1 files changed, 65 insertions, 0 deletions
diff --git a/week-7/Final4/blog/sessions.js b/week-7/Final4/blog/sessions.js
new file mode 100644
index 0000000..3af169f
--- /dev/null
+++ b/week-7/Final4/blog/sessions.js
@@ -0,0 +1,65 @@
+var crypto = require('crypto');
+
+/* The SessionsDAO must be constructed with a connected database object */
+function SessionsDAO(db) {
+    "use strict";
+
+    /* If this constructor is called without the "new" operator, "this" points
+     * to the global object. Log a warning and call it correctly. */
+    if (false === (this instanceof SessionsDAO)) {
+        console.log('Warning: SessionsDAO constructor called without "new" operator');
+        return new SessionsDAO(db);
+    }
+
+    var sessions = db.collection("sessions");
+
+    this.startSession = function(username, callback) {
+        "use strict";
+
+        // Generate session id
+        var current_date = (new Date()).valueOf().toString();
+        var random = Math.random().toString();
+        var session_id = crypto.createHash('sha1').update(current_date + random).digest('hex');
+
+        // Create session document
+        var session = {'username': username, '_id': session_id}
+
+        // Insert session document
+        sessions.insert(session, function (err, result) {
+            "use strict";
+            callback(err, session_id);
+        });
+    }
+
+    this.endSession = function(session_id, callback) {
+        "use strict";
+        // Remove session document
+        sessions.remove({ '_id' : session_id }, function (err, numRemoved) {
+            "use strict";
+            callback(err);
+        });
+    }
+    this.getUsername = function(session_id, callback) {
+        "use strict";
+
+        if (!session_id) {
+            callback(Error("Session not set"), null);
+            return;
+        }
+
+        sessions.findOne({ '_id' : session_id }, function(err, session) {
+            "use strict";
+
+            if (err) return callback(err, null);
+
+            if (!session) {
+                callback(new Error("Session: " + session + " does not exist"), null);
+                return;
+            }
+
+            callback(null, session.username);
+        });
+    }
+}
+
+module.exports.SessionsDAO = SessionsDAO;