use std::env;
use std::fs;
use std::io;
use std::io::Write;
use std::process;

mod rlox;
mod scanner;
mod token_type;
mod token;

use crate::rlox::RLox;
use crate::scanner::Scanner;

// Exit codes from #include <sysexits.h>
const EX_OK: i32 = 0;
const EX_DATAERR: i32 = 65;
const EX_USAGE : i32 = 66;

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

    let exit_code = match args.len() {
        1 => run_prompt(),
        2 => run_file(&args[1]),
        _ => {
            println!("Usage : rlox [script]");
            EX_USAGE
        }
    };

    process::exit(exit_code);
}

fn run_file( file_path: &str ) -> i32 {
    let contents = fs::read_to_string(file_path)
        .expect(&format!("Should have been able to read the file {file_path}"));

    run(contents)
}

fn run_prompt() -> i32 {
    let mut exit_code = EX_OK;
    loop {
        print!("> ");
        io::stdout().flush().expect("Unable to flush stdout");
        let mut line = String::new();

        io::stdin()
            .read_line(&mut line)
            .expect("Failed to read line");

        if line.trim().is_empty() {
            break;
        }

        exit_code = run(line);
    }
    exit_code
}

fn run( script: String ) -> i32 {
    let rlox_interpreter = RLox { had_error: false };
    if rlox_interpreter.had_error { EX_DATAERR } else { EX_OK }
}

// Implémentations de référence :
// https://github.com/munificent/craftinginterpreters/wiki/Lox-implementations#rust

// Pause :
// http://www.craftinginterpreters.com/scanning.html#lexical-errors