import { IBlock, IExercise, IRating } from './types'

/**
 * Takes a block of exercises and calculates the duration in seconds.
 * @param block
 */
export function calculateDuration(block: IBlock): number {
  if (block.duration) return block.duration
  const repetitions = block.repetitions || 1
  const rest = block.rest || 0
  if (block.blocks) {
    const subblockDuration = block.blocks.reduce(
      (accumulator, block) =>
        accumulator + (block.duration || calculateDuration(block)),
      0
    )
    return repetitions * (subblockDuration + rest)
  } else {
    return 0
  }
}

/**
 * Formats a time in seconds into 0:00
 * @param seconds
 */
export function formatTime(seconds: number) {
  return `${Math.floor(seconds / 60)}:${(seconds % 60)
    .toString()
    .padStart(2, '0')}`
}

/**
 * Takes an array of exercises and formats them into
 * 4x Exercise 1 - Exercise 2 - 2x Exercise 3
 * @param exercises
 */
export function printExercises(exercises: IExercise[]) {
  return exercises
    .map(exercise =>
      exercise.repetitions > 1
        ? `${exercise.repetitions}x ${exercise.name}`
        : exercise.name
    )
    .join(' - ')
}

/**
 * Takes an array of rating and calculates the average rating
 * @param ratings
 */
export function calculateRating(ratings: IRating[]) {
  const numberOfRatings = ratings.length
  const sumOfRatings = ratings.reduce(
    (accumulator, rating) => accumulator + rating.value,
    0
  )
  return numberOfRatings ? sumOfRatings / numberOfRatings : '-'
}