/* Localization + time formatting for the Work Package Suite.

   Every date the app shows should agree, wherever it's rendered. Three sources,
   most specific first:
     1. the signed-in user's own preference   (users.locale / users.timezone)
     2. the app default set by an admin       (Admin console → Localization)
     3. the browser's own locale / timezone   (the previous behaviour)

   Why store it server-side: on a shared field tablet the browser's locale isn't
   the person's, and a package due date that reads a day early because the device
   sits in another zone is a real scheduling problem — not a cosmetic one.

   Exposes:
     wpFormatDate(v)       → 3 Aug 2026            (date only)
     wpFormatDateTime(v)   → 3 Aug 2026, 14:07     (date + time)
     wpFormatTime(v)       → 14:07
     wpFormatNumber(v)     → locale-grouped number
     wpTimeZoneLabel()     → the zone in effect, for a UI hint
     wpPreferences()       → opens the preferences dialog
   All formatters take an ISO string, Date, or epoch ms, and return '' for empty
   input (never 'Invalid Date'), so they're safe to drop into a template. */
(function () {
  'use strict';

  function prefs() {
    var u = window.WP_USER || {};
    var f = window.WP_FLAGS || {};
    return {
      locale: (u.locale || f.default_locale || '') || undefined,
      timezone: (u.timezone || f.default_timezone || '') || undefined
    };
  }

  // A date-only value ('2026-08-03') is a calendar date, not an instant. Parsed as
  // UTC midnight by the platform, it can render as the previous day in a western
  // zone — so format these from their parts and never apply a timezone.
  var DATE_ONLY = /^\d{4}-\d{2}-\d{2}$/;

  function toDate(v) {
    if (v == null || v === '') return null;
    if (v instanceof Date) return isNaN(v.getTime()) ? null : v;
    if (typeof v === 'number') { var n = new Date(v); return isNaN(n.getTime()) ? null : n; }
    var s = String(v).trim();
    if (!s) return null;
    var d = new Date(s);
    return isNaN(d.getTime()) ? null : d;
  }

  function fmt(v, opts, forceNoTz) {
    var s = (typeof v === 'string') ? v.trim() : v;
    var dateOnly = (typeof s === 'string') && DATE_ONLY.test(s);
    var d = dateOnly ? new Date(s + 'T12:00:00') : toDate(s);   // noon: immune to ±12h shifts
    if (!d) return '';
    var p = prefs();
    var o = {};
    for (var k in opts) if (Object.prototype.hasOwnProperty.call(opts, k)) o[k] = opts[k];
    if (p.timezone && !dateOnly && !forceNoTz) o.timeZone = p.timezone;
    try {
      return new Intl.DateTimeFormat(p.locale, o).format(d);
    } catch (e) {
      // Bad locale/zone (e.g. a preference set before tzdata was available):
      // fall back to the platform default rather than showing nothing.
      try { return new Intl.DateTimeFormat(undefined, opts).format(d); } catch (e2) { return String(v); }
    }
  }

  window.wpFormatDate = function (v) {
    return fmt(v, { year: 'numeric', month: 'short', day: 'numeric' });
  };
  window.wpFormatDateTime = function (v) {
    return fmt(v, { year: 'numeric', month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' });
  };
  window.wpFormatTime = function (v) {
    return fmt(v, { hour: '2-digit', minute: '2-digit' });
  };
  window.wpFormatNumber = function (v, opts) {
    if (v == null || v === '' || isNaN(+v)) return '';
    try { return new Intl.NumberFormat(prefs().locale, opts || {}).format(+v); }
    catch (e) { return String(v); }
  };
  window.wpTimeZoneLabel = function () {
    var p = prefs();
    if (p.timezone) return p.timezone;
    try { return Intl.DateTimeFormat().resolvedOptions().timeZone || 'browser default'; }
    catch (e) { return 'browser default'; }
  };
  window.wpLocaleLabel = function () {
    var p = prefs();
    if (p.locale) return p.locale;
    try { return Intl.DateTimeFormat().resolvedOptions().locale || 'browser default'; }
    catch (e) { return 'browser default'; }
  };

