package facade;

/**
 * Facade — the single, simple entry point to a complex video subsystem.
 *
 * Without this class, clients need to know about CodecFactory,
 * BitrateReader, AudioMixer, and VideoFile — 4 classes, dozens of methods.
 * The facade reduces that to ONE method call.
 *
 * The subsystem classes still exist and can be used directly
 * by advanced users who need fine-grained control.
 */
public class VideoConversionFacade {

    public String convertVideo(String inputFile, String targetFormat) {
        System.out.println("VideoConversionFacade: starting conversion of " + inputFile);

        // Step 1: open the file and detect codec
        VideoFile file = new VideoFile(inputFile);
        Codec sourceCodec = CodecFactory.extract(file);

        // Step 2: prepare destination codec
        Codec destCodec;
        if ("mp4".equals(targetFormat)) {
            destCodec = new MPEG4CompressionCodec();
        } else {
            destCodec = new OggCompressionCodec();
        }

        // Step 3: read, mix audio, encode
        VideoFile buffer = BitrateReader.read(file, sourceCodec);
        VideoFile intermediateResult = BitrateReader.convert(buffer, destCodec);
        VideoFile result = AudioMixer.fix(intermediateResult);

        String outputFilename = inputFile.replaceAll("\\.[^.]+$", "." + targetFormat);
        System.out.println("VideoConversionFacade: conversion complete -> " + outputFilename);
        return outputFilename;
    }
}