self.x, self.y, f)
    }
    pub fn is_valid_coord(x: i32, y: i32) -> bool {
        (x + y).abs() <= 2 && x.abs() <= 2 && y.abs() <= 2
    }
}
<|endoftext|>


<commit_before>use super::*;

use schema::{submission_files, submissions};

/// File of a submission. (submission_id, field_id) is the primary key
#[derive(juniper::GraphQLObject)]
pub struct SubmissionFile {
    /// id of the submmission
    submission_id: String,

    /// id of the field in the sumbission form
    field_id: String,

    /// type of the file (e.g MIME text/plain)
    type_id: String,

    /// name of the file, as uploaded by the user (ex. solution.cpp)
    name: String,

    /// content of the file codified in the base64 format
    content_base64: String,
}

/// A submission in the database
#[derive(juniper::GraphQLObject)]
pub struct Submission {
    /// id of the submission, that is a random generated UUID
    id: String,

    /// id of user who made submission
    user_id: String,

    /// name of problem wich the submission refers to
    problem_name: String,

    /// time in wich the submission was created, saved as a RFC3339 date
    created_at: String,

    /// files submitted in this submission
    files: Vec<SubmissionFile>,
}

/// Input file for a submission file
#[derive(juniper::GraphQLInputObject)]
pub struct FileInput {
    /// type of the file submitted
    type_id: String,

    /// name of the field that this file refears to
    field_id: String,

    /// filename as uploaded by the user
    name: String,

    /// content of the file codified in base64
    content_base64: String,
}

#[derive(Queryable, Insertable)]
#[table_name = "submissions"]
struct SubmissionTable {
    id: String,
    user_id: String,
    problem_name: String,
    created_at: String,
}

#[derive(Queryable, Insertable)]
#[table_name = "submission_files"]
struct SubmissionFileTable {
    submission_id: String,
    field_id: String,
    type_id: String,
    name: String,
    content: Vec<u8>,
}

/// Insert a new submission into the database, returning a submission object
pub fn insert(
    conn: &SqliteConnection,
    user_id: String,
    problem_name: String,
    files: Vec<FileInput>,
) -> Result<Submission, Box<dyn std::error::Error>> {
    let id = uuid::Uuid::new_v4().to_string();
    let created_at = chrono::Local::now().to_rfc3339();
    let submission = SubmissionTable {
        id: id.clone(),
        user_id,
        problem_name,
        created_at,
    };
    diesel::insert_into(submissions::table)
        .values(submission)
        .execute(conn)?;
    for file in files {
        let submission_file = SubmissionFileTable {
            submission_id: id.clone(),
            field_id: file.field_id,
            type_id: file.type_id,
            name: file.name,
            content: base64::decode(&file.content_base64)?,
        };
        diesel::insert_into(submission_files::table)
            .values(submission_file)
            .execute(conn)?;
    }
    Ok(query(conn, id)?)
}

/// Gets the submission with the specified id from the database
pub fn query(
    conn: &SqliteConnection,
    id: String,
) -> Result<Submission, Box<dyn std::error::Error>> {
    let submission = submissions::table
        .filter(submissions::dsl::id.eq(id))
        .first::<SubmissionTable>(conn)?;
    let files = submission_files::table
        .load::<SubmissionFileTable>(conn)?
        .into_iter()
        .map(|submission_file| SubmissionFile {
            submission_id: submission_file.submission_id,
            field_id: submission_file.field_id,
            type_id: submission_file.type_id,
            name: submission_file.name,
            content_base64: base64::encode(&submission_file.content),
        })
        .collect();
    Ok(Submission {
        id: submission.id,
        user_id: submission.user_id,
        problem_name: submission.problem_name,
        created_at: submission.created_at,
        files,
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::contest::Contest;

    #[test]
    fn test_submission_insert() {
        let db = tempdir::TempDir::new("tests").unwrap();
        let db = db.path().join("db.sqlite");
        let contest = Contest::with_database(db.to_str().unwrap());
        contest.init_db();
        contest.add_user("user", "x", "x");
        contest.add_problem("problem", "test-path");
        let mut files = Vec::new();
        files.push(GraphQLFileInput {
            field_id: "field1".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        files.push(GraphQLFileInput {
            field_id: "field2".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        files.push(GraphQLFileInput {
            field_id: "field3".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        let sub = insert(
            &contest.connect_db().unwrap(),
            "user".to_owned(),
            "problem".to_owned(),
            files,
        )
        .unwrap();
        assert_eq!(sub.problem_name, "problem");
        assert_eq!(sub.user_id, "user");
        assert_eq!(sub.files.len(), 3);
        assert_eq!(sub.files[0].content_base64, "dGVzdHRlc3R0ZXN0cHJvdmEK");
    }
}
<commit_msg>Fix tests<commit_after>use super::*;

use schema::{submission_files, submissions};

