/**
 * Convert a duration in seconds into a human-readable format i.e. "x hr y min z sec".
 * Only show hours if the duration is longer than an hour.
 * Also, only show seconds if the duration is less than an hour.
 */
export const secondsToHumanReadable = (total: number) => {
  total = Math.round(total)

  const hours = Math.floor(total / 3600)
  const minutes = Math.floor((total - hours * 3600) / 60)
  const seconds = total - hours * 3600 - minutes * 60

  const parts: string[] = []

  if (hours > 0) {
    parts.push(`${hours} hr`)
  }

  if (minutes > 0) {
    parts.push(`${minutes} min`)
  }

  if (seconds > 0 && hours < 1) {
    parts.push(`${seconds} sec`)
  }

  return parts.join(' ') || '0 sec'
}

/**
 * Convert a duration in seconds into H:i:s format.
 * Only show hours if the duration is longer than an hour.
 */
export const secondsToHis = (total: number) => {
  total = Math.round(total)
  const parts: string[] = []

  const hours = Math.floor(total / 3600)

  if (hours > 0) {
    parts.push(hours.toString().padStart(2, '0'))
  }

  parts.push(
    Math.floor((total / 60) % 60)
      .toString()
      .padStart(2, '0'),
  )
  parts.push((total % 60).toString().padStart(2, '0'))

  return parts.join(':')
}

export interface ServerValidationError {
  message: string
  errors: Record<string, string[]>
}

/**
 * Parse the validation error from the server into a flattened array of messages.
 */
export const parseValidationError = (error: ServerValidationError) => {
  let messages: string[] = []

  Object.keys(error.errors).forEach(key => {
    messages = messages.concat(...error.errors[key])
  })

  return messages
}

/**
 * Turn <br> into new line characters.
 */
export const br2nl = (str: string) => (str ? str.replace(/<br\s*\/?>/gi, '\n') : '')

/**
 * Turn carriage returns (\r) to line feeds (\n) using JavaScript's implicit DOM-writing behavior
 */
export const cr2lf = (str: string) => {
  const div = document.createElement('div')
  div.innerHTML = str
  return div.innerHTML
}

export const slugToTitle = (slug: string, separator = '-') => {
  const title = slug
    .split(separator)
    .map(w => w.charAt(0).toUpperCase() + w.substring(1).toLowerCase())
    .join(' ')
  return title.replace(/\s+/g, ' ').trim()
}

export const pluralize = (count: any[] | number | undefined, singular: string) => {
  count = Array.isArray(count) ? count.length : (count ?? 0)
  return count === 1 ? `${count} ${singular}` : `${count.toLocaleString()} ${singular}s`
}

export const formatBytes = (bytes: number): string => {
  if (bytes === 0) return '0 B'

  const units = ['B', 'KB', 'MB', 'GB']
  const i = Math.floor(Math.log(bytes) / Math.log(1024))
  const value = bytes / Math.pow(1024, i)

  return `${value.toFixed(i === 0 ? 0 : 1)} ${units[i]}`
}

/**
 * Normalize a string for comparison by stripping diacritics, punctuation, symbols, and extra whitespace.
 * Works with all scripts (Latin, CJK, Arabic, Cyrillic, etc.).
 */
export const normalizeForComparison = (str: string) =>
  str
    .normalize('NFKD')
    .replace(/\p{M}/gu, '') // strip all combining marks (diacritics)
    .replace(/[\p{P}\p{S}]/gu, '') // strip punctuation and symbols
    .toLowerCase()
    .replace(/\s+/g, ' ')
    .trim()

const fnv1a = (str: string) => {
  let h = 0x811c9dc5

  for (let i = 0; i < str.length; i++) {
    h ^= str.charCodeAt(i)
    h = (h >>> 0) * 0x01000193
  }

  return h >>> 0
}

export const textToHsl = (text: string, l = 55) => {
  const hash = fnv1a(text)
  const h = hash % 360
  const s = 50 + ((hash >>> 8) % 30)
  return `hsl(${h} ${s}% ${l}%)`
}