support for ankhbot commands, static commands, cooldowns, implemented fun/ham facts

lib/cooldowns.js

@@ -0,0 +1,48 @@
+module.exports = {
+  get: isOnCooldown,
+  set: placeOnCooldown
+};
+
+const memcache = require('memcache'),
+  md5 = require('md5'),
+  keyPrefix = 'cd';
+
+const cache = new memcache.Client();
+cache.on('error', console.error);
+cache.connect();
+
+// Given a cooldownTime in seconds and a command, returns false if the command is not on cooldown
+// returns the time in seconds until the command will be ready again otherwise
+function isOnCooldown(command, cooldownTime, callback)
+{
+  return new Promise((resolve, reject) => {
+    let now = Date.now();
+    let onCooldown = false;
+    let key = keyPrefix + md5(command);
+
+    cache.get(key, function(err, timeUsed) {
+      if (err) reject(err);
+
+      if (timeUsed !== null) {
+        // Command was recently used, check timestamp to see if it's on cooldown
+        if ((now - timeUsed) <= (cooldownTime*1000)) {
+          // Calculate how much longer it's on cooldown
+          onCooldown = ((cooldownTime*1000) - (now - timeUsed))/1000;
+        }
+      }
+
+      resolve(onCooldown);
+    });
+  });
+}
+
+// Places a command on cooldown for cooldownTime (in seconds)
+function placeOnCooldown(command, cooldownTime)
+{
+  let key = keyPrefix + md5(command);
+  return cache.set(key, Date.now(), handleCacheSet, cooldownTime);
+}
+
+function handleCacheSet(error, result) {}
+
+process.on('exit', (code) => {cache.close()});