package Database

import (
	"errors"

	"github.com/gofrs/uuid"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

// BeforeUpdate prevents updating the username or email if it has not changed
// This stops a unique constraint error
func (u *User) BeforeUpdate(tx *gorm.DB) (err error) {
	if !tx.Statement.Changed("Username") {
		tx.Statement.Omit("Username")
	}
	if !tx.Statement.Changed("Email") {
		tx.Statement.Omit("Email")
	}
	return nil
}

// User holds user data
type User struct {
	Base
	Username             string        `gorm:"not null;unique"   json:"username"`
	Password             string        `gorm:"not null"          json:"password"`
	ConfirmPassword      string        `gorm:"-"                 json:"confirm_password"`
	Email                string        `                         json:"email"`
	AsymmetricPrivateKey string        `gorm:"not null"          json:"asymmetric_private_key"` // Stored encrypted
	AsymmetricPublicKey  string        `gorm:"not null"          json:"asymmetric_public_key"`
	SymmetricKey         string        `gorm:"not null"          json:"symmetric_key"` // Stored encrypted
	AttachmentID         *uuid.UUID    `                         json:"attachment_id"`
	Attachment           Attachment    `                         json:"attachment"`
	MessageExpiryDefault MessageExpiry `gorm:"default:no_expiry" json:"-" sql:"type:ENUM('fifteen_min', 'thirty_min', 'one_hour', 'three_hour', 'six_hour', 'twelve_hour', 'one_day', 'three_day', 'no_expiry')"` // Stored encrypted
}

func GetUserById(id string) (User, error) {
	var (
		user User
		err  error
	)

	err = DB.Preload(clause.Associations).
		First(&user, "id = ?", id).
		Error

	return user, err
}

func GetUserByUsername(username string) (User, error) {
	var (
		user User
		err  error
	)

	err = DB.Preload(clause.Associations).
		First(&user, "username = ?", username).
		Error

	return user, err
}

func CheckUniqueUsername(username string) error {
	var (
		exists bool
		err    error
	)

	err = DB.Model(User{}).
		Select("count(*) > 0").
		Where("username = ?", username).
		Find(&exists).
		Error

	if err != nil {
		return err
	}

	if exists {
		return errors.New("Invalid username")
	}

	return nil
}

func (user *User) CreateUser() error {
	var err error

	err = DB.Session(&gorm.Session{FullSaveAssociations: true}).
		Create(user).
		Error

	return err
}

func (user *User) UpdateUser() error {
	var err error
	err = DB.Model(&user).
		Omit("id").
		Where("id = ?", user.ID.String()).
		Updates(user).
		Error

	if err != nil {
		return err
	}

	err = DB.Model(User{}).
		Where("id = ?", user.ID.String()).
		First(user).
		Error

	return err
}

func (user *User) DeleteUser() error {
	return DB.Session(&gorm.Session{FullSaveAssociations: true}).
		Delete(user).
		Error
}