(function () {
    function $(id) { return document.getElementById(id); }
  
    function showResults(show) {
      var r = $("results");
      if (r) r.style.display = show ? "" : "none";
    }
  
    function escapeHtml(str) {
      return String(str)
        .replace(/&/g, "&")
        .replace(/</g, "&lt;")
        .replace(/>/g, "&gt;")
        .replace(/"/g, "&quot;")
        .replace(/'/g, "&#039;");
    }
  
    function getParam(name) {
      var qs = window.location.search || "";
      qs = qs.replace(/^\?/, "");
      if (!qs) return "";
      var parts = qs.split("&");
      for (var i = 0; i < parts.length; i++) {
        var kv = parts[i].split("=");
        var k = decodeURIComponent(kv[0] || "");
        if (k === name) return decodeURIComponent((kv[1] || "").replace(/\+/g, " "));
      }
      return "";
    }
  
    function xhrJson(url, accept, cb) {
      try {
        var x = new XMLHttpRequest();
        x.open("GET", url, true);
        if (accept) x.setRequestHeader("Accept", accept);
        x.onreadystatechange = function () {
          if (x.readyState !== 4) return;
          if (x.status >= 200 && x.status < 300) {
            var data;
            try { data = JSON.parse(x.responseText); }
            catch (e) { return cb("Bad JSON from: " + url); }
            return cb(null, data);
          }
          cb("HTTP " + x.status + " from: " + url);
        };
        x.send(null);
      } catch (e2) {
        cb("Request failed: " + e2.message);
      }
    }
  
    function isLatLon(s) {
      return /^\s*-?\d+(\.\d+)?\s*,\s*-?\d+(\.\d+)?\s*$/.test(s);
    }
  
    function parseLatLon(s) {
      var parts = s.split(",");
      return { lat: parseFloat(parts[0]), lon: parseFloat(parts[1]) };
    }
  
    function isZip(s) {
      return /^\s*\d{5}\s*$/.test(s);
    }
  
    // Resolve user input to lat/lon
    // - lat,lon => direct
    // - ZIP => zippopotam.us (for coordinates)
    // - City, ST => OpenStreetMap Nominatim (for coordinates)
    function resolveLocation(q, cb) {
      q = (q || "").replace(/^\s+|\s+$/g, "");
      if (!q) return cb("Empty query");
  
      if (isLatLon(q)) {
        var ll = parseLatLon(q);
        return cb(null, { input: q, display: q, lat: ll.lat, lon: ll.lon });
      }
  
      if (isZip(q)) {
        var zip = q.replace(/\s+/g, "");
        var url = "https://api.zippopotam.us/us/" + encodeURIComponent(zip);
        return xhrJson(url, "application/json", function (err, data) {
          if (err) return cb("Could not resolve ZIP to coordinates. " + err);
          try {
            var place = data.places && data.places[0];
            var lat = parseFloat(place.latitude);
            var lon = parseFloat(place.longitude);
            var city = place["place name"];
            var st = place["state abbreviation"] || place.state;
            return cb(null, {
              input: q,
              display: (city && st) ? (city + ", " + st + " " + zip) : zip,
              lat: lat,
              lon: lon
            });
          } catch (e) {
            cb("ZIP lookup returned unexpected data.");
          }
        });
      }
  
      var nom = "https://nominatim.openstreetmap.org/search?format=json&limit=1&countrycodes=us&q=" + encodeURIComponent(q);
      xhrJson(nom, "application/json", function (err, arr) {
        if (err) return cb("Could not resolve city/state to coordinates. " + err);
        if (!arr || !arr.length) return cb("No results for: " + q);
  
        var r = arr[0];
        return cb(null, {
          input: q,
          display: r.display_name || q,
          lat: parseFloat(r.lat),
          lon: parseFloat(r.lon)
        });
      });
    }
  
    function cToF(c) {
      if (c === null || c === undefined) return null;
      return (c * 9 / 5) + 32;
    }
  
    function fmtNum(n) {
      if (n === null || n === undefined || isNaN(n)) return "—";
      return String(Math.round(n));
    }
  
    function fmtLatLon(lat, lon) {
      function f(x) { return (Math.round(x * 10000) / 10000).toFixed(4); }
      return f(lat) + ", " + f(lon);
    }
  
    function renderForecast(periods) {
      var wrap = $("forecast");
      if (!wrap) return;
  
      if (!periods || !periods.length) {
        wrap.innerHTML = "<p>No forecast available.</p>";
        return;
      }
  
      var max = Math.min(periods.length, 8);
      var html = "";
  
      for (var i = 0; i < max; i++) {
        var p = periods[i];
  
        var name = escapeHtml(p.name || "");
        var icon = escapeHtml(p.icon || "");
        var temp = (p.temperature !== null && p.temperature !== undefined)
          ? (escapeHtml(String(p.temperature)) + "&deg;" + escapeHtml(p.temperatureUnit || ""))
          : "—";
        var shortF = escapeHtml(p.shortForecast || "");
        var detail = escapeHtml(p.detailedForecast || "");
  
