Added message "memorisation"

scripts/chat.js

@@ -48,8 +48,8 @@ areCredentialsValid({username:username, secret_hash:secret_hash})
         socket.onmessage = event => {
             let message = JSON.parse(event.data); 
             let from_user = message.from.username;
-
-            let constructed_message_to_display = `${from_user}: ${message.contents}` + "\n";
+            let date = new Date(message.timestamp).toLocaleString();
+            let constructed_message_to_display = `[${date}] ${from_user}: ${message.contents}` + "\n";
 
             let chatbox = document.getElementById("chatbox");
             chatbox.innerHTML += constructed_message_to_display;

src/api/db.go

@@ -26,7 +26,7 @@ import (
 
 const (
 	UsersTablename    string = "users"
-	// MessagesTablename string = "messages"
+	MessagesTablename string = "messages"
 )
 
 // SQL database wrapper
@@ -51,21 +51,21 @@ func (db *DB) createUsersTable() error {
 	return nil
 }
 
-// func (db *DB) createMessagesTable() error {
-// 	command := fmt.Sprintf(
-// 		`CREATE TABLE IF NOT EXISTS %s
-// 		(id INTEGER NOT NULL PRIMARY KEY, content TEXT NOT NULL,
-// 		from_name TEXT NOT NULL, FOREIGN KEY(from_name) REFERENCES %s(username))`,
-// 		MessagesTablename, UsersTablename,
-// 	)
+func (db *DB) createMessagesTable() error {
+	command := fmt.Sprintf(
+		`CREATE TABLE IF NOT EXISTS %s
+		(id INTEGER NOT NULL PRIMARY KEY, content TEXT NOT NULL,
+		sender TEXT NOT NULL, timestamp INTEGER, FOREIGN KEY(sender) REFERENCES %s(username))`,
+		MessagesTablename, UsersTablename,
+	)
 
-// 	_, err := db.Exec(command)
-// 	if err != nil {
-// 		return err
-// 	}
+	_, err := db.Exec(command)
+	if err != nil {
+		return err
+	}
 
-// 	return nil
-// }
+	return nil
+}
 
 func (db *DB) setUpTables() error {
 	err := db.createUsersTable()
@@ -73,6 +73,11 @@ func (db *DB) setUpTables() error {
 		return fmt.Errorf("error creating users table: %s", err)
 	}
 
+	err = db.createMessagesTable()
+	if err != nil {
+		return fmt.Errorf("error creating messages table: %s", err)
+	}
+
 	return nil
 }
 

src/api/limits.go

@@ -0,0 +1,7 @@
+package api
+
+// How many characters can message hold
+const MaxMessageContentLen uint = 500
+
+// How many messages can be "remembered" until removal
+const MaxMessagesRemembered uint = 50

src/api/message.go

@@ -16,43 +16,69 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 package api
 
+import (
+	"fmt"
+	"strconv"
+)
+
 // A message struct that is converted back and forth to JSON in order to communicate with frontend
 type Message struct {
+	ID        uint64
 	TimeStamp uint64 `json:"timestamp"`
 	From      User   `json:"from"`
 	Contents  string `json:"contents"`
 }
 
-/* PROBABLY come back later and implement a message-remembering feature */
-
-// func (db *DB) AddMessage(message Message) error {
-// 	command := fmt.Sprintf("INSERT INTO %s(from, contents) VALUES(%s, %s)", MessagesTablename, message.From.Name, message.Contents)
-// 	_, err := db.Exec(command)
-// 	if err != nil {
-// 		return err
-// 	}
-
-// 	return nil
-// }
-
-// func (db *DB) GetAllMessages() (*[]Message, error) {
-// 	command := fmt.Sprintf("SELECT * FROM %s", MessagesTablename)
-// 	rows, err := db.Query(command)
-// 	if err != nil {
-// 		return nil, err
-// 	}
-
-// 	var messages []Message
-
-// 	/*
-// 		(id INTEGER NOT NULL PRIMARY KEY, content TEXT NOT NULL,
-// 		 to_name TEXT NOT NULL, from_name TEXT NOT NULL, FOREIGN KEY(from_name, to_name) REFERENCES %s(username, username))`,
-// 	*/
-// 	for rows.Next() {
-// 		var message Message
-// 		rows.Scan(&message.ID, &message.Contents, message.From.Name)
-// 		messages = append(messages, message)
-// 	}
-
-// 	return &messages, nil
-// }
+// Add a new message to the database, following the limitations and removing the
+// oldest one as well if the capacity has been exceeded
+func (db *DB) AddMessage(message Message) error {
+	// check how many messages are already stored
+	command := fmt.Sprintf("SELECT COUNT(*) FROM %s", MessagesTablename)
+	result := db.QueryRow(command)
+	err := result.Err()
+	if err != nil {
+		return err
+	}
+
+	var countStr string
+	result.Scan(&countStr)
+	count, err := strconv.ParseUint(countStr, 10, 64)
+	if err != nil {
+		return err
+	}
+
+	if count >= uint64(MaxMessagesRemembered) {
+		// remove the last one
+		command = fmt.Sprintf("DELETE FROM %s WHERE timestamp = (SELECT MIN(timestamp) FROM %s)", MessagesTablename, MessagesTablename)
+		_, err := db.Exec(command)
+		if err != nil {
+			return err
+		}
+	}
+
+	command = fmt.Sprintf("INSERT INTO %s(sender, content, timestamp) VALUES(\"%s\", \"%s\", %d)", MessagesTablename, message.From.Name, message.Contents, message.TimeStamp)
+	_, err = db.Exec(command)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (db *DB) GetAllMessages() (*[]Message, error) {
+	command := fmt.Sprintf("SELECT * FROM %s", MessagesTablename)
+	rows, err := db.Query(command)
+	if err != nil {
+		return nil, err
+	}
+
+	var messages []Message
+
+	for rows.Next() {
+		var message Message
+		rows.Scan(&message.ID, &message.Contents, &message.From.Name, &message.TimeStamp)
+		messages = append(messages, message)
+	}
+
+	return &messages, nil
+}

