/* app.js - fetch only when Refresh is pressed */

(function () {
    function $(id) { return document.getElementById(id); }
  
    function parseQuery() {
      var out = {};
      var qs = window.location.search || "";
      if (qs.indexOf("?") === 0) qs = qs.substring(1);
      if (!qs) return out;
  
      var parts = qs.split("&");
      for (var i = 0; i < parts.length; i++) {
        var kv = parts[i].split("=");
        var k = decodeURIComponent(kv[0] || "").trim();
        var v = decodeURIComponent(kv.slice(1).join("=") || "").trim();
        if (k) out[k] = v;
      }
      return out;
    }
  
    function setQuery(params) {
      var keys = [];
      for (var k in params) {
        if (params.hasOwnProperty(k) && params[k] !== "" && params[k] != null) {
          keys.push(encodeURIComponent(k) + "=" + encodeURIComponent(params[k]));
        }
      }
      var qs = keys.length ? ("?" + keys.join("&")) : "";
      if (window.history && window.history.replaceState) {
        window.history.replaceState(null, "", window.location.pathname + qs);
      }
    }
  
    function findById(arr, id, fallback) {
      for (var i = 0; i < arr.length; i++) if (arr[i].id === id) return arr[i];
      return fallback || null;
    }
  
    function buildFeedUrl(feed, region) {
      var base;
      if (feed.type === "top") {
        base = "https://news.google.com/rss";
      } else if (feed.type === "topic" && feed.topic) {
        base = "https://news.google.com/rss/headlines/section/topic/" + encodeURIComponent(feed.topic);
      } else {
        base = "https://news.google.com/rss";
      }
  
      var q = [];
      q.push("hl=" + encodeURIComponent(region.hl));
      q.push("gl=" + encodeURIComponent(region.gl));
      q.push("ceid=" + encodeURIComponent(region.ceid));
      return base + "?" + q.join("&");
    }
  
    function fetchText(url, cb) {
      var xhr = new XMLHttpRequest();
      xhr.open("GET", url, true);
      xhr.timeout = 15000;
  
      xhr.onreadystatechange = function () {
        if (xhr.readyState !== 4) return;
        if (xhr.status >= 200 && xhr.status < 300) return cb(null, xhr.responseText);
        cb(new Error("HTTP " + xhr.status + " while fetching feed"));
      };
  
      xhr.ontimeout = function () {
        cb(new Error("Timed out while fetching feed"));
      };
  
      xhr.onerror = function () {
        cb(new Error("Network error while fetching feed"));
      };
  
      xhr.send(null);
    }
  
    function safeText(s) {
      if (s == null) return "";
      return String(s);
    }
  
    function escapeHtml(s) {
      s = safeText(s);
      return s
        .replace(/&/g, "&amp;")
        .replace(/</g, "&lt;")
        .replace(/>/g, "&gt;")
        .replace(/"/g, "&quot;")
        .replace(/'/g, "&#039;");
    }
  
    function escapeAttr(s) {
      return escapeHtml(s);
    }
  
    function stripHtml(s) {
      return safeText(s).replace(/<[^>]*>/g, "");
    }
  
    function parseRss(xmlText) {
      var items = [];
      var doc = null;
  
      if (window.DOMParser) {
        try {
          doc = new DOMParser().parseFromString(xmlText, "text/xml");
        } catch (e) {
          doc = null;
        }
      }
      if (!doc || !doc.getElementsByTagName) return items;
  
      var nodes = doc.getElementsByTagName("item");
      for (var i = 0; i < nodes.length; i++) {
        var it = nodes[i];
  
        function get(tag) {
          var n = it.getElementsByTagName(tag);
          if (!n || !n[0] || !n[0].textContent) return "";
          return n[0].textContent;
        }
  
        var title = get("title");
        var link = get("link");
        var pubDate = get("pubDate");
        var desc = get("description");
  
        var source = "";
        if (title.indexOf(" - ") !== -1) {
          var parts = title.split(" - ");
          source = parts[parts.length - 1];
        }
  
        items.push({
          title: title,
          link: link,
          pubDate: pubDate,
          source: source,
          description: desc
        });
      }
      return items;
    }
  
