Create and Show Posts (#3)

* 📝 Update changelog (retroactive)

SORRY

* Add JSDoc

* Document twitter helper

* Add posts handler

* Remove cookies, set routes under /api

* Update readme for clearer callback instructions

* Redirect callback to login with token

* Add dasein paw helper

* Remove unused hostname

* Remove hostname, add expiration to config

* Rename expiration ttl

* Send TTL to posts handler

* Add redis dependency

* Add redis config to config file

* Add DASEIN_REDIS_HOST to env.dist

* Correct redis config structure

* Add redis db to compose

* Add redis to posts handler

* Update dasein paw file

* Git add uuid

* Add first iteration of post handlers

* Ignore docs in linter

* Ignore generated assets

* Ignore docs and assets

* Add frontend dependencies + more koa

* Add post creation to backend

* Adjust readme to show actual callback route

* Add npm build as part of docker process

* Configure babel

* Update paw

* Add webpack config

* Add frontend code

* List globals

4 files changed, 353 insertions, 52 deletions

diff --git a/lib/dasein.js b/lib/dasein.js
index 38654a4..3a537bd 100644
--- a/lib/dasein.js
+++ b/lib/dasein.js
@@ -1,17 +1,28 @@
 'use strict';
 
 const Koa = require('koa');
+const KoaBodyParser = require('koa-bodyparser');
 const KoaJwt = require('koa-jwt');
-const KoaStatic = require('koa-static');
 const KoaRoute = require('koa-route');
+const KoaSend = require('koa-send');
+const KoaStatic = require('koa-static');
+const Path = require('path');
 
 const AuthHandler = require('./handlers/auth');
+const PostsHandler = require('./handlers/posts');
 
 const internals = {};
 
 internals.k401Location = '/401.html';
 internals.kMainLocation = '/';
 
+/**
+ * The Dasein class is the main entry point for the application.
+ *
+ * @class Dasein
+ * @param {Dasein.tConfiguration} config the initialization options to
+ * extend the instance
+ */
 module.exports = internals.Dasein = class Dasein {
 
   constructor(config) {
@@ -19,6 +30,14 @@ module.exports = internals.Dasein = class Dasein {
     Object.assign(this, config);
   }
 
+  /**
+   * Initializes the application and starts listening. Also prints a
+   * nice robotic banner with information.
+   *
+   * @function run
+   * @memberof Dasein
+   * @instance
+   */
   run() {
 
     this._initializeServer();
@@ -28,15 +47,18 @@ module.exports = internals.Dasein = class Dasein {
     return Promise.resolve();
   }
 
+  // Initializes the Koa application and all the handlers.
+
   _initializeServer() {
 
-    this._app = Koa();
+    const self = this;
 
-    this._app.keys = this.cookieKeys;
+    this._app = Koa();
 
     this._app.use(KoaStatic(this.staticDirectory));
+    this._app.use(KoaBodyParser());
 
-    // Redirect all 401s to the 401 static page
+    // Error handler
 
     this._app.use(function * (next) {
 
@@ -44,51 +66,74 @@ module.exports = internals.Dasein = class Dasein {
         yield next;
       }
       catch (err) {
-        if (err.status === 401) {
-          return this.redirect(internals.k401Location);
+        this.status = err.status || 500;
+
+        const response = {
+          error: err.message,
+          status: this.status
+        };
+
+        if (response.status === 401) {
+          response.error === 'Protected resource, use Authorization header to get access';
         }
 
-        throw err;
+        this.body = response;
+
+        this.app.emit('error', err, this);
       }
     });
 
     this._app.use(KoaJwt({
       secret: this.jwt.secret,
-      passthrough: true,
-      cookie: this.jwt.cookieName
+      passthrough: true
     }));
 
-    // Handlers for Twitter Auth Related Routes
+    this._initializeAuthRoutes();
+    this._initializePostsRoutes();
+
+    this._app.use(function * () {
+
+      yield KoaSend(this, Path.join(self.staticDirectory, 'index.html'));
+    });
+
+  }
+
+  // Initialize routes for auth
+
+  _initializeAuthRoutes() {
 
     const authHandler = new AuthHandler({
-      hostname: this.hostname,
       jwt: this.jwt,
       twitter: this.twitter
     });
-    this._app.use(KoaRoute.get('/login', authHandler.login()));
-    this._app.use(KoaRoute.get('/login-callback', authHandler.callback()));
-    this._app.use(KoaRoute.get('/logout', authHandler.logout()));
+    this._app.use(KoaRoute.get('/api/auth/login', authHandler.login()));
+    this._app.use(KoaRoute.post('/api/auth/callback', authHandler.callback()));
+  }
 
