using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Paca.Core.Platform;
using Xunit;

namespace Paca.Tests.Platform;

public class PlatformMediaToolsExtremeRedTests
{
    // ==========================================
    // 1. ChapterSplitter
    // ==========================================

    [Fact]
    public void ChapterSplitter_GenerateFfmetadata_NullChapters_ReturnsValidHeaderWithoutCrashing()
    {
        var meta = ChapterSplitter.GenerateFfmetadata(null!);
        Assert.NotNull(meta);
        Assert.Contains(";FFMETADATA1", meta);
    }

    [Fact]
    public void ChapterSplitter_GenerateFfmetadata_ListContainingNullChapter_SkipsNullChapter()
    {
        var chapters = new List<ChapterInfo>
        {
            null!,
            new(1, "Intro", 0.0, 30.0),
            null!
        };

        var meta = ChapterSplitter.GenerateFfmetadata(chapters);
        Assert.NotNull(meta);
        Assert.Contains("title=Intro", meta);
    }

    [Fact]
    public void ChapterSplitter_GetChapterFileName_NullTitle_ReturnsSafeDefault()
    {
        var name = ChapterSplitter.GetChapterFileName(1, null!, "mp4");
        Assert.NotNull(name);
        Assert.StartsWith("01_", name);
        Assert.EndsWith(".mp4", name);
    }

    // ==========================================
    // 2. LosslessSmartTrimmer
    // ==========================================

    [Theory]
    [InlineData(double.NaN)]
    [InlineData(double.NegativeInfinity)]
    [InlineData(double.PositiveInfinity)]
    public void LosslessSmartTrimmer_FindNearestKeyframe_InvalidTargetSec_ReturnsDefault(double target)
    {
        var keyframes = new[] { 0.0, 5.0, 10.0, 15.0 };
        var nearest = LosslessSmartTrimmer.FindNearestKeyframe(keyframes, target);
        Assert.False(double.IsNaN(nearest));
        Assert.False(double.IsInfinity(nearest));
    }

    [Fact]
    public void LosslessSmartTrimmer_FindNearestKeyframe_KeyframesWithNaNOrNegatives_FiltersCorrectly()
    {
        var keyframes = new[] { double.NaN, -10.0, 5.0, 10.0 };
        var nearest = LosslessSmartTrimmer.FindNearestKeyframe(keyframes, 6.0);
        Assert.Equal(5.0, nearest);
    }

    [Fact]
    public async Task LosslessSmartTrimmer_TrimLosslessAsync_NaNTimestamps_ThrowsArgumentException()
    {
        var trimmer = new LosslessSmartTrimmer(DesktopProcessRunner.Default);
        await Assert.ThrowsAsync<ArgumentException>(() =>
            trimmer.TrimLosslessAsync("ffmpeg.exe", "in.mp4", "out.mp4", double.NaN, 10.0, CancellationToken.None));
    }

    // ==========================================
    // 3. VideoWatermarkBurner
    // ==========================================

    [Fact]
    public void VideoWatermarkBurner_BuildDrawTextFilter_NullText_DoesNotThrow()
    {
        var filter = VideoWatermarkBurner.BuildDrawTextFilter(null!);
        Assert.NotNull(filter);
        Assert.Contains("drawtext=", filter);
    }

    [Fact]
    public void VideoWatermarkBurner_BuildDrawTextFilter_TextWithNewlines_EscapedOrStripped()
    {
        var filter = VideoWatermarkBurner.BuildDrawTextFilter("Line 1\r\nLine 2\nLine 3");
        Assert.NotNull(filter);
        Assert.DoesNotContain("\r", filter);
        Assert.DoesNotContain("\n", filter);
    }

    [Theory]
    [InlineData(-0.1)]
    [InlineData(1.1)]
    [InlineData(double.NaN)]
    public void VideoWatermarkBurner_BuildOverlayFilter_InvalidOpacity_ThrowsArgumentOutOfRangeException(double opacity)
    {
        Assert.Throws<ArgumentOutOfRangeException>(() =>
            VideoWatermarkBurner.BuildOverlayFilter(WatermarkPosition.Center, opacity: opacity));
    }
}