bph.js

// TODO

const args = process.argv.slice(2)
const size = parseFloat(args[0])
const seedtime = parseFloat(args[1])
let seeders = parseInt(args[2])

;(async () => {
  if (!args.length)
    throw new Error('Usage: bph.js <size=GB> <seedtime=H> [seeders]')

  if (isNaN(size) || size <= 0)
    throw new Error('Invalid torrent size.')

  if (isNaN(seedtime) || seedtime <= 0)
    throw new Error('Invalid seeding time.')

  if (isNaN(seeders) || seeders <= 0)
    seeders = 1

  const seedtimeday = 1 / 24 * seedtime // hours to days
  const a = 0.07 * Math.log(1 + seedtimeday)
  const b = seeders ^ 0.35 // Math.max(seeders, 1) ^ 0.35
  const c = 0.0433 + (a / b)
  const bph = size * c

  return bph
})()
  .catch(error => {
    console.error(error.toString())
    process.exit(1)
  })
  .then(result => {
    console.log(`Torrent size: ${size} GiB`)
    console.log(`Seeding time: ${seedtime} hour(s)`)
    console.log(`Seeders     : ${seeders}`)
    console.log(`BP/hour     : ${result.toFixed(2)}`)
    console.log(`BP/day      : ${(result * 24).toFixed(2)}`)
    console.log(`BP/week     : ${(result * 24 * 7).toFixed(2)}`)
    console.log(`BP/month    : ${(result * 24 * 30).toFixed(2)}`)
    console.log(`BP/year     : ${(result * 24 * 365.25).toFixed(2)}`)
    process.exit(0)
  })