using Gs2.Unity.Util;
using System;
using System.Threading.Tasks;
using UnityEngine;
using GS2Studio.Generated.Quest;
using GS2Studio.Generated.Progress;
using GS2Studio.Generated.Wallet;

public sealed class AdventureStudioView : MonoBehaviour
{
    [SerializeField] private QuestListHandler quests;
    private bool busy;
    private bool unresolved;
    private string message = "";
    [SerializeField] private ProgressHandler progress;
    [SerializeField] private WalletHandler wallet;

    private void OnEnable()
    {
        if (quests != null) quests.Failed += ShowLoadError;
        if (progress != null) progress.Failed += ShowLoadError;
        if (wallet != null) wallet.Failed += ShowLoadError;
    }

    private void OnDisable()
    {
        if (quests != null) quests.Failed -= ShowLoadError;
        if (progress != null) progress.Failed -= ShowLoadError;
        if (wallet != null) wallet.Failed -= ShowLoadError;
    }

    private void ShowLoadError(Exception error)
    {
        message = "Could not load: " + error.GetType().Name;
    }

    private void OnGUI()
    {
        var sessionHolder = Gs2GameSessionHolder.Instance;
        if (quests == null || sessionHolder == null || !sessionHolder.Initialized)
        {
            return;
        }

        GUILayout.BeginArea(new Rect(20, 100, 650, 650), GUI.skin.box);
        GUILayout.Label(message);

        if (quests.IsLoaded)
        {
            DrawQuestButtons();
            DrawPlayerStatus();
        }
        else
        {
            GUILayout.Label("Loading adventures...");
        }

        GUI.enabled = true;
        GUILayout.EndArea();
    }

    private void DrawQuestButtons()
    {
        var canOperate = !busy && !unresolved && progress.HasValue;

        GUI.enabled = canOperate && !progress.Model.InProgress;
        foreach (var quest in quests.Binders)
        {
            GUILayout.Label(quest.DisplayName);
            if (GUILayout.Button("Start: " + quest.DisplayName))
            {
                Run(() => quest.Start());
            }
        }

        GUI.enabled = canOperate && progress.Model.InProgress;
        if (GUILayout.Button("Complete"))
        {
            Run(() => progress.Binder.Complete());
        }
        GUI.enabled = true;
    }

    private void DrawPlayerStatus()
    {
        GUILayout.Label(wallet.HasValue
            ? "Coins: " + wallet.Model.Free
            : "Loading coins...");

        if (!progress.HasValue)
        {
            GUILayout.Label("Loading progress...");
        }
        else
        {
            GUILayout.Label(progress.Model.InProgress
                ? "Adventure in progress"
                : "Choose an adventure");
        }
    }

    private async void Run(Func<Task> operation)
    {
        if (busy || unresolved) return;
        busy = true;
        unresolved = true;
        message = "Processing...";
        try
        {
            await operation();
            unresolved = false;
            message = "Action completed";
        }
        catch (Exception error)
        {
            message = "Cannot confirm the result. New actions are paused: " + error.GetType().Name;
        }
        finally { busy = false; }
    }

}