/**
 * Google Apps Script - WhatsApp API Proxy
 *
 * This script proxies WhatsApp API requests to graph.facebook.com
 * from Google's infrastructure (script.google.com / script.googleusercontent.com).
 *
 * HuggingFace Spaces can connect to Google domains but blocks
 * graph.facebook.com and workers.dev, so this acts as a bridge.
 *
 * DEPLOYMENT INSTRUCTIONS:
 * 1. Go to https://script.google.com
 * 2. Create a new project ("Untitled project")
 * 3. Replace all code with this file's contents
 * 4. Click "Deploy" → "New deployment"
 * 5. Type: "Web app"
 * 6. Execute as: "Me"
 * 7. Who has access: "Anyone"
 * 8. Click "Deploy"
 * 9. Copy the Web App URL (looks like: https://script.google.com/macros/s/XXXXX/exec)
 * 10. Set META_API_PROXY_URL env var on HuggingFace to that URL
 */

function doPost(e) {
  try {
    var payload = JSON.parse(e.postData.contents);

    var phoneNumberId = payload.phone_number_id;
    var accessToken = payload.access_token;
    var messageData = payload.message_data;

    if (!phoneNumberId || !accessToken || !messageData) {
      return ContentService.createTextOutput(JSON.stringify({
        error: "Missing required fields: phone_number_id, access_token, message_data"
      })).setMimeType(ContentService.MimeType.JSON);
    }

    // Forward to Meta Graph API
    var url = "https://graph.facebook.com/v21.0/" + phoneNumberId + "/messages";

    var options = {
      method: "post",
      contentType: "application/json",
      headers: {
        "Authorization": "Bearer " + accessToken
      },
      payload: JSON.stringify(messageData),
      muteHttpExceptions: true
    };

    var response = UrlFetchApp.fetch(url, options);
    var responseCode = response.getResponseCode();
    var responseBody = response.getContentText();

    return ContentService.createTextOutput(JSON.stringify({
      status: responseCode,
      body: JSON.parse(responseBody)
    })).setMimeType(ContentService.MimeType.JSON);

  } catch (err) {
    return ContentService.createTextOutput(JSON.stringify({
      error: err.toString()
    })).setMimeType(ContentService.MimeType.JSON);
  }
}

function doGet(e) {
  return ContentService.createTextOutput(JSON.stringify({
    status: "ok",
    service: "WhatsApp API Proxy",
    description: "POST to this URL with {phone_number_id, access_token, message_data}"
  })).setMimeType(ContentService.MimeType.JSON);
}