Add background script; implement custom build system

.gitignore

@@ -10,4 +10,5 @@ pom.xml.asc
 .hgignore
 .hg/
 out/
-ext/main.js
+ext/content.js
+ext/background.js

ext/manifest.json

@@ -11,15 +11,16 @@
         {
             "matches": ["<all_urls>"],
             "js": [
-                "main.js"
+                "content.js"
             ]
         }
     ],
+    "background": {
+        "scripts": ["background.js"]
+    },
     "browser_action": {
-        "default_icon": {
-            "16": "icons/icon.svg",
-            "32": "icons/icon.svg"
-        }
+        "default_icon": "icons/icon.svg",
+        "default_title": "Looped In"
     },
     "content_security_policy": "script-src 'self'; object-src 'self'; connect-src 'self' http://hn.algolia.com"
 }

project.clj

@@ -7,9 +7,6 @@
                  [org.clojure/clojurescript "1.9.946"]
                  [org.clojure/core.async "0.3.465"]
                  [cljs-ajax "0.7.3"]]
-  :plugins [[lein-cljsbuild "1.1.7"]]
-  :cljsbuild {:builds
-              [{:source-paths ["src"]
-                :compiler {:output-to "ext/main.js"
-                           :output-dir "out"
-                           :optimizations :whitespace}}]})
+  :source-paths ["src/build"]
+  :main looped-in.build
+  :aliases {"build" ["run"]})

src/background/looped_in/background.cljs

@@ -0,0 +1,11 @@
+(ns looped-in.background)
+
+(enable-console-print!)
+
+(-> js/browser
+    (.-runtime)
+    (.-onMessage)
+    (.addListener (fn [msg]
+                    (-> js/browser
+                        (.-browserAction)
+                        (.setBadgeText (.-numComments msg))))))

src/build/looped_in/build.clj

@@ -0,0 +1,12 @@
+(ns looped-in.build
+  (:require [cljs.build.api :refer [build]]))
+
+(defn -main [& args]
+  (build "src/content" {:output-to "ext/content.js"
+                        :output-dir "out"
+                        :optimizations :whitespace
+                        :pretty-print true})
+  (build "src/background" {:output-to "ext/background.js"
+                           :output-dir "out"
+                           :optimizations :whitespace
+                           :pretty-print true}))

src/content/looped_in/content.cljs

@@ -0,0 +1,44 @@
+(ns looped-in.content
+  (:require-macros [cljs.core.async.macros :refer [go]])
+  (:require [ajax.core :refer [GET]]
+            [cljs.core.async :as async :refer [chan <! >!]]))
+
+(enable-console-print!)
+
+(defn fetch-submission
+  "Fetches submissions from Hacker News by `url`"
+  [url]
+  (let [response-chan (chan)]
+    (GET "http://hn.algolia.com/api/v1/search"
+         {:params {"query" url
+                   "hitsPerPage" 1000
+                   "restrictSearchableAttributes" "url"}
+          :handler (fn [res] (go (>! response-chan res)))
+          :error-handler (fn [err] (go (>! response-chan err)))})
+    response-chan))
+
+(defn filter-response
+  "Filters a response from hn.algolia.com to give just the relevant results"
+  ;; TODO implement a cache by URL and timestamp that caches the results of the
+  ;; request and this method for 5 minutes using localStorage
+  [url response]
+  (let [{:strs [hits]} response]
+    (filter #(= (get % "url") url) hits)))
+
+(defn total-num-comments
+  "Returns the total number of comments from some hits"
+  [hits]
+  (reduce (fn [acc {:strs [num_comments]}] (+ acc num_comments)) 0 hits))
+
+(defn handle-hits
+  "Handles a filtered response"
+  [hits]
+  (js/console.log (clj->js hits))
+  (let [num-comments (total-num-comments hits)]
+    (-> js/browser
+        (.-runtime)
+        (.sendMessage #js {:numComments num-comments}))))
+
+(let [current-url (-> js/window (.-location) (.-href))
+      sub-chan (fetch-submission current-url)]
+  (go (handle-hits (filter-response current-url (<! sub-chan)))))

src/looped_in/core.cljs

@@ -1,22 +0,0 @@
-(ns looped-in.core
-  (:require-macros [cljs.core.async.macros :refer [go]])
-  (:require [ajax.core :refer [GET]]
-            [cljs.core.async :as async :refer [chan <! >!]]))
-
-(enable-console-print!)
-
-(defn fetch-submission
-  "Fetches submissions from Hacker News by `url`"
-  [url]
-  (let [response-chan (chan)]
-    (GET "http://hn.algolia.com/api/v1/search"
-         {:params {"query" url
-                   "hitsPerPage" 1000
-                   "restrictSearchableAttributes" "url"}
-          :handler (fn [res] (go (>! response-chan res)))
-          :error-handler (fn [err] (go (>! response-chan err)))})
-    response-chan))
-
-(let [current-url (-> js/window (.-location) (.-href))
-      sub-chan (fetch-submission current-url)]
-  (go (console.log (clj->js (<! sub-chan)))))