using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Paca.App.Services;
using Paca.Core.Config;
using Xunit;

namespace Paca.Tests.App;

public class ThumbnailCacheServiceGateTests : IDisposable
{
    private readonly string _tempDir;
    private readonly ThumbnailCacheService _service;

    public ThumbnailCacheServiceGateTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), "paca_thumb_test_" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(_tempDir);
        _service = new ThumbnailCacheService(new AppConfig(), _tempDir);
    }

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

    [Fact]
    public async Task Gate_SaveBase64Thumbnail_DecodesAndWritesFile()
    {
        // 1x1 투명/단색 픽셀 mock base64 (JFIF header)
        var fakeJpgBytes = new byte[] { 0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00, 0x01, 0xFF, 0xD9 };
        var b64 = "data:image/jpeg;base64," + Convert.ToBase64String(fakeJpgBytes);

        var filePath = await _service.SaveBase64ThumbnailAsync(b64, "video_123");

        Assert.NotNull(filePath);
        Assert.True(File.Exists(filePath));
        var readBytes = await File.ReadAllBytesAsync(filePath);
        Assert.Equal(fakeJpgBytes, readBytes);
    }

    [Fact]
    public async Task Gate_DownloadAndCacheThumbnail_SendsRefererAndCaches()
    {
        var fakeJpgBytes = new byte[] { 0xFF, 0xD8, 0xFF, 0xE0, 0x00, 0x10, 0x4A, 0x46, 0x49, 0x46, 0x00, 0x01, 0xFF, 0xD9 };
        string? capturedReferer = null;

        var handler = new FakeHttpHandler(req =>
        {
            capturedReferer = req.Headers.Referrer?.ToString();
            return new HttpResponseMessage(HttpStatusCode.OK)
            {
                Content = new ByteArrayContent(fakeJpgBytes)
            };
        });

        var customService = new ThumbnailCacheService(new AppConfig(), _tempDir, new HttpClient(handler));
        var filePath = await customService.DownloadAndCacheThumbnailAsync(
            "https://img.ruliweb.com/thumb/1a099d.jpg",
            "https://bbs.ruliweb.com/best/123",
            "ruliweb_123"
        );

        Assert.NotNull(filePath);
        Assert.True(File.Exists(filePath));
        Assert.Equal("https://bbs.ruliweb.com/best/123", capturedReferer);
    }

    [Fact]
    public async Task Gate_EnsureThumbnail_RoutesDataUriOrHttpProperly()
    {
        var fakeJpgBytes = new byte[] { 0xFF, 0xD8, 0xFF, 0xD9 };
        var b64 = "data:image/jpeg;base64," + Convert.ToBase64String(fakeJpgBytes);

        var result = await _service.EnsureThumbnailAsync(
            rawThumbOrPoster: b64,
            mediaUrl: "https://example.com/video.mp4",
            referer: "https://example.com"
        );

        Assert.NotNull(result);
        Assert.True(File.Exists(result));
    }

    private sealed class FakeHttpHandler : HttpMessageHandler
    {
        private readonly Func<HttpRequestMessage, HttpResponseMessage> _handler;
        public FakeHttpHandler(Func<HttpRequestMessage, HttpResponseMessage> handler) => _handler = handler;
        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
            => Task.FromResult(_handler(request));
    }
}