using System;
using Cysharp.Threading.Tasks;
using UnityEngine;

public sealed class AdventurePlay : MonoBehaviour
{
    [SerializeField] private AdventureLogin login;
    private AdventurePlayer player;
    private bool busy;
    private bool awaitingResult;
    private bool blocked;
    private string message = "Waiting for login";

    private bool CanInteract => player?.Ready == true && !busy;
    private bool CanWrite => CanInteract && player.HasPlayerData && !blocked;

    private async UniTask BeginQuest(string questName)
    {
        var transaction = await player.Gs2.Quest.Namespace("adventure-quest").Me(player.Session)
            .StartAsync("main", questName, force: false, speculativeExecute: false);
        awaitingResult = true;
        if (transaction != null) await transaction.WaitAsync(all: true);
    }

    private async UniTask CompleteQuest()
    {
        var transaction = await player.Gs2.Quest.Namespace("adventure-quest").Me(player.Session)
            .Progress().EndAsync(isComplete: true, speculativeExecute: false);
        awaitingResult = true;
        if (transaction != null) await transaction.WaitAsync(all: true);
    }

    private void OnGUI()
    {
        if (login.Session == null) return;
        GUILayout.BeginArea(new Rect(20, 210, 650, 650), GUI.skin.box);
        GUILayout.Label(message);
        if (player?.Ready == true)
        {
            DrawStatus();
            DrawQuestButtons();
        }
        GUI.enabled = true;
        GUILayout.EndArea();
    }

    private void DrawQuestButtons()
    {
        GUI.enabled = CanWrite && player.Progress == null;
        foreach (var quest in player.Quests)
        {
            GUILayout.Label(quest.Metadata + " (" + quest.Name + ")");
            if (GUILayout.Button("Start: " + quest.Name)) RunWrite(() => BeginQuest(quest.Name)).Forget();
        }
        GUI.enabled = CanWrite && player.Progress != null;
        if (GUILayout.Button("Complete")) RunWrite(CompleteQuest).Forget();
    }

    private void DrawStatus()
    {
        GUILayout.Label(player.Wallet?.Summary != null ? "Coins: " + player.Wallet.Summary.Free : "Could not load the coin balance");
        GUILayout.Label(player.Progress == null ? "Choose an adventure" : "Adventure in progress");
    }

    private void Start() => Initialize().Forget();
    private void OnDestroy() => player?.Dispose();

    private async UniTask Initialize()
    {
        busy = true;
        try
        {
            await UniTask.WaitUntil(() => login.Session != null,
                cancellationToken: this.GetCancellationTokenOnDestroy());
            message = "Loading...";
            player = new AdventurePlayer(login.Gs2, login.Session);
            await player.Load();
            message = "";
        }
        catch (OperationCanceledException) { }
        catch (Exception error) { message = "Could not load: " + error.GetType().Name; }
        finally { busy = false; }
    }

    private async UniTask RunWrite(Func<UniTask> operation)
    {
        if (!CanWrite) return;
        busy = true;
        awaitingResult = false;
        try
        {
            blocked = true;
            await operation();
            blocked = false;
            message = "";
        }
        catch (Exception error) { message = WriteError(error); }
        finally { busy = false; }
    }

    private string WriteError(Exception error)
    {
        if (awaitingResult)
        {
            return "Cannot confirm the submitted operation's result: " + error.GetType().Name;
        }
        if (error is Gs2.Core.Exception.BadRequestException)
        {
            blocked = false;
            return "Action failed. Check the settings.";
        }
        return "Cannot confirm the result. New actions are paused: " + error.GetType().Name;
    }
}