package com.flower.order;

import com.flower.common.ApiException;
import com.flower.common.ApiResponse;
import com.flower.product.Product;
import com.flower.product.ProductRepository;
import com.flower.security.AdminOnly;
import com.flower.security.AuthContext;
import com.flower.user.Address;
import com.flower.user.AddressRepository;
import lombok.Data;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import javax.validation.constraints.NotEmpty;
import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

@RestController
@RequestMapping("/api/orders")
public class OrderController {
    private final OrderRepository orderRepository;
    private final OrderItemRepository orderItemRepository;
    private final ProductRepository productRepository;
    private final AddressRepository addressRepository;

    public OrderController(OrderRepository orderRepository,
                           OrderItemRepository orderItemRepository,
                           ProductRepository productRepository,
                           AddressRepository addressRepository) {
        this.orderRepository = orderRepository;
        this.orderItemRepository = orderItemRepository;
        this.productRepository = productRepository;
        this.addressRepository = addressRepository;
    }

    @PostMapping
    public ApiResponse<OrderDetail> create(@Valid @RequestBody CreateOrderRequest request) {
        Address address = addressRepository.findById(request.getAddressId())
                .orElseThrow(() -> new ApiException(404, "地址不存在"));
        if (!address.getUserId().equals(AuthContext.get().getId())) {
            throw new ApiException(403, "无权限");
        }
        List<OrderItem> items = new ArrayList<>();
        BigDecimal total = BigDecimal.ZERO;
        for (CreateOrderItem item : request.getItems()) {
            Product product = productRepository.findById(item.getProductId())
                    .orElseThrow(() -> new ApiException(404, "商品不存在"));
            if (!"ON".equals(product.getStatus())) {
                throw new ApiException(400, "商品已下架");
            }
            if (product.getStock() < item.getQuantity()) {
                throw new ApiException(400, "库存不足");
            }
            product.setStock(product.getStock() - item.getQuantity());
            productRepository.save(product);
            OrderItem orderItem = new OrderItem();
            orderItem.setProductId(product.getId());
            orderItem.setProductName(product.getName());
            orderItem.setProductPrice(product.getPrice());
            orderItem.setQuantity(item.getQuantity());
            orderItem.setProductCover(product.getCoverUrl());
            items.add(orderItem);
            total = total.add(product.getPrice().multiply(new BigDecimal(item.getQuantity())));
        }
        Order order = new Order();
        order.setOrderNo("NO" + UUID.randomUUID().toString().replace("-", "").substring(0, 12));
        order.setUserId(AuthContext.get().getId());
        order.setStatus("CREATED");
        order.setTotalAmount(total);
        order.setReceiverName(address.getRecipientName());
        order.setReceiverPhone(address.getPhone());
        order.setReceiverAddress(String.join(" ", safe(address.getProvince()),
                safe(address.getCity()), safe(address.getDistrict()), safe(address.getDetail())));
        orderRepository.save(order);
        for (OrderItem item : items) {
            item.setOrderId(order.getId());
            orderItemRepository.save(item);
        }
        return ApiResponse.ok(new OrderDetail(order, items));
    }

    @GetMapping
    public ApiResponse<List<OrderDetail>> listMine() {
        List<Order> orders = orderRepository.findByUserIdOrderByCreatedAtDesc(AuthContext.get().getId());
        List<OrderDetail> result = new ArrayList<>();
        for (Order order : orders) {
            result.add(new OrderDetail(order, orderItemRepository.findByOrderId(order.getId())));
        }
        return ApiResponse.ok(result);
    }

    @GetMapping("/{id}")
    public ApiResponse<OrderDetail> detail(@PathVariable Long id) {
        Order order = orderRepository.findById(id).orElseThrow(() -> new ApiException(404, "订单不存在"));
        if (!order.getUserId().equals(AuthContext.get().getId())) {
            throw new ApiException(403, "无权限");
        }
        return ApiResponse.ok(new OrderDetail(order, orderItemRepository.findByOrderId(id)));
    }

    @PutMapping("/{id}/cancel")
    public ApiResponse<Order> cancel(@PathVariable Long id) {
        Order order = orderRepository.findById(id).orElseThrow(() -> new ApiException(404, "订单不存在"));
        if (!order.getUserId().equals(AuthContext.get().getId())) {
            throw new ApiException(403, "无权限");
        }
        if (!"CREATED".equals(order.getStatus())) {
            throw new ApiException(400, "订单无法取消");
        }
        order.setStatus("CANCELED");
        orderRepository.save(order);
        return ApiResponse.ok(order);
    }

    @PostMapping("/{id}/pay")
    public ApiResponse<Order> pay(@PathVariable Long id) {
        Order order = orderRepository.findById(id).orElseThrow(() -> new ApiException(404, "订单不存在"));
        if (!order.getUserId().equals(AuthContext.get().getId())) {
            throw new ApiException(403, "无权限");
        }
        if (!"CREATED".equals(order.getStatus())) {
            throw new ApiException(400, "订单无法支付");
        }
        order.setStatus("PAID");
        order.setPayAt(LocalDateTime.now());
        orderRepository.save(order);
        return ApiResponse.ok(order);
    }

    @AdminOnly
    @GetMapping("/admin/all")
    public ApiResponse<List<OrderDetail>> listAll() {
        List<Order> orders = orderRepository.findAll();
        List<OrderDetail> result = new ArrayList<>();
        for (Order order : orders) {
            result.add(new OrderDetail(order, orderItemRepository.findByOrderId(order.getId())));
        }
        return ApiResponse.ok(result);
    }

    @AdminOnly
    @PutMapping("/admin/{id}/status")
    public ApiResponse<Order> updateStatus(@PathVariable Long id, @RequestBody UpdateStatusRequest request) {
        Order order = orderRepository.findById(id).orElseThrow(() -> new ApiException(404, "订单不存在"));
        order.setStatus(request.getStatus());
        orderRepository.save(order);
        return ApiResponse.ok(order);
    }

    private String safe(String value) {
        return value == null ? "" : value;
    }

    @Data
    public static class CreateOrderRequest {
        private Long addressId;
        @NotEmpty
        private List<CreateOrderItem> items;
    }

    @Data
    public static class CreateOrderItem {
        private Long productId;
        private Integer quantity;
    }

    @Data
    public static class UpdateStatusRequest {
        private String status;
    }

    @Data
    public static class OrderDetail {
        private Order order;
        private List<OrderItem> items;

        public OrderDetail(Order order, List<OrderItem> items) {
            this.order = order;
            this.items = items;
        }
    }
}