// src/integrations/webex/BotClient.js
import axios from 'axios';
import FormData from 'form-data';
import { logger } from '../../utils/logger.js';

class BotClient {
  static #instance = null;

  constructor() {
    if (BotClient.#instance) {
      return BotClient.#instance;
    }

    const token = process.env.WEBEX_BOT_TOKEN;
    const baseURL = process.env.WEBEX_BASE_URL || 'https://webexapis.com/v1';

    if (!token) {
      logger('webex:bot', 'WEBEX_BOT_TOKEN is missing – messaging will fail', 'error');
      throw new Error('Missing WEBEX_BOT_TOKEN environment variable');
    }

    this.axios = axios.create({
      baseURL,
      timeout: 15000,
      headers: {
        Authorization: `Bearer ${token}`,
        'Content-Type': 'application/json',
      },
    });

    // Global error interceptor for better logging
    this.axios.interceptors.response.use(
      (response) => response,
      (err) => {
        const msg = err.response
          ? `${err.response.status} - ${JSON.stringify(err.response.data || {})}`
          : err.message;
        logger('webex:bot', `API error: ${msg}`, 'error');
        return Promise.reject(err);
      }
    );

    BotClient.#instance = this;
    logger('webex:bot', 'BotClient initialized with bot token from environment');
  }

  async sendMarkdown(roomId, markdown, textFallback = null) {
    if (!roomId || !markdown) {
      logger('webex:bot', 'sendMarkdown called with missing roomId or markdown', 'warn');
      return null;
    }

    const payload = { roomId, markdown };
    if (textFallback) payload.text = textFallback;

    try {
      const response = await this.axios.post('/messages', payload);
      logger('webex:bot', `Sent markdown message to room ${roomId.slice(0, 8)}...`);
      return response.data;
    } catch (err) {
      // Error already logged by interceptor
      throw err;
    }
  }

  async sendWithAttachment(roomId, buffer, fileName, contentType = 'application/octet-stream', text = 'Attached file') {
    if (!roomId || !buffer || !fileName) {
      logger('webex:bot', 'sendWithAttachment called with missing parameters', 'warn');
      return null;
    }

    try {
      const form = new FormData();
      form.append('roomId', roomId);
      form.append('text', text);
      form.append('files', buffer, {
        filename: fileName,
        contentType: contentType
      });

      const response = await this.axios.post('/messages', form, {
        headers: form.getHeaders(),   // Let form-data set the correct Content-Type with boundary
      });

      logger('webex:bot', `Sent attachment "${fileName}" to room ${roomId.slice(0, 8)}...`);
      return response.data;
    } catch (err) {
      logger('webex:bot', `Failed to send attachment ${fileName}: ${err.message}`, 'error');
      throw err;
    }
  }

  async getRoomDetails(roomId) {
    try {
      const response = await this.axios.get(`/rooms/${roomId}`);
      logger('webex:bot', `Retrieved details for room ${roomId}`);
      return response.data;
    } catch (err) {
      logger('webex:bot', `Failed to get room details for ${roomId}: ${err.message}`, 'warn');
      return null;
    }
  }

  async addMemberToRoom(roomId, personEmail) {
    try {
      const response = await this.axios.post('/memberships', { roomId, personEmail });
      logger('webex:bot', `Added member ${personEmail} to room ${roomId}`);
      return response.data;
    } catch (err) {
      logger('webex:bot', `Failed to add member ${personEmail} to room ${roomId}: ${err.message}`, 'error');
      throw err;
    }
  }
}

// Export singleton instance
export default new BotClient();