mod lexer;
mod ast;
mod parser;
mod interpreter;
mod error;

use lexer::Lexer;
use parser::Parser;
use interpreter::Interpreter;
use std::env;
use std::fs;
use std::io::{self, Read};

fn main() {
    let src = match env::args().len() {
        1 => {
            // 无参数：从 stdin 读取
            let mut buf = String::new();
            if let Err(e) = io::stdin().read_to_string(&mut buf) {
                eprintln!("Failed to read stdin: {}", e);
                std::process::exit(1);
            }
            buf
        }
        2 => {
            // 一个参数：作为文件路径
            let path = env::args().nth(1).unwrap();
            match fs::read_to_string(&path) {
                Ok(s) => s,
                Err(e) => {
                    eprintln!("Failed to read file '{}': {}", path, e);
                    std::process::exit(1);
                }
            }
        }
        _ => {
            eprintln!("Usage: aster [script_file]");
            eprintln!("  aster          - run from stdin");
            eprintln!("  aster <file>   - run script file");
            std::process::exit(1);
        }
    };

    let tokens = Lexer::new(&src).tokenize();
    let mut parser = Parser::new(tokens);
    let stmts = parser.parse();

    let mut interpreter = Interpreter::new();
    if let Err(e) = interpreter.interpret(stmts) {
        eprintln!("{}", e);
        std::process::exit(1);
    }
}