implement ADD_QUOTA admin decree

lib/decrees.js

@@ -71,11 +71,37 @@ commands.UPDATE_DEFAULT_STORAGE = function (Env, args) {
     return true;
 };
 
-//var Quota = require("./commands/quota");
+var Quota = require("./commands/quota");
+var Keys = require("./keys");
 
+// CryptPad_AsyncStore.rpc.send('ADMIN', [ 'ADMIN_DECREE', ['ADD_QUOTA', ['[user@box:3000/VzeS4vP1DF+tXGuq1i50DKYuBL+09Yqy8kGxoUKRzhA=]', { limit: 2 * 1024 * 1024 * 1024, plan: 'buddy', note: "you're welcome" } ] ] ], console.log)
 commands.ADD_QUOTA = function (Env, args) {
-    args = args;
-    throw new Error("NOT_IMPLEMENTED");
+    if (!Array.isArray(args) || args.length !== 2) {
+        throw new Error("INVALID_ARGS");
+    }
+
+    var publicSigningKey = args[0];
+    // this might throw, but that's fine
+    var user = Keys.parseUser(publicSigningKey);
+    if (!user || !user.pubkey || user.pubkey.length !== 44) {
+        throw new Error("INVALID_ARGS");
+    }
+
+    // make sure you're not overwriting an existing limit
+    if (Env.customLimits[user.pubkey]) {
+        throw new Error("EEXISTS");
+    }
+
+    var limit = args[1];
+    if (!Quota.isValidLimit(limit)) { // do we really want this?
+        throw new Error("INVALID_ARGS");
+    }
+
+    // map the new limit to the user's unsafeKey
+    Env.customLimits[user.pubkey] = limit;
+    Env.limits[user.pubkey] = limit;
+
+    return true;
 };
 
 commands.RM_QUOTA = function (Env, args) {