        html += "<div class='forecastItem'>";
        html += "<h3>" + name + "</h3>";
        if (icon) html += "<img src='" + icon + "' alt='Forecast Icon'/>";
        html += "<p><b>" + temp + "</b></p>";
        html += "<p>" + shortF + "</p>";
        html += "<p style='max-width: 700px; margin-left:auto; margin-right:auto;'>" + detail + "</p>";
        html += "</div><hr>";
      }
  
      wrap.innerHTML = html;
    }
  
    function loadWeather(lat, lon, resolvedDisplay) {
      showResults(false);
  
      var pointsUrl = "https://api.weather.gov/points/" + lat + "," + lon;
  
      xhrJson(pointsUrl, "application/geo+json", function (err, points) {
        if (err) {
          // No status box; just hide results
          showResults(false);
          return;
        }
  
        var props = (points && points.properties) ? points.properties : {};
        var rel = props.relativeLocation && props.relativeLocation.properties ? props.relativeLocation.properties : null;
  
        var city = rel && rel.city ? rel.city : "";
        var state = rel && rel.state ? rel.state : "";
  
        var placeText = (city && state) ? (city + ", " + state) : (resolvedDisplay || (lat + "," + lon));
        $("placeTitle").innerHTML = escapeHtml(placeText);
        $("latlon").innerHTML = escapeHtml(fmtLatLon(lat, lon));
  
        var forecastUrl = props.forecast;
        var stationsUrl = props.observationStations || null;
  
        if (!forecastUrl) {
          showResults(false);
          return;
        }
  
        // 1) Forecast
        xhrJson(forecastUrl, "application/geo+json", function (errF, forecast) {
          if (errF) {
            showResults(false);
            return;
          }
  
          var periods = forecast && forecast.properties && forecast.properties.periods ? forecast.properties.periods : [];
          renderForecast(periods);
  
          // 2) Current conditions (optional)
          if (!stationsUrl) {
            $("tempNow").innerHTML = "—";
            $("humidity").innerHTML = "—";
            $("wind").innerHTML = "—";
            $("observedAt").innerHTML = "—";
            showResults(true);
            return;
          }
  
          xhrJson(stationsUrl, "application/geo+json", function (errS, stations) {
            if (errS) {
              $("tempNow").innerHTML = "—";
              $("humidity").innerHTML = "—";
              $("wind").innerHTML = "—";
              $("observedAt").innerHTML = "—";
              showResults(true);
              return;
            }
  
            var feat = stations && stations.features && stations.features.length ? stations.features[0] : null;
            var stationId = feat && feat.id ? feat.id : null;
  
            if (!stationId) {
              $("tempNow").innerHTML = "—";
              $("humidity").innerHTML = "—";
              $("wind").innerHTML = "—";
              $("observedAt").innerHTML = "—";
              showResults(true);
              return;
            }
  
            var obsUrl = stationId.replace(/\/$/, "") + "/observations/latest";
            xhrJson(obsUrl, "application/geo+json", function (errO, obs) {
              if (errO) {
                $("tempNow").innerHTML = "—";
                $("humidity").innerHTML = "—";
                $("wind").innerHTML = "—";
                $("observedAt").innerHTML = "—";
                showResults(true);
                return;
              }
  
              var op = obs && obs.properties ? obs.properties : {};
  
              // temperature is Celsius
              var c = op.temperature && op.temperature.value !== null ? op.temperature.value : null;
              var f = c !== null ? cToF(c) : null;
  
              var humidity = op.relativeHumidity && op.relativeHumidity.value !== null ? op.relativeHumidity.value : null;
  
              // windSpeed meters/sec => mph
              var windMs = op.windSpeed && op.windSpeed.value !== null ? op.windSpeed.value : null;
              var windMph = (windMs !== null) ? (windMs * 2.236936) : null;
  
              var windDir = op.windDirection && op.windDirection.value !== null ? op.windDirection.value : null;
              var ts = op.timestamp || "—";
  
              $("tempNow").innerHTML =
                (f !== null && c !== null)
                  ? (fmtNum(f) + "&deg;F (" + fmtNum(c) + "&deg;C)")
                  : "—";
  
              $("humidity").innerHTML = (humidity !== null) ? (fmtNum(humidity) + "%") : "—";
              $("wind").innerHTML =
                (windMph !== null && windDir !== null)
                  ? (fmtNum(windMph) + " mph @ " + fmtNum(windDir) + "&deg;")
                  : "—";
  
              $("observedAt").innerHTML = escapeHtml(ts);
  
              showResults(true);
            });
          });
        });
      });
    }
  
    window.addEventListener("DOMContentLoaded", function () {
      var q = getParam("q");
  
      if (!q) {
        $("q").value = "";
        showResults(false);
        return;
      }
  
      $("q").value = q;
  
      resolveLocation(q, function (err, loc) {
        if (err) {
          showResults(false);
          return;
        }
        loadWeather(loc.lat, loc.lon, loc.display);
      });
    });
  })();