use std::io::{Result, Write};

/// A 24-bit pixel represented by a red, green, and blue value.
pub struct Pixel(pub u8, pub u8, pub u8);

/// A representation of an image
pub struct Image {
  /// Width in pixels
  pub(crate) width: usize,
  
  /// Height in pixels
  pub(crate) height: usize,

  /// Pixel data in row-major form.
  pub(crate) data: Vec<Pixel>,
}

impl Image {
  /// Write the image in PPM format to a file.
  pub fn write(&self, mut w: impl Write) -> Result<()> {
    // Header
    let header = format!("P3 {} {} 255\n", self.width, self.height);
    w.write_all(header.as_bytes())?;

    // Pixel data
    for pixel in self.data.iter() {
      let Pixel(red, green, blue) = pixel;
      let pixel = format!("{red} {green} {blue}\n");
      w.write_all(pixel.as_bytes())?;
    }

    Ok(())
  }
}