add cache for groups and clients, http sending message remains to be add

database.go

@@ -22,13 +22,13 @@ func InitDatabase(ctx context.Context) {
 		    id SERIAL PRIMARY KEY,
 		    name VARCHAR(20) UNIQUE NOT NULL,
 		    pass_hash VARCHAR(60) NOT NULL,
-		    color VARCHAR(3) DEFAULT NULL,
+		    color VARCHAR(3) DEFAULT NULL
 		);
 		CREATE TABLE IF NOT EXISTS chat_groups (
 		    id SERIAL PRIMARY KEY,
 		    name VARCHAR(48) NOT NULL,
-		    creator_id INTEGER NOT NULL REFERENCES users(id) ON DELETE SET NULL,
-		    owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE SET NULL,
+		    creator_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+		    owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
 		    enable_user_colors BOOLEAN NOT NULL DEFAULT true,
 		    group_color VARCHAR(3),
 		    created_at TIMESTAMP NOT NULL DEFAULT NOW()
@@ -43,7 +43,9 @@ func InitDatabase(ctx context.Context) {
 	if err != nil {
 		panic(err)
 	}
+
 	dbConnection = conn
+	InitCache()
 }
 
 func AddNewUser(ctx context.Context, user *User) (uint32, error) {
@@ -65,7 +67,7 @@ func AddNewUser(ctx context.Context, user *User) (uint32, error) {
 		}
 		user.Password = string(hashed)
 	}
-	if len(user.Color) != 1 && len(user.Color) != 3 {
+	if user.Color == ([3]byte{}) {
 		return 0, errors.New("color invalid")
 	}
 	err = dbConnection.QueryRow(ctx, `
@@ -86,6 +88,24 @@ func isPassValid(ctx context.Context, id uint32, plainPassword string) bool {
 	return bcrypt.CompareHashAndPassword([]byte(controlHash), []byte(plainPassword)) == nil
 }
 
+func GetAllUsers(ctx context.Context) ([]User, error) {
+	rows, err := dbConnection.Query(ctx, "SELECT id, name, color FROM users")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var users []User
+	for rows.Next() {
+		var user User
+		if err := rows.Scan(&user.Id, &user.Name, &user.Color); err != nil {
+			return nil, err
+		}
+		users = append(users, user)
+	}
+	return users, rows.Err()
+}
+
 func GetUserDataById(ctx context.Context, id uint32) (User, error) {
 	var user User
 	err := dbConnection.QueryRow(ctx, "SELECT id, name, pass_hash, color FROM users WHERE id = $1", id).
@@ -120,9 +140,29 @@ func CreateChatGroupWithoutMembers(ctx context.Context, group *ChatGroup) (uint3
 			VALUES ($1, $2, $3, $4)
 			RETURNING id
 		`, group.Name, group.CreatorId, group.OwnerId, group.CreatedAt).Scan(&id)
+
+	AddOrUpdateGroupToCache(&mu, *group)
 	return id, err
 }
 
+func GetAllChatGroups(ctx context.Context) ([]ChatGroup, error) {
+	rows, err := dbConnection.Query(ctx, "SELECT id, name, creator_id, owner_id, enable_user_colors, group_color, created_at FROM chat_groups")
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var groups []ChatGroup
+	for rows.Next() {
+		var group ChatGroup
+		if err := rows.Scan(&group.Id, &group.Name, &group.CreatorId, &group.OwnerId, &group.EnableUserColors, &group.Color, &group.CreatedAt); err != nil {
+			return nil, err
+		}
+		groups = append(groups, group)
+	}
+	return groups, rows.Err()
+}
+
 func GetChatGroupWithoutMembers(ctx context.Context, id uint32) (ChatGroup, error) {
 	var group ChatGroup
 	err := dbConnection.QueryRow(ctx, `SELECT name, creator_id, owner_id, enable_user_colors, group_color, created_at FROM chat_groups WHERE id = $1`,