using System;
using System.IO;
using System.Threading;
using System.Windows;
using Paca.App.Core;
using Paca.App.Services;
using Paca.Tests.Infrastructure;
using Xunit;

namespace Paca.Tests.App;

public class AppDebugScreenshotServiceTests
{
    [Fact]
    public void AppDebugScreenshotService_GetDefaultScreenshotPath_ReturnsValidPngPath()
    {
        var path = AppDebugScreenshotService.GetDefaultScreenshotPath();
        Assert.False(string.IsNullOrWhiteSpace(path));
        Assert.EndsWith(".png", path, StringComparison.OrdinalIgnoreCase);
        Assert.Contains(AppPaths.DataDir, path, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void AppDebugScreenshotService_CaptureWindow_STA_GeneratesValidPngFile()
    {
        using var sta = StaDispatcher.Start();
        WpfTestApp.Ensure(sta.Dispatcher);

        var tempOut = Path.Combine(Path.GetTempPath(), $"paca_test_shot_{Guid.NewGuid():N}.png");
        try
        {
            var result = sta.Invoke(() =>
            {
                var window = new Window
                {
                    Width = 300,
                    Height = 200,
                    Title = "TestCaptureWindow"
                };
                window.Show();

                var ok = AppDebugScreenshotService.CaptureWindow(window, tempOut);
                window.Close();
                return ok;
            });

            Assert.True(result, "CaptureWindow should return true for a valid window.");
            Assert.True(File.Exists(tempOut), "Screenshot file must exist.");
            var fi = new FileInfo(tempOut);
            Assert.True(fi.Length > 0, "Screenshot file must not be empty.");

            // PNG magic byte verification: 0x89, 'P', 'N', 'G'
            var header = new byte[8];
            using (var fs = File.OpenRead(tempOut))
            {
                fs.Read(header, 0, 8);
            }
            Assert.Equal(0x89, header[0]);
            Assert.Equal((byte)'P', header[1]);
            Assert.Equal((byte)'N', header[2]);
            Assert.Equal((byte)'G', header[3]);
        }
        finally
        {
            if (File.Exists(tempOut))
            {
                try { File.Delete(tempOut); } catch { }
            }
        }
    }

    [Fact]
    public void AppDebugScreenshotService_ProcessTriggerContent_ParsesTargetPath()
    {
        var customPath = @"C:\dummy\target.png";
        var resolved = AppDebugScreenshotService.ResolveTriggerPath(customPath);
        Assert.Equal(customPath, resolved);

        var emptyResolved = AppDebugScreenshotService.ResolveTriggerPath("");
        Assert.Equal(AppDebugScreenshotService.GetDefaultScreenshotPath(), emptyResolved);
    }
}