import { execFile } from 'child_process';
import { promisify } from 'util';

const execFileAsync = promisify(execFile);

export const runFFmpeg = async (args, options = {}) => {
  const { stdio = 'pipe', ...otherOptions } = options;
  try {
    const { stdout, stderr } = await execFileAsync('ffmpeg', args, {
      stdio,
      ...otherOptions,
    });
    return { stdout, stderr };
  } catch (error) {
    throw new Error(`FFmpeg error: ${error.message}\nStderr: ${error.stderr}`);
  }
};

export const getMediaDuration = async (inputPath) => {
  const args = [
    '-v', 'error',
    '-show_entries', 'format=duration',
    '-of', 'default=noprint_wrappers=1:nokey=1:noinvalidchars=1',
    inputPath,
  ];
  const { stdout } = await runFFmpeg(args);
  return parseFloat(stdout.trim());
};

export const extractFrameAtTime = async (inputPath, outputPath, timeCode) => {
  const args = [
    '-i', inputPath,
    '-ss', timeCode,
    '-vframes', '1',
    '-q:v', '2',
    outputPath,
  ];
  await runFFmpeg(args);
};

export const transcodeVideo = async (inputPath, outputPath, options = {}) => {
  const {
    videoCodec = 'libx264',
    videoPreset = 'fast',
    videoBitrate = '10M',
    audioCodec = 'aac',
    audioBitrate = '192k',
  } = options;

  const args = [
    '-i', inputPath,
    '-c:v', videoCodec,
    '-preset', videoPreset,
    '-b:v', videoBitrate,
    '-c:a', audioCodec,
    '-b:a', audioBitrate,
    '-movflags', '+faststart',
    outputPath,
  ];

  await runFFmpeg(args);
};

export const trimSegment = async (inputPath, outputPath, inPoint, outPoint) => {
  const args = [
    '-i', inputPath,
    '-ss', inPoint,
    '-to', outPoint,
    '-c', 'copy',
    outputPath,
  ];
  await runFFmpeg(args);
};

export const concatSegments = async (segmentListFile, outputPath) => {
  const args = [
    '-f', 'concat',
    '-safe', '0',
    '-i', segmentListFile,
    '-c', 'copy',
    outputPath,
  ];
  await runFFmpeg(args);
};