use std::{fs, io, path::PathBuf};

use clap::Parser;
use color_eyre::eyre::{bail, Result};
use indicatif::{MultiProgress, ProgressBar, ProgressDrawTarget, ProgressStyle};
use is_terminal::IsTerminal;

mod gpx;
mod layer;
mod renderer;

#[derive(Parser, Debug, Clone)]
#[command(author, version, about)]
struct Args {
    /// The GPX files to parse.
    #[arg(required = true)]
    files: Vec<PathBuf>,

    #[arg(long, default_value_t = 0)]
    min_zoom: u32,

    #[arg(long, default_value_t = 19)]
    max_zoom: u32,
}

fn main() -> Result<()> {
    color_eyre::install()?;

    let args = Args::parse();

    if args.max_zoom < args.min_zoom {
        bail!("Max zoom cannot be smaller than min zoom!");
    }

    let progress_style =
        ProgressStyle::with_template("[{elapsed}] {prefix:.cyan} {wide_bar} {pos:.green}/{len}")?;
    let zoom_style =
        ProgressStyle::with_template("[{elapsed}] {prefix:.yellow} {wide_bar} {pos:.green}/{len}")?;

    let use_progress_bars = io::stdout().is_terminal();
    let make_bar = |len| {
        if use_progress_bars {
            ProgressBar::new(len)
        } else {
            ProgressBar::hidden()
        }
    };

    let bar = make_bar(args.files.len().try_into().unwrap()).with_style(progress_style.clone());
    bar.set_prefix("Reading GPX files");

    let mut tracks = Vec::new();
    for file in &args.files {
        let data = gpx::extract_from_file(file, gpx::Compression::None).unwrap();
        tracks.push(data);
        bar.inc(1);
    }
    bar.finish();

    let multibar = MultiProgress::new();
    if !use_progress_bars {
        multibar.set_draw_target(ProgressDrawTarget::hidden())
    }
    let zoom_bar = make_bar((args.max_zoom - args.min_zoom + 1).into()).with_style(zoom_style);
    multibar.add(zoom_bar.clone());
    zoom_bar.set_prefix("Zoom levels");

    for zoom in args.min_zoom..=args.max_zoom {
        let bar = make_bar(tracks.len().try_into().unwrap()).with_style(progress_style.clone());
        multibar.insert_from_back(1, bar.clone());
        bar.set_prefix("Rendering heat zones");
        let counter =
            renderer::render_heatcounter(zoom, &tracks, |x| bar.inc(x.try_into().unwrap()));
        bar.finish();
        multibar.remove(&bar);

        let target = ["tiles", &zoom.to_string()].iter().collect::<PathBuf>();
        fs::create_dir(&target)?;

        let bar =
            make_bar(counter.tile_count().try_into().unwrap()).with_style(progress_style.clone());
        multibar.insert_from_back(1, bar.clone());
        bar.set_prefix("Saving heat tiles");
        renderer::lazy_colorization(counter, &target, |x| bar.inc(x.try_into().unwrap()))?;
        bar.finish();
        multibar.remove(&bar);
        zoom_bar.inc(1);
    }
    zoom_bar.finish();

    Ok(())
}