// integrations/webex/WebexClient.js
import axios from 'axios';
import WebexServiceAppAuth from './WebexServiceAppAuth.js';
import { logger } from '../../utils/logger.js';   // ← Your new custom logger

class WebexClient {
  constructor() {
    this.auth = new WebexServiceAppAuth();
    this.baseURL = 'https://webexapis.com/v1';
    logger('webex:client', 'WebexClient initialized with Service App auth');
  }

  async request(method, endpoint, data = null, params = null) {
    const { data: body } = await this.requestRaw(method, endpoint, data, params);
    return body;
  }

  // Like `request()` but returns `{ data, headers, status }`. Use this when
  // callers need response headers — most notably the `Link` header for
  // Webex's cursor-based pagination (`Link: <…?next=cursor>; rel="next"`).
  // If `endpointOrUrl` looks like an absolute URL (e.g. a `Link: <…>; rel="next"`
  // value extracted from a previous page), it's used as-is and `params` are
  // ignored — the URL already carries the cursor. Otherwise it's treated as
  // a path relative to `this.baseURL`.
  async requestRaw(method, endpointOrUrl, data = null, params = null) {
    const token = await this.auth.getAccessToken();
    const isAbsolute = /^https?:\/\//i.test(endpointOrUrl);
    const url = isAbsolute ? endpointOrUrl : `${this.baseURL}/${endpointOrUrl}`;

    try {
      const response = await axios({
        method,
        url,
        headers: { Authorization: `Bearer ${token}` },
        data,
        params: isAbsolute ? undefined : params,
      });
      return { data: response.data, headers: response.headers, status: response.status };
    } catch (err) {
      if (err.response?.status === 401) {
        logger('webex:client', '401 received from Webex — forcing token refresh', 'warn');
        await this.auth.forceRefresh(); // serialized through auth mutex
        return this.requestRaw(method, endpointOrUrl, data, params); // retry once
      }

      logger('webex:client', `API error on ${endpointOrUrl}: ${err.message}`, 'error');
      if (err.response?.data) {
        logger('webex:client', `Response data: ${JSON.stringify(err.response.data)}`, 'error');
      }
      throw err;
    }
  }

  // Convenience wrappers
  async getMe() {
    return this.request('GET', 'people/me');
  }

  async listMessages(roomId, options = {}) {
    return this.request('GET', 'messages', null, { roomId, ...options });
  }

  async createMessage(roomId, textOrObject) {
    const payload = typeof textOrObject === 'string' 
      ? { roomId, text: textOrObject } 
      : { roomId, ...textOrObject };
    return this.request('POST', 'messages', payload);
  }

  // Add more as needed
  async listRooms(max = 100) {
    return this.request('GET', 'rooms', null, { max });
  }

  async getRoom(roomId) {
    return this.request('GET', `rooms/${roomId}`);
  }

  // ── People lookup ──────────────────────────────────────────────────────────
  // Returns the first person matching the given email, or null if none found.
  // Routes through this.request() so it inherits auth + mutex + 401 retry.
  //
  // CAUTION: the list endpoint (`GET /v1/people?email=…`) returns a
  // *partial* person record — admin-only fields such as `licenses`, `roles`,
  // and `siteUrls` are only populated when fetching a single person via
  // `GET /v1/people/{id}` (see `getPerson` below). If you need any of those
  // fields, call `getPerson(returnedUser.id)` instead of trusting this
  // result. The Webex API does this on purpose for list-endpoint
  // performance.
  async findPersonByEmail(email) {
    const data = await this.request('GET', 'people', null, { email });
    return data.items?.[0] || null;
  }

