/**
 * Network people routes — DC-141.
 *
 * CRUD for the Private Network people store (spec §2/§5) plus a provider
 * sync endpoint. Mounted on the authed apiRouter under
 * /api/v1/network/people — auth middleware is the caller's job (same as
 * every other route module in this repo).
 *
 *   GET    /network/people          → list all people
 *   GET    /network/people/:id     → one person
 *   POST   /network/people         → create (first person = bootstrap
 *                                    admin: groups ['Admin'] + protectedAt)
 *   PATCH  /network/people/:id     → update
 *   DELETE /network/people/:id     → delete (assertNotLastAdmin first)
 *   POST   /network/people/sync    → merge provider.listPeople() into the
 *                                    store (idempotent, guarded)
 *
 * The provider registry (DC-140, src/network/) is built in parallel; the
 * only dependency is deps.networkRegistry.getActiveProvider() — treated
 * as optional. When absent, POST /sync returns a clean "provider
 * inactive" response instead of throwing.
 */

'use strict';

const { ValidationError, NotFoundError, ConflictError } = require('../src/utilities/errors');
const { ok, created } = require('../src/utils/responses');
const { createPeopleStore } = require('../src/security/network-people-store');
const { LastAdminError } = require('../src/security/network-people-store');

const VALID_STATUSES = new Set(['active', 'blocked', 'removed']);

function _validDisplayName(s) {
  return typeof s === 'string' && s.trim().length > 0 && s.length <= 200;
}

function _validProviderUserId(s) {
  return typeof s === 'string' && s.length > 0 && s.length <= 256;
}

module.exports = function networkPeopleRoutesFactory({
  peopleStore,
  networkRegistry,
  asyncHandler,
  log = { info() {}, warn() {}, error() {} },
} = {}) {
  const router = require('express').Router(); // eslint-disable-line global-require

  const store = peopleStore || createPeopleStore({});
  if (!asyncHandler) {
    // Must always be wired in prod (see share.js); test fallback only.
    if (process.env.NODE_ENV !== 'test') {
      throw new Error('networkPeopleRoutes requires asyncHandler');
    }
    asyncHandler = (fn) => (req, res, next) => Promise.resolve(fn(req, res, next)).catch(next); // eslint-disable-line no-param-reassign
  }

  // ─── Reads ──────────────────────────────────────────────────────────────

  router.get('/', asyncHandler(async (req, res) => {
    const people = await store.listPeople();
    ok(res, { data: people, count: people.length });
  }, 'network-people-list'));

  router.get('/:id', asyncHandler(async (req, res) => {
    const person = await store.getPerson(req.params.id);
    if (!person) throw new NotFoundError('person');
    ok(res, { person });
  }, 'network-people-get'));

  // ─── Create ─────────────────────────────────────────────────────────────

  router.post('/', asyncHandler(async (req, res) => {
    const { displayName, providerUserId, groups, devices } = req.body || {};
    if (!_validDisplayName(displayName)) {
      throw new ValidationError('displayName is required (1-200 chars)', 'displayName');
    }
    if (!_validProviderUserId(providerUserId)) {
      throw new ValidationError('providerUserId is required (1-256 chars)', 'providerUserId');
    }
    if (groups !== undefined && !Array.isArray(groups)) {
      throw new ValidationError('groups must be an array of strings', 'groups');
    }
    if (devices !== undefined && !Array.isArray(devices)) {
      throw new ValidationError('devices must be an array', 'devices');
    }
    // First person created in an empty store becomes the bootstrap admin
    // (groups ['Admin'] + protectedAt) — enforced inside the store.
    const person = await store.upsertPerson({
      displayName: displayName.trim(),
      providerUserId,
      ...(groups !== undefined ? { groups } : {}),
      ...(devices !== undefined ? { devices } : {}),
    });
    log.info && log.info('people', 'person created via API', { id: person.id });
    created(res, { person });
  }, 'network-people-create'));

