class VideoTranscoder
  require 'streamio-ffmpeg'

  def initialize
    @ffmpeg_path = ENV['FFMPEG_PATH'] || 'ffmpeg'
    @ffprobe_path = ENV['FFPROBE_PATH'] || 'ffprobe'
  end

  def transcode_for_web(input_path:, output_path:, on_progress: nil)
    movie = FFMPEG::Movie.new(input_path)

    # Calculate progress callback
    progress_callback = ->(progress) {
      on_progress&.call(progress, 100)
    }

    # Transcoding options for web compatibility
    options = {
      video_codec: 'libx264',
      audio_codec: 'aac',
      custom: [
        '-pix_fmt yuv420p',
        '-preset medium',
        '-crf 23',
        '-movflags +faststart',
        '-tune fastdecode'
      ]
    }

    movie.transcode(output_path, options, &progress_callback)

    output_path
  end

  def extract_frame(input_path, seconds)
    movie = FFMPEG::Movie.new(input_path)
    output_path = "#{Rails.root}/tmp/thumbnail_#{SecureRandom.hex(8)}.jpg"

    movie.screenshot(output_path, seek_time: seconds, resolution: '320x240')
    output_path
  end

  def extract_metadata(input_path)
    movie = FFMPEG::Movie.new(input_path)

    {
      width: movie.width,
      height: movie.height,
      duration: movie.duration,
      video_codec: movie.video_codec,
      audio_codec: movie.audio_codec,
      bit_rate: movie.bitrate,
      frame_rate: movie.frame_rate,
      format: movie.container
    }
  end

  def web_compatible?(input_path)
    movie = FFMPEG::Movie.new(input_path)

    # Check if video is already web-compatible
    return false unless movie.valid?

    # Common web-compatible formats
    web_formats = %w[mp4 webm]
    web_video_codecs = %w[h264 av1 vp9]
    web_audio_codecs = %w[aac opus]

    format_compatible = web_formats.include?(movie.container.downcase)
    video_compatible = web_video_codecs.include?(movie.video_codec&.downcase)
    audio_compatible = movie.audio_codec.blank? || web_audio_codecs.include?(movie.audio_codec&.downcase)

    format_compatible && video_compatible && audio_compatible
  end
end