(function () {

  // ============================================================
  // CONFIG
  // ============================================================
  const PROD_URL    = 'https://www.modernanimal.com/v3/public/';
  const STAGING_URL = 'https://staging.modernanimal.com/v3/public/';
  const CORS_PROXY  = 'https://ma-cors-proxy.info-e9b.workers.dev';
  const AUTH_TOKEN  = '10dd78c8441ed4079f2b21e8e17690e7c3122151';
  const HOURS_LABEL = '8am – 6pm';
  const NO_AVAIL    = 'No availability this week';

  const ALL_DAYS      = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'];
  const JS_DAY_TO_IDX = [6, 0, 1, 2, 3, 4, 5];

  // ============================================================
  // URL ROUTING
  // ============================================================
  const hostname = window.location.hostname;
  let targetURL;
  if (hostname === 'www.modernanimal.com' || hostname === 'modernanimal.com') {
    targetURL = PROD_URL;
  } else if (hostname === 'staging.modernanimal.com') {
    targetURL = STAGING_URL;
  } else {
    targetURL = CORS_PROXY;
  }

  // ============================================================
  // ENTRY
  // ============================================================
  document.querySelectorAll('[data-clinic-hours]').forEach(initWidget);

  function initWidget(el) {
    const locationId = el.dataset.locationId;
    const hoursEl    = el.querySelector('[data-hours-days-time]');

    if (!locationId || !hoursEl) return;

    const { startGte, endLte } = getCurrentWeekRange();

    fetchOpenDays(locationId, startGte, endLte)
      .then(function (days) {
        if (days.length === 0) {
          hoursEl.innerHTML = NO_AVAIL;
        } else {
          hoursEl.innerHTML = formatDays(days) + '<br>' + HOURS_LABEL;
        }
      })
      .catch(function () {
        // fail silently — static HTML left untouched
      });
  }

  // ============================================================
  // API
  // ============================================================
  async function fetchOpenDays(locationId, startGte, endLte) {
    const payload = {
      query: `
        query GetSlots($startGte: DateTime!, $endLte: DateTime!, $locationIds: [ID!]) {
          slots(
            filters: {
              start: { gte: $startGte }
              end: { lte: $endLte }
              location: { id: { inList: $locationIds } }
              published: true
            }
            order: { start: ASC }
          ) {
            start
          }
        }
      `,
      variables: { startGte, endLte, locationIds: [locationId] }
    };

    const res = await fetch(targetURL, {
      method: 'POST',
      headers: {
        'Content-Type':  'application/json',
        'Accept':        '*/*',
        'Authorization': `Bearer ${AUTH_TOKEN}`
      },
      body: JSON.stringify(payload)
    });

    if (!res.ok) throw new Error('API error ' + res.status);

    const json  = await res.json();
    const slots = json?.data?.slots ?? [];

    const daySet = new Set();
    slots.forEach(function (s) {
      daySet.add(JS_DAY_TO_IDX[new Date(s.start).getDay()]);
    });

    return ALL_DAYS.filter(function (_, i) { return daySet.has(i); });
  }

  // ============================================================
  // DATE HELPERS
  // ============================================================
  function getCurrentWeekRange() {
    const now   = new Date();
    const jsDay = now.getDay();
    const toMon = jsDay === 0 ? -6 : 1 - jsDay;
    const mon   = new Date(now);
    mon.setDate(now.getDate() + toMon);
    mon.setHours(0, 0, 0, 0);

    const sun = new Date(mon);
    sun.setDate(mon.getDate() + 6);
    sun.setHours(23, 59, 59, 999);

    return {
      startGte: toISOWithOffset(mon),
      endLte:   toISOWithOffset(sun)
    };
  }

  function toISOWithOffset(date) {
    const pad    = n => String(n).padStart(2, '0');
    const off    = -date.getTimezoneOffset();
    const sign   = off >= 0 ? '+' : '-';
    const absOff = Math.abs(off);
    return (
      date.getFullYear() + '-' +
      pad(date.getMonth() + 1) + '-' +
      pad(date.getDate()) + 'T' +
      pad(date.getHours()) + ':' +
      pad(date.getMinutes()) + ':' +
      pad(date.getSeconds()) +
      sign + pad(Math.floor(absOff / 60)) + ':' + pad(absOff % 60)
    );
  }

  // ============================================================
  // DAY FORMATTING
  //
  //   3+ consecutive → dash:       Mon–Fri
  //   pair           → comma:      Mon, Tue
  //   singles        → comma list, & before last (no Oxford comma)
  //
  //   Mon–Fri                     → Mon–Fri
  //   Mon Tue Wed Fri             → Mon–Wed & Fri
  //   Mon Tue Thu Fri             → Mon, Tue, Thu & Fri
  //   Mon Tue Thu Sat Sun         → Mon, Tue, Thu, Sat & Sun
  // ============================================================
  function formatDays(days) {
    if (!days || days.length === 0) return '';

    const indices = days.map(function (d) { return ALL_DAYS.indexOf(d); });

    const runs = [];
    let s = indices[0], e = indices[0];
    for (let i = 1; i < indices.length; i++) {
      if (indices[i] === e + 1) {
        e = indices[i];
      } else {
        runs.push([s, e]);
        s = e = indices[i];
      }
    }
    runs.push([s, e]);

    const tokens = runs.map(function ([s, e]) {
      const len = e - s + 1;
      if (len >= 3) return ALL_DAYS[s] + ' – ' + ALL_DAYS[e];
      if (len === 2) return ALL_DAYS[s] + ', ' + ALL_DAYS[e];
      return ALL_DAYS[s];
    });

    if (tokens.length === 1) return tokens[0];
    return tokens.slice(0, -1).join(', ') + ' & ' + tokens[tokens.length - 1];
  }

})();