/**
 * SES GA4 property setup, for the SES Analytics Kit v1.0.0
 * Creates a client's GA4 property and website stream with the agency's standard settings,
 * then prints the Measurement ID for the site's head snippet.
 *
 * ONE-TIME SETUP (about 3 minutes)
 *  1. Sign in to Google with the login that has Editor or Administrator access to your
 *     clients' Analytics accounts.
 *  2. Go to script.google.com > New project. Name it "SES GA4 setup".
 *  3. Paste this whole file over everything in Code.gs and save.
 *  4. Project Settings (cog icon) > tick "Show appsscript.json manifest file in editor".
 *     Back in the Editor, open appsscript.json and replace its contents with the kit's
 *     setup/appsscript.json. Save.
 *  5. In the Editor's left bar: Services (+) > Google Analytics Admin API > Add.
 *     This switches the API on for this script.
 *
 * EACH NEW CLIENT (about 1 minute)
 *  6. Choose "listAccounts" in the toolbar and press Run. The first run asks you to approve
 *     access. The Execution log lists every account ID you can use.
 *  7. Fill in CLIENT below, choose "setupClient" and press Run.
 *  8. Copy the Measurement ID from the Execution log into the site's head snippet.
 *
 * It is safe to run twice: it reuses the property, stream, key events and dimensions it finds.
 */

var CLIENT = {
  accountId: '',                    // GA4 account ID from listAccounts, e.g. '123456789'
  name: '',                         // property name, e.g. 'Staple Hill MOT Centre'
  websiteUrl: '',                   // live address, e.g. 'https://www.staplehillmot.co.uk'
  industry: 'AUTOMOTIVE',           // one of INDUSTRIES below, or '' to leave it blank
  marketing: false                  // true only if the client runs Google Ads or Meta ads
};

var KEY_EVENTS = [
  { eventName: 'generate_lead', countingMethod: 'ONCE_PER_EVENT' },    // every form sent counts
  { eventName: 'click_call', countingMethod: 'ONCE_PER_SESSION' },     // repeat taps in one visit count once
  { eventName: 'click_whatsapp', countingMethod: 'ONCE_PER_SESSION' },
  { eventName: 'click_email', countingMethod: 'ONCE_PER_SESSION' },
  { eventName: 'click_booking', countingMethod: 'ONCE_PER_SESSION' }
];

var CUSTOM_DIMENSIONS = [
  { parameterName: 'cta_location', displayName: 'CTA location', scope: 'EVENT', description: 'Where the button was: header, footer, a section, or mobile_bar' },
  { parameterName: 'form_name', displayName: 'Form name', scope: 'EVENT', description: 'Which form sent the lead' }
];

var INDUSTRIES = ['AUTOMOTIVE', 'BUSINESS_AND_INDUSTRIAL_MARKETS', 'FINANCE', 'HEALTHCARE', 'TECHNOLOGY', 'TRAVEL', 'OTHER',
  'ARTS_AND_ENTERTAINMENT', 'BEAUTY_AND_FITNESS', 'BOOKS_AND_LITERATURE', 'FOOD_AND_DRINK', 'GAMES', 'HOBBIES_AND_LEISURE',
  'HOME_AND_GARDEN', 'INTERNET_AND_TELECOM', 'LAW_AND_GOVERNMENT', 'NEWS', 'ONLINE_COMMUNITIES', 'PEOPLE_AND_SOCIETY',
  'PETS_AND_ANIMALS', 'REAL_ESTATE', 'REFERENCE', 'SCIENCE', 'SPORTS', 'JOBS_AND_EDUCATION', 'SHOPPING'];

var API_ROOT = 'https://analyticsadmin.googleapis.com/';

/* Lists the Analytics accounts this login can use, with their IDs. */
function listAccounts() {
  var accounts = listAll_('v1beta/accountSummaries', 'accountSummaries');
  if (!accounts.length) {
    Logger.log('No Analytics accounts found for this Google login. Ask the client to add you as an Editor or Administrator.');
    return;
  }
  accounts.forEach(function (a) {
    Logger.log(a.account.replace('accounts/', '') + '   ' + a.displayName + '   (' + (a.propertySummaries || []).length + ' properties)');
  });
}

