package repository

import (
	"apskel-pos-be/internal/entities"
	"context"
	"fmt"

	"github.com/google/uuid"
	"gorm.io/gorm"
)

type CustomerPointsRepository struct {
	db *gorm.DB
}

func NewCustomerPointsRepository(db *gorm.DB) *CustomerPointsRepository {
	return &CustomerPointsRepository{db: db}
}

func (r *CustomerPointsRepository) Create(ctx context.Context, customerPoints *entities.CustomerPoints) error {
	return r.db.WithContext(ctx).Create(customerPoints).Error
}

func (r *CustomerPointsRepository) GetByID(ctx context.Context, id uuid.UUID) (*entities.CustomerPoints, error) {
	var customerPoints entities.CustomerPoints
	err := r.db.WithContext(ctx).Preload("Customer").Where("id = ?", id).First(&customerPoints).Error
	if err != nil {
		return nil, err
	}
	return &customerPoints, nil
}

func (r *CustomerPointsRepository) GetByCustomerID(ctx context.Context, customerID uuid.UUID) (*entities.CustomerPoints, error) {
	var customerPoints entities.CustomerPoints
	err := r.db.WithContext(ctx).Preload("Customer").Where("customer_id = ?", customerID).First(&customerPoints).Error
	if err != nil {
		return nil, err
	}
	return &customerPoints, nil
}

func (r *CustomerPointsRepository) List(ctx context.Context, offset, limit int, search string, sortBy, sortOrder string) ([]entities.CustomerPoints, int64, error) {
	var customerPoints []entities.CustomerPoints
	var total int64

	query := r.db.WithContext(ctx).Preload("Customer")

	if search != "" {
		searchTerm := "%" + search + "%"
		query = query.Joins("JOIN customers ON customer_points.customer_id = customers.id").
			Where("customers.name ILIKE ? OR customers.email ILIKE ?", searchTerm, searchTerm)
	}

	if err := query.Model(&entities.CustomerPoints{}).Count(&total).Error; err != nil {
		return nil, 0, err
	}

	if sortBy != "" {
		if sortOrder == "" {
			sortOrder = "asc"
		}
		query = query.Order(fmt.Sprintf("customer_points.%s %s", sortBy, sortOrder))
	} else {
		query = query.Order("customer_points.created_at DESC")
	}

	err := query.Offset(offset).Limit(limit).Find(&customerPoints).Error
	if err != nil {
		return nil, 0, err
	}

	return customerPoints, total, nil
}

func (r *CustomerPointsRepository) Update(ctx context.Context, customerPoints *entities.CustomerPoints) error {
	return r.db.WithContext(ctx).Save(customerPoints).Error
}

func (r *CustomerPointsRepository) Delete(ctx context.Context, id uuid.UUID) error {
	return r.db.WithContext(ctx).Delete(&entities.CustomerPoints{}, id).Error
}

func (r *CustomerPointsRepository) AddPoints(ctx context.Context, customerID uuid.UUID, points int64) error {
	return r.db.WithContext(ctx).Model(&entities.CustomerPoints{}).
		Where("customer_id = ?", customerID).
		Update("balance", gorm.Expr("balance + ?", points)).Error
}

func (r *CustomerPointsRepository) DeductPoints(ctx context.Context, customerID uuid.UUID, points int64) error {
	return r.db.WithContext(ctx).Model(&entities.CustomerPoints{}).
		Where("customer_id = ? AND balance >= ?", customerID, points).
		Update("balance", gorm.Expr("balance - ?", points)).Error
}

func (r *CustomerPointsRepository) EnsureCustomerPoints(ctx context.Context, customerID uuid.UUID) (*entities.CustomerPoints, error) {
	customerPoints, err := r.GetByCustomerID(ctx, customerID)
	if err == nil {
		return customerPoints, nil
	}

	if err != gorm.ErrRecordNotFound {
		return nil, err
	}

	// Create new customer points record
	newCustomerPoints := &entities.CustomerPoints{
		CustomerID: customerID,
		Balance:    0,
	}

	err = r.Create(ctx, newCustomerPoints)
	if err != nil {
		return nil, err
	}

	return newCustomerPoints, nil
}