using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Google.Apis.YouTube.v3;
using Google.Apis.Services;
using System.Text.RegularExpressions;
using Google.Apis.Urlshortener.v1;
using Google.Apis.Urlshortener.v1.Data;
using NLog;
using Google.Apis.Customsearch.v1;
using System.Net.Http;
using System.Net;
using Newtonsoft.Json.Linq;
using NadekoBot.Extensions;

namespace NadekoBot.Services.Impl
{
    public class GoogleApiService : IGoogleApiService
    {
        const string search_engine_id = "018084019232060951019:hs5piey28-e";

        private YouTubeService yt;
        private UrlshortenerService sh;
        private CustomsearchService cs;

        private Logger _log { get; }

        public GoogleApiService(IBotCredentials creds)
        {
            _creds = creds;

            var bcs = new BaseClientService.Initializer
            {
                ApplicationName = "Nadeko Bot",
                ApiKey = _creds.GoogleApiKey,
            };

            _log = LogManager.GetCurrentClassLogger();

            yt = new YouTubeService(bcs);
            sh = new UrlshortenerService(bcs);
            cs = new CustomsearchService(bcs);
        }
        private static readonly Regex plRegex = new Regex("(?:youtu\\.be\\/|list=)(?<id>[\\da-zA-Z\\-_]*)", RegexOptions.Compiled);
        public async Task<IEnumerable<string>> GetPlaylistIdsByKeywordsAsync(string keywords, int count = 1)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(keywords))
                throw new ArgumentNullException(nameof(keywords));

            if (count <= 0)
                throw new ArgumentOutOfRangeException(nameof(count));

            var match = plRegex.Match(keywords);
            if (match.Length > 1)
            {
                return new[] { match.Groups["id"].Value.ToString() };
            }
            var query = yt.Search.List("snippet");
            query.MaxResults = count;
            query.Type = "playlist";
            query.Q = keywords;

            return (await query.ExecuteAsync()).Items.Select(i => i.Id.PlaylistId);
        }

        //private readonly Regex YtVideoIdRegex = new Regex(@"(?:youtube\.com\/\S*(?:(?:\/e(?:mbed))?\/|watch\?(?:\S*?&?v\=))|youtu\.be\/)(?<id>[a-zA-Z0-9_-]{6,11})", RegexOptions.Compiled);
        private readonly IBotCredentials _creds;

        public async Task<IEnumerable<string>> GetRelatedVideosAsync(string id, int count = 1)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(id))
                throw new ArgumentNullException(nameof(id));

            if (count <= 0)
                throw new ArgumentOutOfRangeException(nameof(count));
            var query = yt.Search.List("snippet");
            query.MaxResults = count;
            query.RelatedToVideoId = id;
            query.Type = "video";
            return (await query.ExecuteAsync()).Items.Select(i => "http://www.youtube.com/watch?v=" + i.Id.VideoId);
        }

        public async Task<IEnumerable<string>> GetVideoLinksByKeywordAsync(string keywords, int count = 1)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(keywords))
                throw new ArgumentNullException(nameof(keywords));

            if (count <= 0)
                throw new ArgumentOutOfRangeException(nameof(count));
            
            var query = yt.Search.List("snippet");
            query.MaxResults = count;
            query.Q = keywords;
            query.Type = "video";
            return (await query.ExecuteAsync()).Items.Select(i => "http://www.youtube.com/watch?v=" + i.Id.VideoId);
        }

        public async Task<IEnumerable<(string Name, string Id, string Url)>> GetVideoInfosByKeywordAsync(string keywords, int count = 1)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(keywords))
                throw new ArgumentNullException(nameof(keywords));

            if (count <= 0)
                throw new ArgumentOutOfRangeException(nameof(count));

            var query = yt.Search.List("snippet");
            query.MaxResults = count;
            query.Q = keywords;
            query.Type = "video";
            return (await query.ExecuteAsync()).Items.Select(i => (i.Snippet.Title.TrimTo(50), i.Id.VideoId, "http://www.youtube.com/watch?v=" + i.Id.VideoId));
        }

        public async Task<string> ShortenUrl(string url)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(url))
                throw new ArgumentNullException(nameof(url));

            if (string.IsNullOrWhiteSpace(_creds.GoogleApiKey))
                return url;

            try
            {
                var response = await sh.Url.Insert(new Url { LongUrl = url }).ExecuteAsync();
                return response.Id;
            }
            catch (Exception ex)
            {
                _log.Warn(ex);
                return url;
            }
        }

        public async Task<IEnumerable<string>> GetPlaylistTracksAsync(string playlistId, int count = 50)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(playlistId))
                throw new ArgumentNullException(nameof(playlistId));

            if (count <= 0)
                throw new ArgumentOutOfRangeException(nameof(count));

            string nextPageToken = null;

