using Google.Apis.Auth.OAuth2;
using Google.Apis.Services;
using Google.Apis.YouTube.v3;
using Google.Apis.YouTube.v3.Data;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Xml;
using Windows.ApplicationModel.Background;
using Windows.Storage;
using Windows.UI.Notifications;

namespace FoxTube.Background
{
    public delegate void NotificationHandler(object sender, Notification item);

    public sealed class BackgroundProcessor : IBackgroundTask
    {
        public static event NotificationHandler NotificationRecieved;

        List<Notification> Notifications = new List<Notification>();
        private DateTime lastCheck = DateTime.Now;

        private ApplicationDataContainer settings = ApplicationData.Current.LocalSettings;

        private ClientSecrets Secrets => new ClientSecrets()
        {
            ClientId = "349735264870-2ekqlm0a4mkg3mmrfcv90s3qp3o15dq0.apps.googleusercontent.com",
            ClientSecret = "BkVZOAaCU2Zclf0Zlicg6y2_"
        };
        private YouTubeService Service => new YouTubeService(new BaseClientService.Initializer()
        {
            ApiKey = "AIzaSyBgHrCnrlzlVmk0cJKL8RqP9Y8x6XSuk_0",
            ApplicationName = "FoxTube"
        });

        XmlDocument doc = new XmlDocument();
        BackgroundTaskDeferral def;

        public void Run(IBackgroundTaskInstance taskInstance)
        {
            def = taskInstance.GetDeferral();
            if (settings.Values["lastCheck"] == null)
                settings.Values.Add("lastCheck", XmlConvert.ToString(DateTime.Now, "YYYY-MM-DDThh:mm:ss"));
            else lastCheck = XmlConvert.ToDateTime(settings.Values["lastCheck"] as string, XmlDateTimeSerializationMode.Unspecified);

            try
            {
                doc.LoadXml(settings.Values["notificationsHistory"] as string);
            }
            catch
            {
                return;
            }

            CheckAnnouncements();
            CheckAccount();

            SendNSave();

            def.Complete();
        }

        async void CheckAccount()
        {
            UserCredential credential = await GoogleWebAuthorizationBroker.AuthorizeAsync(Secrets, new[] { Google.Apis.Oauth2.v2.Oauth2Service.Scope.UserinfoProfile, YouTubeService.Scope.YoutubeForceSsl }, "user", CancellationToken.None);
            if (credential == null)
                return;

            SubscriptionsResource.ListRequest subRequest = new YouTubeService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credential,
                ApplicationName = "FoxTube"
            }).Subscriptions.List("snippet");
            subRequest.Mine = true;
            subRequest.MaxResults = 50;
            SubscriptionListResponse subResponse = await subRequest.ExecuteAsync();
            Dictionary<string, string> subs = new Dictionary<string, string>();

            foreach (Subscription s in subResponse.Items)
                subs.Add(s.Snippet.ResourceId.ChannelId, s.Snippet.Thumbnails.Standard.Url);

            string nextToken = subResponse.NextPageToken;
            while (nextToken != null)
            {
                subRequest.PageToken = nextToken;
                subResponse = await subRequest.ExecuteAsync();
                nextToken = subResponse.NextPageToken;

                foreach (Subscription s in subResponse.Items)
                    subs.Add(s.Snippet.ResourceId.ChannelId, s.Snippet.Thumbnails.Standard.Url);
            }

            foreach(var s in subs)
            {
                SearchResource.ListRequest request = Service.Search.List("snippet");
                request.PublishedAfter = lastCheck;
                request.ChannelId = s.Key;
                request.Type = "video";
                SearchListResponse response = await request.ExecuteAsync();

                foreach (var i in response.Items)
                    Notifications.Add(new Notification("video", i.Id.VideoId,
                        i.Snippet.ChannelTitle,
                        i.Snippet.Title,
                        i.Snippet.PublishedAt.Value,
                        i.Snippet.Thumbnails.Standard.Url,
                        s.Value));
            }
        }

        void CheckAnnouncements()
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(XmlReader.Create("http://foxgame.hol.es/foxtube-messages.xml"));
            if ((XmlConvert.ToDateTimeOffset((doc["posts"].FirstChild as XmlElement).GetAttribute("time"), "YYYY-MM-DDThh:mm:ss") - lastCheck.ToUniversalTime()).TotalSeconds > 0)
                Notifications.Add(new Notification("internal", (doc["posts"].FirstChild as XmlElement).GetAttribute("id"),
                    doc["posts"].FirstChild["header"].InnerText,
                    doc["posts"].FirstChild["notificationHeader"].InnerText,
                    XmlConvert.ToDateTimeOffset((doc["posts"].FirstChild as XmlElement).GetAttribute("time"), "YYYY-MM-DDThh:mm:ss"),
                    (doc["posts"].FirstChild as XmlElement).GetAttribute("image"), (doc["posts"].FirstChild as XmlElement).GetAttribute("avatar")));
        }

        void SendNotification(Notification notification)
        {
            ToastNotificationManager.CreateToastNotifier().Show(notification.GetToast());
        }

        void SendNSave()
        {
            foreach (Notification n in Notifications)
            {
                NotificationRecieved.Invoke(this, n);
                doc["history"].InnerXml += n.GetXml();
            }
            settings.Values.Add("notificationsHistory", doc.InnerXml);

            foreach (Notification n in Notifications)
                switch (n.Type)
                {
                    case NotificationType.Video:
                        if ((bool)settings.Values["newVideoNotification"])
                            SendNotification(n);
                        break;

                    case NotificationType.Internal:
                        SendNotification(n);
                        break;
                }
        }
    }
}