/**
 * Archive passwords that spotters put in the title or description instead of
 * the NZB's `<meta type="password">`:
 *   `Title{{secret}}` (the newznab/SABnzbd convention),
 *   `Wachtwoord: KKKK2`, `[b]Password[/b]: x`, `WW: p3IU5Rz9R`, `ww= 0112358`,
 *   `WW FC0401` (abbreviation without separator: only with a digit in it).
 * The value must be the rest of its line and a single token, so sentences
 * such as "Wachtwoord: deze download is zonder wachtwoord geplaatst" or
 * "met een password beschermd" don't count.
 */
const KEYWORD = String.raw`wachtwoord|wachtw|password|passwort|passwd|pwd|pass|ww|pw`
const WITH_SEPARATOR = new RegExp(String.raw`(?:^|[^a-z0-9])(?:${KEYWORD})\s*(?:is\s*)?[:=]\s*(.*)$`, 'i')
const ABBREVIATION = /(?:^|[^a-z0-9])(?:ww|pw)\s+(\S+)\s*$/i
const NO_PASSWORD = /\b(zonder|geen|no|without|none|niet|kein|ohne)\b.{0,20}\b(wachtwoord|password|passwort|ww|pw)\b|\b(wachtwoord|password|passwort)\b.{0,20}\b(niet nodig|not needed|none|geen|nvt|n\/a)\b/i
const NOT_A_VALUE = /^(?:-+|geen|none|no|nee|nvt|n\/a|niet|not|leeg|empty|zonder|without|onbekend|unknown|zie|see|in|staat|volgt|nzb|spot)$/i

/** Lines of a spot description: UBB/HTML line breaks split, other tags dropped. */
function lines(description: string): string[] {
  return description
    .replace(/\[br\]|<br\s*\/?>/gi, '\n')
    .replace(/\[\/?[a-z]+(?:=[^\]]*)?\]|<\/?[a-z][^>]*>/gi, '')
    .split(/\r?\n/)
    .map((line) => line.trim())
}

function clean(value: string): string | null {
  const token = value.trim().replace(/^["'“‘«(<]+|["'”’»)>.,;!]+$/g, '')
  if (!token || /\s/.test(token) || token.length < 2 || token.length > 64 || NOT_A_VALUE.test(token)) return null
  return token
}

export function passwordFromSpot(title: string, description?: string | null): string | null {
  const braces = /\{\{([^{}]{1,64})\}\}/.exec(title)
  if (braces && clean(braces[1])) return clean(braces[1])
  for (const line of lines(description ?? '')) {
    if (!line || NO_PASSWORD.test(line)) continue
    const separated = WITH_SEPARATOR.exec(line)
    if (separated) {
      const value = clean(separated[1])
      if (value) return value
      continue
    }
    const abbreviated = ABBREVIATION.exec(line)
    if (abbreviated && /\d/.test(abbreviated[1])) {
      const value = clean(abbreviated[1])
      if (value) return value
    }
  }
  return null
}