            List<string> toReturn = new List<string>(count);

            do
            {
                var toGet = count > 50 ? 50 : count;
                count -= toGet;

                var query = yt.PlaylistItems.List("contentDetails");
                query.MaxResults = toGet;
                query.PlaylistId = playlistId;
                query.PageToken = nextPageToken;

                var data = await query.ExecuteAsync();

                toReturn.AddRange(data.Items.Select(i => i.ContentDetails.VideoId));
                nextPageToken = data.NextPageToken;
            }
            while (count > 0 && !string.IsNullOrWhiteSpace(nextPageToken));

            return toReturn;
        }

        public async Task<IReadOnlyDictionary<string, TimeSpan>> GetVideoDurationsAsync(IEnumerable<string> videoIds)
        {
            await Task.Yield();
            var videoIdsList = videoIds as List<string> ?? videoIds.ToList();

            Dictionary<string, TimeSpan> toReturn = new Dictionary<string, TimeSpan>();

            if (!videoIdsList.Any())
                return toReturn;
            var toGet = 0;
            var remaining = videoIdsList.Count;

            do
            {
                toGet = remaining > 50 ? 50 : remaining;
                remaining -= toGet;

                var q = yt.Videos.List("contentDetails");
                q.Id = string.Join(",", videoIdsList.Take(toGet));
                videoIdsList = videoIdsList.Skip(toGet).ToList();
                var items = (await q.ExecuteAsync().ConfigureAwait(false)).Items;
                foreach (var i in items)
                {
                    toReturn.Add(i.Id, System.Xml.XmlConvert.ToTimeSpan(i.ContentDetails.Duration));
                }
            }
            while (remaining > 0);

            return toReturn;
        }

        public async Task<ImageResult> GetImageAsync(string query, int start = 1)
        {
            await Task.Yield();
            if (string.IsNullOrWhiteSpace(query))
                throw new ArgumentNullException(nameof(query));

            var req = cs.Cse.List(query);
            req.Cx = search_engine_id;
            req.Num = 1;
            req.Fields = "items(image(contextLink,thumbnailLink),link)";
            req.SearchType = CseResource.ListRequest.SearchTypeEnum.Image;
            req.Start = start;

            var search = await req.ExecuteAsync().ConfigureAwait(false);

            return new ImageResult(search.Items[0].Image, search.Items[0].Link);
        }

        public IEnumerable<string> Languages => _languageDictionary.Keys.OrderBy(x => x);
        private readonly Dictionary<string, string> _languageDictionary = new Dictionary<string, string>() {
                    { "afrikaans", "af"},
                    { "albanian", "sq"},
                    { "arabic", "ar"},
                    { "armenian", "hy"},
                    { "azerbaijani", "az"},
                    { "basque", "eu"},
                    { "belarusian", "be"},
                    { "bengali", "bn"},
                    { "bulgarian", "bg"},
                    { "catalan", "ca"},
                    { "chinese-traditional", "zh-TW"},
                    { "chinese-simplified", "zh-CN"},
                    { "chinese", "zh-CN"},
                    { "croatian", "hr"},
                    { "czech", "cs"},
                    { "danish", "da"},
                    { "dutch", "nl"},
                    { "english", "en"},
                    { "esperanto", "eo"},
                    { "estonian", "et"},
                    { "filipino", "tl"},
                    { "finnish", "fi"},
                    { "french", "fr"},
                    { "galician", "gl"},
                    { "german", "de"},
                    { "georgian", "ka"},
                    { "greek", "el"},
                    { "haitian Creole", "ht"},
                    { "hebrew", "iw"},
                    { "hindi", "hi"},
                    { "hungarian", "hu"},
                    { "icelandic", "is"},
                    { "indonesian", "id"},
                    { "irish", "ga"},
                    { "italian", "it"},
                    { "japanese", "ja"},
                    { "korean", "ko"},
                    { "lao", "lo"},
                    { "latin", "la"},
                    { "latvian", "lv"},
                    { "lithuanian", "lt"},
                    { "macedonian", "mk"},
                    { "malay", "ms"},
                    { "maltese", "mt"},
                    { "norwegian", "no"},
                    { "persian", "fa"},
                    { "polish", "pl"},
                    { "portuguese", "pt"},
                    { "romanian", "ro"},
                    { "russian", "ru"},
                    { "serbian", "sr"},
                    { "slovak", "sk"},
                    { "slovenian", "sl"},
                    { "spanish", "es"},
                    { "swahili", "sw"},
                    { "swedish", "sv"},
                    { "tamil", "ta"},
                    { "telugu", "te"},
                    { "thai", "th"},
                    { "turkish", "tr"},
                    { "ukrainian", "uk"},
                    { "urdu", "ur"},
                    { "vietnamese", "vi"},
                    { "welsh", "cy"},
                    { "yiddish", "yi"},

