use minijinja::{context, Environment};
use owo_colors::OwoColorize;
use std::fs;

fn main() {
    let board_dir = "src/board";
    let boards: Vec<String> = fs::read_dir(board_dir).unwrap()
        .filter_map(|e| {
            let p = e.ok()?.path();
            if p.is_file() && p.extension()? == "rs" && p.file_stem()? != "mod" {
                return Some(p.file_stem()?.to_str()?.to_string());
            }
            None
        }).collect();

    let enabled: Vec<_> = std::env::vars()
        .filter(|(k, _)| k.starts_with("CARGO_FEATURE_"))
        .map(|(k, _)| k.replace("CARGO_FEATURE_", "").to_lowercase())
        .filter(|f| boards.contains(f)).collect();

    match enabled.len() {
        0 => panic!("\n\n{}\n", format!("No board selected! Found: {:?}", boards).red().bold()),
        1 => println!("cargo:rustc-cfg=board_selected"),
        _ => panic!("\n\n{}\n", format!("Conflict: Multiple boards enabled {:?}", enabled).yellow().bold()),
    }

    let mut env = Environment::new();
    let template = fs::read_to_string("src/board/mod.rs.j2").expect("Missing template .j2");
    env.add_template("mod", &template).unwrap();
    let rendered = env.get_template("mod").unwrap().render(context!(boards => boards)).unwrap();
    fs::write("src/board/mod.rs", rendered).unwrap();

    println!("cargo:rerun-if-changed=src/board/mod.rs.j2");
    println!("cargo:rerun-if-changed={}", board_dir);
}