// Meta (Facebook Ads) service — ESM conversion of meta-server/services/meta.service.js.
// No Redis caching (matches the original — Meta calls are cheap-enough; reach/spend
// rolls over once per request). Uses axios.

import axios from 'axios';

function getConfig() {
  const version = process.env.META_API_VERSION || 'v21.0';
  return {
    baseUrl: `https://graph.facebook.com/${version}`,
    accessToken: process.env.META_ACCESS_TOKEN,
    adAccountId: process.env.META_AD_ACCOUNT_ID,
  };
}

async function metaApiRequest(endpoint, params = {}) {
  const { baseUrl, accessToken } = getConfig();
  try {
    const response = await axios.get(`${baseUrl}/${endpoint}`, {
      params: {
        access_token: accessToken,
        time_zone: 'America/New_York',
        ...params,
      },
    });
    return response.data;
  } catch (error) {
    console.error('Meta API Error:', {
      message: error.message,
      response: error.response?.data,
      endpoint,
    });
    throw error;
  }
}

export async function fetchCampaigns(since, until) {
  const { adAccountId } = getConfig();
  const campaigns = await metaApiRequest(`act_${adAccountId}/campaigns`, {
    fields: [
      'id',
      'name',
      'status',
      'objective',
      'daily_budget',
      'lifetime_budget',
      'adsets{daily_budget,lifetime_budget}',
      `insights.time_range({'since':'${since}','until':'${until}'}).level(campaign){
        spend,
        impressions,
        clicks,
        ctr,
        reach,
        frequency,
        cpm,
        cpc,
        actions,
        action_values,
        cost_per_action_type
      }`,
    ].join(','),
    limit: 100,
  });

  return campaigns.data.filter((c) => c.insights?.data?.[0]?.spend > 0);
}

export async function fetchAccountInsights(since, until) {
  const { adAccountId } = getConfig();
  const accountInsights = await metaApiRequest(`act_${adAccountId}/insights`, {
    fields: 'reach,spend,impressions,clicks,ctr,cpm,actions,action_values',
    time_range: JSON.stringify({ since, until }),
  });
  return accountInsights.data[0] || null;
}

export async function updateCampaignBudget(campaignId, budget) {
  const { baseUrl, accessToken } = getConfig();
  try {
    const response = await axios.post(`${baseUrl}/${campaignId}`, {
      access_token: accessToken,
      daily_budget: budget * 100, // dollars → cents
    });
    return response.data;
  } catch (error) {
    console.error('Update campaign budget error:', error);
    throw error;
  }
}

export async function updateCampaignStatus(campaignId, action) {
  const { baseUrl, accessToken } = getConfig();
  try {
    const status = action === 'pause' ? 'PAUSED' : 'ACTIVE';
    const response = await axios.post(`${baseUrl}/${campaignId}`, {
      access_token: accessToken,
      status,
    });
    return response.data;
  } catch (error) {
    console.error('Update campaign status error:', error);
    throw error;
  }
}