package egg

import std.env.*

main(): Int64 {
    var test = "(printf \"hello\")"
    runProgram(test)
    // 简单运算符
    test = "(printf (+ 1 2 3) (* 4 5))"
    runProgram(test)
    // 定义并调用函数
    test = "(do (define plusOne (fun (a) (+ a 1))) \n" +
                "    (printf \"plusOne(10) 的结果:\" (plusOne 10)))"
    runProgram(test)

    // 递归函数 (计算幂)
    test = "(do (define pow (fun (base exp) \n" +
                "                (if (== exp 0) \n" +
                "                    1 \n" +
                "                    (* base (pow base (- exp 1)))))) \n" +
                "    (printf \"2 的 10 次方:\" (pow 2 10)))"
    runProgram(test)

    // 作用域与闭包
    test = "(do (define f (fun (a) (fun (b) (+ a b)))) \n" +
                "    (define add5 (f 5)) \n" +
                "    (printf \"add5(10) 的结果:\" (add5 10)))"
    runProgram(test)

    test = "(do ( define x (array 1 2 3)) (printf (length x)) (printf (element x 0)))"
    runProgram(test)
    runRepl()
    return 0
}

func runProgram(program: String): Unit {
    println("------------------------------")
    println("执行程序")
    println(program)
    try {
        let expr: Expression = Parser(program).parse(program)
        let result = expr.evaluate(TopLevel.create())
        println("结果: ${Utils.convertObjectToString(result)}")
    } catch (e: ParseException) {
        println("解析错误: ${e.message}")
    } catch (e: EvaluateException) {
        println("求值错误: ${e.message}")
    } catch (e: Exception) {
        println("错误: ${e.message}")
    }
    println("------------------------------")
}

func runRepl(): Unit {
    println("Egg REPL (输入 'exit' 退出)")
    while (true) {
        print("egg> ")
        let input: String = (getStdIn().readln()).getOrThrow({=> Exception("读取输入失败")})
        if (input == "exit") {
            break
        }
        if (Utils.isBank(input)) {
            continue
        }
        // println("输入: ${input}")
        try {
            let expr: Expression = Parser(input).parse(input)
            let result = expr.evaluate(TopLevel.create())
            println("结果: ${Utils.convertObjectToString(result)}")
        } catch (e: ParseException) {
            println("解析错误: ${e.message}")
        } catch (e: EvaluateException) {
            println("求值错误: ${e.message}")
        } catch (e: Exception) {
            println("错误: ${e.message}")
        }
    }
}