using System;
using Paca.Core;
using Xunit;

namespace Paca.Tests.Core;

public class AudioPitchShiftEngineGateTests
{
    [Fact]
    public void Gate385_AudioPitchShift_CalculatesAccuratePitchScale()
    {
        // 0 semitones -> 1.0
        Assert.Equal(1.0, AudioPitchShiftEngine.CalculatePitchScale(0.0), 4);

        // +12 semitones (1 octave up) -> 2.0
        Assert.Equal(2.0, AudioPitchShiftEngine.CalculatePitchScale(12.0), 4);

        // -12 semitones (1 octave down) -> 0.5
        Assert.Equal(0.5, AudioPitchShiftEngine.CalculatePitchScale(-12.0), 4);

        // +1 semitone -> ~1.0595
        Assert.Equal(1.0595, AudioPitchShiftEngine.CalculatePitchScale(1.0), 4);
    }

    [Fact]
    public void Gate386_AudioPitchShift_BuildsFfmpegFilterChain()
    {
        // +2 semitones (scale ~ 1.1225)
        var filter = AudioPitchShiftEngine.BuildPitchShiftFilter(semitones: 2.0, sampleRate: 44100);

        Assert.Contains("asetrate=", filter);
        Assert.Contains("atempo=", filter);
        Assert.Contains("aresample=44100", filter);
    }

    [Fact]
    public void Gate387_AudioPitchShift_ClampsExtremeSemitoneRanges()
    {
        var clampedHigh = AudioPitchShiftEngine.ClampSemitones(24.0);
        Assert.Equal(12.0, clampedHigh);

        var clampedLow = AudioPitchShiftEngine.ClampSemitones(-30.0);
        Assert.Equal(-12.0, clampedLow);
    }

    [Fact]
    public void Gate388_AudioPitchShift_BuildsFullCommandLine_WithVideoCopy()
    {
        var cmd = AudioPitchShiftEngine.BuildPitchShiftCommandLine(
            inputPath: "C:\\music\\karaoke.mp4",
            outputPath: "C:\\music\\karaoke_plus1.mp4",
            semitones: 1.0,
            isAudioOnly: false,
            sampleRate: 48000
        );

        Assert.Contains("-i \"C:\\music\\karaoke.mp4\"", cmd);
        Assert.Contains("-c:v copy", cmd);
        Assert.Contains("-filter:a \"asetrate=", cmd);
        Assert.Contains("aresample=48000", cmd);
        Assert.Contains("-c:a aac -b:a 192k", cmd);
        Assert.EndsWith("\"C:\\music\\karaoke_plus1.mp4\" -y", cmd);
    }
}