/// File of a submission. (submission_id, field_id) is the primary key
#[derive(juniper::GraphQLObject)]
pub struct SubmissionFile {
    /// id of the submmission
    submission_id: String,

    /// id of the field in the sumbission form
    field_id: String,

    /// type of the file (e.g MIME text/plain)
    type_id: String,

    /// name of the file, as uploaded by the user (ex. solution.cpp)
    name: String,

    /// content of the file codified in the base64 format
    content_base64: String,
}

/// A submission in the database
#[derive(juniper::GraphQLObject)]
pub struct Submission {
    /// id of the submission, that is a random generated UUID
    id: String,

    /// id of user who made submission
    user_id: String,

    /// name of problem wich the submission refers to
    problem_name: String,

    /// time in wich the submission was created, saved as a RFC3339 date
    created_at: String,

    /// files submitted in this submission
    files: Vec<SubmissionFile>,
}

/// Input file for a submission file
#[derive(juniper::GraphQLInputObject)]
pub struct FileInput {
    /// type of the file submitted
    type_id: String,

    /// name of the field that this file refears to
    field_id: String,

    /// filename as uploaded by the user
    name: String,

    /// content of the file codified in base64
    content_base64: String,
}

#[derive(Queryable, Insertable)]
#[table_name = "submissions"]
struct SubmissionTable {
    id: String,
    user_id: String,
    problem_name: String,
    created_at: String,
}

#[derive(Queryable, Insertable)]
#[table_name = "submission_files"]
struct SubmissionFileTable {
    submission_id: String,
    field_id: String,
    type_id: String,
    name: String,
    content: Vec<u8>,
}

/// Insert a new submission into the database, returning a submission object
pub fn insert(
    conn: &SqliteConnection,
    user_id: String,
    problem_name: String,
    files: Vec<FileInput>,
) -> Result<Submission, Box<dyn std::error::Error>> {
    let id = uuid::Uuid::new_v4().to_string();
    let created_at = chrono::Local::now().to_rfc3339();
    let submission = SubmissionTable {
        id: id.clone(),
        user_id,
        problem_name,
        created_at,
    };
    diesel::insert_into(submissions::table)
        .values(submission)
        .execute(conn)?;
    for file in files {
        let submission_file = SubmissionFileTable {
            submission_id: id.clone(),
            field_id: file.field_id,
            type_id: file.type_id,
            name: file.name,
            content: base64::decode(&file.content_base64)?,
        };
        diesel::insert_into(submission_files::table)
            .values(submission_file)
            .execute(conn)?;
    }
    Ok(query(conn, id)?)
}

/// Gets the submission with the specified id from the database
pub fn query(
    conn: &SqliteConnection,
    id: String,
) -> Result<Submission, Box<dyn std::error::Error>> {
    let submission = submissions::table
        .filter(submissions::dsl::id.eq(id))
        .first::<SubmissionTable>(conn)?;
    let files = submission_files::table
        .load::<SubmissionFileTable>(conn)?
        .into_iter()
        .map(|submission_file| SubmissionFile {
            submission_id: submission_file.submission_id,
            field_id: submission_file.field_id,
            type_id: submission_file.type_id,
            name: submission_file.name,
            content_base64: base64::encode(&submission_file.content),
        })
        .collect();
    Ok(Submission {
        id: submission.id,
        user_id: submission.user_id,
        problem_name: submission.problem_name,
        created_at: submission.created_at,
        files,
    })
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::contest::Contest;

    #[test]
    fn test_submission_insert() {
        let db = tempdir::TempDir::new("tests").unwrap();
        let db = db.path().join("db.sqlite");
        let contest = Contest::with_database(db.to_str().unwrap());
        contest.init_db();
        contest.add_user("user", "x", "x");
        contest.add_problem("problem", "test-path");
        let mut files = Vec::new();
        files.push(FileInput {
            field_id: "field1".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        files.push(FileInput {
            field_id: "field2".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        files.push(FileInput {
            field_id: "field3".to_owned(),
            type_id: "text/plain".to_owned(),
            name: "solution.cpp".to_owned(),
            content_base64: "dGVzdHRlc3R0ZXN0cHJvdmEK".to_owned(),
        });
        let sub = insert(
            &contest.connect_db().unwrap(),
            "user".to_owned(),
            "problem".to_owned(),
            files,
        )
        .unwrap();
        assert_eq!(sub.problem_name, "problem");
        assert_eq!(sub.user_id, "user");
        assert_eq!(sub.files.len(), 3);
        assert_eq!(sub.files[0].content_base64, "dGVzdHRlc3R0ZXN0cHJvdmEK");
    }
}
<|endoftext|>