-    // The index
+  // Initialize routes for posts
 
-    this._app.use(function * () {
+  _initializePostsRoutes() {
 
-      if (this.state.user) {
-        this.body = `<img src="${this.state.user.profile_image_url_https}"> Hello ${this.state.user.screen_name}`;
-        return;
-      }
-
-      this.body = 'Go to /login to login';
-      return;
+    const postsHandler = new PostsHandler({
+      ttl: this.ttl,
+      redis: this.redis
     });
+    this._app.use(KoaRoute.get('/api/posts', postsHandler.findAll()));
+    this._app.use(KoaRoute.get('/api/posts/:id', postsHandler.find()));
+    this._app.use(KoaRoute.post('/api/posts', postsHandler.create()));
+    this._app.use(KoaRoute.delete('/api/posts/:id', postsHandler.delete()));
+
   }
 
+  // Starts listening
+
   _startServer() {
 
     this._app.listen(this.port);
   }
 
   // Prints the banner.
+
   _printBanner() {
 
     console.log('        .');
diff --git a/lib/handlers/auth.js b/lib/handlers/auth.js
index d16e15d..1db9494 100644
--- a/lib/handlers/auth.js
+++ b/lib/handlers/auth.js
@@ -1,41 +1,63 @@
 'use strict';
 
 const Co = require('co');
-const TwitterHelper = require('../twitter_helper');
 const JsonWebToken = require('jsonwebtoken');
 const Pify = require('pify');
+const TwitterHelper = require('../twitter_helper');
 
 const internals = {};
 
 internals.kRedirectUrl = 'https://api.twitter.com/oauth/authenticate?oauth_token=';
-internals.kMainLocation = '/';
+internals.kLoginRedirect = '/login';
 
 internals.signJsonWebToken = Pify(JsonWebToken.sign);
 
+/**
+ * Handles the HTTP requests for auth related operations.
+ *
+ * @class AuthHandler
+ * @param {Dasein.tConfiguration} config The configuration to
+ * initialize.
+ */
 module.exports = internals.AuthHandler = class AuthHandler {
 
   constructor(config) {
 
     this._twitterHelper = new TwitterHelper(config.twitter);
     this._jwtConfig = config.jwt;
-    this._hostname = config.hostname;
   }
 
+  /**
+   * Triggers the twitter login flow. Redirects to twitter's oauth
+   * request page
+   *
+   * @function login
+   * @memberof AuthHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
   login() {
 
     const twitterHelper = this._twitterHelper;
 
     return function *handleLogin() {
 
-      if (this.state.user) {
-        return this.redirect(internals.kMainLocation);
-      }
-
       const requestToken = yield twitterHelper.getRequestToken();
-      this.redirect(`${internals.kRedirectUrl}${requestToken.oAuthToken}`);
+      const loginUrl = `${internals.kRedirectUrl}${requestToken.oAuthToken}`;
+
+      this.body = { loginUrl };
     };
   }
 
+  /**
+   * Handles twitter's callback. Fetches the oAuth Verifier, attempts to
+   * obtain a user object and responds with the JWT
+   *
+   * @function callback
+   * @memberof AuthHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
   callback() {
 
     const self = this;
@@ -46,8 +68,8 @@ module.exports = internals.AuthHandler = class AuthHandler {
         return this.throw(401);
       }
 
-      const oAuthToken = this.request.query.oauth_token;
-      const oAuthVerifier = this.request.query.oauth_verifier;
+      const oAuthToken = this.request.body.oAuthToken;
+      const oAuthVerifier = this.request.body.oAuthVerifier;
       let user;
 
       try {
@@ -59,25 +81,23 @@ module.exports = internals.AuthHandler = class AuthHandler {
         return this.throw(401);
       }
 
-      yield self._setJWT(user, this);
-
-      this.redirect(internals.kMainLocation);
-    };
-  }
-
-  logout() {
+      const expiresAt = Date.now() + self._jwtConfig.duration * 1000;
 
-    const self = this;
+      const token = yield self._getToken(user);
 
-    return function * () {
+      const response = {
+        expiresAt,
+        user,
+        token
+      };
 
-      this.cookies.set(self._jwtConfig.cookieName, null);
-      this.redirect(internals.kMainLocation);
+      this.body = response;
     };
   }
 
