/**
 * settings.js
 * -----------
 * SMTP email settings modal.
 *
 * Loads saved settings from the server on open, lets the user edit and
 * save them, and sends a test email to verify the configuration works.
 *
 * Exports
 * -------
 *   initSettings()       — wire up all listeners; call once at startup
 *   smtpIsConfigured()   — returns true if the server has smtp_host saved
 */

import { announce } from './state.js';

// ─── DOM refs (local to this module) ─────────────────────────────────────────

const $  = id => document.getElementById(id);

const modal         = $('settings-modal');
const openBtn       = $('settings-btn');
const openFromHint  = $('open-settings-from-hint');
const closeBtn      = $('close-settings');
const cancelBtn     = $('settings-cancel');
const saveBtn       = $('settings-save');
const saveStatus    = $('settings-save-status');

const hostInput     = $('smtp-host');
const portInput     = $('smtp-port');
const securitySel   = $('smtp-security');
const fromInput     = $('smtp-from');
const userInput     = $('smtp-user');
const passwordInput = $('smtp-password');
const passwordHint  = $('smtp-password-hint');
const togglePwBtn   = $('toggle-password');

const testToInput   = $('smtp-test-to');
const testBtn       = $('smtp-test-btn');
const testResult    = $('smtp-test-result');

// ─── Module-level state ───────────────────────────────────────────────────────

let _configured = false;   // whether smtp_host is set on the server

// ─── Public API ───────────────────────────────────────────────────────────────

/**
 * Returns true if the server has an SMTP host configured.
 * Used by compress.js to warn the user before they start a job with
 * notifications enabled but no SMTP server set up.
 */
export function smtpIsConfigured() {
  return _configured;
}

/**
 * Attach all event listeners for the settings modal.
 * Call once during app initialisation.
 */
export function initSettings() {
  openBtn.addEventListener('click', openSettings);
  if (openFromHint) openFromHint.addEventListener('click', openSettings);
  const openFromWarn = document.getElementById('open-settings-from-warn');
  if (openFromWarn) openFromWarn.addEventListener('click', openSettings);

  closeBtn.addEventListener('click',  closeSettings);
  cancelBtn.addEventListener('click', closeSettings);
  modal.addEventListener('click', e => { if (e.target === modal) closeSettings(); });
  document.addEventListener('keydown', e => {
    if (e.key === 'Escape' && !modal.hidden) closeSettings();
  });

  saveBtn.addEventListener('click', saveSettings);
  testBtn.addEventListener('click', sendTestEmail);

  // Password show/hide toggle
  togglePwBtn.addEventListener('click', () => {
    const isHidden = passwordInput.type === 'password';
    passwordInput.type = isHidden ? 'text' : 'password';
    togglePwBtn.setAttribute('aria-label', isHidden ? 'Hide password' : 'Show password');
  });

  // Auto-fill port when security mode changes
  securitySel.addEventListener('change', () => {
    const presets = { tls: '587', ssl: '465', none: '25' };
    portInput.value = presets[securitySel.value] || portInput.value;
  });

  // Load current config silently at startup so smtpIsConfigured() works
  _fetchConfig(false);
}

// ─── Open / close ─────────────────────────────────────────────────────────────

async function openSettings() {
  modal.hidden = false;
  document.body.style.overflow = 'hidden';
  clearStatus();
  await _fetchConfig(true);
  closeBtn.focus();
  announce('SMTP settings panel opened');
}

function closeSettings() {
  modal.hidden = true;
  document.body.style.overflow = '';
  openBtn.focus();
  announce('SMTP settings panel closed');
}

// ─── Load settings from server ────────────────────────────────────────────────

async function _fetchConfig(populateForm) {
  try {
    const resp = await fetch('/api/settings/smtp');
    if (!resp.ok) return;
    const cfg = await resp.json();

