Skip existing local submissions

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

lib/commands/submission.js

@@ -24,7 +24,7 @@ function getSubmissionDone(e, msg, problem, cb) {
   console.log(sprintf('[%3d] %-60s %s',
         problem.id,
         problem.name,
-        (e ? chalk.red('ERROR: ' + e) : chalk.yellow.underline(msg))
+        (e ? chalk.red('ERROR: ' + e) : msg)
         ));
   if (cb) cb(e);
 }
@@ -45,14 +45,22 @@ function getSubmission(problem, cb) {
     // if no accepted, use the latest non-accepted one
     submission = submission || submissions[0];
 
+    var filename = sprintf('%s.%s.%s%s',
+        problem.key,
+        submission.id,
+        problem.state,
+        h.langToExt(submission.lang));
+
+    // skip the existing cached submissions
+    if (fs.existsSync(filename)) {
+      return done(null, chalk.underline(filename));
+    }
+
     core.getSubmission(submission, function(e, submission) {
       if (e) return done(e);
 
-      var f = sprintf('%s.%s.%s%s', problem.key, submission.id,
-                      problem.state, h.langToExt(submission.lang));
-      fs.writeFileSync(f, submission.code);
-
-      done(null, f);
+      fs.writeFileSync(filename, submission.code);
+      done(null, chalk.yellow.underline(filename));
     });
   });
 }