use std::env;
use std::fs::File;
use std::io::prelude::*;
use std::io::BufWriter;

extern crate rawloader;
use rawloader::decoders;

fn main() {
  let args: Vec<_> = env::args().collect();
  if args.len() != 2 {
    println!("Usage: {} <file>", args[0]);
    std::process::exit(2);
  }
  let file = &args[1];
  println!("Loading file \"{}\"", file);

  let rawloader = decoders::RawLoader::new();
  let image = rawloader.decode_safe(file).unwrap();

  println!("Found camera \"{}\" model \"{}\"", image.make, image.model);
  println!("Found canonical named camera \"{}\" model \"{}\"", image.canonical_make, image.canonical_model);
  println!("Image size is {}x{}", image.width, image.height);
  println!("WB coeffs are {:?}", image.wb_coeffs);
  println!("black levels are {:?}", image.blacklevels);
  println!("white levels are {:?}", image.whitelevels);
  println!("color matrix is {:?}", image.color_matrix);
  println!("CFA is {:?}", image.cfa);
  println!("crops are {:?}", image.crops);

  // Write out the image as a grayscale PPM
  let mut f = BufWriter::new(File::create(format!("{}.ppm",file)).unwrap());
  let preamble = format!("P6 {} {} {}\n", image.width, image.height, image.whitelevels[0]).into_bytes();
  f.write_all(&preamble).unwrap();
  for row in 0..image.height {
    let from: usize = (row as usize) * (image.width as usize);
    let to: usize = ((row+1) as usize) * (image.width as usize);
    let imgline = &image.data[from .. to];

    for pixel in imgline {
      // Do an extremely crude "demosaic" by setting R=G=B
      let bytes = [(pixel>>4) as u8, (pixel&0x0f) as u8, (pixel>>4) as u8, (pixel&0x0f) as u8, (pixel>>4) as u8, (pixel&0x0f) as u8];
      f.write_all(&bytes).unwrap();
    }
  }
}

  // Decode to the largest image that fits in 1080p size. If the original image is
  // smaller this will not scale up but otherwise you will get an image that is either
  // 1920 pixels wide or 1080 pixels tall and maintains the image ratio.
  let decoded = imageops::simple_decode(&image, 1920, 1080);

  let mut f = BufWriter::new(File::create(format!("{}.ppm",file)).unwrap());
  let preamble = format!("P6 {} {} {}\n", decoded.width, decoded.height, 255).into_bytes();
  f.write_all(&preamble).unwrap();
  for pix in decoded.data {
    let pixel = ((pix.max(0.0)*255.0).min(255.0)) as u8;
    f.write_all(&[pixel]).unwrap();
  }