using System.Collections.ObjectModel;
using System.IO;
using Paca.App.Browser.Features;
using Paca.App.Core;
using Paca.App.ViewModels;
using Paca.Browser;
using Paca.Browser.Tabs;
using Paca.Core.Config;
using Paca.Core.Detection;

namespace Paca.Tests.Infrastructure;

/// <summary>
/// 19차 핵심 시나리오 파이프라인 프레임워크:
/// 다운로드 엔진, 탭 세션, 재생목록, 미디어 감지 파이프라인의 종단간 생명주기를
/// Fluent DSL로 간결하고 강력하게 테스트할 수 있는 프레임워크.
/// </summary>
public sealed class AppScenarioPipeline : IDisposable
{
    public string TempDir { get; }
    public AppConfig Config { get; }
    public DownloadManager DownloadManager { get; }
    public MediaPlaylist Playlist { get; }
    public TabManager TabManager { get; }
    public List<DownloadItemViewModel> DetectedItems { get; } = new();

    private AppScenarioPipeline()
    {
        TempDir = Path.Combine(Path.GetTempPath(), "VD_Test_" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(TempDir);
        Environment.SetEnvironmentVariable("VD_DATA_DIR", TempDir);

        Config = new AppConfig
        {
            OutputFolder = Path.Combine(TempDir, "downloads"),
            RestoreSession = true,
            PlaylistLoopMode = "all"
        };
        Directory.CreateDirectory(Config.OutputFolder);

        DownloadManager = new DownloadManager(
            Config,
            _ => Task.FromResult(new List<Microsoft.Web.WebView2.Core.CoreWebView2Cookie>()),
            _ => { });

        DownloadManager.ItemDetected += item => DetectedItems.Add(item);

        Playlist = new MediaPlaylist();
        TabManager = new TabManager(() => new TabItem(), _ => { });
    }

    public static AppScenarioPipeline Create() => new();

    public AppScenarioPipeline SimulateMediaDetection(string url, MediaKind kind, string? pageUrl = null)
    {
        DownloadManager.OnDetected(new DetectionContext(url, pageUrl ?? "https://test.local", kind));
        return this;
    }

    public AppScenarioPipeline AddPlaylistTrack(string url, string title, string kind)
    {
        Playlist.Add(new MediaTrack(url, title, kind, DateTime.UtcNow));
        return this;
    }

    public AppScenarioPipeline SimulateNextTrack()
    {
        Playlist.Next();
        return this;
    }

    public AppScenarioPipeline SimulateTrackPlayed(MediaTrack track)
    {
        Playlist.MarkPlayed(track);
        return this;
    }

    public AppScenarioPipeline OpenTab(string url)
    {
        TabManager.NewTab(url);
        return this;
    }

    public SessionSnapshot SaveSession() => TabManager.CaptureSession();

    public AppScenarioPipeline RestoreSession(SessionSnapshot snapshot)
    {
        TabManager.RestoreSession(snapshot);
        return this;
    }

    public void AssertQueueCount(int count)
    {
        Xunit.Assert.Equal(count, DownloadManager.Items.Count);
    }

    public void AssertDetectedCount(int count)
    {
        Xunit.Assert.Equal(count, DetectedItems.Count);
    }

    public AppScenarioPipeline SetScheduleGate(Func<bool> gate)
    {
        DownloadManager.DownloadGate = gate;
        return this;
    }

    public AppScenarioPipeline SelectItems(Func<DownloadItemViewModel, bool> predicate)
    {
        foreach (var item in DownloadManager.Items)
        {
            item.IsSelected = predicate(item);
        }
        return this;
    }

    public AppScenarioPipeline BatchPause()
    {
        foreach (var item in DownloadManager.Items.Where(i => i.IsSelected).ToList())
        {
            DownloadManager.Pause(item);
        }
        return this;
    }

    public AppScenarioPipeline BatchResume()
    {
        foreach (var item in DownloadManager.Items.Where(i => i.IsSelected).ToList())
        {
            DownloadManager.Resume(item);
        }
        return this;
    }

    public AppScenarioPipeline BatchCancel()
    {
        foreach (var item in DownloadManager.Items.Where(i => i.IsSelected).ToList())
        {
            DownloadManager.Cancel(item);
        }
        return this;
    }

    public AppScenarioPipeline BatchDelete()
    {
        foreach (var item in DownloadManager.Items.Where(i => i.IsSelected).ToList())
        {
            DownloadManager.Items.Remove(item);
        }
        return this;
    }

    public void AssertPlaylistCount(int count)
    {
        Xunit.Assert.Equal(count, Playlist.Tracks.Count);
    }

    public void AssertCurrentTrack(Func<MediaTrack?, bool> predicate)
    {
        Xunit.Assert.True(predicate(Playlist.Current), "현재 재생목록 트랙이 조건에 부합하지 않습니다.");
    }

    public void Dispose()
    {
        try
        {
            if (Directory.Exists(TempDir))
                Directory.Delete(TempDir, recursive: true);
        }
        catch { }
    }
}