using System.Windows.Threading;
using VideoDownloader.App.ViewModels;
using VideoDownloader.Server;
using VideoDownloader.Core.Detection;

namespace VideoDownloader.App.Services;

/// <summary>
/// DownloadManager(UI 컬렉션) ↔ 서버 큐 API 브릿지. 모든 접근을 UI 디스패처로 마샬링.
/// </summary>
public sealed class DownloadQueueAdapter : IQueueAdapter
{
    private readonly Core.DownloadManager _manager;
    private readonly Dispatcher _dispatcher;

    public DownloadQueueAdapter(Core.DownloadManager manager, Dispatcher dispatcher)
    {
        _manager = manager;
        _dispatcher = dispatcher;
    }

    public Task<IReadOnlyList<QueueItemDto>> GetItemsAsync() => _dispatcher.InvokeAsync(() =>
        (IReadOnlyList<QueueItemDto>)_manager.Items.Select(Map).ToList()).Task;

    public Task<string> AddAsync(string url, string? title)
    {
        // 서버에서 온 URL → 감지 파이프라인으로(소셜/HLS/DASH 자동 분류)
        return _dispatcher.InvokeAsync(() =>
        {
            if (Uri.TryCreate(url, UriKind.Absolute, out var uri) &&
                SocialSiteDetector.TryMatch(uri, out var normalized, out var label))
            {
                _manager.OnDetected(new DetectionContext(normalized, normalized, MediaKind.Social, Tag: label));
                return normalized;
            }
            var kind = MediaDetector.Classify(url, "", -1, _manager.Config) ?? MediaKind.Direct;
            _manager.OnDetected(new DetectionContext(url, url, kind, ""));
            return url;
        }).Task;
    }

    public Task PauseAsync(string id) => _dispatcher.InvokeAsync(() =>
    {
        var item = Find(id);
        if (item != null) _manager.Cancel(item); // v1: 제어 매핑 — 진행 항목 취소
    }).Task;

    public Task ResumeAsync(string id) => _dispatcher.InvokeAsync(() =>
    {
        var item = Find(id);
        if (item != null) _ = _manager.RetryDownload(item);
    }).Task;

    public Task CancelAsync(string id) => _dispatcher.InvokeAsync(() =>
    {
        var item = Find(id);
        if (item != null) _manager.Cancel(item);
    }).Task;

    public event Action? Changed { add { } remove { } }

    private DownloadItemViewModel? Find(string id) =>
        _manager.Items.FirstOrDefault(i => i.Id == id);

    private static QueueItemDto Map(DownloadItemViewModel i) =>
        new(i.Id, i.Title, i.Url ?? "", i.Status ?? "", i.Progress);
}