package services

import (
	"errors"
	"gobeyhan/database"
	"gobeyhan/database/models"

	"gorm.io/gorm"
)

type RoleService struct{}

func NewRoleService() *RoleService {
	return &RoleService{}
}

// GetAllRoles retrieves all roles
func (s *RoleService) GetAllRoles() ([]models.Role, error) {
	var roles []models.Role
	err := database.DB.Preload("Permissions").Find(&roles).Error
	return roles, err
}

// GetRoleByID retrieves a role by ID
func (s *RoleService) GetRoleByID(id uint64) (*models.Role, error) {
	var role models.Role
	err := database.DB.Preload("Permissions").First(&role, id).Error

	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}

	return &role, nil
}

// CreateRole creates a new role
func (s *RoleService) CreateRole(role *models.Role) error {
	return database.DB.Create(role).Error
}

// UpdateRole updates an existing role
func (s *RoleService) UpdateRole(id uint64, updates map[string]interface{}) error {
	result := database.DB.Model(&models.Role{}).Where("id = ?", id).Updates(updates)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return gorm.ErrRecordNotFound
	}
	return nil
}

// DeleteRole deletes a role by ID
func (s *RoleService) DeleteRole(id uint64) error {
	result := database.DB.Delete(&models.Role{}, id)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return gorm.ErrRecordNotFound
	}
	return nil
}

// AssignPermission assigns a permission to a role
func (s *RoleService) AssignPermission(roleID, permissionID uint64) error {
	var role models.Role
	if err := database.DB.First(&role, roleID).Error; err != nil {
		return err
	}

	var permission models.Permission
	if err := database.DB.First(&permission, permissionID).Error; err != nil {
		return err
	}

	return database.DB.Model(&role).Association("Permissions").Append(&permission)
}

// RemovePermission removes a permission from a role
func (s *RoleService) RemovePermission(roleID, permissionID uint64) error {
	var role models.Role
	if err := database.DB.Preload("Permissions").First(&role, roleID).Error; err != nil {
		return err
	}

	var permission models.Permission
	if err := database.DB.First(&permission, permissionID).Error; err != nil {
		return err
	}

	return database.DB.Model(&role).Association("Permissions").Delete(&permission)
}