src/api/user.go

@@ -18,8 +18,6 @@ package api
 
 import (
 	"fmt"
-
-	"unbewohnte.xyz/gochat/log"
 )
 
 const HashLength uint = 64
@@ -63,8 +61,6 @@ func (db *DB) CreateUser(user *User) error {
 		return err
 	}
 
-	log.Info("created user \"%s\"", user.Name)
-
 	return nil
 }
 

src/api/websocket.go

@@ -95,11 +95,12 @@ func (holder *WSHolder) HandleNewWebSocketMessages(ws *WS, output chan Message)
 				break
 			}
 
-			if len(newMessage.Contents) < 1 {
+			if len(newMessage.Contents) < 1 || uint(len(newMessage.Contents)) > MaxMessageContentLen {
 				break
 			}
 
 			newMessage.From = ws.User
+			newMessage.TimeStamp = uint64(time.Now().UnixMilli())
 			output <- newMessage
 		}
 

src/log/log.go

@@ -32,7 +32,7 @@ var (
 func init() {
 	infoLog = log.New(os.Stdout, "[INFO] ", log.Ldate|log.Ltime)
 	warningLog = log.New(os.Stdout, "[WARNING] ", log.Ldate|log.Ltime)
-	errorLog = log.New(os.Stdout, "[ERROR] ", log.Ldate|log.Ltime|log.Lshortfile)
+	errorLog = log.New(os.Stdout, "[ERROR] ", log.Ldate|log.Ltime)
 }
 
 // Set up loggers to write to the given writer

src/server/websocketHandler.go

@@ -19,6 +19,7 @@ package server
 import (
 	"fmt"
 	"net/http"
+	"time"
 
 	"github.com/gorilla/websocket"
 	"unbewohnte.xyz/gochat/api"
@@ -64,9 +65,21 @@ func (s *Server) HandlerWebsockets(w http.ResponseWriter, req *http.Request) {
 	// add this new authorized socket to the broadcast
 	s.websockets.Sockets = append(s.websockets.Sockets, &newWS)
 
-	log.Info("A new websocket connection has been established with %s as \"%s\"", newWS.Socket.RemoteAddr(), newWS.User.Name)
+	log.Info("a new websocket connection has been established with %s as \"%s\"", newWS.Socket.RemoteAddr(), newWS.User.Name)
 	go s.websockets.HandleNewWebSocketMessages(&newWS, s.incomingMessages)
 
+	// send this new socket all previous messages to display
+	allMessages, err := s.db.GetAllMessages()
+	if err != nil {
+		// well, or not
+		log.Error("could not get all previous messages to display for %s: %s", newWS.User.Name, err)
+	} else {
+		for _, message := range *allMessages {
+			newWS.Socket.WriteJSON(&message)
+		}
+	}
+
+	// notify chat that a new user has connected
 	newConnectionMessage := api.Message{
 		From:     api.UserSystem,
 		Contents: fmt.Sprintf("%s has connected", newWS.User.Name),
@@ -82,6 +95,17 @@ func (s *Server) BroadcastMessages() {
 			break
 		}
 
+		if message.From.Name == api.UserSystem.Name {
+			// add timestapm manually for the system user
+			message.TimeStamp = uint64(time.Now().Unix())
+		}
+
+		// add incoming message to the db
+		err := s.db.AddMessage(message)
+		if err != nil {
+			log.Error("could not add a new message from %s to the db: %s", message.From.Name, err)
+		}
+
 		for _, ws := range s.websockets.Sockets {
 			ws.Socket.WriteJSON(&message)
 		}