mod init;

use std::path::PathBuf;

fn main() {
    let args: Vec<String> = std::env::args().collect();

    match args.get(1).map(String::as_str) {
        Some("init") => {
            let is_lib = args.iter().any(|a| a == "--lib");
            let dir = args
                .iter()
                .skip(2)
                .find(|a| !a.starts_with('-'))
                .map(String::as_str)
                .unwrap_or(".");
            init::run(dir, is_lib);
        }
        Some(_) => compile(&args),
        None => {
            print_usage();
            std::process::exit(1);
        }
    }
}

fn compile(args: &[String]) {
    let input_path = PathBuf::from(&args[1]);
    let src = match std::fs::read_to_string(&input_path) {
        Ok(s) => s,
        Err(e) => {
            eprintln!("error reading {}: {}", input_path.display(), e);
            std::process::exit(1);
        }
    };

    let ast = match misses::parse(&src) {
        Ok(a) => a,
        Err(e) => {
            eprintln!("parse error: {}", e);
            std::process::exit(1);
        }
    };

    let generated = misses::codegen(&ast);

    if args.len() >= 3 {
        let output_path = PathBuf::from(&args[2]);
        if let Err(e) = std::fs::write(&output_path, &generated) {
            eprintln!("error writing {}: {}", output_path.display(), e);
            std::process::exit(1);
        }
    } else {
        print!("{}", generated);
    }
}

fn print_usage() {
    eprintln!("Usage:");
    eprintln!("  misses <input.mrs> [output.rs]   Compile a .mrs file to Rust");
    eprintln!("  misses init [--lib] [dir]         Scaffold a new misses project");
    eprintln!();
    eprintln!("Modes for `misses init`:");
    eprintln!("  (default)   Binary — .mrs sources are compiled at build time via build.rs;");
    eprintln!("              generated code lives in \\$OUT_DIR and is never committed.");
    eprintln!("  --lib       Library — generated code is committed to generated/ so");
    eprintln!("              downstream users need no misses install. Rebuild with");
    eprintln!("              `cargo build --features misses-source`.");
}