using System;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using Paca.Mobile.Core;
using Xunit;

namespace Paca.Tests.Mobile;

/// <summary>
/// Gate 167 ~ 170: PacaDrop 다중 미디어 배치 번들링 & 자동 스트리밍 언패커 기계적 검증
/// </summary>
public class MobilePacaDropBatchBundleGateTests
{
    [Fact]
    public void Gate167_BatchBundleManifest_Integrity()
    {
        var file1Data = Encoding.UTF8.GetBytes("Media Content 1 - 4K Video Stream");
        var file2Data = Encoding.UTF8.GetBytes("Media Content 2 - 128k Audio Track");

        var entries = new List<BundleEntryMetadata>
        {
            new("video1.mp4", file1Data.Length, Convert.ToHexString(SHA256.HashData(file1Data))),
            new("audio1.mp3", file2Data.Length, Convert.ToHexString(SHA256.HashData(file2Data)))
        };

        var manifest = new BatchBundleManifest("bundle-001", entries, DateTimeOffset.UtcNow);

        Assert.Equal("bundle-001", manifest.BundleId);
        Assert.Equal(2, manifest.Entries.Count);
        Assert.Equal(file1Data.Length + file2Data.Length, manifest.TotalBytes);
        Assert.True(manifest.VerifyEntry("video1.mp4", file1Data));
        Assert.False(manifest.VerifyEntry("video1.mp4", Encoding.UTF8.GetBytes("Corrupted")));
    }

    [Fact]
    public async Task Gate168_BatchBundle_Pack_And_Unpack_Streaming()
    {
        var file1Data = Encoding.UTF8.GetBytes("Payload for Track 1");
        var file2Data = Encoding.UTF8.GetBytes("Payload for Track 2");

        using var bundleStream = new MemoryStream();

        // 1. 번들 생성 (PC 측 동작 시뮬레이션)
        await PacaBatchBundlePacker.PackAsync(bundleStream, new Dictionary<string, byte[]>
        {
            ["intro.mp4"] = file1Data,
            ["outro.mp3"] = file2Data
        });

        bundleStream.Position = 0;

        // 2. 모바일 언패커로 추출 (모바일 수신 시뮬레이션)
        var tempExtractDir = Path.Combine(Path.GetTempPath(), "Paca_Test_Bundle_" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(tempExtractDir);

        try
        {
            var extractedFiles = await PacaBatchBundleExtractor.ExtractAsync(bundleStream, tempExtractDir);

            Assert.Equal(2, extractedFiles.Count);
            Assert.True(File.Exists(Path.Combine(tempExtractDir, "intro.mp4")));
            Assert.True(File.Exists(Path.Combine(tempExtractDir, "outro.mp3")));

            var read1 = await File.ReadAllBytesAsync(Path.Combine(tempExtractDir, "intro.mp4"));
            var read2 = await File.ReadAllBytesAsync(Path.Combine(tempExtractDir, "outro.mp3"));

            Assert.Equal(file1Data, read1);
            Assert.Equal(file2Data, read2);
        }
        finally
        {
            if (Directory.Exists(tempExtractDir))
            {
                Directory.Delete(tempExtractDir, recursive: true);
            }
        }
    }

    [Fact]
    public async Task Gate169_BatchBundle_CorruptedEntry_FailsSafely()
    {
        using var garbageStream = new MemoryStream(Encoding.UTF8.GetBytes("Not A Valid Paca Bundle Data"));
        var tempExtractDir = Path.Combine(Path.GetTempPath(), "Paca_Corrupt_" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(tempExtractDir);

        try
        {
            await Assert.ThrowsAnyAsync<Exception>(async () =>
            {
                await PacaBatchBundleExtractor.ExtractAsync(garbageStream, tempExtractDir);
            });
        }
        finally
        {
            if (Directory.Exists(tempExtractDir)) Directory.Delete(tempExtractDir, recursive: true);
        }
    }

    [Fact]
    public void Gate170_AutoIngestToLibraryManager()
    {
        var manager = new OfflineLibraryManager();
        var extractedEntries = new List<BundleExtractedFile>
        {
            new("item-1", "video.mp4", 50_000_000, "/temp/video.mp4", true),
            new("item-2", "song.mp3", 5_000_000, "/temp/song.mp3", true)
        };

        foreach (var entry in extractedEntries)
        {
            manager.RegisterMedia(new OfflineMediaItem(
                entry.Id,
                entry.FileName,
                entry.SizeBytes,
                entry.FilePath,
                DateTimeOffset.UtcNow,
                entry.IsChecksumVerified
            ));
        }

        Assert.Equal(55_000_000L, manager.TotalPacaBytes);
        Assert.Equal(2, manager.GetItems(MediaFilter.All, MediaSortOrder.NewestFirst).Count);
    }
}