using System;
using Paca.Core;
using Xunit;

namespace Paca.Tests.Core;

public class MediaPlaybackSpeedPitchGateTests
{
    [Fact]
    public void Gate341_MediaPlaybackSpeedPitch_BuildsSingleAtempo_ForNormalRange()
    {
        var filter15 = MediaPlaybackSpeedPitchEngine.BuildAtempoFilterChain(1.5);
        Assert.Equal("atempo=1.50", filter15);

        var filter075 = MediaPlaybackSpeedPitchEngine.BuildAtempoFilterChain(0.75);
        Assert.Equal("atempo=0.75", filter075);
    }

    [Fact]
    public void Gate342_MediaPlaybackSpeedPitch_ChainsAtempo_ForSpeedsExceedingTwo()
    {
        // 3.0x -> atempo=2.0,atempo=1.5
        var filter30 = MediaPlaybackSpeedPitchEngine.BuildAtempoFilterChain(3.0);
        Assert.Equal("atempo=2.00,atempo=1.50", filter30);

        // 4.0x -> atempo=2.0,atempo=2.0
        var filter40 = MediaPlaybackSpeedPitchEngine.BuildAtempoFilterChain(4.0);
        Assert.Equal("atempo=2.00,atempo=2.00", filter40);
    }

    [Fact]
    public void Gate343_MediaPlaybackSpeedPitch_ClampsExtremeSpeeds()
    {
        // Min 0.25
        var min = MediaPlaybackSpeedPitchEngine.ClampSpeed(0.1);
        Assert.Equal(0.25, min);

        // Max 4.0
        var max = MediaPlaybackSpeedPitchEngine.ClampSpeed(10.0);
        Assert.Equal(4.0, max);
    }

    [Fact]
    public void Gate344_MediaPlaybackSpeedPitch_BuildsFullCommandLine_ForVideoAndAudio()
    {
        // Video 1.5x
        var videoCmd = MediaPlaybackSpeedPitchEngine.BuildSpeedCommandLine(
            inputPath: "C:\\lecture.mp4",
            outputPath: "C:\\lecture_1.5x.mp4",
            speed: 1.5,
            isAudioOnly: false
        );

        Assert.Contains("-i \"C:\\lecture.mp4\"", videoCmd);
        Assert.Contains("-filter:v \"setpts=0.6667*PTS\"", videoCmd);
        Assert.Contains("-filter:a \"atempo=1.50\"", videoCmd);
        Assert.EndsWith("\"C:\\lecture_1.5x.mp4\" -y", videoCmd);

        // Audio only 2.0x
        var audioCmd = MediaPlaybackSpeedPitchEngine.BuildSpeedCommandLine(
            inputPath: "C:\\podcast.mp3",
            outputPath: "C:\\podcast_2x.mp3",
            speed: 2.0,
            isAudioOnly: true
        );

        Assert.DoesNotContain("-filter:v", audioCmd);
        Assert.Contains("-filter:a \"atempo=2.00\"", audioCmd);
    }
}