using FoxTube.Utils;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Oauth2.v2;
using Google.Apis.Oauth2.v2.Data;
using Google.Apis.Services;
using Google.Apis.YouTube.v3;
using Google.Apis.YouTube.v3.Data;
using System;
using System.Linq;
using System.Collections.Generic;
using System.Threading.Tasks;
using YouTube;
using YoutubeExplode;
using FoxTube.Services;

namespace FoxTube.Models
{
	public class User
	{
		public Userinfoplus UserInfo { get; private set; }
		public UserCredential Credential { get; private set; }
		public Channel Channel { get; private set; }
		public List<Subscription> Subscriptions { get; } = new List<Subscription>();

		public ExtendedYouTubeService Service { get; private set; }
		public YoutubeClient Client { get; private set; }

		private User() { }

		public async Task<bool> UpdateSubscriptionState(string channelId)
		{
			if (Subscriptions.Find(i => i.ChannelId == channelId) is Subscription subscription)
			{
				try { await Service.Subscriptions.Delete(subscription.SubscriptionId).ExecuteAsync(); }
				catch (Exception e)
				{
					Metrics.SendReport(new Exception("Failed to unsubscribe", e));
					return true;
				}

				UserService.SubscriptionsChangedInvoker(this, subscription);
				Subscriptions.Remove(subscription);
				return false;
			}
			else
			{
				var request = Service.Subscriptions.Insert(new Google.Apis.YouTube.v3.Data.Subscription()
				{
					Snippet = new SubscriptionSnippet()
					{
						ResourceId = new ResourceId()
						{
							ChannelId = channelId,
							Kind = "youtube#channel"
						}
					}
				}, "id");

				var subscriptionData = await request.ExecuteAsync();
				if (subscriptionData == null)
					return false;

				Channel channel = await Extensions.GetChannel(subscriptionData.Snippet.ChannelId, "snippet,statistics,brandingSettins");

				subscription = new Subscription
				{
					Title = channel.Snippet.Title,
					ChannelId = channel.Id,
					SubscriptionId = subscriptionData.Id,
					VideosCount = channel.Statistics.VideoCount.Value,
					SubscribersCount = channel.Statistics.SubscriberCount,
					Avatar = channel.Snippet.Thumbnails,
					Banner = channel.BrandingSettings.Image
				};
				Subscriptions.Add(subscription);

				UserService.SubscriptionsChangedInvoker(this, subscription);
				return true;
			}
		}

		public static async Task<User> GetUser(UserCredential credential)
		{
			User user = new User
			{
				Credential = credential
			};

			BaseClientService.Initializer initializer = new BaseClientService.Initializer
			{
				ApplicationName = "FoxTube",
				HttpClientInitializer = credential
			};

			user.Service = new ExtendedYouTubeService(initializer);

			user.UserInfo = await new Oauth2Service(initializer).Userinfo.Get().ExecuteAsync();

			var request = user.Service.Channels.List("snippet,contentDetails,brandingSettings");
			request.Mine = true;
			user.Channel = request.Execute().Items[0];

			// TODO: Retrieve history and WL

			await user.LoadSubscriptions();

			return user;
		}

		public async Task LoadSubscriptions()
		{
			Subscriptions.Clear();

			SubscriptionsResource.ListRequest subRequest = Service.Subscriptions.List("snippet");
			subRequest.Mine = true;
			subRequest.MaxResults = 50;
			subRequest.Order = SubscriptionsResource.ListRequest.OrderEnum.Relevance;
			SubscriptionListResponse subResponse;

			do
			{
				subResponse = await subRequest.ExecuteAsync();
				subRequest.PageToken = subResponse.NextPageToken;

				Subscriptions.AddRange(subResponse.Items.Select(i => new Subscription
				{
					Title = i.Snippet.Title,
					ChannelId = i.Snippet.ResourceId.ChannelId,
					SubscriptionId = i.Id,
					Avatar = i.Snippet.Thumbnails,
					Description = i.Snippet.Description
				}));

			} while (!string.IsNullOrWhiteSpace(subRequest.PageToken));

			var request = Service.Channels.List("statistics,brandingSettings");
			request.Id = string.Join(',', Subscriptions.Select(i => i.ChannelId));
			request.MaxResults = 50;
			ChannelListResponse response;

			if (Subscriptions.Count > 0)
				do
				{
					response = await request.ExecuteAsync();
					request.PageToken = response.NextPageToken;

					Subscriptions.ForEach(i =>
					{
						Channel channel = response.Items.FirstOrDefault(c => c.Id == i.ChannelId);
						i.Banner = channel.BrandingSettings.Image;
						i.SubscribersCount = channel.Statistics.HiddenSubscriberCount.Value ? null : channel.Statistics.SubscriberCount;
						i.VideosCount = channel.Statistics.VideoCount.Value;
					});
				}
				while (!string.IsNullOrWhiteSpace(request.PageToken));
		}
	}
}