use clap::Parser;
use crftng_intrprtrs::{exec, lex, parse};
use std::path::PathBuf;
use std::{fs, io};
use tracing::Level;
use tracing_subscriber::{EnvFilter, FmtSubscriber};

#[derive(Parser, Debug)]
struct Args {
	#[clap(parse(from_os_str))]
	file: Option<PathBuf>,

	#[clap(short)]
	dump_ast: bool,
	#[clap(short)]
	no_run: bool,
}

fn run(code: &str, args: &Args) {
	let src_file = args.file.as_ref().map(|f| f.to_string_lossy().to_string());
	let tokens = match lex(code, src_file.as_deref()) {
		Ok(v) => v,
		Err(e) => {
			for error in e {
				println!("{}", error);
			}
			return;
		}
	};
	let ast = match parse(tokens) {
		Ok(v) => v,
		Err(e) => {
			for error in e {
				println!("{}", error);
			}
			return;
		}
	};

	if args.dump_ast {
		for node in &ast {
			println!("{:?}", node);
		}
	}

	if !args.no_run {
		println!("{:?}", exec(ast));
	}
}

fn run_file(args: &Args) -> Result<(), io::Error> {
	let src = fs::read_to_string(args.file.as_ref().unwrap())?;
	run(&src, args);
	Ok(())
}

fn run_repl(args: &Args) {
	assert!(args.file.is_none());

	let mut line_buf = String::new();
	loop {
		match io::stdin().read_line(&mut line_buf) {
			Ok(n) => {
				// Check for EOF
				if n == 0 {
					break;
				}

				let line = line_buf.trim();
				if !line.is_empty() {
					run(&line_buf, args);
					line_buf.clear();
				}
			}
			Err(e) => panic!("{:?}", e),
		}
	}
}

fn main() {
	dotenv::dotenv().ok();
	color_eyre::install().expect("Failed to install color-eyre");
	let subscriber = FmtSubscriber::builder()
		.with_max_level(Level::TRACE)
		.with_env_filter(EnvFilter::from_env("LOG"))
		.finish();

	tracing::subscriber::set_global_default(subscriber).unwrap();

	let args = Args::parse();

	if args.file.is_some() {
		run_file(&args).unwrap();
	} else {
		run_repl(&args)
	}
}