  // ─── Update ─────────────────────────────────────────────────────────────

  router.patch('/:id', asyncHandler(async (req, res) => {
    const patch = req.body || {};
    if (patch.displayName !== undefined && !_validDisplayName(patch.displayName)) {
      throw new ValidationError('displayName must be 1-200 chars', 'displayName');
    }
    if (patch.providerUserId !== undefined && !_validProviderUserId(patch.providerUserId)) {
      throw new ValidationError('providerUserId must be 1-256 chars', 'providerUserId');
    }
    if (patch.groups !== undefined && !Array.isArray(patch.groups)) {
      throw new ValidationError('groups must be an array of strings', 'groups');
    }
    if (patch.devices !== undefined && !Array.isArray(patch.devices)) {
      throw new ValidationError('devices must be an array', 'devices');
    }
    if (patch.status !== undefined && !VALID_STATUSES.has(patch.status)) {
      throw new ValidationError(`status must be one of active|blocked|removed`, 'status');
    }
    const updated = await store.updatePerson(req.params.id, patch);
    if (!updated) throw new NotFoundError('person');
    ok(res, { person: updated });
  }, 'network-people-update'));

  // ─── Delete ─────────────────────────────────────────────────────────────

  router.delete('/:id', asyncHandler(async (req, res) => {
    // Lockout guard first (spec §5): the last active admin is undeletable.
    try {
      await store.assertNotLastAdmin(req.params.id);
    } catch (err) {
      if (err instanceof LastAdminError) {
        throw new ConflictError('cannot remove the last active admin');
      }
      throw err;
    }
    const deleted = await store.deletePerson(req.params.id);
    if (!deleted) throw new NotFoundError('person');
    ok(res, { deleted: true, id: req.params.id });
  }, 'network-people-delete'));

  // ─── Provider sync ──────────────────────────────────────────────────────
  //
  // Merge provider.listPeople() into the local store:
  //   - match by providerUserId
  //   - add people not present locally
  //   - update displayName of existing people
  //   - idempotent: running twice yields no further change
  //   - never downgrades protectedAt (admin protection is sticky)
  //   - blocked/removed people are NOT resurrected by sync — a local
  //     terminal status wins over the provider saying the user exists.

  router.post('/sync', asyncHandler(async (req, res) => {
    const registry = networkRegistry;
    if (!registry || typeof registry.getActiveProvider !== 'function') {
      // Feature inactive (provider registry not built yet / no provider
      // configured) — report cleanly instead of 500ing.
      ok(res, { synced: false, reason: 'network provider not active', added: 0, updated: 0 });
      return;
    }
    let provider = null;
    try {
      provider = registry.getActiveProvider();
    } catch (_) {
      provider = null;
    }
    if (!provider || typeof provider.listPeople !== 'function') {
      ok(res, { synced: false, reason: 'network provider not active', added: 0, updated: 0 });
      return;
    }

    const providerPeople = await provider.listPeople();
    if (!Array.isArray(providerPeople)) {
      throw new ValidationError('provider listPeople() must return an array', 'provider');
    }

    let added = 0;
    let updated = 0;
    for (const pp of providerPeople) {
      if (!pp || !_validProviderUserId(pp.providerUserId)) continue; // skip junk
      const existing = await store.findByProviderUserId(pp.providerUserId);
      if (!existing) {
        await store.upsertPerson({
          displayName: _validDisplayName(pp.displayName) ? pp.displayName : pp.providerUserId,
          providerUserId: pp.providerUserId,
          groups: [],
          devices: [],
        });
        added += 1;
      } else if (existing.status === 'active'
        && _validDisplayName(pp.displayName)
        && pp.displayName !== existing.displayName) {
        await store.updatePerson(existing.id, { displayName: pp.displayName });
        updated += 1;
      }
    }

    log.info && log.info('people', 'provider sync complete', { added, updated });
    ok(res, { synced: true, added, updated });
  }, 'network-people-sync'));

  return router;
};