-  // Sets a JSON Web Token Cookie
-  _setJWT(payload, context) {
+  // Generates a JSON Web Token
+
+  _getToken(payload) {
 
     const self = this;
 
@@ -87,12 +107,7 @@ module.exports = internals.AuthHandler = class AuthHandler {
         expiresIn: self._jwtConfig.duration
       });
 
-      context.cookies.set(self._jwtConfig.cookieName, token, {
-        maxAge: self._jwtConfig.duration * 1000,
-        signed: true,
-        domain: self._hostname,
-        overwrite: true
-      });
+      return token;
     });
   }
 };
diff --git a/lib/handlers/posts.js b/lib/handlers/posts.js
new file mode 100644
index 0000000..425fb5e
--- /dev/null
+++ b/lib/handlers/posts.js
@@ -0,0 +1,177 @@
+'use strict';
+
+const Joi = require('joi');
+const Pify = require('pify');
+const Redis = require('redis');
+const UUID = require('uuid/v4');
+
+const internals = {};
+
+internals.kPostsPrefix = 'posts';
+internals.kMaxPostSize = 255;
+
+internals.kPostsSchema = Joi.object().keys({
+  uuid: Joi.string().required(),
+  content: Joi.string().max(internals.kMaxPostSize).required(),
+  timestamp: Joi.number().integer().required(),
+  userId: Joi.string().required(),
+  userName: Joi.string().required(),
+  userImage: Joi.string().required()
+});
+
+/**
+ * Handles the HTTP requests for posts related operations
+ *
+ * @class PostsHandler
+ * @param {Dasein.tConfiguration} config The configuration to
+ * initialize.
+ */
+module.exports = internals.PostsHandler = class PostsHandler {
+  constructor(config) {
+
+    this._ttl = config.ttl;
+    this._redis = Redis.createClient(config.redis);
+
+    // Log an error if it happens.
+    this._redis.on('error', (err) => {
+
+      console.error(err);
+    });
+  }
+
+  /**
+   * Fetches all available posts
+   *
+   * @function findAll
+   * @memberof PostsHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
+  findAll() {
+
+    const self = this;
+
+    return function * () {
+
+      if (!this.state.user) {
+        return this.throw('Unauthorized', 401);
+      }
+
+      const scan = Pify(self._redis.scan.bind(self._redis));
+      const hgetall = Pify(self._redis.hgetall.bind(self._redis));
+
+      const cursor = parseInt(this.request.query.cursor) || 0;
+      const [nextCursor, keys] = yield scan(cursor, 'MATCH', `${internals.kPostsPrefix}:*`);
+
+      if (nextCursor > 0) {
+        this.append('Link', `<${this.request.origin}${this.request.path}?cursor=${nextCursor}>; rel="next"`);
+      }
+
+      const posts = yield keys.map((key) => hgetall(key));
+
+      this.body = posts;
+    };
+  }
+
+  /**
+   * Fetches a single post
+   *
+   * @function find
+   * @memberof PostsHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
+  find() {
+
+    const self = this;
+
+    return function * (uuid) {
+
+      if (!this.state.user) {
+        return this.throw('Unauthorized', 401);
+      }
+
+      const hgetall = Pify(self._redis.hgetall.bind(self._redis));
+
+      const postKey = `${internals.kPostsPrefix}:${uuid}`;
+
+      const post = yield hgetall(postKey);
+
+      if (!post) {
+        this.throw('Post not found', 404);
+      }
+
+      this.body = post;
+    };
+  }
+
+  /**
+   * Creates a post
+   *
+   * @function create
+   * @memberof PostsHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
+  create() {
+
+    const self = this;
+
+    return function * () {
+
+      if (!this.state.user) {
+        return this.throw('Unauthorized', 401);
+      }
+
+      const hmset = Pify(self._redis.hmset.bind(self._redis));
+      const hgetall = Pify(self._redis.hgetall.bind(self._redis));
+      const expire = Pify(self._redis.expire.bind(self._redis));
+
+      const uuid = UUID();
+      const timestamp = Date.now();
+      const user = this.state.user;
+
+      const postKey = `${internals.kPostsPrefix}:${uuid}`;
+
+      const post = {
+        uuid,
+        content: this.request.body.content,
+        timestamp,
+        userId: user.screen_name,
+        userName: user.name,
+        userImage: user.profile_image_url_https
+      };
+
+      yield self._validate(post).catch((err) => {
+
+        this.throw(err.message, 422);
+      });
+
+      yield hmset(postKey, post);
+      yield expire(postKey, self._ttl);
+
+      this.body = yield hgetall(postKey);
+    };
+  }
+
+  /**
+   * Deletes a post
+   *
+   * @function delete
+   * @memberof PostsHandler
+   * @instance
+   * @return {generator} a koa compatible handler generator function
+   */
+  delete() {
+
+    return function * () {};
+  }
+
+  // Validates the post schema
+
+  _validate(post) {
+
+    const validate = Pify(Joi.validate.bind(Joi));
+    return validate(post, internals.kPostsSchema);
+  }
+};
diff --git a/lib/twitter_helper.js b/lib/twitter_helper.js
index 3ab51fa..6edf030 100644
--- a/lib/twitter_helper.js
+++ b/lib/twitter_helper.js
@@ -12,6 +12,16 @@ internals.kVerifyCredentialsUrl = 'https://api.twitter.com/1.1/account/verify_cr
 internals.kOauthVersion = '1.0A';
 internals.kOauthSignatureMethod = 'HMAC-SHA1';
 
