// OpenTween - Client of Twitter
// Copyright (c) 2013 kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
// All rights reserved.
//
// This file is part of OpenTween.
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program. If not, see <http://www.gnu.org/licenses/>, or write to
// the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
// Boston, MA 02110-1301, USA.

#nullable enable

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using OpenTween.Connection;
using OpenTween.Models;

namespace OpenTween.Thumbnail.Services
{
    /// <summary>
    /// Twitter の DM に添付された画像をサムネイル表示するためのクラス
    /// </summary>
    public class TonTwitterCom : IThumbnailService
    {
        internal static Func<IApiConnection>? GetApiConnection;

        public override Task<ThumbnailInfo?> GetThumbnailInfoAsync(string url, PostClass post, CancellationToken token)
        {
            return Task.Run(() =>
            {
                if (GetApiConnection == null)
                    return null;

                if (!url.StartsWith(@"https://ton.twitter.com/1.1/ton/data/", StringComparison.Ordinal))
                    return null;

                var largeUrl = url + ":large";
                var apiConnection = GetApiConnection();

                return new ThumbnailInfo(largeUrl, url)
                {
                    FullSizeImageUrl = largeUrl,
                    Loader = new ThumbnailLoader(apiConnection, new(url)),
                };
            },
            token);
        }

        public class ThumbnailLoader : IThumbnailLoader
        {
            private readonly IApiConnection apiConnection;
            private readonly Uri imageUri;

            public ThumbnailLoader(IApiConnection apiConnection, Uri imageUri)
            {
                this.apiConnection = apiConnection;
                this.imageUri = imageUri;
            }

            public Task<MemoryImage> Load(HttpClient http, CancellationToken cancellationToken)
            {
                return Task.Run(async () =>
                {
                    var request = new GetRequest
                    {
                        RequestUri = this.imageUri,
                    };

                    using var response = await this.apiConnection.SendAsync(request)
                        .ConfigureAwait(false);

                    var imageBytes = await response.ReadAsBytes()
                        .ConfigureAwait(false);

                    cancellationToken.ThrowIfCancellationRequested();

                    return MemoryImage.CopyFromBytes(imageBytes);
                },
                cancellationToken);
            }
        }
    }
}