  // ── Authorizations (admin-only) ────────────────────────────────────────────
  // List and revoke a user's OAuth authorizations. Requires the service app to
  // have the `identity:tokens_read` + `identity:tokens_write` scopes *and* the
  // signed-in admin to have Full / User / Device Admin role. See
  // https://developer.webex.com/admin/docs/api/v1/authorizations
  async listAuthorizations(personId) {
    return this.request('GET', 'authorizations', null, { personId });
  }

  async deleteAuthorization(authorizationId) {
    return this.request('DELETE', `authorizations/${authorizationId}`);
  }

  // ── People (admin) ─────────────────────────────────────────────────────────
  // Full person record including the `licenses` array (license IDs the user
  // currently holds). Used to determine whether a user already has a meeting
  // license on a given site.
  async getPerson(personId) {
    return this.request('GET', `people/${personId}`);
  }

  // ── Licenses (admin) ───────────────────────────────────────────────────────
  // List org licenses. Each item carries `{ id, name, totalUnits,
  // consumedUnits, subscriptionId, siteUrl, siteType }`. Requires the service
  // app to hold the `spark-admin:licenses_read` scope.
  async listLicenses(orgId = null) {
    return this.request('GET', 'licenses', null, orgId ? { orgId } : null);
  }

  // Assign / remove licenses on a single user. Endpoint is `licenses/users`
  // (not `/licenses/people` — confirmed via the wxc_sdk source). Body shape:
  //   {
  //     personId: '...',  // OR email
  //     licenses: [{ id, operation: 'add'|'remove', properties? }],
  //     siteUrls: [{ siteUrl, accountType: 'attendee', operation }],
  //     orgId?: '...',
  //   }
  // Returns 200 (full success) or 206 (partial) with `{ licenses[],
  // pendingLicenses[], siteUrls[], pendingSiteUrls[] }`. Requires
  // `spark-admin:people_write`.
  async assignLicensesToUser({ personId, email, licenses, siteUrls, orgId } = {}) {
    const body = {};
    if (email) body.email = email;
    if (personId) body.personId = personId;
    if (orgId) body.orgId = orgId;
    if (licenses) body.licenses = licenses;
    if (siteUrls) body.siteUrls = siteUrls;
    return this.request('PATCH', 'licenses/users', body);
  }

  // Returns the full deduplicated list of users assigned to a license,
  // following Webex's `Link: <…>; rel="next"` cursor pagination. Each entry:
  //   { id, type: 'INTERNAL'|'EXTERNAL', displayName?, email? }
  // This is the reliable way to determine whether a specific user holds a
  // specific license — the per-person `licenses` field on `/v1/people/{id}`
  // is unreliable for service-app tokens (returns empty even for assigned
  // users). Requires `spark-admin:licenses_read`.
  async listLicenseAssignees(licenseId, { pageSize = 300 } = {}) {
    const all = [];
    let { data, headers } = await this.requestRaw(
      'GET',
      `licenses/${licenseId}`,
      null,
      { includeAssignedTo: 'user', limit: pageSize },
    );
    if (Array.isArray(data?.users)) all.push(...data.users);

    let nextUrl = parseLinkNext(headers?.link || headers?.Link);
    while (nextUrl) {
      ({ data, headers } = await this.requestRaw('GET', nextUrl));
      if (Array.isArray(data?.users)) all.push(...data.users);
      nextUrl = parseLinkNext(headers?.link || headers?.Link);
    }
    return all;
  }
}

// Parses a Webex `Link` header (RFC 5988) and returns the URL of the `next`
// page, or null. Webex headers look like:
//   Link: <https://webexapis.com/v1/licenses/X?...&next=CURSOR>; rel="next"
function parseLinkNext(linkHeader) {
  if (!linkHeader || typeof linkHeader !== 'string') return null;
  // Tolerate multiple link entries (comma-separated) by splitting and matching each.
  for (const part of linkHeader.split(',')) {
    const m = part.match(/<([^>]+)>\s*;\s*rel\s*=\s*"?next"?/i);
    if (m) return m[1];
  }
  return null;
}

// Create and export the singleton instance
const webex = new WebexClient();
export default webex;