/**
 * CDP Edge — GA4 Measurement Protocol
 * Envia eventos server-side para o GA4 via Measurement Protocol.
 */

import { normalizePhone } from '../utils.js';
import { logApiFailure } from '../db.js';
import { Env, TrackPayload } from '../../types.js';
import { ExecutionContext } from '@cloudflare/workers-types';

export async function sendGA4Mp(env: Env, ga4EventName: string, payload: TrackPayload, ctx: ExecutionContext | null): Promise<{ ok?: boolean; status?: number; skipped?: string; error?: string }> {
  if (!env.GA4_API_SECRET) return { skipped: 'GA4_API_SECRET not set' };

  const {
    gaClientId: clientId, sessionId,
    value, currency, contentName,
    email, phone, firstName,
    orderId,
  } = payload;

  if (!clientId) return { skipped: 'no clientId' };

  const eventParams: Record<string, string | number> = {
    ...(value       !== undefined && { value: parseFloat(String(value)) }),
    ...(currency    && { currency: String(currency).toUpperCase() }),
    ...(contentName && { content_name: contentName }),
    ...(orderId     && { transaction_id: orderId }),
    ...(email       && { user_data_email_address: email.toLowerCase().trim() }),
    ...(phone       && { user_data_phone_number: normalizePhone(phone) || '' }),
    ...(firstName   && { user_data_first_name: firstName.toLowerCase().trim() }),
    ...(sessionId   && { session_id: sessionId }),
    engagement_time_msec: 100,
  };

  const body = {
    client_id: clientId,
    events: [{ name: ga4EventName, params: eventParams }],
  };

  const url = `https://www.google-analytics.com/mp/collect`
            + `?measurement_id=${env.GA4_MEASUREMENT_ID}`
            + `&api_secret=${env.GA4_API_SECRET}`;

  try {
    const res = await fetch(url, {
      method:  'POST',
      headers: { 'Content-Type': 'application/json' },
      body:    JSON.stringify(body),
    });

    if (res.status !== 204) {
      if (env.DB && ctx) {
        ctx.waitUntil(logApiFailure(env.DB, 'ga4', ga4EventName, String(res.status), 'GA4 returned non-204 status', '', JSON.stringify(body)));
      }
    }

    return res.status === 204 ? { ok: true } : { status: res.status };
  } catch (err: any) {
    console.error('GA4 MP fetch failed:', err?.message || String(err));

    if (env.DB && ctx) {
      ctx.waitUntil(logApiFailure(env.DB, 'ga4', ga4EventName, 'FETCH_ERROR', err?.message || String(err), '', JSON.stringify(body)));
    }

    if (env.RETRY_QUEUE) {
      const send = env.RETRY_QUEUE.send({ eventType: ga4EventName, payload, platform: 'ga4' });
      if (ctx) ctx.waitUntil(send); else send.catch(() => {});
    }

    return { error: err?.message || String(err) };
  }
}