package repository

import (
	"context"
	"encoding/json"
	"strings"

	"bugulma/backend/internal/domain"

	"gorm.io/gorm"
)

// UserRepository implements domain.UserRepository with GORM
type UserRepository struct {
	*BaseRepository[domain.User]
	db *gorm.DB
}

// NewUserRepository creates a new GORM-based user repository
func NewUserRepository(db *gorm.DB) domain.UserRepository {
	return &UserRepository{
		BaseRepository: NewBaseRepository[domain.User](db),
		db:             db,
	}
}

// GetByEmail retrieves a user by email
func (r *UserRepository) GetByEmail(ctx context.Context, email string) (*domain.User, error) {
	return r.FindOneWhereWithContext(ctx, "email = ?", email)
}

// GetByID retrieves a user by ID
func (r *UserRepository) GetByID(ctx context.Context, id string) (*domain.User, error) {
	return r.BaseRepository.GetByID(ctx, id)
}

// Create creates a new user with context
func (r *UserRepository) Create(ctx context.Context, user *domain.User) error {
	return r.BaseRepository.Create(ctx, user)
}

// Update updates a user (inherited from BaseRepository)
// Delete deletes a user (inherited from BaseRepository)

// List retrieves users with filters and pagination
func (r *UserRepository) List(ctx context.Context, filters domain.UserListFilters, pagination domain.PaginationParams) (*domain.PaginatedResult[domain.User], error) {
	var users []domain.User
	var total int64

	query := r.db.WithContext(ctx).Model(&domain.User{})

	// Apply filters
	if filters.Role != nil {
		query = query.Where("role = ?", *filters.Role)
	}
	if filters.IsActive != nil {
		query = query.Where("is_active = ?", *filters.IsActive)
	}
	if filters.Search != "" {
		search := "%" + strings.ToLower(filters.Search) + "%"
		query = query.Where("LOWER(email) LIKE ? OR LOWER(name) LIKE ?", search, search)
	}

	// Get total count
	if err := query.Count(&total).Error; err != nil {
		return nil, err
	}

	// Apply pagination and get results
	result := query.
		Order("created_at DESC").
		Limit(pagination.Limit).
		Offset(pagination.Offset).
		Find(&users)
	if result.Error != nil {
		return nil, result.Error
	}

	return &domain.PaginatedResult[domain.User]{
		Items: users,
		Total: total,
	}, nil
}

// UpdateRole updates a user's role
func (r *UserRepository) UpdateRole(ctx context.Context, userID string, role domain.UserRole) error {
	result := r.db.WithContext(ctx).
		Model(&domain.User{}).
		Where("id = ?", userID).
		Update("role", role)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return ErrNotFound
	}
	return nil
}

// UpdatePermissions updates a user's permissions
func (r *UserRepository) UpdatePermissions(ctx context.Context, userID string, permissions []string) error {
	permissionsJSON, err := json.Marshal(permissions)
	if err != nil {
		return err
	}

	result := r.db.WithContext(ctx).
		Model(&domain.User{}).
		Where("id = ?", userID).
		Update("permissions", string(permissionsJSON))
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return ErrNotFound
	}
	return nil
}

// Deactivate deactivates a user
func (r *UserRepository) Deactivate(ctx context.Context, userID string) error {
	result := r.db.WithContext(ctx).
		Model(&domain.User{}).
		Where("id = ?", userID).
		Update("is_active", false)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return ErrNotFound
	}
	return nil
}

// Activate activates a user
func (r *UserRepository) Activate(ctx context.Context, userID string) error {
	result := r.db.WithContext(ctx).
		Model(&domain.User{}).
		Where("id = ?", userID).
		Update("is_active", true)
	if result.Error != nil {
		return result.Error
	}
	if result.RowsAffected == 0 {
		return ErrNotFound
	}
	return nil
}

// UpdateLastLogin updates the user's last login timestamp
func (r *UserRepository) UpdateLastLogin(ctx context.Context, userID string) error {
	result := r.db.WithContext(ctx).
		Model(&domain.User{}).
		Where("id = ?", userID).
		Update("last_login_at", gorm.Expr("NOW()"))
	if result.Error != nil {
		return result.Error
	}
	return nil
}