/**
 * GET /api/mail/lead-emails?leadId=<AD_User_ID>[&provider=imap|archive][&account=<index>]
 * GET /api/mail/lead-emails?partnerId=<C_BPartner_ID>[&provider=…][&account=<index>&address=<one of the partner's addresses>]
 * E-mail history of a lead / contact, or of a business partner (all its addresses:
 * partner e-mail, invoice e-mail, contacts — ADMIN roles only). Nothing stored.
 * Two interchangeable providers:
 *  - imap    (default): live search in the configured mailboxes, one per `account`
 *  - archive: the mailpiler archive (all mailboxes, one indexed lookup)
 * Without `account`: { status, email, name, accounts: [{ index, label }] }.
 * With `account`:    { status, email, account, rows, folders, truncated, ms } for
 * that ONE source — the modal calls every source in parallel and merges the rows
 * as they arrive. Staff only. Never throws to the client.
 */
import { gateFromEvent } from '../../../utils/chatAccess'
import { listMailAccounts, searchAccount } from '../../../utils/mail/leadMailbox'
import { archiveAvailable, searchArchive } from '../../../utils/mail/mailArchive'
import { resolveMailTarget } from '../../../utils/mail/leadEmailAddress'

export default defineEventHandler(async (event) => {
  let token = ''
  try { token = (await gateFromEvent(event)).token } catch (err: any) { return { status: err?.statusCode || 403, message: 'Forbidden', accounts: [], rows: [] } }
  const q = getQuery(event)
  const provider = String(q.provider || 'imap') === 'archive' ? 'archive' : 'imap'
  const accounts: { index: number | string; label: string }[] = provider === 'archive'
    ? (archiveAvailable() ? [{ index: 'archive', label: 'Mailpiler-Archiv' }] : [])
    : listMailAccounts()
  try {
    const target = await resolveMailTarget(event, q, token)
    const { name, addresses } = target
    if (q.account === undefined || q.account === '') {
      // Without `account` the partner mode has no single address yet — report the first for the header.
      const email = target.email || addresses[0]?.email || ''
      if (provider === 'archive' && !accounts.length) return { status: 503, message: 'Mail archive not configured', email, name, accounts, addresses }
      return { status: 200, email, name, provider, accounts, addresses }
    }
    const email = target.email
    if (target.isPartner && !email) return { status: 400, message: 'Unknown address', rows: [] }
    const started = Date.now()
    if (provider === 'archive') {
      if (!email) return { status: 200, email, account: 'archive', rows: [], folders: 0, truncated: false }
      const res = await searchArchive(email)
      return { status: 200, email, account: 'archive', ...res, ms: Date.now() - started }
    }
    const index = Number(q.account)
    if (!Number.isInteger(index) || !listMailAccounts()[index]) return { status: 400, message: 'Unknown mail account', rows: [] }
    if (!email) return { status: 200, email, account: index, rows: [], folders: 0, truncated: false }
    const res = await searchAccount(index, email)
    return { status: 200, email, account: index, ...res, ms: Date.now() - started }
  } catch (err: any) {
    if (err?.statusCode === 403) return { status: 403, message: 'Forbidden', accounts: [], rows: [] }
    console.warn('[lead-emails] search failed:', err?.message || err)
    return { status: 502, message: err?.authenticationFailed ? 'Mailbox login failed' : (err?.message || 'Mailbox unavailable'), accounts, rows: [] }
  }
})