import path from 'path';
import { getTranscodeConfig } from './config';
import { probeHardwareEncoder } from './hw-probe';
import { PROFILES, TranscodeProfileName } from './profiles';

function bitrateToNumber(bitrate: string): number {
  return Number.parseInt(bitrate.replace(/k$/i, ''), 10);
}

export function buildRemuxArgs(inputPath: string, outDir: string, startTime: number): string[] {
  const config = getTranscodeConfig();
  return [
    '-hide_banner',
    '-loglevel',
    'error',
    '-nostats',
    ...(startTime > 0 ? ['-ss', startTime.toString()] : []),
    '-i',
    inputPath,
    '-map',
    '0:v:0',
    '-map',
    '0:a:0?',
    '-c:v',
    'copy',
    '-bsf:v',
    'h264_mp4toannexb',
    '-c:a',
    'copy',
    '-f',
    'hls',
    '-hls_time',
    config.segmentDuration.toString(),
    '-hls_list_size',
    '0',
    '-hls_segment_type',
    'mpegts',
    '-hls_flags',
    'independent_segments+temp_file',
    '-hls_segment_filename',
    path.join(outDir, 'seg_%05d.ts'),
    '-start_number',
    '0',
    path.join(outDir, 'index.m3u8'),
  ];
}

export function buildTranscodeArgs(inputPath: string, outDir: string, profileName: Exclude<TranscodeProfileName, 'remux-copy'>, startTime: number): string[] {
  const config = getTranscodeConfig();
  const profile = PROFILES[profileName];
  const encoder = probeHardwareEncoder();
  const bitrate = bitrateToNumber(profile.vBitrate);

  return [
    '-hide_banner',
    '-loglevel',
    'error',
    '-nostats',
    ...(startTime > 0 ? ['-ss', startTime.toString()] : []),
    '-i',
    inputPath,
    '-map',
    '0:v:0',
    '-map',
    '0:a:0?',
    '-c:v',
    encoder.codec,
    ...encoder.presetArgs,
    '-profile:v',
    'main',
    '-level',
    '4.1',
    '-pix_fmt',
    'yuv420p',
    '-vf',
    `scale=-2:min(${profile.maxHeight}\\,ih):flags=lanczos`,
    '-b:v',
    profile.vBitrate,
    '-maxrate',
    profile.vBitrate,
    '-bufsize',
    `${bitrate * 2}k`,
    '-force_key_frames',
    `expr:gte(t,n_forced*${config.segmentDuration})`,
    '-c:a',
    profile.aCodec,
    '-b:a',
    profile.aBitrate,
    '-ac',
    '2',
    '-f',
    'hls',
    '-hls_time',
    config.segmentDuration.toString(),
    '-hls_list_size',
    '0',
    '-hls_segment_type',
    'mpegts',
    '-hls_flags',
    'independent_segments+temp_file',
    '-hls_segment_filename',
    path.join(outDir, 'seg_%05d.ts'),
    '-start_number',
    '0',
    path.join(outDir, 'index.m3u8'),
  ];
}