Implement 'list -s -l'

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

Author: skygragon

.eslintrc.js

@@ -6,7 +6,8 @@ module.exports = {
       "no-multi-spaces": [2, { exceptions: { "SwitchCase": true }}],
       "no-unused-expressions": 1,
       "no-unused-vars": 1,
+      "no-warning-comments": 0,
       "quote-props": 1,
-      "require-jsdoc": 0,  // currently we don't need JSDoc
+      "require-jsdoc": 0,
     }
 };

lib/commands/list.js

@@ -5,12 +5,17 @@ var core = require('../core');
 var h = require('../helper');
 
 var cmd = {
-  command: 'list [--cached|-c] [--undone|-D]',
+  command: 'list [--level|-l] [--stat|-s] [--undone|-D]',
   desc:    'List all problems.',
   builder: {
-    cached: {
-      alias:    'c',
-      describe: 'List cached problems.'
+    level: {
+      alias:    'l',
+      choices:  ['easy', 'medium', 'hard', 'e', 'm', 'h'],
+      describe: 'Filter problems by level.'
+    },
+    stat: {
+      alias:    's',
+      describe: 'Show stats of the problems.'
     },
     undone: {
       alias:    'D',
@@ -23,17 +28,39 @@ cmd.handler = function(argv) {
   core.getProblems(function(e, problems) {
     if (e) return console.log('ERROR:', e);
 
+    var all = problems.length;
+
     if (argv.undone) {
       problems = _.filter(problems, function(x) {
         return x.state !== 'ac';
       });
     }
 
+    if (argv.level) {
+      problems = _.filter(problems, function(x) {
+        return x.level[0].toLowerCase() === argv.level[0];
+      });
+    }
+
+    var stat = {};
     problems.forEach(function(problem) {
+      stat[problem.level] = (stat[problem.level] || 0) + 1;
+      stat[problem.state] = (stat[problem.state] || 0) + 1;
+
       console.log(sprintf('%s [%3d] %-60s %-6s (%s)',
             h.prettyState(problem.state), problem.id,
             problem.name, problem.level, problem.percent));
     });
+
+    if (argv.stat) {
+      console.log();
+      console.log(sprintf('  All:  %-9d Listed: %-9d',
+            all, problems.length));
+      console.log(sprintf('  AC:   %-9d Not-AC: %-9d New:  %-9d',
+            (stat.ac || 0), (stat.notac || 0), (stat.None || 0)));
+      console.log(sprintf('  Easy: %-9d Medium: %-9d Hard: %-9d',
+            (stat.Easy || 0), (stat.Medium || 0), (stat.Hard || 0)));
+    }
   });
 };