  // ── preferences dialog ─────────────────────────────────────────────────────
  var COMMON_LOCALES = [
    ['', 'Browser default'],
    ['en-US', 'English (United States) — 8/3/2026, 2:07 PM'],
    ['en-GB', 'English (United Kingdom) — 03/08/2026, 14:07'],
    ['en-CA', 'English (Canada)'],
    ['es-MX', 'Español (México)'],
    ['es-US', 'Español (Estados Unidos)'],
    ['fr-CA', 'Français (Canada)'],
    ['de-DE', 'Deutsch (Deutschland)'],
    ['ja-JP', '日本語 (日本)'],
    ['ko-KR', '한국어 (대한민국)'],
    ['zh-TW', '中文 (台灣)']
  ];
  // Zones the fabs and offices actually sit in, offered before the full list.
  var COMMON_ZONES = [
    'America/Chicago', 'America/New_York', 'America/Denver', 'America/Phoenix',
    'America/Los_Angeles', 'America/Boise', 'Asia/Tokyo', 'Asia/Taipei',
    'Asia/Seoul', 'Asia/Singapore', 'Europe/Dublin', 'Europe/London', 'UTC'
  ];

  window.wpPreferences = function () {
    if (document.getElementById('wp-prefs-modal')) return;
    var u = window.WP_USER || {};
    var ov = document.createElement('div');
    ov.id = 'wp-prefs-modal';
    ov.style.cssText = 'position:fixed;inset:0;background:rgba(20,30,50,.5);display:flex;align-items:center;' +
      'justify-content:center;z-index:10002;padding:20px;font:14px/1.45 "IBM Plex Sans",-apple-system,' +
      'BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;';
    var fld = 'width:100%;padding:9px 10px;margin-bottom:4px;border:1px solid var(--cds-border-strong);border-radius:4px;font-size:14px;background:var(--cds-layer);';
    var lbl = 'display:block;font-size:12px;color:var(--cds-text-secondary);margin:14px 0 4px;font-weight:600;';
    var hint = 'font-size:11.5px;color:var(--cds-text-helper);margin-bottom:6px;';
    ov.innerHTML =
      '<div style="background:var(--cds-layer);color:var(--cds-text-primary);border-radius:10px;max-width:460px;width:100%;box-shadow:0 12px 40px rgba(20,30,50,.3);overflow:hidden;">' +
        '<div style="padding:14px 18px;border-bottom:1px solid var(--cds-border-subtle);font-weight:700;">Language &amp; time</div>' +
        '<div style="padding:4px 18px 16px;">' +
          '<div id="wp-prefs-msg" style="display:none;font-size:12.5px;padding:8px 10px;border-radius:6px;margin:12px 0 0;"></div>' +
          '<label style="' + lbl + '">Language &amp; number format</label>' +
          '<select id="wp-prefs-locale" style="' + fld + '"></select>' +
          '<div style="' + hint + '">Sets how dates and numbers are written. It does not translate the app.</div>' +
          '<label style="' + lbl + '">Time zone</label>' +
          '<select id="wp-prefs-tz" style="' + fld + '"></select>' +
          '<div style="' + hint + '">Times (MIMO windows, history, notifications) are shown in this zone. ' +
            'Calendar dates like a due date are never shifted.</div>' +
          '<div id="wp-prefs-preview" style="margin-top:14px;padding:10px 12px;background:var(--cds-layer-accent);border-radius:6px;font-size:12.5px;"></div>' +
        '</div>' +
        '<div style="padding:12px 18px;border-top:1px solid var(--cds-border-subtle);display:flex;gap:8px;justify-content:flex-end;">' +
          '<button type="button" id="wp-prefs-cancel" style="padding:8px 14px;border:1px solid var(--cds-border-strong);background:var(--cds-layer);border-radius:6px;cursor:pointer;font-weight:600;">Cancel</button>' +
          '<button type="button" id="wp-prefs-save" style="padding:8px 14px;border:none;background:var(--cds-interactive-01);color:var(--cds-text-on-color);border-radius:6px;cursor:pointer;font-weight:600;">Save</button>' +
        '</div>' +
      '</div>';
    function close() { var m = document.getElementById('wp-prefs-modal'); if (m) m.remove(); }
    function msg(text, ok) {
      var e = document.getElementById('wp-prefs-msg');
      e.style.display = 'block'; e.textContent = text;
      e.style.background = ok ? 'var(--wp-status-success-bg)' : 'var(--wp-status-error-bg)';
      e.style.color = ok ? 'var(--wp-status-success-text)' : 'var(--cds-support-error)';
    }
    ov.addEventListener('click', function (e) { if (e.target === ov) close(); });
    document.body.appendChild(ov);