                    { "af", "af"},
                    { "sq", "sq"},
                    { "ar", "ar"},
                    { "hy", "hy"},
                    { "az", "az"},
                    { "eu", "eu"},
                    { "be", "be"},
                    { "bn", "bn"},
                    { "bg", "bg"},
                    { "ca", "ca"},
                    { "zh-tw", "zh-TW"},
                    { "zh-cn", "zh-CN"},
                    { "hr", "hr"},
                    { "cs", "cs"},
                    { "da", "da"},
                    { "nl", "nl"},
                    { "en", "en"},
                    { "eo", "eo"},
                    { "et", "et"},
                    { "tl", "tl"},
                    { "fi", "fi"},
                    { "fr", "fr"},
                    { "gl", "gl"},
                    { "de", "de"},
                    { "ka", "ka"},
                    { "el", "el"},
                    { "ht", "ht"},
                    { "iw", "iw"},
                    { "hi", "hi"},
                    { "hu", "hu"},
                    { "is", "is"},
                    { "id", "id"},
                    { "ga", "ga"},
                    { "it", "it"},
                    { "ja", "ja"},
                    { "ko", "ko"},
                    { "lo", "lo"},
                    { "la", "la"},
                    { "lv", "lv"},
                    { "lt", "lt"},
                    { "mk", "mk"},
                    { "ms", "ms"},
                    { "mt", "mt"},
                    { "no", "no"},
                    { "fa", "fa"},
                    { "pl", "pl"},
                    { "pt", "pt"},
                    { "ro", "ro"},
                    { "ru", "ru"},
                    { "sr", "sr"},
                    { "sk", "sk"},
                    { "sl", "sl"},
                    { "es", "es"},
                    { "sw", "sw"},
                    { "sv", "sv"},
                    { "ta", "ta"},
                    { "te", "te"},
                    { "th", "th"},
                    { "tr", "tr"},
                    { "uk", "uk"},
                    { "ur", "ur"},
                    { "vi", "vi"},
                    { "cy", "cy"},
                    { "yi", "yi"},
                };

        public async Task<string> Translate(string sourceText, string sourceLanguage, string targetLanguage)
        {
            await Task.Yield();
            string text;

            if (!_languageDictionary.ContainsKey(sourceLanguage) ||
               !_languageDictionary.ContainsKey(targetLanguage))
                throw new ArgumentException();


            var url = string.Format("https://translate.googleapis.com/translate_a/single?client=gtx&sl={0}&tl={1}&dt=t&q={2}",
                                        ConvertToLanguageCode(sourceLanguage),
                                        ConvertToLanguageCode(targetLanguage),
                                       WebUtility.UrlEncode(sourceText));
            using (var http = new HttpClient())
            {
                http.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36");
                text = await http.GetStringAsync(url).ConfigureAwait(false);
            }

            return (string.Concat(JArray.Parse(text)[0].Select(x => x[0])));
        }

        private string ConvertToLanguageCode(string language)
        {
            _languageDictionary.TryGetValue(language, out var mode);
            return mode;
        }
    }
}