package user

import (
	"errors"

	"cardverse/internal/pkg/utils"
)

var ErrEmailTaken = errors.New("email sudah terdaftar")
var ErrUserNotFound = errors.New("user tidak ditemukan")
var ErrUserSuspended = errors.New("akun anda sedang disuspensi")
var ErrForbiddenRoleCreation = errors.New("hanya superadmin yang dapat membuat atau mengubah akun dengan role admin atau superadmin")

type Service interface {
	Create(creatorID *uint, req CreateUserRequest) (*User, error)
	GetAll() ([]User, error)
	GetAllPaginated(query ListUserQuery) ([]User, int64, error)
	GetByID(id uint) (*User, error)
	Update(modifierID uint, id uint, req UpdateUserRequest) (*User, error)
	UpdateProfile(userID uint, req UpdateProfileRequest) (*User, error)
	UpdateAvatar(userID uint, avatarURL string) (*User, error)
	SuspendUser(modifierID uint, id uint) (*User, error)
	UnsuspendUser(modifierID uint, id uint) (*User, error)
	Delete(id uint) error
}

type service struct {
	repo Repository
}

func NewService(repo Repository) Service {
	return &service{repo: repo}
}

func (s *service) Create(creatorID *uint, req CreateUserRequest) (*User, error) {
	existing, _ := s.repo.FindByEmail(req.Email)
	if existing != nil {
		return nil, ErrEmailTaken
	}

	role := req.Role
	if role == "" {
		role = RoleUser
	}

	// Batasan role: Hanya Superadmin yang boleh membuat akun dengan role admin atau superadmin
	if role == RoleAdmin || role == RoleSuperAdmin {
		if creatorID == nil {
			return nil, ErrForbiddenRoleCreation
		}
		creator, err := s.repo.FindByID(*creatorID)
		if err != nil || creator.Role != RoleSuperAdmin {
			return nil, ErrForbiddenRoleCreation
		}
	}

	hashedPassword, err := utils.HashPassword(req.Password)
	if err != nil {
		return nil, err
	}

	newUser := &User{
		Name:            req.Name,
		Email:           req.Email,
		Password:        hashedPassword,
		Role:            role,
		Status:          StatusActive,
		IsEmailVerified: true,
		CreatedBy:       creatorID,
	}

	if err := s.repo.Create(newUser); err != nil {
		return nil, err
	}

	return newUser, nil
}

func (s *service) GetAll() ([]User, error) {
	return s.repo.FindAll()
}

func (s *service) GetAllPaginated(query ListUserQuery) ([]User, int64, error) {
	page := query.Page
	if page < 1 {
		page = 1
	}
	limit := query.Limit
	if limit < 1 {
		limit = 20
	}

	return s.repo.FindAllPaginated(page, limit, query)
}

func (s *service) GetByID(id uint) (*User, error) {
	u, err := s.repo.FindByID(id)
	if err != nil {
		return nil, ErrUserNotFound
	}
	return u, nil
}

func (s *service) Update(modifierID uint, id uint, req UpdateUserRequest) (*User, error) {
	u, err := s.repo.FindByID(id)
	if err != nil {
		return nil, ErrUserNotFound
	}

	if req.Name != "" {
		u.Name = req.Name
	}
	if req.Email != "" && req.Email != u.Email {
		existing, _ := s.repo.FindByEmail(req.Email)
		if existing != nil {
			return nil, ErrEmailTaken
		}
		u.Email = req.Email
	}
	if req.AvatarURL != "" {
		if u.AvatarURL != nil && *u.AvatarURL != "" && *u.AvatarURL != req.AvatarURL {
			utils.DeleteLocalFile(*u.AvatarURL)
		}
		u.AvatarURL = &req.AvatarURL
	}
	if req.Role != "" && req.Role != u.Role {
		// Batasan role: Hanya Superadmin yang boleh mengubah role ke admin atau superadmin
		if req.Role == RoleAdmin || req.Role == RoleSuperAdmin {
			creator, err := s.repo.FindByID(modifierID)
			if err != nil || creator.Role != RoleSuperAdmin {
				return nil, ErrForbiddenRoleCreation
			}
		}
		u.Role = req.Role
	}
	if req.Status != "" {
		u.Status = req.Status
	}

	u.UpdatedBy = &modifierID

	if err := s.repo.Update(u); err != nil {
		return nil, err
	}

	return u, nil
}

func (s *service) UpdateProfile(userID uint, req UpdateProfileRequest) (*User, error) {
	u, err := s.repo.FindByID(userID)
	if err != nil {
		return nil, ErrUserNotFound
	}

	if req.Name != "" {
		u.Name = req.Name
	}
	if req.AvatarURL != "" {
		if u.AvatarURL != nil && *u.AvatarURL != "" && *u.AvatarURL != req.AvatarURL {
			utils.DeleteLocalFile(*u.AvatarURL)
		}
		u.AvatarURL = &req.AvatarURL
	}

	u.UpdatedBy = &userID

	if err := s.repo.Update(u); err != nil {
		return nil, err
	}

	return u, nil
}

func (s *service) UpdateAvatar(userID uint, avatarURL string) (*User, error) {
	u, err := s.repo.FindByID(userID)
	if err != nil {
		return nil, ErrUserNotFound
	}

	// Hapus file avatar lama jika ada
	if u.AvatarURL != nil && *u.AvatarURL != "" && *u.AvatarURL != avatarURL {
		utils.DeleteLocalFile(*u.AvatarURL)
	}

	u.AvatarURL = &avatarURL
	u.UpdatedBy = &userID

	if err := s.repo.Update(u); err != nil {
		return nil, err
	}

	return u, nil
}

func (s *service) SuspendUser(modifierID uint, id uint) (*User, error) {
	u, err := s.repo.FindByID(id)
	if err != nil {
		return nil, ErrUserNotFound
	}

	u.Status = StatusSuspended
	u.UpdatedBy = &modifierID

	if err := s.repo.Update(u); err != nil {
		return nil, err
	}

	return u, nil
}

func (s *service) UnsuspendUser(modifierID uint, id uint) (*User, error) {
	u, err := s.repo.FindByID(id)
	if err != nil {
		return nil, ErrUserNotFound
	}

	u.Status = StatusActive
	u.UpdatedBy = &modifierID

	if err := s.repo.Update(u); err != nil {
		return nil, err
	}

	return u, nil
}

func (s *service) Delete(id uint) error {
	_, err := s.repo.FindByID(id)
	if err != nil {
		return ErrUserNotFound
	}
	return s.repo.Delete(id)
}