using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using YoutubeExplode.Channels;
using YoutubeExplode.Playlists;
using YoutubeExplode.Videos;
using MailKit.Net.Smtp;
using MimeKit;
using MailKit;
using MailKit.Net.Imap;
using System.IO;
using System.Threading;

namespace Tesses.YouTubeDownloader.MailKit
{
    public sealed class SMTPDownloader : IDownloader
    {
        string fromEmail;
        string toEmail;
        Func<Task<SmtpClient>> new_client;
        public SMTPDownloader(Func<Task<SmtpClient>> client,string fromEmail,string toEmail)
        {
            this.new_client = client;
            this.fromEmail=fromEmail;
            this.toEmail=toEmail;
        }

        public SMTPDownloader(string smtpServer,string fromEmail,string toEmail,string username,string password,int port=587,global::MailKit.Security.SecureSocketOptions options=global::MailKit.Security.SecureSocketOptions.StartTls)
        {
            this.new_client = async ()=>{
                var clt= new SmtpClient();
                await clt.ConnectAsync(smtpServer,port,options);
                await clt.AuthenticateAsync(username,password);
                return clt;
            };
            this.fromEmail=fromEmail;
            this.toEmail = toEmail;
        }

        public event EventHandler<VideoStartedEventArgs> VideoStarted;
        public event EventHandler<VideoProgressEventArgs> VideoProgress;
        public event EventHandler<VideoFinishedEventArgs> VideoFinished;
        public event EventHandler<TYTDErrorEventArgs> Error;
        public event EventHandler<BellEventArgs> Bell;

        private async Task AddItemToAsync(string url)
        {
            using(var clt = await new_client())
            {
                var messageToSend = new MimeMessage();
                messageToSend.From.Add(MailboxAddress.Parse(fromEmail));
                messageToSend.To.Add(MailboxAddress.Parse(toEmail));
                messageToSend.Body = new TextPart(MimeKit.Text.TextFormat.Plain){Text=url};
                messageToSend.Subject="Sent By Tesses.YouTubeDownloader.MailKit";
                await clt.SendAsync(messageToSend);
                await clt.DisconnectAsync(true);
            }
        }

        public async Task AddChannelAsync(ChannelId id, Resolution resolution = Resolution.PreMuxed)
        {
            await AddItemToAsync($"https://www.youtube.com/channel/{id.Value}");
        }

        public async Task AddFileAsync(string url, bool download = true)
        {
            await Task.CompletedTask;
        }

        public async Task AddPlaylistAsync(PlaylistId id, Resolution resolution = Resolution.PreMuxed)
        {
            await AddItemToAsync($"https://www.youtube.com/playlist?list={id.Value}");
        }

        public async Task AddToPersonalPlaylistAsync(string name, IEnumerable<ListContentItem> items)
        {
            await Task.CompletedTask;
        }

        public async Task AddUserAsync(UserName userName, Resolution resolution = Resolution.PreMuxed)
        {
            await AddItemToAsync($"https://www.youtube.com/user/{userName.Value}");
        }

        public async Task AddVideoAsync(VideoId id, Resolution resolution = Resolution.PreMuxed)
        {
            await AddItemToAsync($"https://www.youtube.com/watch?v={id.Value}");
        }
        public async Task AddSlugAsync(ChannelSlug slug,Resolution resolution=Resolution.PreMuxed)
        {
             await AddItemToAsync($"https://www.youtube.com/c/{slug.Value}");
        }
        public async Task AddHandleAsync(ChannelHandle handle,Resolution resolution =Resolution.PreMuxed)
        {
            await AddItemToAsync($"https://www.youtube.com/@{handle.Value}");
        }
        public void CancelDownload(bool restart = false)
        {
            
