#!/usr/bin/env node
/**
 * Seed the Webex Service App tokens file from an existing source.
 *
 * Two seed paths, both end with one immediate refresh against
 * https://webexapis.com/v1/access_token. That verifies the seed actually
 * works, rotates to a fresh pair (Cisco rotates refresh tokens), and writes
 * the rotated pair to this project's WEBEX_TOKENS_PATH.
 *
 * Usage:
 *   npm run webex:seed                                 # uses default --from-file path (collabFinder)
 *   npm run webex:seed -- --from-file /path/to/tokens.json
 *   npm run webex:seed -- --refresh-token <refresh-token-string>
 *
 * Requires WEBEX_CLIENT_ID + WEBEX_CLIENT_SECRET in .env.
 */

require('dotenv').config();
const fs = require('fs').promises;
const path = require('path');
const axios = require('axios');

const TOKEN_URL = 'https://webexapis.com/v1/access_token';
const DEFAULT_SOURCE = '/Volumes/jmcqueen/Docker/collabFinder/config/webex-service-tokens.json';
const SAFETY_BUFFER_MS = 5 * 60 * 1000;

const args = process.argv.slice(2);
function flag(name) {
  const idx = args.indexOf(name);
  if (idx >= 0 && idx + 1 < args.length) return args[idx + 1];
  const inline = args.find(a => a.startsWith(`${name}=`));
  if (inline) return inline.split('=').slice(1).join('=');
  return null;
}

async function readSeedRefreshToken() {
  const refreshTokenFlag = flag('--refresh-token');
  if (refreshTokenFlag) {
    return { source: 'refresh-token flag', refreshToken: refreshTokenFlag.trim() };
  }

  const fromFile = flag('--from-file') || DEFAULT_SOURCE;
  console.log(`Seeding from file: ${fromFile}`);

  let raw;
  try {
    raw = await fs.readFile(fromFile, 'utf8');
  } catch (err) {
    if (err.code === 'ENOENT') {
      throw new Error(
        `Source tokens file not found: ${fromFile}\n` +
          'Pass --from-file <path> or --refresh-token <token>.',
        { cause: err }
      );
    }
    throw err;
  }

  let parsed;
  try {
    parsed = JSON.parse(raw);
  } catch (err) {
    throw new Error(`Source tokens file is not valid JSON (${fromFile}): ${err.message}`, {
      cause: err,
    });
  }

  const refreshToken = parsed.refreshToken || parsed.refresh_token;
  if (!refreshToken) {
    throw new Error(`Source tokens file has no refreshToken / refresh_token field (${fromFile})`);
  }
  return { source: fromFile, refreshToken };
}

async function exchangeRefreshToken(refreshToken) {
  const clientId = process.env.WEBEX_CLIENT_ID;
  const clientSecret = process.env.WEBEX_CLIENT_SECRET;
  if (!clientId || !clientSecret) {
    throw new Error('WEBEX_CLIENT_ID and WEBEX_CLIENT_SECRET must be set in .env');
  }

  const params = new URLSearchParams({
    grant_type: 'refresh_token',
    client_id: clientId,
    client_secret: clientSecret,
    refresh_token: refreshToken,
  });

  try {
    const res = await axios.post(TOKEN_URL, params.toString(), {
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
      timeout: 15000,
    });
    return res.data;
  } catch (err) {
    const status = err.response?.status;
    const detail = err.response?.data ? JSON.stringify(err.response.data) : err.message;
    throw new Error(`Token refresh failed (status=${status || 'n/a'}): ${detail}`, {
      cause: err,
    });
  }
}

async function writeTokens(targetPath, data) {
  const payload = {
    accessToken: data.access_token,
    refreshToken: data.refresh_token,
    expiresAt: Date.now() + Number(data.expires_in || 0) * 1000 - SAFETY_BUFFER_MS,
    updatedAt: new Date().toISOString(),
  };
  await fs.mkdir(path.dirname(targetPath), { recursive: true });
  await fs.writeFile(targetPath, JSON.stringify(payload, null, 2), 'utf8');
  return payload;
}

(async () => {
  try {
    const targetPath = path.resolve(
      process.env.WEBEX_TOKENS_PATH ||
        path.join(process.cwd(), 'tokens', 'webex-service-tokens.json')
    );

    const { source, refreshToken } = await readSeedRefreshToken();
    console.log(`Seed source: ${source}`);
    console.log(`Target path: ${targetPath}`);

    console.log('Performing initial refresh against Webex...');
    const data = await exchangeRefreshToken(refreshToken);

    const payload = await writeTokens(targetPath, data);
    console.log('Webex tokens seeded successfully.');
    console.log(`  expiresIn:  ${data.expires_in}s (buffered)`);
    console.log(`  expiresAt:  ${new Date(payload.expiresAt).toISOString()}`);
    console.log(`  updatedAt:  ${payload.updatedAt}`);
    process.exit(0);
  } catch (err) {
    console.error('Seed failed:', err.message);
    process.exit(1);
  }
})();