    var locSel = document.getElementById('wp-prefs-locale');
    var tzSel = document.getElementById('wp-prefs-tz');
    var preview = document.getElementById('wp-prefs-preview');

    locSel.innerHTML = COMMON_LOCALES.map(function (p) {
      return '<option value="' + p[0] + '"' + (p[0] === (u.locale || '') ? ' selected' : '') + '>' + p[1] + '</option>';
    }).join('');
    // A stored locale that isn't in the shortlist stays selectable.
    if (u.locale && !COMMON_LOCALES.some(function (p) { return p[0] === u.locale; })) {
      locSel.add(new Option(u.locale, u.locale, true, true));
    }

    function fillZones(all) {
      var cur = u.timezone || '';
      var browser = '';
      try { browser = Intl.DateTimeFormat().resolvedOptions().timeZone || ''; } catch (e) {}
      var html = '<option value=""' + (cur ? '' : ' selected') + '>Browser default' +
        (browser ? ' (' + browser + ')' : '') + '</option>';
      html += '<optgroup label="Common">' + COMMON_ZONES.map(function (z) {
        return '<option value="' + z + '"' + (z === cur ? ' selected' : '') + '>' + z + '</option>';
      }).join('') + '</optgroup>';
      var rest = (all || []).filter(function (z) { return COMMON_ZONES.indexOf(z) < 0; });
      if (rest.length) {
        html += '<optgroup label="All time zones">' + rest.map(function (z) {
          return '<option value="' + z + '"' + (z === cur ? ' selected' : '') + '>' + z + '</option>';
        }).join('') + '</optgroup>';
      } else if (cur && COMMON_ZONES.indexOf(cur) < 0) {
        html += '<option value="' + cur + '" selected>' + cur + '</option>';
      }
      tzSel.innerHTML = html;
      updatePreview();
    }

    // Preview uses the picked values, not the saved ones, so the effect is visible
    // before committing.
    function updatePreview() {
      var l = locSel.value || undefined, z = tzSel.value || undefined;
      var now = new Date();
      var out;
      try {
        out = new Intl.DateTimeFormat(l, {
          year: 'numeric', month: 'short', day: 'numeric',
          hour: '2-digit', minute: '2-digit', timeZone: z
        }).format(now);
      } catch (e) { out = 'Not supported by this browser'; }
      preview.innerHTML = '<strong>Preview</strong><br>Right now: ' +
        String(out).replace(/[<>]/g, '') +
        '<br>A due date (2026-08-03) always reads: ' + window.wpFormatDate('2026-08-03');
    }
    locSel.addEventListener('change', updatePreview);
    tzSel.addEventListener('change', updatePreview);

    // The picker offers exactly what the server will accept.
    fetch('/api/timezones', { headers: { Accept: 'application/json' } })
      .then(function (r) { return r.ok ? r.json() : []; })
      .then(fillZones)
      .catch(function () { fillZones([]); });

    document.getElementById('wp-prefs-cancel').onclick = close;
    document.getElementById('wp-prefs-save').onclick = function () {
      var body = { locale: locSel.value || '', timezone: tzSel.value || '' };
      fetch('/api/auth/preferences', {
        method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body)
      })
        .then(function (r) { return r.json().catch(function () { return null; }).then(function (j) { return { ok: r.ok, status: r.status, j: j }; }); })
        .then(function (res) {
          if (!res.ok) { msg((res.j && res.j.detail) || ('Could not save (HTTP ' + res.status + ').'), false); return; }
          if (res.j && res.j.user) window.WP_USER = res.j.user;
          try { localStorage.setItem('wp_auth_cache', JSON.stringify({ user: window.WP_USER, at: Date.now() })); } catch (e) {}
          msg('Saved. Reloading so every date on the page agrees…', true);
          // Dates are formatted at render time all over the app; a reload is the
          // honest way to apply the change everywhere at once.
          setTimeout(function () { location.reload(); }, 700);
        })
        .catch(function () { msg('Could not reach the server.', false); });
    };
  };
})();