package repository

import (
	"context"
	"errors"
	"fmt"
	"time"

	"github.com/cloudprint/cloudprint-backend/internal/model"
	"gorm.io/gorm"
)

type OrderRepository struct {
	db *gorm.DB
}

func NewOrderRepository(db *gorm.DB) *OrderRepository {
	return &OrderRepository{db: db}
}

func (r *OrderRepository) Create(ctx context.Context, order *model.Order) error {
	return r.db.WithContext(ctx).Create(order).Error
}

func (r *OrderRepository) CreateWithItems(ctx context.Context, order *model.Order, items []*model.OrderItem) error {
	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		if err := tx.Create(order).Error; err != nil {
			return err
		}
		for _, item := range items {
			item.OrderID = order.ID
			if err := tx.Create(item).Error; err != nil {
				return err
			}
		}
		return nil
	})
}

func (r *OrderRepository) GetByID(ctx context.Context, id int32) (*model.Order, error) {
	var order model.Order
	err := r.db.WithContext(ctx).Preload("Items").Preload("Items.File").Preload("Payment").
		First(&order, id).Error
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &order, nil
}

func (r *OrderRepository) GetByOrderNo(ctx context.Context, orderNo string) (*model.Order, error) {
	var order model.Order
	err := r.db.WithContext(ctx).Preload("Items").Preload("Items.File").Preload("Items.Printer").Preload("Payment").
		Where("order_no = ?", orderNo).First(&order).Error
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &order, nil
}

func (r *OrderRepository) GetListByUserID(ctx context.Context, userID int32, status int8, page, pageSize int) ([]*model.Order, int64, error) {
	var orders []*model.Order
	var total int64

	query := r.db.WithContext(ctx).Model(&model.Order{}).Where("user_id = ?", userID)
	if status >= 0 {
		query = query.Where("status = ?", status)
	}

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

	offset := (page - 1) * pageSize
	err = query.Preload("Items").Preload("Items.File").
		Offset(offset).Limit(pageSize).Order("created_at DESC").
		Find(&orders).Error
	if err != nil {
		return nil, 0, err
	}

	return orders, total, nil
}

func (r *OrderRepository) UpdateStatus(ctx context.Context, orderNo string, status int8) error {
	updates := map[string]interface{}{
		"status": status,
	}
	if status == model.OrderStatusPaid {
		now := time.Now()
		updates["paid_at"] = &now
	}
	return r.db.WithContext(ctx).Model(&model.Order{}).
		Where("order_no = ?", orderNo).Updates(updates).Error
}

func (r *OrderRepository) GetStatistics(ctx context.Context) (totalUsers, totalOrders, todayOrders int64, todayRevenue float64, pendingOrders int64, err error) {
	// 总用户数
	if err = r.db.WithContext(ctx).Model(&model.User{}).Count(&totalUsers).Error; err != nil {
		return 0, 0, 0, 0, 0, fmt.Errorf("count users failed: %w", err)
	}
	// 总订单数
	if err = r.db.WithContext(ctx).Model(&model.Order{}).Count(&totalOrders).Error; err != nil {
		return 0, 0, 0, 0, 0, fmt.Errorf("count orders failed: %w", err)
	}
	// 待处理订单数
	if err = r.db.WithContext(ctx).Model(&model.Order{}).Where("status IN ?", []int8{0, 1, 2}).Count(&pendingOrders).Error; err != nil {
		return 0, 0, 0, 0, 0, fmt.Errorf("count pending orders failed: %w", err)
	}
	// 今日订单数
	today := time.Now().Format("2006-01-02")
	if err = r.db.WithContext(ctx).Model(&model.Order{}).
		Where("created_at::date = ? AND status = ?", today, model.OrderStatusPaid).
		Count(&todayOrders).Error; err != nil {
		return 0, 0, 0, 0, 0, fmt.Errorf("count today orders failed: %w", err)
	}
	// 今日收入
	if err = r.db.WithContext(ctx).Model(&model.Order{}).
		Select("COALESCE(SUM(total_amount), 0)").
		Where("created_at::date = ? AND status = ?", today, model.OrderStatusPaid).
		Scan(&todayRevenue).Error; err != nil {
		return 0, 0, 0, 0, 0, fmt.Errorf("sum today revenue failed: %w", err)
	}

	return
}

type OrderItemRepository struct {
	db *gorm.DB
}

func NewOrderItemRepository(db *gorm.DB) *OrderItemRepository {
	return &OrderItemRepository{db: db}
}

func (r *OrderItemRepository) GetByID(ctx context.Context, id int32) (*model.OrderItem, error) {
	var item model.OrderItem
	err := r.db.WithContext(ctx).Preload("File").First(&item, id).Error
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &item, nil
}

func (r *OrderItemRepository) Create(ctx context.Context, item *model.OrderItem) error {
	return r.db.WithContext(ctx).Create(item).Error
}

func (r *OrderItemRepository) GetByOrderID(ctx context.Context, orderID int32) ([]*model.OrderItem, error) {
	var items []*model.OrderItem
	err := r.db.WithContext(ctx).Where("order_id = ?", orderID).Find(&items).Error
	return items, err
}