using System;
using Paca.Core;
using Xunit;

namespace Paca.Tests.Core;

public class VideoPosterExtractorGateTests
{
    [Fact]
    public void Gate381_VideoPosterExtractor_CalculatesOptimalSeekTime()
    {
        // For short 5s clip -> 1.0s
        var shortClip = VideoPosterExtractor.CalculateOptimalSeekTime(5.0);
        Assert.Equal(1.0, shortClip);

        // For 60s video -> 10% is 6.0s
        var midVideo = VideoPosterExtractor.CalculateOptimalSeekTime(60.0);
        Assert.Equal(6.0, midVideo);

        // For 2-hour movie (7200s) -> Capped at 10.0s (to avoid spoilers while skipping black intro)
        var movie = VideoPosterExtractor.CalculateOptimalSeekTime(7200.0);
        Assert.Equal(10.0, movie);
    }

    [Fact]
    public void Gate382_VideoPosterExtractor_BuildsScalingFilter_PreservingAspect()
    {
        var spec = new PosterExtractionSpec(
            SeekTimeSec: 4.5,
            Width: 640,
            Height: 360,
            Format: PosterFormat.Jpeg,
            Quality: 85
        );

        var filter = VideoPosterExtractor.BuildScalingFilter(spec);
        Assert.Equal("scale=640:360:force_original_aspect_ratio=decrease", filter);
    }

    [Fact]
    public void Gate383_VideoPosterExtractor_BuildsWebpAndJpegQualityFlags()
    {
        var webpSpec = new PosterExtractionSpec(3.0, 400, 400, PosterFormat.WebP, Quality: 80);
        var webpCmd = VideoPosterExtractor.BuildPosterCommandLine("in.mp4", "out.webp", webpSpec);
        Assert.Contains("-c:v libwebp -quality 80", webpCmd);

        var jpegSpec = new PosterExtractionSpec(3.0, 400, 400, PosterFormat.Jpeg, Quality: 90);
        var jpegCmd = VideoPosterExtractor.BuildPosterCommandLine("in.mp4", "out.jpg", jpegSpec);
        Assert.Contains("-q:v 2", jpegCmd); // High quality jpeg
    }

    [Fact]
    public void Gate384_VideoPosterExtractor_BuildsFullSingleFrameCommandLine()
    {
        var spec = new PosterExtractionSpec(5.0, 1280, 720, PosterFormat.Jpeg, 85);
        var cmd = VideoPosterExtractor.BuildPosterCommandLine("C:\\vid.mp4", "C:\\thumb.jpg", spec);

        Assert.Contains("-ss 5.00 -i \"C:\\vid.mp4\"", cmd);
        Assert.Contains("-vframes 1", cmd);
        Assert.EndsWith("\"C:\\thumb.jpg\" -y", cmd);
    }
}