// src/google/google.service.ts
import { Injectable, Logger } from '@nestjs/common';
import axios from 'axios';
import { GmailApiStrategy } from '../strategies/email/gmail-api.strategy';

@Injectable()
export class GoogleService {
  private readonly logger = new Logger(GoogleService.name);

  constructor(private readonly gmailApiStrategy: GmailApiStrategy) {}

  /**
   * Create a Google Calendar event
   */
  async createEvent(creds: any, payload: any) {
    if (!creds?.refreshToken) {
      throw new Error('Missing refresh token');
    }

    const accessToken = await this.gmailApiStrategy.refreshAccessToken(creds);

    // Normalize attendees into [{ email: "..." }]
    const normalizeAttendees = (attendees: any[] = []) =>
      attendees
        .flatMap((a) =>
          typeof a === 'string'
            ? [{ email: a }]
            : Array.isArray(a?.email)
              ? a.email.map((e) => ({ email: e }))
              : a?.email
                ? [{ email: a.email }]
                : [],
        )
        .filter((a) => a.email && a.email.trim() !== '');

    const event = {
      summary: payload.title,
      description: payload.description,
      location: payload.location,
      start: {
        dateTime: payload.startTime,
        timeZone: payload.timeZone || 'Asia/Kolkata',
      },
      end: {
        dateTime: payload.endTime,
        timeZone: payload.timeZone || 'Asia/Kolkata',
      },
      attendees: normalizeAttendees(payload.attendees),
    };

    const response = await axios.post(
      'https://www.googleapis.com/calendar/v3/calendars/primary/events?sendUpdates=all',
      event,
      {
        headers: {
          Authorization: `Bearer ${accessToken}`,
          'Content-Type': 'application/json',
        },
      },
    );

    this.logger.debug('Google calendar event created', response.data);

    return response.data;
  }

  /**
   * Update a Google Calendar event
   */
  async updateEvent(creds: any, eventId: string, payload: any) {
    if (!creds?.refreshToken) {
      throw new Error('Missing refresh token');
    }

    const accessToken = await this.gmailApiStrategy.refreshAccessToken(creds);

    const normalizeAttendees = (attendees: any[] = []) =>
      attendees
        .flatMap((a) =>
          typeof a === 'string'
            ? [{ email: a }]
            : Array.isArray(a?.email)
              ? a.email.map((e) => ({ email: e }))
              : a?.email
                ? [{ email: a.email }]
                : [],
        )
        .filter((a) => a.email && a.email.trim() !== '');

    const event = {
      summary: payload.title,
      description: payload.description,
      location: payload.location,
      start: {
        dateTime: payload.startTime,
        timeZone: payload.timeZone || 'Asia/Kolkata',
      },
      end: {
        dateTime: payload.endTime,
        timeZone: payload.timeZone || 'Asia/Kolkata',
      },
      attendees: normalizeAttendees(payload.attendees),
    };

    const response = await axios.patch(
      `https://www.googleapis.com/calendar/v3/calendars/primary/events/${eventId}?sendUpdates=all`,
      event,
      {
        headers: {
          Authorization: `Bearer ${accessToken}`,
          'Content-Type': 'application/json',
        },
      },
    );

    return response.data;
  }
}