+/**
+ * Helper to communicate with the twitter API
+ *
+ * @class TwitterHelper
+ * @param {Dasein.tTwitterConfiguration} config the configuration to
+ * initialize the twitter API
+ * @see {@link https://dev.twitter.com/web/sign-in/implementing|Implementing
+ * Sign in with Twitter}
+ *
+ */
 module.exports = internals.TwitterHelper = class TwitterHelper {
 
   constructor(config) {
@@ -27,6 +37,14 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
     );
   }
 
+  /**
+   * Calls the API to get a request token.
+   *
+   * @function getRequestToken
+   * @memberof TwitterHelper
+   * @instance
+   * @return {Promise<TwitterHelper.tRequestToken>} the request token response
+   */
   getRequestToken() {
 
     const self = this;
@@ -36,6 +54,15 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
       const getOAuthRequestToken = Pify(self._oAuth.getOAuthRequestToken.bind(self._oAuth), { multiArgs: true });
       const [oAuthToken, oAuthTokenSecret] = yield getOAuthRequestToken();
 
+      /**
+       * The request token and secret pair from the twitter API
+       *
+       * @memberof TwitterHelper
+       * @typedef {object} tRequestToken
+       * @property {string} oAuthToken The oAuth request token
+       * @property {string} oAuthTokenSecret The oAuth request token
+       * secret
+       */
       return {
         oAuthToken,
         oAuthTokenSecret
@@ -43,6 +70,17 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
     });
   }
 
+  /**
+   * Calls the API to get an access token
+   *
+   * @function getAccessToken
+   * @memberof TwitterHelper
+   * @instance
+   * @param {string} oAuthToken An oAuth request token
+   * @param {string} oAuthVerifier An oAuth verifier sent from the
+   * twitter callback
+   * @return {Promise<TwitterHelper.tAccessToken>} the acess token response
+   */
   getAccessToken(oAuthToken, oAuthVerifier) {
 
     const self = this;
@@ -54,6 +92,15 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
                                                                                    '',
                                                                                    oAuthVerifier);
 
+      /**
+       * The access token and secret pair from the twitter API
+       *
+       * @memberof TwitterHelper
+       * @typedef {object} tAccessToken
+       * @property {string} oAuthAccessToken The oAuth access token
+       * @property {string} oAuthAccessTokenSecret The oAuth access token
+       * secret
+       */
       return {
         oAuthAccessToken,
         oAuthAccessTokenSecret
@@ -61,6 +108,17 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
     });
   }
 
+  /**
+   * Gets a user object from twitter
+   *
+   * @function getUser
+   * @memberof TwitterHelper
+   * @instance
+   * @param {string} oAuthAccessToken An oAuth access token
+   * @param {string} oAuthAccessTokenSecret An oAuth access token secret
+   * @return {Promise<external:TwitterUser>} the user object from
+   * twitter
+   */
   getUser(oAuthAccessToken, oAuthAccessTokenSecret) {
 
     const self = this;
@@ -72,6 +130,12 @@ module.exports = internals.TwitterHelper = class TwitterHelper {
                                        oAuthAccessToken,
                                        oAuthAccessTokenSecret);
 
+      /**
+       * The twitter user from the API
+       * @external TwitterUser
+       * @see {@link https://dev.twitter.com/overview/api/users|Twitter
+       * Api Overview: Users}
+       */
       return JSON.parse(userResponse);
     });
   }