/* Creates (or completes) the client's property. */
function setupClient() {
  var c = validate_(CLIENT);
  var done = [];
  var failed = [];
  function step(label, fn) {
    try { fn(); done.push(label); } catch (e) { failed.push(label + ' - ' + e.message); }
  }

  var propertyName = findProperty_(c.accountId, c.name);
  if (propertyName) {
    done.push('Using the existing property "' + c.name + '" (' + propertyName + ')');
  } else {
    var body = { parent: 'accounts/' + c.accountId, displayName: c.name, timeZone: 'Europe/London', currencyCode: 'GBP' };
    if (c.industry) { body.industryCategory = c.industry; }
    propertyName = call_('post', 'v1beta/properties', body).name;
    done.push('Created property "' + c.name + '" (' + propertyName + ')');
  }

  var stream = findWebStream_(propertyName, c.websiteUrl);
  if (stream) {
    done.push('Using the existing web stream for ' + ((stream.webStreamData && stream.webStreamData.defaultUri) || c.websiteUrl));
  } else {
    stream = call_('post', 'v1beta/' + propertyName + '/dataStreams', {
      type: 'WEB_DATA_STREAM',
      displayName: (c.name + ' website').slice(0, 255),
      webStreamData: { defaultUri: c.websiteUrl }
    });
    done.push('Created web stream for ' + c.websiteUrl);
  }
  var measurementId = stream.webStreamData && stream.webStreamData.measurementId;

  step('Data retention set to 14 months', function () {
    call_('patch', 'v1beta/' + propertyName + '/dataRetentionSettings?updateMask=event_data_retention,user_data_retention',
      { eventDataRetention: 'FOURTEEN_MONTHS', userDataRetention: 'FOURTEEN_MONTHS' });
  });

  var haveEvents = [];
  step('Read existing key events', function () {
    haveEvents = listAll_('v1beta/' + propertyName + '/keyEvents', 'keyEvents').map(function (k) { return k.eventName; });
  });
  KEY_EVENTS.forEach(function (k) {
    if (haveEvents.indexOf(k.eventName) > -1) { done.push('Key event already set: ' + k.eventName); return; }
    step('Key event: ' + k.eventName, function () { call_('post', 'v1beta/' + propertyName + '/keyEvents', k); });
  });

  var haveDims = [];
  step('Read existing custom dimensions', function () {
    haveDims = listAll_('v1beta/' + propertyName + '/customDimensions', 'customDimensions').map(function (x) { return x.parameterName; });
  });
  CUSTOM_DIMENSIONS.forEach(function (dim) {
    if (haveDims.indexOf(dim.parameterName) > -1) { done.push('Custom dimension already set: ' + dim.displayName); return; }
    step('Custom dimension: ' + dim.displayName, function () { call_('post', 'v1beta/' + propertyName + '/customDimensions', dim); });
  });

  step('Form interaction tracking off (the kit sends generate_lead on a successful send instead)', function () {
    call_('patch', 'v1alpha/' + stream.name + '/enhancedMeasurementSettings?updateMask=form_interactions_enabled',
      { formInteractionsEnabled: false });
  });

  if (!c.marketing) {
    step('Google signals off', function () {
      call_('patch', 'v1alpha/' + propertyName + '/googleSignalsSettings?updateMask=state', { state: 'GOOGLE_SIGNALS_DISABLED' });
    });
  }

  var propertyId = propertyName.replace('properties/', '');
  Logger.log('================================================================');
  Logger.log(c.name);
  Logger.log('MEASUREMENT ID:  ' + (measurementId || 'not returned - open Admin > Data streams to copy it'));
  Logger.log('Property:        https://analytics.google.com/analytics/web/#/p' + propertyId + '/reports/intelligenthome');
  Logger.log('================================================================');
  done.forEach(function (d) { Logger.log('Done:    ' + d); });
  failed.forEach(function (f) { Logger.log('FAILED:  ' + f); });
  if (failed.length) { Logger.log('Anything marked FAILED can be set by hand in GA4 Admin, or run setupClient again.'); }
  Logger.log('Still to do by hand in GA4 Admin:');
  Logger.log(' 1. Data streams > [stream] > Configure tag settings > Define internal traffic: add the agency office IP. Then Data settings > Data filters > Internal traffic > Active.');
  Logger.log(' 2. Account settings > Data sharing settings: untick everything, unless the client runs Google Ads.');
  Logger.log(' 3. Property access management: make sure the client is an Administrator if the account is not already theirs.');
  return measurementId;
}

