releases/tests/Paca.Tests/Core/ExtremeResilienceAndStressGateTests.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Paca.Core;
using Paca.Mobile.Core;
using Xunit;

namespace Paca.Tests.Core;

/// <summary>
/// 데스크톱 & 모바일 융합 극한 복원성, 대규모 스트레스 및 엣지 케이스 게이트 (Gate 123 ~ Gate 130)
/// </summary>
public class ExtremeResilienceAndStressGateTests
{
    [Fact]
    public void Gate123_MassiveQueue_Stress_And_Virtualization_Audit()
    {
        var qm = new MobileQueueManager();
        // 500개 대규모 큐 아이템 고속 등록
        for (int i = 0; i < 500; i++)
        {
            qm.Enqueue($"https://example.com/video_{i}.mp4", $"Batch Video #{i}");
        }
        Assert.Equal(500, qm.Items.Count);

        // 첫 번째와 마지막 항목 무결성 확인
        Assert.Equal("Batch Video #0", qm.Items[0].Title);
        Assert.Equal("Batch Video #499", qm.Items[499].Title);

        // 일괄 완료 처리 후 청소 성능
        for (int i = 0; i < 250; i++)
        {
            qm.Items[i].Status = MobileQueueStatus.Completed;
        }
        qm.ClearCompleted();
        Assert.Equal(250, qm.Items.Count);
    }

    [Fact]
    public void Gate124_ConcurrentDownloadLock_Audit()
    {
        var lockEngine = new ConcurrentDownloadLockEngine();
        var testUrl = "https://example.com/unique_movie.mp4";

        // 첫 번째 세션 락 획득 성공
        Assert.True(lockEngine.TryAcquireLock(testUrl, sessionId: "desktop-client"));

        // 두 번째 세션(모바일) 동일 URL 시도 시 락 획득 실패 (중복 방지)
        Assert.False(lockEngine.TryAcquireLock(testUrl, sessionId: "mobile-client"));

        // 첫 번째 세션 락 반환 후 두 번째 세션 재시도 성공
        lockEngine.ReleaseLock(testUrl, sessionId: "desktop-client");
        Assert.True(lockEngine.TryAcquireLock(testUrl, sessionId: "mobile-client"));
    }

    [Fact]
    public void Gate125_DiskFull_RollbackEngine_Audit()
    {
        var rollbackEngine = new DiskFullRollbackEngine();
        var tempPartFile = System.IO.Path.Combine(System.IO.Path.GetTempPath(), $"paca_temp_{Guid.NewGuid():N}.part");
        System.IO.File.WriteAllBytes(tempPartFile, new byte[1024]);

        Assert.True(System.IO.File.Exists(tempPartFile));

        // 가상 디스크 풀 에러 발생 시 부분 다운로드 임시 파일 안전 롤백(제거)
        var result = rollbackEngine.HandleDiskFull(tempPartFile, requiredBytes: 50_000_000, availableBytes: 10_000);
        Assert.True(result.IsRollbackSuccessful);
        Assert.False(System.IO.File.Exists(tempPartFile));
        Assert.Contains("디스크 용량 부족", result.ErrorMessage);
    }

    [Fact]
    public void Gate126_SegmentChunkHealer_CorruptChunkRetry_Audit()
    {
        var healer = new SegmentChunkHealer();
        // 헤더 매직 넘버가 손상된 4바이트 청크
        var corruptChunk = new byte[] { 0x00, 0x00, 0x00, 0x00 };
        Assert.False(healer.ValidateSegmentIntegrity(corruptChunk, expectedSegmentType: "ts"));

        // 정상 TS 세그먼트 Sync byte (0x47)
        var validTsChunk = new byte[] { 0x47, 0x40, 0x11, 0x10 };
        Assert.True(healer.ValidateSegmentIntegrity(validTsChunk, expectedSegmentType: "ts"));
    }

    [Fact]
    public void Gate127_OAuthTokenRefresher_Audit()
    {
        var refresher = new OAuthTokenRefresher();
        var token = new AuthTokenInfo(AccessToken: "old_token", RefreshToken: "refresh_123", ExpiresAtUtc: DateTime.UtcNow.AddMinutes(-5));

        Assert.True(refresher.IsExpired(token));

        var newToken = refresher.RefreshToken(token);
        Assert.False(refresher.IsExpired(newToken));
        Assert.Equal("new_access_token_refresh_123", newToken.AccessToken);
    }

    [Fact]
    public void Gate128_LocalizationResourceValidator_Audit()
    {
        var loc = new LocalizationResourceCatalog();
        var languages = new[] { "ko", "en", "ja", "zh" };

        foreach (var lang in languages)
        {
            Assert.NotNull(loc.GetString("Download", lang));
            Assert.NotNull(loc.GetString("Pause", lang));
            Assert.NotNull(loc.GetString("Settings", lang));
        }

        Assert.Equal("다운로드", loc.GetString("Download", "ko"));
        Assert.Equal("Download", loc.GetString("Download", "en"));
        Assert.Equal("ダウンロード", loc.GetString("Download", "ja"));
        Assert.Equal("下载", loc.GetString("Download", "zh"));
    }

    [Fact]
    public void Gate129_QrConfigBackupRestore_Audit()
    {
        var backup = new QrConfigBackupManager();
        var originalPayload = new ConfigBackupPayload("192.168.0.50:52100", "secret_tok_999", "dark", 5120);

        var qrString = backup.ExportToQrString(originalPayload);
        Assert.StartsWith("PACA_CFG_V1|", qrString);

        var restoredPayload = backup.ImportFromQrString(qrString);
        Assert.NotNull(restoredPayload);
        Assert.Equal(originalPayload.Endpoint, restoredPayload.Endpoint);
        Assert.Equal(originalPayload.AuthToken, restoredPayload.AuthToken);
        Assert.Equal(originalPayload.Theme, restoredPayload.Theme);
        Assert.Equal(originalPayload.SpeedLimitKbps, restoredPayload.SpeedLimitKbps);
    }

    [Fact]
    public void Gate130_MediaTaggingEngine_Audit()
    {
        var tagger = new MediaTaggingEngine();
        var metadata = new MediaMetadataInfo(
            Title: "My Epic Video",
            Artist: "Creative Creator",
            AlbumOrPlaylist: "2026 Hits",
            Year: 2026
        );

        var tagDictionary = tagger.GenerateFfmpegMetadataArgs(metadata);
        Assert.Contains("-metadata title=\"My Epic Video\"", tagDictionary);
        Assert.Contains("-metadata artist=\"Creative Creator\"", tagDictionary);
        Assert.Contains("-metadata album=\"2026 Hits\"", tagDictionary);
        Assert.Contains("-metadata date=\"2026\"", tagDictionary);
    }
}