#!/usr/bin/env node

const { copyFileSync, chmodSync, existsSync, mkdirSync, statSync } = require('node:fs')
const path = require('node:path')
const { spawnSync } = require('node:child_process')

const args = process.argv.slice(2)
const optional = args.includes('--optional')
const sourceIndex = args.indexOf('--source')
const explicitSource = sourceIndex >= 0 ? args[sourceIndex + 1] : ''

const root = path.resolve(__dirname, '..')
const exe = process.platform === 'win32' ? 'ffmpeg.exe' : 'ffmpeg'
const targetDir = path.join(root, 'bin', process.platform)
const target = path.join(targetDir, exe)

try {
  mkdirSync(targetDir, { recursive: true })

  if (existsSync(target) && statSync(target).isFile()) {
    chmodIfNeeded(target)
    console.log(`ffmpeg already staged at ${path.relative(root, target)}`)
    process.exit(0)
  }

  const source = explicitSource || process.env.FFMPEG_PATH || findOnPath()
  if (!source) {
    finishWithoutBinary('ffmpeg was not found. Set FFMPEG_PATH or pass --source /path/to/ffmpeg.')
  }

  const resolvedSource = path.resolve(source)
  if (!existsSync(resolvedSource) || !statSync(resolvedSource).isFile()) {
    finishWithoutBinary(`ffmpeg source is not a file: ${source}`)
  }

  copyFileSync(resolvedSource, target)
  chmodIfNeeded(target)
  console.log(`staged ffmpeg from ${resolvedSource} to ${path.relative(root, target)}`)
} catch (err) {
  if (optional) {
    console.warn(`warning: could not stage ffmpeg: ${err.message}`)
    process.exit(0)
  }
  throw err
}

function findOnPath() {
  const command = process.platform === 'win32' ? 'where' : 'which'
  const result = spawnSync(command, [exe], { encoding: 'utf8' })
  if (result.status !== 0) return ''
  return result.stdout.split(/\r?\n/).map((line) => line.trim()).find(Boolean) || ''
}

function chmodIfNeeded(file) {
  if (process.platform !== 'win32') chmodSync(file, 0o755)
}

function finishWithoutBinary(message) {
  if (optional) {
    console.warn(`warning: ${message}`)
    process.exit(0)
  }
  console.error(message)
  process.exit(1)
}