    _configured = Boolean(cfg.host);

    if (!populateForm) return;

    hostInput.value    = cfg.host     || '';
    portInput.value    = cfg.port     || '587';
    fromInput.value    = cfg.from_addr || '';
    userInput.value    = cfg.user     || '';
    passwordInput.value = '';   // never pre-fill passwords

    // Select the right security option
    const opt = securitySel.querySelector(`option[value="${cfg.security || 'tls'}"]`);
    if (opt) opt.selected = true;

    passwordHint.textContent = cfg.password_set
      ? 'A password is saved. Enter a new value to replace it, or leave blank to keep it.'
      : '';

  } catch {
    // Silently ignore — server may not be reachable during init
  }
}

// ─── Save ────────────────────────────────────────────────────────────────────

async function saveSettings() {
  const host     = hostInput.value.trim();
  const port     = portInput.value.trim();
  const security = securitySel.value;
  const from     = fromInput.value.trim();
  const user     = userInput.value.trim();
  const password = passwordInput.value;   // not trimmed — passwords may have spaces

  if (!host) {
    showStatus('SMTP server host is required.', 'fail');
    hostInput.focus();
    return;
  }
  if (!port || isNaN(Number(port))) {
    showStatus('A valid port number is required.', 'fail');
    portInput.focus();
    return;
  }
  if (!from || !from.includes('@')) {
    showStatus('A valid From address is required.', 'fail');
    fromInput.focus();
    return;
  }

  saveBtn.disabled    = true;
  saveBtn.textContent = 'Saving…';
  clearStatus();

  try {
    const body = { host, port, security, from_addr: from, user };
    if (password) body.password = password;

    const resp = await fetch('/api/settings/smtp', {
      method:  'POST',
      headers: { 'Content-Type': 'application/json' },
      body:    JSON.stringify(body),
    });
    const data = await resp.json();

    if (!resp.ok) {
      showStatus(`Error: ${data.error}`, 'fail');
      return;
    }

    _configured = Boolean(data.config?.host);
    passwordInput.value = '';
    passwordHint.textContent =
      'Password saved. Enter a new value to replace it, or leave blank to keep it.';
    showStatus('Settings saved successfully.', 'ok');
    announce('SMTP settings saved.');

  } catch (err) {
    showStatus(`Network error: ${err.message}`, 'fail');
  } finally {
    saveBtn.disabled    = false;
    saveBtn.textContent = 'Save Settings';
  }
}

// ─── Test email ───────────────────────────────────────────────────────────────

async function sendTestEmail() {
  const to = testToInput.value.trim();
  if (!to || !to.includes('@')) {
    setTestResult('Please enter a valid recipient address.', 'fail');
    testToInput.focus();
    return;
  }

  testBtn.disabled    = true;
  testBtn.textContent = 'Sending…';
  setTestResult('Sending test email…', '');

  try {
    const resp = await fetch('/api/settings/smtp/test', {
      method:  'POST',
      headers: { 'Content-Type': 'application/json' },
      body:    JSON.stringify({ to }),
    });
    const data = await resp.json();

    if (data.ok) {
      setTestResult(`✓ ${data.message}`, 'ok');
      announce(`Test email sent to ${to}.`);
    } else {
      setTestResult(`✗ ${data.message}`, 'fail');
      announce(`Test email failed: ${data.message}`);
    }
  } catch (err) {
    setTestResult(`Network error: ${err.message}`, 'fail');
  } finally {
    testBtn.disabled    = false;
    testBtn.textContent = 'Send Test';
  }
}

// ─── Helpers ─────────────────────────────────────────────────────────────────

function showStatus(msg, type) {
  saveStatus.textContent = msg;
  saveStatus.className   = `settings-save-status ${type}`;
}

function clearStatus() {
  saveStatus.textContent = '';
  saveStatus.className   = 'settings-save-status';
  setTestResult('', '');
}

function setTestResult(msg, type) {
  testResult.textContent = msg;
  testResult.style.color =
    type === 'ok'   ? 'var(--text-success)'
    : type === 'fail' ? 'var(--text-danger)'
    : 'var(--text-muted)';
}