Implement user login/logout.

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

Author: skygragon

lib/cache.js

@@ -14,16 +14,24 @@ var cache = {};
 
 cache.get = function(k) {
   var fullpath = getFullPath(k);
-  if (!fs.existsSync(fullpath))
-    return null;
+  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));
-}
+  return true;
+};
+
+cache.del = function(k) {
+  var fullpath = getFullPath(k);
+  if (!fs.existsSync(fullpath)) return false;
+
+  fs.unlinkSync(fullpath);
+  return true;
+};
 
 module.exports = cache;

lib/commands/user.js

@@ -0,0 +1,56 @@
+var prompt = require('prompt'),
+    util = require('util');
+
+var core = require('../core');
+
+var cmd = {
+  command: 'user [--login|-l] [--logout|-L]',
+  desc: 'Login/logout with leetcode account.',
+  builder: {
+    login: {
+      alias: 'l',
+      describe: 'Login leetcode.'
+    },
+    logout: {
+      alias: 'L',
+      describe: 'Logout leetcode.'
+    }
+  }
+};
+
+cmd.handler = function(argv) {
+  if (argv.login) {
+    // login
+    prompt.colors = false;
+    prompt.message = '';
+    prompt.start();
+    prompt.get([
+      { name: 'login', required: true },
+      { name: 'pass', required: true, hidden: true }
+    ], function(e, user){
+      if (e) return console.log('Login failed:', e);
+
+      core.login(user, function(e, user){
+        if (e) return console.log('Login failed:', e);
+
+        console.log('Successfully login as', user.name);
+      });
+    });
+  } else if (argv.logout) {
+    // logout
+    core.logout(null, function(e, user){
+      if (e) return console.log('Logout failed:', e);
+
+      console.log('Successfully logout as', user.name);
+    });
+  } else {
+    // show current user
+    core.getUser(function(e, user){
+      if (e) return console.log('ERROR:', e);
+
+      console.log('You are now login as', user.name);
+    });
+  }
+}
+
+module.exports = cmd;

lib/config.js

@@ -1,4 +1,5 @@
 module.exports = {
   BASE_URL:     'https://leetcode.com',
+  LOGIN_URL:    'https://leetcode.com/accounts/login/',
   PROBLEMS_URL: 'https://leetcode.com/problems/'
 };

lib/core.js

@@ -35,4 +35,28 @@ core.getProblem = function(keyword, cb) {
   });
 };
 
+core.login = function(user, cb) {
+  client.login(user, function(e, user){
+    if (e) return cb(e);
+
+    // FIXME: need expire all.json
+    cache.set('.user', user);
+    return cb(null, user);
+  });
+};
+
+core.logout = function(user, cb) {
+  user = cache.get('.user');
+  if (!cache.del('.user')) return cb('You are not login yet?');
+
+  return cb(null, user);
+}
+
+core.getUser = function(cb) {
+  var cached = cache.get('.user');
+  if (!cached) return cb('User not found! Please login first.');
+
+  return cb(null, cached);
+}
+
 module.exports = core;

lib/leetcode_client.js

@@ -9,7 +9,7 @@ var leetcode_client = {};
 leetcode_client.getProblems = function(cb) {
   request(config.PROBLEMS_URL, function(e, resp, body) {
     if (e) return cb(e);
-    if (resp.statusCode != 200) return cb('Invalid HTTP response: ' + resp.statusCode);
+    if (resp.statusCode != 200) return cb('HTTP failed:' + resp.statusCode);
 
     var $ = cheerio.load(body);
     var problems = $('#problemList tbody tr').map(function(){
@@ -36,7 +36,7 @@ leetcode_client.getProblems = function(cb) {
 leetcode_client.getProblem = function(problem, cb) {
   request(problem.link, function(e, resp, body){
     if (e) return cb(e);
-    if (resp.statusCode != 200) return cb('Invalid HTTP response: ' + resp.statusCode);
+    if (resp.statusCode != 200) return cb('HTTP failed:' + resp.statusCode);
 
     var $ = cheerio.load(body);
     var info = $('div[class="question-info text-info"] ul li strong');
@@ -49,4 +49,49 @@ leetcode_client.getProblem = function(problem, cb) {
   });
 };
 
+function getCookie(resp, name) {
+  var cookies = resp.headers['set-cookie'];
+  if (!cookies) return null;
+  for (var i=0; i<cookies.length; ++i) {
+    var sections = cookies[i].split(';');
+    for (var j=0; j<sections.length; ++j) {
+      var kv = sections[j].trim().split('=');
+      if (kv[0] == name) return kv[1];
+    }
+  }
+}
+
+leetcode_client.login = function(user, cb) {
+  request(config.LOGIN_URL, function(e, resp, body){
+    if (e) return cb(e);
+    if (resp.statusCode != 200) return cb('HTTP failed:' + resp.statusCode);
+
+    user.csrf = getCookie(resp, 'csrftoken');
+
+    var opts = {
+      url: config.LOGIN_URL,
+      headers: {
+        Origin: config.BASE_URL,
+        Referer: config.LOGIN_URL,
+        Cookie: 'csrftoken='+user.csrf+';'
+      },
+      form: {
+        csrfmiddlewaretoken: user.csrf,
+        login: user.login,
+        password: user.pass
+      }
+    };
+    request.post(opts, function(e, resp, body){
+      if (e) return cb(e);
+      if (resp.statusCode != 302) return cb('HTTP failed:' + resp.statusCode);
+
+      user.session_csrf = getCookie(resp, 'csrftoken');
+      user.session_id = getCookie(resp, 'PHPSESSID');
+      user.name = getCookie(resp, 'messages').match('Successfully signed in as ([^.]*)')[1];
+
+      return cb(null, user);
+    });
+  });
+};
+
 module.exports = leetcode_client;

package.json

@@ -30,6 +30,7 @@
   "homepage": "https://github.com/skygragon/leetcode-cli#readme",
   "dependencies": {
     "cheerio": "^0.20.0",
+    "prompt": "^1.0.0",
     "request": "^2.74.0",
     "sprintf-js": "^1.0.3",
     "underscore": "^1.8.3",