using Gs2.Unity.Util;
using Gs2.Unity.Core;
using System;
using Cysharp.Threading.Tasks;
using Gs2.Unity.Gs2Inventory.Model;
using UnityEngine;

public sealed class AdventureItems : MonoBehaviour
{
    private Gs2Domain Client => Gs2ClientHolder.Instance.Gs2;
    private IGameSession Session => Gs2GameSessionHolder.Instance != null && Gs2GameSessionHolder.Instance.Initialized
        ? Gs2GameSessionHolder.Instance.GameSession : null;
    private EzSimpleItem potion;
    private bool ready;
    private bool busy;
    private Func<UniTask> pendingOperation;
    private bool destroyed;
    private Action unsubscribe;
    private string message = "로딩 중";
    private const string InventoryNamespace = "Inventory";

    private void OnGUI()
    {
        if (Session == null) return;
        GUILayout.BeginArea(new Rect(700, 20, 650, 650), GUI.skin.box);
        GUILayout.Label("회복약");
        GUILayout.Label(message);
        if (!ready) { GUILayout.EndArea(); return; }
        GUILayout.Label("회복약: " + (potion?.Count ?? 0) + "개");
        GUI.enabled = !busy && pendingOperation == null;
        if (GUILayout.Button("회복약 1개로 스태미나 5 회복")) RunWrite(id => Exchange("use_potion", id)).Forget();
        if (GUILayout.Button("20코인으로 회복약 1개 구매")) RunWrite(id => Exchange("buy_potion", id)).Forget();
        GUI.enabled = !busy && pendingOperation != null;
        if (GUILayout.Button("같은 작업 재시도")) RetryWrite().Forget();
        GUI.enabled = true;
        GUILayout.EndArea();
    }

    private void Start() => Subscribe().Forget();

    private void OnDestroy()
    {
        destroyed = true;
        unsubscribe?.Invoke();
    }

    private async UniTask Subscribe()
    {
        try
        {
            await UniTask.WaitUntil(() => Session != null,
                cancellationToken: this.GetCancellationTokenOnDestroy());
            var item = Client.Inventory.Namespace(InventoryNamespace).Me(Session)
                .SimpleInventory("Inventory").SimpleItem("potion");
            var id = await item.SubscribeWithInitialCallAsync(value => potion = value);
            unsubscribe = () => item.Unsubscribe(id);
            if (destroyed) { unsubscribe(); return; }
            ready = true;
            message = "";
        }
        catch (OperationCanceledException) { }
        catch (Exception error) { message = "불러오지 못했습니다: " + error.GetType().Name; }
    }

    private async UniTask Exchange(string rate, string requestId)
    {
        var transaction = await Client.Exchange.Namespace("adventure-item-actions").Me(Session).Exchange()
            .ExchangeAsync(rate, 1, speculativeExecute: false, duplicationAvoider: requestId);
        if (transaction != null) await transaction.WaitAsync(all: true);
    }

    private async UniTask RunWrite(Func<string, UniTask> operation)
    {
        if (busy || pendingOperation != null || Session == null) return;
        var requestId = Guid.NewGuid().ToString();
        pendingOperation = () => operation(requestId);
        await RetryWrite();
    }

    private async UniTask RetryWrite()
    {
        if (busy || pendingOperation == null) return;
        busy = true;
        message = "처리 중";
        try
        {
            await pendingOperation();
            pendingOperation = null;
            message = "완료했습니다";
        }
        catch (Exception error) when (
            error is Gs2.Core.Exception.BadRequestException ||
            error is Gs2.Gs2Money2.Exception.InsufficientException ||
            error is Gs2.Gs2Inventory.Exception.InsufficientException ||
            error is Gs2.Gs2Stamina.Exception.InsufficientException)
        {
            pendingOperation = null;
            message = "작업을 실행하지 못했습니다: " + error.Message;
        }
        catch (Exception error)
        {
            message = "연결을 확인하고 같은 작업을 재시도하세요: " + error.GetType().Name;
        }
        finally { busy = false; }
    }
}