use regex::Regex;
use std::{borrow::Cow, env::args, process::exit};

fn main() {
    let path = args().nth(1).expect("usage: file [--nosize]");
    let nosize = match args().nth(2) {
        None => false,
        Some(t) => {
            if t == "--nosize" {
                true
            } else {
                eprint!("usage: file [--nosize]");
                exit(1)
            }
        }
    };
    let (data, name, width, height) = path_to_img(path.as_str());
    println!("{name}:");
    if !nosize {
        println!("    D {width}");
        println!("    D {height}");
    }
    for d in data {
        println!("    D 0x{d:08x}");
    }
}
fn remove_non_alphanumeric(input: &str) -> Cow<'_, str> {
    let re = Regex::new(r"[^a-zA-Z0-9_]+").unwrap();
    re.replace_all(input, "")
}

fn path_to_img(path: &str) -> (Vec<u32>, String, u32, u32) {
    let img = match image::open(path) {
        Ok(img) => img.to_luma8(),
        Err(e) => panic!("failed to open image {path}: {e}"),
    };

    let width = img.width();
    let height = img.height();

    let mut bytes = Vec::new();
    let mut bit = 0;
    let mut byte = 0;
    for y in 0..height {
        for x in 0..width {
            let pix = img.get_pixel(x, y)[0];
            if pix >= 127 {
                byte |= 1 << bit
            }
            bit += 1;
            if bit == 32 {
                bytes.push(byte);
                byte = 0;
                bit = 0;
            }
        }
    }
    if bit != 0 {
        bytes.push(byte);
    }
    let path = path.split('/').next_back().unwrap();
    let split: Vec<_> = path.split('.').collect();
    let name = format!(
        "picture_{}",
        remove_non_alphanumeric(&split[0..split.len() - 1].join("_")).to_lowercase()
    );
    (bytes, name, width, height)
}