// Pure helpers for the moderation-appeals feature (Phase 6c). No DB access —
// just the status/type vocabularies and row-shaping so both the model layer and
// the tests can reason about appeal state without a database.

// Terminal statuses: an appeal that has reached one of these is closed and can
// no longer be withdrawn, claimed, or resolved.
const TERMINAL = new Set(['approved', 'denied', 'withdrawn'])

// Active statuses: an appeal that still occupies the "one active appeal per
// action" slot. A player cannot open a second appeal for a mod_action while one
// of these is outstanding.
const ACTIVE = new Set(['pending', 'under_review'])

// Only bans and mutes are appealable (kicks/warns are not — a kick is not a
// standing state, and a warn carries no access restriction to reverse).
const APPEALABLE_TYPES = new Set(['ban', 'mute'])

// True if a status is one an appeal can still transition away from.
function isTerminal(status) {
  return TERMINAL.has(status)
}

function isActive(status) {
  return ACTIVE.has(status)
}

function isAppealableType(actionType) {
  return APPEALABLE_TYPES.has(actionType)
}

// Map an approve/deny resolution to the reversal_status the row should carry.
// A denial never reverses; an approval only reverses when the underlying action
// is appealable (ban/mute) and the bot call succeeded.
function reversalStatusFor({ status, actionType, botOk }) {
  if (status !== 'approved') return 'none'
  if (!APPEALABLE_TYPES.has(actionType)) return 'none'
  return botOk ? 'done' : 'failed'
}

module.exports = {
  TERMINAL,
  ACTIVE,
  APPEALABLE_TYPES,
  isTerminal,
  isActive,
  isAppealableType,
  reversalStatusFor,
}
