package auth

import (
	"database/sql"
	"errors"
	"testing"
	"time"

	"github.com/DATA-DOG/go-sqlmock"
	"golang.org/x/crypto/bcrypt"
)

func TestAuthenticate(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
	}
	defer db.Close()

	service := NewService(db)

	password := "secret"
	hash, _ := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)

	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
		AddRow(1, "testuser", string(hash), time.Now())

	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
		WithArgs("testuser").
		WillReturnRows(rows)

	user, err := service.Authenticate("testuser", password)
	if err != nil {
		t.Errorf("expected no error, got %v", err)
	}
	if user == nil {
		t.Errorf("expected user, got nil")
	}
	if user.Username != "testuser" {
		t.Errorf("expected username testuser, got %s", user.Username)
	}

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("there were unfulfilled expectations: %s", err)
	}
}

func TestAuthenticate_InvalidCredentials(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
	}
	defer db.Close()

	service := NewService(db)

	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
		WithArgs("nonexistent").
		WillReturnError(sql.ErrNoRows)

	_, err = service.Authenticate("nonexistent", "password")
	if !errors.Is(err, ErrInvalidCredentials) {
		t.Errorf("expected ErrInvalidCredentials, got %v", err)
	}

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("there were unfulfilled expectations: %s", err)
	}
}

func TestCreateUser(t *testing.T) {
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
	}
	defer db.Close()

	service := NewService(db)

	// Expect check if user exists
	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE username = ?").
		WithArgs("newuser").
		WillReturnError(sql.ErrNoRows)

	// Expect insert
	mock.ExpectExec("INSERT INTO users").
		WithArgs("newuser", sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(1, 1))

	// Expect retrieve created user
	rows := sqlmock.NewRows([]string{"id", "username", "password_hash", "created_at"}).
		AddRow(1, "newuser", "hashedpassword", time.Now())
	mock.ExpectQuery("SELECT id, username, password_hash, created_at FROM users WHERE id = ?").
		WithArgs(1).
		WillReturnRows(rows)

	user, err := service.CreateUser("newuser", "password")
	if err != nil {
		t.Errorf("expected no error, got %v", err)
	}
	if user.Username != "newuser" {
		t.Errorf("expected username newuser, got %s", user.Username)
	}

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("there were unfulfilled expectations: %s", err)
	}
}