using System;
using Monad;
using Monad.Parsec;
using UnityEngine;
using UnityEngine.Assertions;

public class TryMonad : MonoBehaviour
{
    private void Start()
    {
        Debug.Log(Test());
    }

    private Monad.Try<int> DoSomething(int value)
    {
        return () => value + 1;
    }

    private Monad.Try<int> DoSomethingError(int value)
    {
        if (value > 10)
        {
            return () => value;
        }

        return () => throw new Exception("Require value is greater than 10!");
    }

    private Monad.Try<int> DoNotEverEnterThisFunction(int value)
    {
        return () => value + 1000;
    }

    private Monad.Try<int> TryDoingBusiness(int value)
    {
        if (value > 100)
        {
            return () => value;
        }

        return () => throw new Exception("not valid value!");
    }

    public string Test()
    {
        var monad = from val1 in DoSomething(10)
            from val2 in DoSomethingError(val1)
            from val3 in DoNotEverEnterThisFunction(val2)
            select val3;

        var result1 = DoSomethingError(1)();

        var result = monad();

        var result2 = DoSomethingError(1)
            .Match(
                Success: v => v,
                Fail: err => -1
            );

        Debug.Log("result2: " + result2);

        return result.IsFaulted ? result.Exception.Message : result.Value + "";
    }
}