package createuser

import (
	"errors"
	"fmt"
	"net/http"
	"strings"

	"git.artlef.fr/PersonalLibraryManager/internal/config"
	"git.artlef.fr/PersonalLibraryManager/internal/model"
	"git.artlef.fr/PersonalLibraryManager/internal/myvalidator"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm"
)

// this method will hash the password
func CreateUser(db *gorm.DB, username string, password string) error {
	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return err
	}
	return CreateUserWithHashedPassword(db, username, string(hashedPassword))
}

// only call this method with hashed password
func CreateUserWithHashedPassword(db *gorm.DB, username string, hashedPassword string) error {
	var existingUser model.User
	err := db.Where("name = ?", username).First(&existingUser).Error
	if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
		return err
	}
	if err == nil {
		return myvalidator.HttpError{
			StatusCode: http.StatusInternalServerError,
			Err:        errors.New("An user with this name already exists."),
		}
	}
	user := model.User{
		Name:     username,
		Password: hashedPassword,
	}
	return db.Model(&model.User{}).Save(&user).Error
}

func CreateDefaultUsers(db *gorm.DB, config *config.Config) error {
	usersPasswordMap := make(map[string]string)
	var usernames []string
	for _, s := range config.AddUser {
		splittedString := strings.Split(s, ":")
		if len(splittedString) < 2 {
			return fmt.Errorf("Error when creating user from string %s", s)
		}
		usernames = append(usernames, splittedString[0])
		usersPasswordMap[splittedString[0]] = splittedString[1]
	}

	var existingUsers []model.User
	err := db.Where("name IN ?", usernames).Find(&existingUsers).Error
	if err != nil {
		return err
	}

	for _, username := range usernames {
		if isInExistingUsers(username, existingUsers) {
			continue
		}
		err = CreateUserWithHashedPassword(db, username, usersPasswordMap[username])
		if err != nil {
			return err
		}
	}
	return nil
}

func isInExistingUsers(username string, existingUsers []model.User) bool {
	for _, existingUser := range existingUsers {
		if username == existingUser.Name {
			return true
		}
	}
	return false
}