ch11.4

internal/models/users.go

@@ -45,7 +45,27 @@ func (m *UserModel) Insert(name, email, password string) error {
 }
 
 func (m *UserModel) Authenticate(email, password string) (int, error) {
-	return 0, nil
+	var id int
+	var hashedPassword []byte
+
+	stmt := `SELECT id, hashed_password FROM users WHERE email = ?`
+
+	err := m.DB.QueryRow(stmt, email).Scan(&id, &hashedPassword)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return 0, ErrInvalidCredentials
+		}
+		return 0, err
+	}
+	err = bcrypt.CompareHashAndPassword(hashedPassword, []byte(password))
+	if err != nil {
+		if errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
+			return 0, ErrInvalidCredentials
+		}
+		return 0, err
+	}
+
+	return id, nil
 }
 
 func (m *UserModel) Exists(id int) (bool, error) {

internal/validator/validator.go

@@ -7,11 +7,12 @@ import (
 )
 
 type Validator struct {
-	FieldErrors map[string]string
+	NonFieldErrors []string
+	FieldErrors    map[string]string
 }
 
 func (v *Validator) Valid() bool {
-	return len(v.FieldErrors) == 0
+	return len(v.FieldErrors) == 0 && len(v.NonFieldErrors) == 0
 }
 
 func (v *Validator) AddFieldError(key, message string) {
@@ -23,6 +24,10 @@ func (v *Validator) AddFieldError(key, message string) {
 	}
 }
 
+func (v *Validator) AddNonFieldError(message string) {
+	v.NonFieldErrors = append(v.NonFieldErrors, message)
+}
+
 func (v *Validator) CheckField(ok bool, key, message string) {
 	if !ok {
 		v.AddFieldError(key, message)