        }

        public void DeletePersonalPlaylist(string name)
        {
           
        }

        public ExtraData GetExtraData()
        {
        
            return new ExtraData();
        }

        public async IAsyncEnumerable<ListContentItem> GetPersonalPlaylistContentsAsync(string name)
        {
            await Task.CompletedTask;
            yield break;
        }

        public SavedVideoProgress GetProgress()
        {
            return new SavedVideoProgress();
        }

        public IReadOnlyList<(SavedVideo Video, Resolution Resolution)> GetQueueList()
        {
             return new List<(SavedVideo Video,Resolution Resolution)>();
        }

        public async IAsyncEnumerable<Subscription> GetSubscriptionsAsync()
        {
            await Task.CompletedTask;
            yield break;
        }

        public bool PersonalPlaylistExists(string name)
        {
           return false;
        }

        public async Task RemoveItemFromPersonalPlaylistAsync(string name, VideoId id)
        {
            await Task.CompletedTask;
        }

        public async Task ReplacePersonalPlaylistAsync(string name, IEnumerable<ListContentItem> items)
        {
           await Task.CompletedTask;
        }

        public async Task ResubscribeAsync(ChannelId id, ChannelBellInfo info = ChannelBellInfo.NotifyAndDownload)
        {
            await Task.CompletedTask;
        }

        public async Task SetResolutionForItemInPersonalPlaylistAsync(string name, VideoId id, Resolution resolution)
        {
            await Task.CompletedTask;
        }

        public async Task SubscribeAsync(ChannelId id, ChannelBellInfo bellInfo = ChannelBellInfo.NotifyAndDownload)
        {
            await Task.CompletedTask;
        }

        public async Task SubscribeAsync(UserName name, ChannelBellInfo info = ChannelBellInfo.NotifyAndDownload)
        {
            await Task.CompletedTask;
        }

        public async Task UnsubscribeAsync(ChannelId id)
        {
            await Task.CompletedTask;
        }
    }

    public sealed class IMAPDownloader
    {
        IDownloader downloader;
        string imapServer;
        int imapPort;
        bool ssl;
        string username;
        string password;
        string[] folders;
        public IMAPDownloader(IDownloader downloader,string imapServer,int imapPort,bool ssl,string username,string password,params string[] folders)
        {
            this.downloader=downloader;
            this.imapServer =imapServer;
            this.imapPort = imapPort;
            this.ssl = ssl;
            this.username = username;
            this.password = password;
            this.folders = folders;
        }

        public void Scan()
        {
            using (var client = new ImapClient())
            {
                client.Connect(imapServer, imapPort,ssl);
                client.Authenticate(username,password);
                foreach (var folder_name in folders)
                {
                    var folder = client.GetFolder(folder_name);
                    folder.Open(FolderAccess.ReadOnly);
                    foreach(var item in folder)
                    {
                        using (var ms = new MemoryStream())
                        {
                            item.Body.WriteTo(ms);
                            ms.Position = 0;
                            using (var sr = new StreamReader(ms))
                            {
                                string line;
                                while((line=sr.ReadLine()) != null)
                                {
                                    try
                                    {
                                        Task.Run(async () => await downloader.AddItemAsync(line)).Wait();
                                    }
                                    catch(Exception ex)
                                    {
                                        _ = ex;
                                    }
                                }
                            }
                        }
                       
                    }
                }
                client.Disconnect(true);
                
            }
        }
        
        public async Task ScanAsync(CancellationToken token=default)
        {
            using (var client = new ImapClient())
            {
                await client.ConnectAsync(imapServer, imapPort,ssl,token);
                await client.AuthenticateAsync(username,password,token);
                foreach (var folder_name in folders)
                {
                    if(token.IsCancellationRequested) break;
                    var folder = await client.GetFolderAsync(folder_name,token);
                    await folder.OpenAsync(FolderAccess.ReadOnly,token);
                    foreach(var item in folder)
                    {
                        if(token.IsCancellationRequested) break;
                        using (var ms = new MemoryStream())
                        {
                            item.Body.WriteTo(ms);
                            ms.Position = 0;
                            using (var sr = new StreamReader(ms))
                            {
                                string line;
                                while((line=await sr.ReadLineAsync()) != null)
                                {
                                    if(token.IsCancellationRequested) break;
                                    try
                                    {
                                        await downloader.AddItemAsync(line);
                                    }
                                    catch(Exception ex)
                                    {
                                        _ = ex;
                                    }
                                }
                            }
                        }
                       
                    }
                }
                await client.DisconnectAsync(true,token);
                
            }
        }
       
        public void ScanLoop(TimeSpan interval,CancellationToken token=default)
        {
            Thread t = new Thread(async()=>{
                try{
                while(!token.IsCancellationRequested)
                {
                    await ScanAsync(token);
                    await Task.Delay(interval.Milliseconds,token);
                }
                }catch(Exception ex)
                {
                    _=ex;
                }
            });
            t.Start();
        }
        
    }

}