server: implement working db transaction with users

server/api/db.go

@@ -0,0 +1,88 @@
+package api
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+
+	"git.dubyatp.xyz/dubyatp/scannerbot/server/db"
+	"github.com/gocql/gocql"
+)
+
+func dbGetUser(id string) (*User, error) {
+	query := `SELECT id, name, password FROM users WHERE id = ?`
+	var user User
+	var gid gocql.UUID
+	err := db.Session.Query(query, id).Scan(&gid, &user.Name, &user.Password)
+	user.ID = [16]byte(gid)
+
+	if err == gocql.ErrNotFound {
+		slog.Debug("db: user not found", "userid", id)
+		return nil, errors.New("User not found")
+	} else if err != nil {
+		slog.Error("db: failed to query user", "error", err)
+		return nil, fmt.Errorf("failed to query user")
+	}
+
+	slog.Debug("db: user found", "userid", user.ID, "username", user.Name)
+	return &user, nil
+}
+
+func dbGetUserByName(username string) (*User, error) {
+	query := `SELECT id, name, password FROM users WHERE name = ?`
+	var user User
+	var gid gocql.UUID
+	err := db.Session.Query(query, username).Scan(&gid, &user.Name, &user.Password)
+	user.ID = [16]byte(gid)
+
+	if err == gocql.ErrNotFound {
+		slog.Debug("db: user not found", "username", username)
+		return nil, errors.New("User not found")
+	} else if err != nil {
+		slog.Error("db: failed to query user", "error", err)
+		return nil, fmt.Errorf("failed to query user")
+	}
+
+	slog.Debug("db: user found", "userid", user.ID, "username", user.Name)
+	return &user, nil
+}
+
+func dbGetAllUsers() ([]*User, error) {
+	query := `SELECT id, name, password FROM users`
+	iter := db.Session.Query(query).Iter()
+	defer iter.Close()
+
+	var users []*User
+	for {
+		user := &User{}
+		var gid gocql.UUID
+		if !iter.Scan(&gid, &user.Name, &user.Password) {
+			break
+		}
+		user.ID = [16]byte(gid)
+		users = append(users, user)
+	}
+	if err := iter.Close(); err != nil {
+		slog.Error("db: failed to iterate users", "error", err)
+		return nil, fmt.Errorf("failed to iterate users")
+	}
+	if len(users) == 0 {
+		slog.Debug("db: no users found")
+		return nil, errors.New("no users found")
+	}
+
+	slog.Debug("db: user list returned")
+	return users, nil
+}
+
+func dbAddUser(user *User) error {
+	query := `INSERT INTO users (id, name, password) VALUES (?, ?, ?)`
+	err := db.Session.Query(query, gocql.UUID(user.ID), user.Name, user.Password).Exec()
+	if err != nil {
+		slog.Error("db: failed to add user", "error", err, "userid", user.ID, "username", user.Name)
+		return fmt.Errorf("failed to add user")
+	}
+
+	slog.Debug("db: user added", "userid", user.ID, "username", user.Name)
+	return nil
+}