using Gs2.Unity.Util;
using Gs2.Unity.Core;
using System;
using Cysharp.Threading.Tasks;
using System.Collections.Generic;
using Gs2.Unity.Gs2Inbox.Model;
using UnityEngine;

public sealed class AdventureEventView : MonoBehaviour
{
    [SerializeField] private AdventureLogin login;
    private Gs2Domain Client => login.Gs2;
    private IGameSession Session => login == null ? null : login.Session;
    private readonly List<EzMessage> messages = new List<EzMessage>();
    private bool busy;
    private Func<UniTask> pendingOperation;
    private bool destroyed;
    private Action unsubscribe;
    private string message = "Load the inbox";
    private Vector2 scroll;
    private string startMinutes = "15";
    private string endMinutes = "30";
    private string startsAt = "";
    private string endsAt = "";
    private string startMillis = "";
    private string endMillis = "";
    private const string Inbox = "adventure-inbox";

    private void OnGUI()
    {
        if (Session == null) return;
        GUILayout.BeginArea(new Rect(700, 20, 650, Screen.height - 40), GUI.skin.box);
        scroll = GUILayout.BeginScrollView(scroll);
        GUILayout.Label("Event announcements and rewards");
        GUILayout.Label(message);
        GUILayout.Label("Set event times (minutes from now)");
        startMinutes = GUILayout.TextField(startMinutes);
        endMinutes = GUILayout.TextField(endMinutes);
        if (GUILayout.Button("Generate start and end times")) MakeDates();
        GUILayout.Label("Studio start time / end time");
        GUILayout.TextField(startsAt);
        GUILayout.TextField(endsAt);
        GUILayout.Label("SDK template START_AT / END_AT");
        GUILayout.TextField(startMillis);
        GUILayout.TextField(endMillis);
        GUI.enabled = !busy && pendingOperation == null;
        if (GUILayout.Button("Receive announcements and update inbox")) Run(() => Load()).Forget();
        foreach (var item in messages)
        {
            GUILayout.Label(item.Metadata);
            GUI.enabled = !busy && pendingOperation == null && !item.IsRead;
            if (GUILayout.Button(item.IsRead ? "Opened" : "Open and claim reward"))
                RunWrite(id => Read(item.Name, id)).Forget();
        }
        GUI.enabled = !busy && pendingOperation != null;
        if (GUILayout.Button("Retry the same operation")) RetryWrite().Forget();
        GUI.enabled = true;
        GUILayout.EndScrollView();
        GUILayout.EndArea();
    }

    private void MakeDates()
    {
        if (!int.TryParse(startMinutes, out var start) || !int.TryParse(endMinutes, out var end) ||
            start >= end || start < -1440 || end > 1440)
        {
            message = "Set start before end, both within 1440 minutes of now";
            return;
        }
        var now = System.DateTimeOffset.Now;
        startsAt = now.AddMinutes(start).ToString("yyyy-MM-dd HH:mm:ss zzz");
        endsAt = now.AddMinutes(end).ToString("yyyy-MM-dd HH:mm:ss zzz");
        startMillis = now.AddMinutes(start).ToUnixTimeMilliseconds().ToString();
        endMillis = now.AddMinutes(end).ToUnixTimeMilliseconds().ToString();
    }

    private async UniTask Run(System.Func<UniTask> action)
    {
        if (busy || pendingOperation != null) return;
        busy = true;
        try { await action(); }
        catch (System.Exception error) { message = error.Message; }
        finally { busy = false; }
    }

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

    private async UniTask Load()
    {
        var user = Client.Inbox.Namespace(Inbox).Me(Session);
        await user.ReceiveGlobalMessageAsync();
        user.InvalidateMessages();
        var items = new List<EzMessage>();
        await foreach (var item in user.MessagesAsync())
            if (item != null) items.Add(item);
        if (destroyed) return;
        unsubscribe?.Invoke();
        UpdateMessages(items.ToArray());
        var id = user.SubscribeMessages(UpdateMessages);
        unsubscribe = () => user.UnsubscribeMessages(id);
        message = messages.Count == 0 ? "No messages received" : "Inbox updated";
    }

    private void UpdateMessages(EzMessage[] items)
    {
        messages.Clear();
        messages.AddRange(items);
    }

    private async UniTask Read(string name, string requestId)
    {
        var transaction = await Client.Inbox.Namespace(Inbox).Me(Session)
            .Message(name).ReadAsync(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 = "Processing...";
        try
        {
            await pendingOperation();
            pendingOperation = null;
            message = "Done";
        }
        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 = "Action failed: " + error.Message;
        }
        catch (Exception error)
        {
            message = "Check the connection and retry the same operation: " + error.GetType().Name;
        }
        finally { busy = false; }
    }
}