const fs = require('fs');
const path = require('path');

// Auto-load .env file if present
const envPath = path.resolve(__dirname, '../.env');
if (fs.existsSync(envPath)) {
  const envContent = fs.readFileSync(envPath, 'utf8');
  envContent.split('\n').forEach(line => {
    const match = line.match(/^\s*([\w.-]+)\s*=\s*(.*)\s*$/);
    if (match) {
      const key = match[1];
      let value = match[2].trim().replace(/^['"]|['"]$/g, '');
      if (!process.env[key]) process.env[key] = value;
    }
  });
}

const AD_ACCOUNT_ID = process.env.META_AD_ACCOUNT_ID;
const ACCESS_TOKEN = process.env.META_ACCESS_TOKEN;

const API_VERSION = 'v19.0';
const BASE_URL = `https://graph.facebook.com/${API_VERSION}`;

async function apiCall(endpoint, method = 'GET', body = null) {
  const token = ACCESS_TOKEN;
  if (!token) {
    throw new Error('META_ACCESS_TOKEN environment variable is missing.');
  }

  const url = new URL(`${BASE_URL}/${endpoint}`);
  url.searchParams.append('access_token', token);

  const options = {
    method,
    headers: { 'Content-Type': 'application/json' }
  };

  if (body && method !== 'GET') {
    options.body = JSON.stringify(body);
  }

  const res = await fetch(url.toString(), options);
  const data = await res.json();
  if (data.error) {
    throw new Error(`Meta API Error [${data.error.code}]: ${data.error.message}`);
  }
  return data;
}

async function getAccountStatus() {
  const actId = AD_ACCOUNT_ID.startsWith('act_') ? AD_ACCOUNT_ID : `act_${AD_ACCOUNT_ID}`;
  const data = await apiCall(`${actId}?fields=name,account_status,currency,balance,amount_spent`);
  return data;
}

async function getCampaigns() {
  const actId = AD_ACCOUNT_ID.startsWith('act_') ? AD_ACCOUNT_ID : `act_${AD_ACCOUNT_ID}`;
  const data = await apiCall(`${actId}/campaigns?fields=id,name,status,objective,daily_budget,lifetime_budget`);
  return data.data || [];
}

async function createCampaign({ name, objective = 'OUTCOME_LEADS', dailyBudgetUsd = 10 }) {
  const actId = AD_ACCOUNT_ID.startsWith('act_') ? AD_ACCOUNT_ID : `act_${AD_ACCOUNT_ID}`;
  const body = {
    name,
    objective,
    status: 'PAUSED',
    special_ad_categories: ['NONE'],
    daily_budget: dailyBudgetUsd * 100 // in cents
  };
  return await apiCall(`${actId}/campaigns`, 'POST', body);
}

async function main() {
  const cmd = process.argv[2] || 'status';
  try {
    if (cmd === 'status') {
      const status = await getAccountStatus();
      console.log('Ad Account Status:', JSON.stringify(status, null, 2));
    } else if (cmd === 'list-campaigns') {
      const campaigns = await getCampaigns();
      console.log('Campaigns:', JSON.stringify(campaigns, null, 2));
    } else {
      console.log(`Usage: node scripts/meta-ads-manager.js [status|list-campaigns]`);
    }
  } catch (err) {
    console.error('Error:', err.message);
  }
}

if (require.main === module) {
  main();
}

module.exports = { apiCall, getAccountStatus, getCampaigns, createCampaign };