/**
 * Connection invites for peardock (no Autopass / no RocksDB).
 *
 * Share string is always:
 *   pd1.<base64url JSON { publicKeyHex, capability, role, jti, ... }>
 *
 * Auth is HMAC capability verified at handshake (shared/crypto-auth.js).
 */
import logger from '../utils/logger.js'
import { mintCapability, deleteInvite as policyDeleteInvite } from './peer-policy.js'
import { getServerPublicKeyHex } from './auth-keys.js'
import { Roles } from '../../shared/protocol.js'
import { encodePeardockInvite, decodePeardockInvite } from '../../shared/crypto-auth.js'

const log = logger.child('invites')

/**
 * @typedef {{
 *   invite: string,
 *   role: string,
 *   createdAt: string,
 *   expiresAt: string|null,
 *   jti: string,
 *   maxUses: number,
 *   note?: string|null,
 *   capability: string,
 *   persistent: boolean,
 *   publicKeyHex: string,
 * }} InviteMeta
 */

/** @type {InviteMeta|null} */
let lastInviteMeta = null

/**
 * Create a pd1 connection invite (operator/admin/viewer grant).
 * @param {{ role?: string, ttlHours?: number, maxUses?: number, note?: string, alias?: string, peerId?: string }} opts
 */
export function createConnectionInvite(opts = {}) {
  const publicKeyHex = getServerPublicKeyHex()
  if (!publicKeyHex || !/^[0-9a-f]{64}$/.test(publicKeyHex)) {
    throw new Error('Server public key not available for invite package')
  }

  const role = opts.role || Roles.operator
  const cap = mintCapability({
    role,
    ttlHours: opts.ttlHours,
    maxUses: opts.maxUses,
    note: opts.note,
    peerId: opts.peerId || null,
  })

  const share = encodePeardockInvite({
    publicKeyHex,
    capability: cap.capability,
    role: cap.role,
    jti: cap.jti,
    alias: opts.alias || null,
    expiresAt: cap.expiresAt,
  })

  lastInviteMeta = {
    invite: share,
    role: cap.role,
    createdAt: new Date().toISOString(),
    expiresAt: cap.expiresAt,
    jti: cap.jti,
    maxUses: cap.maxUses,
    note: opts.note || null,
    capability: cap.capability,
    persistent: cap.persistent,
    publicKeyHex,
  }

  log.info('Created connection invite', {
    role: cap.role,
    jti: cap.jti.slice(0, 8),
    expiresAt: cap.expiresAt,
    maxUses: cap.maxUses,
    inviteLen: share.length,
    format: 'pd1',
  })

  return {
    kind: 'pd1',
    invite: share,
    token: share,
    share,
    role: cap.role,
    expiresAt: cap.expiresAt,
    maxUses: cap.maxUses,
    jti: cap.jti,
    note: opts.note || null,
    publicKeyHex,
    persistent: cap.persistent,
    capability: cap.capability,
    redeemHint:
      'Share this peardock invite (starts with pd1.). Paste the full string in Add peer. Do not share SERVER_SEED.',
  }
}

/**
 * Active invite list for Access UI (single in-memory slot; capability mint is in peer-policy).
 */
export function listConnectionInvites() {
  if (!lastInviteMeta) return []
  if (
    lastInviteMeta.expiresAt &&
    new Date(lastInviteMeta.expiresAt).getTime() < Date.now()
  ) {
    return []
  }
  return [
    {
      kind: 'pd1',
      invite: lastInviteMeta.invite,
      token: lastInviteMeta.invite,
      share: lastInviteMeta.invite,
      role: lastInviteMeta.role,
      expiresAt: lastInviteMeta.expiresAt,
      jti: lastInviteMeta.jti,
      maxUses: lastInviteMeta.maxUses ?? 0,
      uses: 0,
      note: lastInviteMeta.note,
      createdAt: lastInviteMeta.createdAt,
      publicKeyHex: lastInviteMeta.publicKeyHex || null,
      persistent:
        lastInviteMeta.persistent ??
        (lastInviteMeta.expiresAt == null && (lastInviteMeta.maxUses ?? 0) === 0),
      capability: lastInviteMeta.capability || null,
      grant: {
        kind: 'capability',
        jti: lastInviteMeta.jti,
        role: lastInviteMeta.role,
        expiresAt: lastInviteMeta.expiresAt,
        maxUses: lastInviteMeta.maxUses ?? 0,
        uses: 0,
        persistent: lastInviteMeta.persistent,
        embeddedInInvite: true,
      },
    },
  ]
}

/**
 * Delete the active invite and spend its capability jti.
 * @param {{ jti?: string|null, token?: string|null }} [opts]
 * @returns {{ success: boolean, jti: string|null, deleted: string[] }}
 */
export function deleteConnectionInvite(opts = {}) {
  const deleted = []
  let jti = opts.jti || lastInviteMeta?.jti || null

  // Decode pd1 share string if provided
  if (!jti && opts.token) {
    const pkg = decodePeardockInvite(opts.token)
    if (pkg?.jti) jti = pkg.jti
  }

  if (jti && jti !== 'unknown') {
    try {
      const r = policyDeleteInvite({ jti })
      for (const d of r.deleted || []) deleted.push(d)
    } catch (err) {
      log.debug('policy deleteInvite', { error: err.message })
    }
  }

  if (lastInviteMeta) {
    deleted.push('pd1')
    lastInviteMeta = null
  }

  log.info('Deleted connection invite', {
    jti: jti ? String(jti).slice(0, 8) : null,
  })

  return {
    success: deleted.length > 0,
    jti: jti && jti !== 'unknown' ? jti : null,
    deleted,
  }
}

/** Clear in-memory invite slot (server shutdown). */
export async function closeConnectionInvites() {
  lastInviteMeta = null
}