using System;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Paca.Mobile;
using Xunit;

namespace Paca.Tests.Mobile;

/// <summary>
/// PACA Mobile Browser Core 단위 및 도메인 스펙 검증 스위트
/// - 탭 관리자 (생성, 전환, 닫기, 시크릿 모드, 세션 영속화)
/// - 로컬 방문 기록 (추가, 검색, 삭제, 원자적 저장)
/// - 북마크 관리자 (추가, 중복 갱신, 삭제, 조회)
/// - 비디오 스니퍼 (M3U8/MP4/DASH/Blob 네트워크 및 DOM JSON 파서)
/// - 인앱 다운로드 엔진 (작업 큐, 상태 머신)
/// </summary>
public class MobileBrowserCoreTests : IDisposable
{
    private readonly string _testTempDir;

    public MobileBrowserCoreTests()
    {
        _testTempDir = Path.Combine(Path.GetTempPath(), "paca_mobile_tests_" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_testTempDir);
    }

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

    // =========================================================================
    // 1. 모바일 탭 관리자 (MobileTabManager)
    // =========================================================================

    [Fact]
    public void TabManager_InitialState_HasSingleNewTab()
    {
        var manager = new MobileTabManager();
        Assert.Equal(1, manager.Count);
        Assert.NotNull(manager.ActiveTab);
        Assert.True(manager.ActiveTab!.IsNewTabPage);
    }

    [Fact]
    public void TabManager_AddAndSwitchTab_UpdatesActiveTabCorrectly()
    {
        var manager = new MobileTabManager();
        var tab2 = manager.AddTab("https://m.youtube.com", isPrivate: false);

        Assert.Equal(2, manager.Count);
        Assert.Equal(tab2.Id, manager.ActiveTab?.Id);
        Assert.Equal("https://m.youtube.com", manager.ActiveTab?.Url);

        var firstTabId = manager.Tabs[0].Id;
        var switched = manager.SwitchTab(firstTabId);

        Assert.True(switched);
        Assert.Equal(firstTabId, manager.ActiveTab?.Id);
    }

    [Fact]
    public void TabManager_CloseTab_MaintainsValidActiveTab()
    {
        var manager = new MobileTabManager();
        var tab2 = manager.AddTab("https://site2.com");
        var tab3 = manager.AddTab("https://site3.com");

        Assert.Equal(3, manager.Count);
        Assert.Equal(tab3.Id, manager.ActiveTab?.Id);

        // 마지막 탭 닫기 -> 바로 이전 탭(tab2)이 활성화되어야 함
        manager.CloseTab(tab3.Id);
        Assert.Equal(2, manager.Count);
        Assert.Equal(tab2.Id, manager.ActiveTab?.Id);

        // 모든 탭 닫기 -> 자동으로 새 탭 1개 생성
        manager.CloseAllTabs();
        Assert.Equal(1, manager.Count);
        Assert.True(manager.ActiveTab?.IsNewTabPage);
    }

    [Fact]
    public async Task TabManager_SessionPersistence_IgnoresPrivateTabsAndRestoresState()
    {
        var sessionFile = Path.Combine(_testTempDir, "tabs_session.json");
        var manager = new MobileTabManager();
        manager.AddTab("https://public-site1.com", isPrivate: false);
        manager.AddTab("https://secret-site.com", isPrivate: true); // InPrivate

        await manager.SaveSessionAsync(sessionFile);
        Assert.True(File.Exists(sessionFile));

        var restoredManager = new MobileTabManager();
        await restoredManager.RestoreSessionAsync(sessionFile);

        // InPrivate 탭은 저장되지 않아야 함
        Assert.DoesNotContain(restoredManager.Tabs, t => t.Url == "https://secret-site.com");
        Assert.Contains(restoredManager.Tabs, t => t.Url == "https://public-site1.com");
    }

    // =========================================================================
    // 2. 방문 기록 영속 저장소 (MobileHistoryStore)
    // =========================================================================

    [Fact]
    public async Task HistoryStore_AddVisitAndSearch_RanksByRecencyAndFiltersKeyword()
    {
        var historyFile = Path.Combine(_testTempDir, "history.json");
        var store = new MobileHistoryStore(historyFile);

        await store.AddVisitAsync("https://m.youtube.com/watch?v=123", "YouTube Video 1");
        await store.AddVisitAsync("https://news.naver.com", "네이버 뉴스");
        await store.AddVisitAsync("https://m.youtube.com/watch?v=456", "YouTube Video 2");

        var recents = store.GetRecent(10);
        Assert.Equal(3, recents.Count);
        Assert.Equal("YouTube Video 2", recents[0].Title);

        var searchResults = store.Search("youtube");
        Assert.Equal(2, searchResults.Count);

