extern crate getopts;
extern crate image;

use std::io::Read;
use std::fs::File;

pub mod css;
pub mod display;
pub mod dom;
pub mod html;
pub mod layout;
pub mod styling;

fn read_source(filename: String) -> String {
    let mut str = String::new();
    File::open(filename).unwrap().read_to_string(&mut str).unwrap();
    str
}

fn main() {
    let mut opts = getopts::Options::new();
    opts.optopt("h", "html", "HTML document", "FILENAME");
    opts.optopt("o", "out", "PNG output", "FILENAME");

    let matches = opts.parse(std::env::args().skip(1)).unwrap();
    let str_arg = |flag: &str, default: &str| -> String {
        matches.opt_str(flag).unwrap_or(default.to_string())
    };

    let initial_block = layout::Dim {
        content: layout::Rect { x: 0.0, y: 0.0, width: 800.0, height: 600.0 },
        padding: Default::default(),
        border: Default::default(),
        margin: Default::default(),
    };

    let html = read_source(str_arg("h", "examples/test.html"));
    let node = html::parse(html);
    let style = dom::find_style(&node).unwrap();
    let styled_node = styling::style_tree(&node, &style);

    let layout = layout::layout_tree(&styled_node, initial_block);
    let canvas = display::paint(&layout, initial_block.content);

    let filename = str_arg("o", "out.png");
    let mut file = File::create(&filename).unwrap();

    let (w, h) = (canvas.width as u32, canvas.height as u32);
    let img = image::ImageBuffer::from_fn(w, h, move |x, y| {
        let color = canvas.pixels[(y * w + x) as usize];
        image::Pixel::from_channels(color.r, color.g, color.b, color.a)
    });

    let result = image::ImageRgba8(img).save(&mut file, image::PNG);
    match result {
        Ok(_) => println!("Saved output as {}", filename),
        Err(_) => println!("Error saving output as {}", filename)
    }
}