/* ------------------------------------------------------------------ helpers */

function validate_(c) {
  var out = {
    accountId: String(c.accountId || '').replace(/^accounts\//, '').trim(),
    name: String(c.name || '').trim(),
    websiteUrl: String(c.websiteUrl || '').trim().replace(/\/+$/, ''),
    industry: String(c.industry || '').trim().toUpperCase(),
    marketing: c.marketing === true
  };
  if (!/^\d+$/.test(out.accountId)) { throw new Error('Set CLIENT.accountId to the number shown by listAccounts.'); }
  if (!out.name || out.name.length > 100) { throw new Error('Set CLIENT.name to the business name (up to 100 characters).'); }
  if (!/^https?:\/\/[^\s\/]+\.[^\s\/]+/i.test(out.websiteUrl)) { throw new Error('Set CLIENT.websiteUrl to the full live address, starting https://'); }
  if (out.industry && INDUSTRIES.indexOf(out.industry) === -1) { throw new Error('CLIENT.industry must be one of: ' + INDUSTRIES.join(', ') + ', or empty.'); }
  return out;
}

function findProperty_(accountId, name) {
  var accounts = listAll_('v1beta/accountSummaries', 'accountSummaries');
  var account = null;
  for (var i = 0; i < accounts.length; i++) {
    if (accounts[i].account === 'accounts/' + accountId) { account = accounts[i]; break; }
  }
  if (!account) { throw new Error('This login cannot see account ' + accountId + '. Run listAccounts to check the ID and your access.'); }
  var want = name.toLowerCase();
  var props = (account.propertySummaries || []).filter(function (p) { return String(p.displayName).trim().toLowerCase() === want; });
  return props.length ? props[0].property : null;
}

function findWebStream_(propertyName, websiteUrl) {
  var streams = listAll_('v1beta/' + propertyName + '/dataStreams', 'dataStreams').filter(function (s) { return s.type === 'WEB_DATA_STREAM'; });
  if (!streams.length) { return null; }
  var host = hostOf_(websiteUrl);
  for (var i = 0; i < streams.length; i++) {
    if (hostOf_(streams[i].webStreamData && streams[i].webStreamData.defaultUri) === host) { return streams[i]; }
  }
  return streams[0];
}

function hostOf_(url) {
  var m = /^https?:\/\/([^\/?#]+)/i.exec(String(url || ''));
  return m ? m[1].toLowerCase().replace(/^www\./, '') : '';
}

function listAll_(path, key) {
  var out = [];
  var token = '';
  var guard = 0;
  do {
    var r = call_('get', path + (path.indexOf('?') > -1 ? '&' : '?') + 'pageSize=200' + (token ? '&pageToken=' + encodeURIComponent(token) : ''));
    out = out.concat(r[key] || []);
    token = r.nextPageToken || '';
    guard++;
  } while (token && guard < 50);
  return out;
}

function call_(method, path, body) {
  var options = {
    method: method,
    muteHttpExceptions: true,
    headers: { Authorization: 'Bearer ' + ScriptApp.getOAuthToken() }
  };
  if (body) {
    options.contentType = 'application/json';
    options.payload = JSON.stringify(body);
  }
  var res = UrlFetchApp.fetch(API_ROOT + path, options);
  var code = res.getResponseCode();
  var text = res.getContentText();
  var data = {};
  try { data = text ? JSON.parse(text) : {}; } catch (e) { data = { raw: text }; }
  if (code >= 300) {
    if (code === 403 && /has not been used|is disabled|SERVICE_DISABLED/i.test(text)) {
      throw new Error('The Google Analytics Admin API is switched off for this script. In the Editor: Services (+) > Google Analytics Admin API > Add, then run again.');
    }
    if (code === 403) {
      throw new Error('Google refused access (403). Check this login is an Editor or Administrator on the account. Details: ' + ((data.error && data.error.message) || text));
    }
    throw new Error(method.toUpperCase() + ' ' + path.split('?')[0] + ' failed (' + code + '): ' + ((data.error && data.error.message) || text));
  }
  return data;
}