Implement 'list'

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

Author: skygragon

lib/cache.js

@@ -0,0 +1,29 @@
+var fs = require('fs');
+
+// try to save cache in user home.
+var BASE_DIR = (process.env.HOME || process.env.USERPROFILE) + '/.lc/';
+
+function getFullPath(k) {
+  if (!fs.existsSync(BASE_DIR))
+    fs.mkdirSync(BASE_DIR);
+
+  return BASE_DIR + k + '.json';
+}
+
+var cache = {};
+
+cache.get = function(k) {
+  var fullpath = getFullPath(k);
+  if (!fs.existsSync(fullpath))
+    return null;
+
+  var v = JSON.parse(fs.readFileSync(fullpath));
+  return v;
+}
+
+cache.set = function(k, v) {
+  var fullpath = getFullPath(k);
+  fs.writeFileSync(fullpath, JSON.stringify(v));
+}
+
+module.exports = cache;

lib/commands/list.js

@@ -1,6 +1,8 @@
+var sprintf = require('underscore.string/sprintf');
+
 var cmd = {
   command: 'list [--cached|-c] [--undone|-D]',
-  desc: 'List all problems',
+  desc: 'List all problems.',
   builder: {
     cached: {
       alias: 'c',
@@ -14,8 +16,13 @@ var cmd = {
 };
 
 cmd.handler = function(argv) {
-  // TODO
-  console.log(argv);
+  var problems = require('../problems');
+  problems.getAll(function(err, items){
+    items.forEach(function(item){
+      console.log(sprintf('[%3d] %-60s %-6s (%s)',
+            item.id, item.name, item.level, item.percent));
+    });
+  });
 }
 
 module.exports = cmd;

lib/commands/show.js

@@ -1,6 +1,6 @@
 var cmd = {
   command: 'show <problem>',
-  desc: 'Show problem details',
+  desc: 'Show problem details.',
   builder: {
     problem: {
       describe: 'Problem name or number.'

lib/commands/update.js

@@ -1,6 +1,6 @@
 var cmd = {
   command: 'update [--cached|-c] [--all|-a]',
-  desc: 'Update problems list from leetcode',
+  desc: 'Update problems list from leetcode.',
   builder: {
     all: {
       alias: 'a',

lib/config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  BASE_URL: 'https://leetcode.com/',
+  PROBLEMS_URL: 'https://leetcode.com/problems/'
+};

lib/problems.js

@@ -0,0 +1,36 @@
+var cheerio = require('cheerio'),
+    request = require('request');
+
+var cache = require('./cache'),
+    config = require('./config');
+
+var problems = {};
+
+problems.getAll = function(cb) {
+  var items = cache.get('all');
+  if (items) return cb(null, items);
+
+  // cache miss, retrieve it now
+  request(config.PROBLEMS_URL, function(err, resp, body) {
+    if (err) return cb(err);
+    if (resp.statusCode != 200) return cb('Invalid HTTP response: ' + resp.statusCode);
+
+    var $ = cheerio.load(body);
+    items = $('#problemList tbody tr').map(function(){
+      var tds = $(this).children();
+      return {
+        id:      $(tds[1]).text(),
+        name:    $(tds[2]).children('a').text(),
+        link:    $(tds[2]).children('a').attr('href'),
+        percent: $(tds[3]).text(),
+        level:   $(tds[6]).text()
+      };
+    }).get();
+
+    cache.set('all', items);
+
+    return cb(null, items);
+  });
+};
+
+module.exports = problems;

package.json

@@ -29,6 +29,9 @@
   },
   "homepage": "https://github.com/skygragon/leetcode-cli#readme",
   "dependencies": {
+    "cheerio": "^0.20.0",
+    "request": "^2.74.0",
+    "underscore.string": "^3.3.4",
     "yargs": "^5.0.0"
   }
 }