BabyVideoService/VideoDownload/VideoDownload.cs

using System.Threading.Channels;

namespace ACBuildService;

public static class VideoDownload
{
    private static readonly Channel<string> _queue = Channel.CreateUnbounded<string>();
    private static readonly CancellationTokenSource _cts = new CancellationTokenSource();
    private static readonly TimeSpan _interval = TimeSpan.FromSeconds(20);


    static VideoDownload()
    {
        Task.Run(ProcessQueueAsync);
    }

    public static void Add(string shareText)
    {
        _queue.Writer.TryWrite(shareText);
    }

    private static async Task ProcessQueueAsync()
    {
        var timer = new PeriodicTimer(_interval);

        try
        {
            while (await _queue.Reader.WaitToReadAsync(_cts.Token) &&
                   await timer.WaitForNextTickAsync(_cts.Token))
            {
                if (_queue.Reader.TryRead(out var shareText))
                {
                    // 这里开始处理任务，这个处理过程本身的时间不计入间隔
                    // PeriodicTimer 会保证两次 WaitForNextTickAsync 之间间隔10秒
                    await ProcessVideoDownloadAsync(shareText);
                }
            }
        }
        catch (OperationCanceledException)
        {
            // 正常取消
        }
    }

    private static async Task ProcessVideoDownloadAsync(string shareText)
    {
        try
        {
            var service = GetService(shareText);
            if (service != null)
            {
                Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] 开始处理: {shareText}");
                await DownloadVideoAsync(service, shareText);

                Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] 处理完成: {shareText}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[{DateTime.Now:HH:mm:ss}] 处理失败: {shareText}, 错误: {ex.Message}");
        }
    }

    // 模拟下载视频的方法
    private static async Task DownloadVideoAsync(DownloadPlatforms service, string shareText)
    {
        //开始解析数据
        var videoModel = await service.ParseShare(shareText);
        if (videoModel == null) return;

        var rootPath = $"{HttpService.BaseRootPath}videos/";
        var t = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
        var fileName = $"{t}.mp4";
        var filePath = Path.Combine(rootPath, fileName);
        if (File.Exists(filePath))
        {
            Log.Error("文件已存在");
            return;
        }

        var ret = await service.DownloadAsync(videoModel.VideoUrl, rootPath, fileName, null, null);
        if (ret)
        {
            var dbItem = new VideoTable
            {
                SourcePath = shareText,
                FilePath = fileName,
                AuthorName = videoModel.AuthorName,
                Title = videoModel.Title,
                Desc = videoModel.Desc,
                Duration = videoModel.Duration,
                Like = (int)videoModel.DiggCount,
                Collect = (int)videoModel.CollectCount,
                Message = (int)videoModel.CommentCount,
                Share = (int)videoModel.ShareCount,
                CreateTime = DateTime.Now
            };
            DB.Main.Insertable(dbItem).ExecuteCommand();
        }

        //解析数据后等待一会
        await Task.Delay(3000);
    }
    
    #region Service

    private static Dictionary<ShortVideoPlatformEnum, DownloadPlatforms> _services =
        new Dictionary<ShortVideoPlatformEnum, DownloadPlatforms>();

    private static DownloadPlatforms GetService(string text)
    {
        var platform = GetPlatform(text);
        if (_services.TryGetValue(platform, out var value))
        {
            return value;
        }

        if (platform == ShortVideoPlatformEnum.DouYin)
        {
            value = new DouYin();
        }
        else if (platform == ShortVideoPlatformEnum.KuaiShou)
        {
            value = new KuaiShou();
        }

        if (value != null)
        {
            _services[platform] = value;
        }

        return value;
    }

    private static ShortVideoPlatformEnum GetPlatform(string text)
    {
        if (text.Contains("douyin"))
        {
            return ShortVideoPlatformEnum.DouYin;
        }

        if (text.Contains("kuaishou"))
        {
            return ShortVideoPlatformEnum.KuaiShou;
        }

        return ShortVideoPlatformEnum.None;
    }

    #endregion
}