package net.knarcraft.ffmpegconverter.converter;

import net.knarcraft.ffmpegconverter.container.FFMpegCommand;
import net.knarcraft.ffmpegconverter.container.StreamProbeResult;
import net.knarcraft.ffmpegconverter.converter.module.ConverterModule;
import net.knarcraft.ffmpegconverter.converter.module.DebugModule;
import net.knarcraft.ffmpegconverter.converter.module.ModuleExecutor;
import net.knarcraft.ffmpegconverter.converter.module.hardwarecoding.HardwareDecodeModule;
import net.knarcraft.ffmpegconverter.converter.module.mapping.NthAudioStreamModule;
import net.knarcraft.ffmpegconverter.converter.module.mapping.NthSubtitleStreamModule;
import net.knarcraft.ffmpegconverter.converter.module.mapping.NthVideoStreamModule;
import net.knarcraft.ffmpegconverter.converter.module.output.CopyAllModule;
import net.knarcraft.ffmpegconverter.converter.module.output.SetOutputFileModule;
import net.knarcraft.ffmpegconverter.utility.FFMpegHelper;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.ArrayList;
import java.util.List;

/**
 * A transcoder which takes one of each stream from an MKV file and produces an MP4 file
 */
public class MKVToMP4Transcoder extends AbstractConverter {

    private final int videoStreamIndex;
    private final int audioStreamIndex;
    private final int subtitleStreamIndex;

    /**
     * Instantiates a new mkv to mp4 transcoder
     *
     * @param ffprobePath         <p>Path/command to ffprobe.</p>
     * @param ffmpegPath          <p>Path/command to ffmpeg.</p>
     * @param audioStreamIndex    <p>The relative index of the audio stream to use (0 or below selects the first)</p>
     * @param subtitleStreamIndex <p>The relative index of the subtitle stream to use (0 or below selects the first)</p>
     * @param videoStreamIndex    <p>The relative index of the video stream to use (0 or below selects the first)</p>
     */
    public MKVToMP4Transcoder(String ffprobePath, String ffmpegPath, int audioStreamIndex, int subtitleStreamIndex,
                              int videoStreamIndex) {
        super("mp4");
        this.ffprobePath = ffprobePath;
        this.ffmpegPath = ffmpegPath;
        this.videoStreamIndex = videoStreamIndex;
        this.audioStreamIndex = audioStreamIndex;
        this.subtitleStreamIndex = subtitleStreamIndex;
    }

    @Override
    @NotNull
    public List<String> getValidFormats() {
        return List.of("mkv");
    }

    @Override
    @Nullable
    public FFMpegCommand generateConversionCommand(@NotNull String executable, @NotNull StreamProbeResult probeResult,
                                                   @NotNull String outFile) {
        FFMpegCommand command = FFMpegHelper.getFFMpegGeneralFileCommand(executable, probeResult.parsedFiles());
        List<ConverterModule> modules = new ArrayList<>();

        if (this.debug) {
            modules.add(new DebugModule());
        }

        // Copy stream info
        modules.add(new CopyAllModule());

        //Add streams to output file
        if (!probeResult.getAudioStreams().isEmpty()) {
            modules.add(new NthAudioStreamModule(probeResult.getAudioStreams(), this.audioStreamIndex));
        }
        if (!probeResult.getVideoStreams().isEmpty()) {
            modules.add(new NthVideoStreamModule(probeResult.getVideoStreams(), this.videoStreamIndex));
            modules.add(new HardwareDecodeModule());
        }
        if (!probeResult.getSubtitleStreams().isEmpty()) {
            modules.add(new NthSubtitleStreamModule(probeResult.getSubtitleStreams(), this.subtitleStreamIndex));
        }

        modules.add(new SetOutputFileModule(outFile));

        new ModuleExecutor(command, modules).execute();
        return command;
    }

}