initial

background.js

@@ -0,0 +1,79 @@
+(function (root) {
+  "use strict";
+
+  function createBackgroundController(api) {
+    const tabStates = new Map();
+
+    function validTabId(tabId) {
+      return Number.isInteger(tabId) && tabId >= 0;
+    }
+
+    async function broadcast(tabId, enabled) {
+      try {
+        await api.tabs.sendMessage(tabId, {
+          type: "glagolify:set-enabled",
+          enabled
+        });
+        return true;
+      } catch (error) {
+        return false;
+      }
+    }
+
+    api.runtime.onMessage.addListener((message, sender) => {
+      if (!message || typeof message.type !== "string") {
+        return undefined;
+      }
+
+      if (message.type === "glagolify:document-ready") {
+        const tabId = sender && sender.tab && sender.tab.id;
+        return Promise.resolve({
+          enabled: validTabId(tabId) && tabStates.get(tabId) === true
+        });
+      }
+
+      if (message.type === "glagolify:get-tab-state") {
+        const tabId = message.tabId;
+        if (!validTabId(tabId)) {
+          return Promise.resolve({ enabled: false, available: false });
+        }
+
+        const enabled = tabStates.get(tabId) === true;
+        return broadcast(tabId, enabled).then((available) => ({ enabled, available }));
+      }
+
+      if (message.type === "glagolify:set-tab-enabled") {
+        const tabId = message.tabId;
+        if (!validTabId(tabId) || typeof message.enabled !== "boolean") {
+          return Promise.resolve({ enabled: false, available: false });
+        }
+
+        tabStates.set(tabId, message.enabled);
+        return broadcast(tabId, message.enabled).then((available) => ({
+          enabled: message.enabled,
+          available
+        }));
+      }
+
+      return undefined;
+    });
+
+    api.tabs.onRemoved.addListener((tabId) => {
+      tabStates.delete(tabId);
+    });
+
+    return { tabStates, broadcast };
+  }
+
+  const exported = Object.freeze({ createBackgroundController });
+
+  if (typeof browser === "object" && browser.runtime && browser.tabs) {
+    createBackgroundController(browser);
+  }
+
+  if (typeof module === "object" && module.exports) {
+    module.exports = exported;
+  }
+
+  root.GlagolifyBackground = exported;
+})(typeof globalThis === "object" ? globalThis : this);