        // 중복 방문 시 VisitCount 증가
        await store.AddVisitAsync("https://news.naver.com", "네이버 뉴스 - 갱신");
        var naverItem = store.Search("naver").First();
        Assert.Equal(2, naverItem.VisitCount);
        Assert.Equal("네이버 뉴스 - 갱신", naverItem.Title);
    }

    [Fact]
    public async Task HistoryStore_DeleteItemAndClearAll_SavesAtomically()
    {
        var historyFile = Path.Combine(_testTempDir, "history.json");
        var store = new MobileHistoryStore(historyFile);

        await store.AddVisitAsync("https://site1.com", "Site 1");
        await store.AddVisitAsync("https://site2.com", "Site 2");

        var itemToDelete = store.GetRecent().First(i => i.Url == "https://site1.com");
        var deleted = await store.DeleteAsync(itemToDelete.Id);
        Assert.True(deleted);

        // 다시 로드하여 영속화 확인
        var storeReloaded = new MobileHistoryStore(historyFile);
        Assert.Single(storeReloaded.GetRecent());

        await storeReloaded.ClearAllAsync();
        Assert.Empty(storeReloaded.GetRecent());
    }

    // =========================================================================
    // 3. 북마크 영속 저장소 (MobileBookmarkStore)
    // =========================================================================

    [Fact]
    public async Task BookmarkStore_AddUpdateAndRemove_WorksAccurately()
    {
        var bookmarkFile = Path.Combine(_testTempDir, "bookmarks.json");
        var store = new MobileBookmarkStore(bookmarkFile);

        Assert.False(store.IsBookmarked("https://github.com"));

        await store.AddOrUpdateBookmarkAsync("https://github.com", "GitHub", "개발");
        Assert.True(store.IsBookmarked("https://github.com"));

        var all = store.GetAll();
        Assert.Single(all);
        Assert.Equal("개발", all[0].Folder);

        // 삭제
        var removed = await store.RemoveByUrlAsync("https://github.com");
        Assert.True(removed);
        Assert.False(store.IsBookmarked("https://github.com"));
    }

    // =========================================================================
    // 4. 비디오 스니퍼 파서 (VideoSnifferParser)
    // =========================================================================

    [Theory]
    [InlineData("https://cdn.example.com/video/master.m3u8?token=xyz", "application/x-mpegURL", VideoStreamType.Hls)]
    [InlineData("https://cdn.example.com/video/stream.mpd", "application/dash+xml", VideoStreamType.Dash)]
    [InlineData("https://cdn.example.com/files/sample.mp4?dl=1", "video/mp4", VideoStreamType.Mp4)]
    [InlineData("https://cdn.example.com/stream.webm", "video/webm", VideoStreamType.Direct)]
    [InlineData("blob:https://m.youtube.com/83274-1234", null, VideoStreamType.Blob)]
    public void VideoSniffer_NetworkStreams_ClassifiedCorrectly(string url, string? mime, VideoStreamType expectedType)
    {
        var detected = VideoSnifferParser.TrySniffNetworkStream(url, mime, null, out var item);
        Assert.True(detected);
        Assert.NotNull(item);
        Assert.Equal(expectedType, item!.VideoType);
    }

    [Fact]
    public void VideoSniffer_AdsAndFragments_Ignored()
    {
        var adUrl = "https://googleads.g.doubleclick.net/pagead/ads?video_id=123";
        var isVideo = VideoSnifferParser.TrySniffNetworkStream(adUrl, "video/mp4", null, out _);
        Assert.False(isVideo);

        var segUrl = "https://cdn.example.com/segment123.ts";
        var isSeg = VideoSnifferParser.TrySniffNetworkStream(segUrl, "video/mp2t", null, out _);
        Assert.False(isSeg);
    }

    [Fact]
    public void VideoSniffer_DomJsonPayload_ParsesMetadataAccurately()
    {
        var domJson = @"[
            {
                ""src"": ""https://video.example.com/high_1080p.m3u8"",
                ""title"": ""모바일 테스트 비디오"",
                ""width"": 1920,
                ""height"": 1080,
                ""duration"": 145.5,
                ""poster"": ""https://video.example.com/thumb.jpg""
            }
        ]";

        var items = VideoSnifferParser.ParseDomPayload(domJson, "https://example.com/watch");
        Assert.Single(items);

        var video = items[0];
        Assert.Equal("https://video.example.com/high_1080p.m3u8", video.StreamUrl);
        Assert.Equal(VideoStreamType.Hls, video.VideoType);
        Assert.Equal("모바일 테스트 비디오", video.Title);
        Assert.Equal("1920x1080", video.Resolution);
        Assert.Equal(145.5, video.DurationSeconds);
        Assert.Equal("https://video.example.com/thumb.jpg", video.ThumbnailUrl);
    }
}