    function showError(msg, show) {
      var el = $("error");
      if (!el) return;
      if (show) {
        el.style.display = "block";
        el.textContent = msg;
      } else {
        el.style.display = "none";
        el.textContent = "";
      }
    }
  
    function renderItems(items) {
      var host = $("items");
      host.innerHTML = "";
  
      if (!items || !items.length) {
        host.innerHTML =
          "<div class='item'><span class='title'>No items.</span>" +
          "<div class='meta'>Press Refresh to load.</div></div>";
        return;
      }
  
      var html = [];
      for (var i = 0; i < items.length; i++) {
        var it = items[i];
  
        html.push("<div class='item'>");
        html.push(
          "<a class='title' href='" + escapeAttr(it.link) + "' target='_blank' rel='noopener noreferrer'>" +
            escapeHtml(it.title) +
          "</a>"
        );
  
        var meta = [];
        if (it.source) meta.push(escapeHtml(it.source));
        if (it.pubDate) meta.push(escapeHtml(it.pubDate));
        if (meta.length) html.push("<div class='meta'>" + meta.join(" · ") + "</div>");
  
        var snippet = stripHtml(safeText(it.description)).replace(/\s+/g, " ").trim();
        if (snippet.length > 220) snippet = snippet.substring(0, 220) + "...";
        if (snippet) html.push("<div class='desc'>" + escapeHtml(snippet) + "</div>");
  
        html.push("</div>");
      }
  
      host.innerHTML = html.join("");
    }
  
    function buildSelectOptions(selectEl, arr, selectedId) {
      selectEl.innerHTML = "";
      for (var i = 0; i < arr.length; i++) {
        var o = document.createElement("option");
        o.value = arr[i].id;
        o.textContent = arr[i].label;
        if (arr[i].id === selectedId) o.selected = true;
        selectEl.appendChild(o);
      }
    }
  
    function getCurrentSelection() {
      var feeds = window.NEWS_FEEDS || [];
      var regions = window.NEWS_REGIONS || [];
  
      var feedId = $("feedSelect").value;
      var regionId = $("regionSelect").value;
  
      var feed = findById(feeds, feedId, feeds[0] || null);
      var region = findById(regions, regionId, regions[0] || null);
  
      return { feed: feed, region: region };
    }
  
    function syncUrlToSelection() {
      setQuery({ feed: $("feedSelect").value, region: $("regionSelect").value });
    }
  
    function requestNews() {
      var sel = getCurrentSelection();
      if (!sel.feed || !sel.region) {
        showError("feeds.js is missing NEWS_FEEDS or NEWS_REGIONS.", true);
        return;
      }
  
      syncUrlToSelection();
      showError("", false);
  
      var feedUrl = buildFeedUrl(sel.feed, sel.region);
  
      var proxyBase = window.NEWS_PROXY_BASE || "";
      var fetchUrl = proxyBase ? (proxyBase + encodeURIComponent(feedUrl)) : feedUrl;
  
      fetchText(fetchUrl, function (err, txt) {
        if (err) {
          showError(
            "Could not load feed. If this is CORS, set NEWS_PROXY_BASE in feeds.js. Details: " + err.message,
            true
          );
          renderItems([]);
          return;
        }
        renderItems(parseRss(txt));
      });
    }
  
    window.addEventListener("DOMContentLoaded", function () {
      var feeds = window.NEWS_FEEDS || [];
      var regions = window.NEWS_REGIONS || [];
  
      if (!feeds.length || !regions.length) {
        showError("No feeds/regions configured. Check feeds.js.", true);
        renderItems([]);
        return;
      }
  
      var q = parseQuery();
      var feedId = q.feed || window.NEWS_DEFAULT_FEED_ID || feeds[0].id;
      var regionId = q.region || window.NEWS_DEFAULT_REGION_ID || regions[0].id;
  
      buildSelectOptions($("feedSelect"), feeds, feedId);
      buildSelectOptions($("regionSelect"), regions, regionId);
  
      // Keep URL updated when selecting, but DO NOT request.
      $("feedSelect").addEventListener("change", syncUrlToSelection);
      $("regionSelect").addEventListener("change", syncUrlToSelection);
  
      $("refreshBtn").addEventListener("click", requestNews);
  
      // No auto-request on load.
      renderItems([]);
      syncUrlToSelection();
    });
  })();