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

fn main() {
    let root = PathBuf::from(env::var_os("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR"));
    let out = PathBuf::from(env::var_os("OUT_DIR").expect("OUT_DIR"));
    let css_dir = root.join("src/web/css");
    let manifest = css_dir.join("manifest.txt");

    println!("cargo:rerun-if-changed={}", manifest.display());
    println!(
        "cargo:rerun-if-changed={}",
        root.join("src/web/index.html").display()
    );
    println!(
        "cargo:rerun-if-changed={}",
        root.join("src/web/app.js").display()
    );
    println!(
        "cargo:rerun-if-changed={}",
        root.join("src/web/icons.svg").display()
    );
    println!(
        "cargo:rerun-if-changed={}",
        root.join("src/web/i18n/en.json").display()
    );
    println!(
        "cargo:rerun-if-changed={}",
        root.join("src/web/i18n/pl.json").display()
    );

    let manifest_text = fs::read_to_string(&manifest).expect("read src/web/css/manifest.txt");
    let mut bundle = String::from("/* RustBox UI bundle - generated by build.rs */\n");

    for raw in manifest_text.lines() {
        let name = raw.trim();
        if name.is_empty() || name.starts_with('#') {
            continue;
        }
        assert!(
            name.ends_with(".css")
                && !name.contains('/')
                && !name.contains('\\')
                && !name.contains(".."),
            "invalid CSS manifest entry: {name}"
        );
        let path = css_dir.join(name);
        println!("cargo:rerun-if-changed={}", path.display());
        let css =
            fs::read_to_string(&path).unwrap_or_else(|error| panic!("{}: {error}", path.display()));
        bundle.push_str("\n/* ");
        bundle.push_str(name);
        bundle.push_str(" */\n");
        bundle.push_str(&css);
        bundle.push('\n');
    }

    fs::write(out.join("rustbox-ui.css"), bundle).expect("write RustBox CSS bundle");
}