From 665c832058bff885465036788d5fd18932880a9f Mon Sep 17 00:00:00 2001
From: Sam Macbeth <sam@cliqz.com>
Date: Thu, 19 Nov 2020 15:23:47 +0100
Subject: [PATCH] Expose metrics to Ghostery extension via extension messaging.

---
 src/api.js                               | 14 ++++++++
 src/experiment_apis/ghostery_parent.js   |  5 +++
 src/experiment_apis/ghostery_schema.json | 10 ++++++
 src/manifest.json                        |  4 ++-
 src/metrics.js                           | 45 ++++++++++++++++++++++++
 5 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 src/api.js
 create mode 100644 src/metrics.js

diff --git a/src/api.js b/src/api.js
new file mode 100644
index 0000000..ec7d3cd
--- /dev/null
+++ b/src/api.js
@@ -0,0 +1,14 @@
+/**
+ * API for external communication from Ghostery browser extension
+ */
+
+const ALLOWED_ADDON_IDS = new Set(["firefox@ghostery.com"]);
+
+browser.runtime.onMessageExternal.addListener(async (message, sender) => {
+  if (!ALLOWED_ADDON_IDS.has(sender.id)) {
+    return false;
+  }
+  if (message === "getMetrics") {
+    return getMetrics();
+  }
+});
diff --git a/src/experiment_apis/ghostery_parent.js b/src/experiment_apis/ghostery_parent.js
index 43b9672..38ff6b6 100644
--- a/src/experiment_apis/ghostery_parent.js
+++ b/src/experiment_apis/ghostery_parent.js
@@ -34,6 +34,11 @@ global.ghostery = class extends ExtensionCommon.ExtensionAPI {
           const window = getWindow(windowId);
           window.gURLBar.value = query || '';
           window.gURLBar.focus();
+        },
+        isDefaultBrowser() {
+          const shell = Components.classes["@mozilla.org/browser/shell-service;1"]
+            .getService(Components.interfaces.nsIShellService)
+          return shell.isDefaultBrowser();
         }
       }
     }
diff --git a/src/experiment_apis/ghostery_schema.json b/src/experiment_apis/ghostery_schema.json
index de56e82..3c289b5 100644
--- a/src/experiment_apis/ghostery_schema.json
+++ b/src/experiment_apis/ghostery_schema.json
@@ -42,6 +42,16 @@
       "name": "query",
       "optional": true
     }]
+  },
+  {
+    "name": "isDefaultBrowser",
+    "type": "function",
+    "async": true,
+    "description": "Check if this is the OS's default browser",
+    "parameters": [],
+    "returns": {
+      "description": "true if this is the default browser"
+    }
   }
   ],
   "events": [
diff --git a/src/manifest.json b/src/manifest.json
index 35ef0bf..0ff2fba 100644
--- a/src/manifest.json
+++ b/src/manifest.json
@@ -11,7 +11,9 @@
       "token-pool.js",
       "sjcl.js",
       "background.js",
-      "choice-screen.js"
+      "choice-screen.js",
+      "metrics.js",
+      "api.js"
     ]
   },
   "content_scripts": [{
diff --git a/src/metrics.js b/src/metrics.js
new file mode 100644
index 0000000..02273c8
--- /dev/null
+++ b/src/metrics.js
@@ -0,0 +1,45 @@
+// limit engines we can send to the specific set we're interested in from search choice screen
+const searchEngineMap = {
+  "Ghostery Search": "ghostery",
+  Google: "google",
+  Bing: "bing",
+  StartPage: "sp",
+  Yahoo: "yahoo",
+};
+
+async function getMetrics() {
+  return {
+    ds: await getDefaultSearchEngine(),
+    db: await getIsDefaultBrowser(),
+  };
+}
+
+/**
+ * Get the name of the current default search engine (if it is in the searchEngineMap list).
+ * Returns "other" if the engine is not in the shortlist, and empty string if the search API is not
+ * available.
+ */
+async function getDefaultSearchEngine() {
+  if (browser.search) {
+    const engines = await browser.search.get();
+    const defaultSearchEngine = engines.find((s) => s.isDefault).name;
+    return searchEngineMap[defaultSearchEngine] || "other";
+  }
+  return "";
+}
+
+/**
+ * Get default browser state:
+ *  0 = unknown - API to check is missing
+ *  1 = not default browser
+ *  2 = is default browser
+ */
+async function getIsDefaultBrowser() {
+  if (browser.ghostery) {
+    if (await browser.ghostery.isDefaultBrowser()) {
+      return 2;
+    }
+    return 1;
+  }
+  return 0;
+}