// services/callTest/twiml.js
// Store entry steps + shared core steps for /calltest Twilio voice webhooks.

import {
  buildVoiceWebhookUrl,
} from './config.js';

const CORE_STEPS = new Set(['intro', 'listen', 'outro', 'done']);
const STORE_ENTRY_STEPS = new Set(['greeting', 'dtmf', 'wait']);

function xmlEscape(text) {
  return String(text || '')
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&apos;');
}

function redirect(testId, mode, step) {
  const url = xmlEscape(buildVoiceWebhookUrl(testId, mode, step));
  return `<Redirect method="POST">${url}</Redirect>`;
}

/**
 * @param {object} opts
 * @param {'store'|'dial'} opts.mode
 * @param {string} opts.step
 * @param {string} opts.testId
 * @param {object} opts.config
 */
export function buildTwiml({ mode, step, testId, config }) {
  const c = config;
  let body = '';

  if (mode === 'store' && STORE_ENTRY_STEPS.has(step)) {
    switch (step) {
      case 'greeting':
        body = `<Pause length="${c.greetingPauseSec}"/>\n${redirect(testId, mode, 'dtmf')}`;
        break;
      case 'dtmf': {
        const digits = String(c.dtmf || '1').replace(/[^0-9*#w]/gi, '');
        body = `<Play digits="wwww${xmlEscape(digits)}"/>\n${redirect(testId, mode, 'wait')}`;
        break;
      }
      case 'wait':
        body = `<Pause length="${c.answerWaitSec}"/>\n${redirect(testId, mode, 'intro')}`;
        break;
      default:
        body = `<Say>Unknown entry step.</Say>\n<Hangup/>`;
    }
  } else if (CORE_STEPS.has(step)) {
    switch (step) {
      case 'intro':
        body = `<Say voice="Polly.Joanna">${xmlEscape(c.introTts)}</Say>\n${redirect(testId, mode, 'listen')}`;
        break;
      case 'listen':
        body = `<Pause length="${c.listenSec}"/>\n${redirect(testId, mode, 'outro')}`;
        break;
      case 'outro':
        body = `<Say voice="Polly.Joanna">${xmlEscape(c.outroTts)}</Say>\n${redirect(testId, mode, 'done')}`;
        break;
      case 'done':
        body = '<Hangup/>';
        break;
      default:
        body = '<Hangup/>';
    }
  } else if (mode === 'dial' && step === 'intro') {
    body = `<Say voice="Polly.Joanna">${xmlEscape(c.introTts)}</Say>\n${redirect(testId, mode, 'listen')}`;
  } else {
    body = '<Say>Invalid call test step.</Say>\n<Hangup/>';
  }

  return `<?xml version="1.0" encoding="UTF-8"?>\n<Response>\n${body}\n</Response>`;
}

export function initialStepForMode(mode) {
  return mode === 'store' ? 'greeting' : 'intro';
}

export function isCoreStep(step) {
  return CORE_STEPS.has(step);
}

export function isStoreEntryStep(step) {
  return STORE_ENTRY_STEPS.has(step);
}

export const STORE_ENTRY_STEP_ORDER = ['greeting', 'dtmf', 'wait'];
export const CORE_STEP_ORDER = ['intro', 'listen', 'outro', 'done'];