[Plugin] enrich problem info.

* add discuss category id.

Signed-off-by: Eric Wang <[email protected]>

Author: skygragon

Diff for: lib/plugins/leetcode.js

@@ -131,8 +131,8 @@ plugin.getProblem = function(problem, cb) {
 
     var pageData;
     var r = /(var pageData[^;]+;)/m;
-    var result = body.match(r);
-    if (!result) {
+    var re = body.match(r);
+    if (!re) {
       var user = session.getUser();
       if (problem.locked && user.paid) {
         e = session.errors.EXPIRED;
@@ -142,12 +142,16 @@ plugin.getProblem = function(problem, cb) {
       return cb(e);
     }
 
-    eval(result[1]);
+    eval(re[1]);
     problem.templates = pageData.codeDefinition;
     problem.testcase = pageData.sampleTestCase;
     problem.testable = pageData.enableRunCode;
     problem.templateMeta = eval(pageData.metaData);
 
+    r = /https:\/\/discuss.leetcode.com\/category\/(\d+)/;
+    re = body.match(r);
+    if (re) problem.discuss = re[1];
+
     return cb(null, problem);
   });
 };