package handler

import (
	"errors"
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"github.com/wangjia/jiu/backend/internal/middleware"
	"github.com/wangjia/jiu/backend/internal/model"
	"github.com/wangjia/jiu/backend/internal/service"
	"github.com/wangjia/jiu/backend/internal/util"
)

type StockOutHandler struct {
	db       *gorm.DB
	stockSvc *service.StockService
}

func NewStockOutHandler(db *gorm.DB, svc *service.StockService) *StockOutHandler {
	return &StockOutHandler{db: db, stockSvc: svc}
}

// List GET /api/v1/stock-out/orders
// stripStockOutCost 服务端兜底：成本/利润仅管理员可见（2026-07 用户拍板）。
// operator/readonly 的 List/Get 响应把 cost_price/cost_amount/profit_total 抹零，
// 防止非管理员通过抓包看到成本与利润（前端同时隐藏对应列）。
func stripStockOutCost(role string, orders []model.StockOutOrder) {
	if role == "admin" || role == "superadmin" {
		return
	}
	for i := range orders {
		orders[i].ProfitTotal = 0
		for j := range orders[i].Items {
			orders[i].Items[j].CostPrice = 0
			orders[i].Items[j].CostAmount = 0
		}
	}
}

func (h *StockOutHandler) List(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	pageSize = util.ValidatePageSize(pageSize, 20, 200)

	query := h.db.Model(&model.StockOutOrder{}).
		Where("shop_id = ? AND deleted_at IS NULL", shopID)

	if status := c.Query("status"); status != "" {
		query = query.Where("status IN ?", strings.Split(status, ","))
	}
	if startDate := c.Query("start_date"); startDate != "" {
		query = query.Where("order_date >= ?", startDate)
	}
	if endDate := c.Query("end_date"); endDate != "" {
		query = query.Where("order_date <= ?", endDate)
	}
	if kw := strings.TrimSpace(c.Query("keyword")); kw != "" {
		like := "%" + kw + "%"
		// keyword 命中：单号 / 酒名（含全拼+首字母）/ 商品编码 —— 反查含该明细的单据。
		// （不含往来单位；供应商/客户改由工具栏下拉筛选。）
		// 酒名「product 主数据名 OR 明细快照名」任一命中——不能用 COALESCE 二选一：历史导入单的
		// 明细 product_id 统一指向占位商品「历史导入占位」（p.name 非空），COALESCE 会被占位名劫持，
		// 永远取不到真实快照 product_name，导致导入单按真实酒名搜不到。拼音只在 products 上（快照无拼音列）。
		// 编码同理「主数据 p.code OR 快照 it.product_code」双匹配：存量应用建单的明细快照为空串，
		// 只查快照会「页面看得到编码、搜索搜不到」。
		query = query.Where(
			"order_no LIKE ?"+
				" OR id IN (SELECT it.order_id FROM stock_out_items it"+
				"   LEFT JOIN products p ON p.id = it.product_id AND p.shop_id = it.shop_id"+
				"   WHERE it.shop_id = ? AND it.deleted_at IS NULL"+
				"     AND (p.name LIKE ? OR it.product_name LIKE ? OR it.product_code LIKE ?"+
				"          OR p.code LIKE ? OR p.name_pinyin LIKE ? OR p.name_initials LIKE ?))",
			like, shopID, like, like, like, like, like, like,
		)
	}
	// 详细搜索多字段（各参数独立可选、组合为 AND）
	query = applyStockOrderDetailFilters(query, shopID, c, "stock_out_items")

	var total int64
	query.Count(&total)

	orders := make([]model.StockOutOrder, 0)
	query.Preload("Warehouse", "shop_id = ?", shopID).
		Preload("Partner", "shop_id = ?", shopID).
		Preload("Operator", "shop_id = ?", shopID).
		Preload("Reviewer", "shop_id = ?", shopID).
		Offset((page - 1) * pageSize).Limit(pageSize).
		Order("order_date DESC, id DESC").Find(&orders)

	stripStockOutCost(middleware.GetRole(c), orders)
	c.JSON(http.StatusOK, gin.H{"data": orders, "total": total, "page": page, "page_size": pageSize})
}

// Summary GET /api/v1/stock-out/summary —— 全店出库 KPI（守多租户；?window=rolling30 见 summaryBounds）
func (h *StockOutHandler) Summary(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	curFrom, curTo, prevFrom, prevTo := summaryBounds(c, time.Now())
	agg := func(from, to string) (int64, float64) {
		var r struct {
			Cnt int64
			Amt float64
		}
		h.db.Model(&model.StockOutOrder{}).
			Where("shop_id = ? AND deleted_at IS NULL AND order_date >= ? AND order_date < ?", shopID, from, to).
			Select("COUNT(*) AS cnt, COALESCE(SUM(sale_total),0) AS amt").Scan(&r)
		return r.Cnt, r.Amt
	}
	var s stockSummary
	s.MonthCount, s.MonthAmount = agg(curFrom, curTo)
	s.LastMonthCount, s.LastMonthAmount = agg(prevFrom, prevTo)
	h.db.Model(&model.StockOutOrder{}).
		Where("shop_id = ? AND status = ? AND deleted_at IS NULL", shopID, "pending").Count(&s.PendingCount)
	h.db.Model(&model.StockOutOrder{}).
		Where("shop_id = ? AND status = ? AND deleted_at IS NULL", shopID, "draft").Count(&s.DraftCount)
	c.JSON(http.StatusOK, s)
}

// ConfirmSale PUT/POST /api/v1/stock-out/orders/:id/confirm-sale —— 确认售价（先出后定价）
func (h *StockOutHandler) ConfirmSale(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	userID := middleware.GetUserID(c)
	role := middleware.GetRole(c)
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)

	var req struct {
		Items []service.SaleConfirmItem `json:"items"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if len(req.Items) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "未提供要确认的明细"})
		return
	}
	for _, it := range req.Items {
		if it.SalePrice <= 0 {
			c.JSON(http.StatusBadRequest, gin.H{"error": "售价必须大于 0"})
			return
		}
	}
	if err := h.stockSvc.ConfirmStockOutSale(shopID, id, userID, role, req.Items); err != nil {
		if errors.Is(err, service.ErrForbidden) {
			c.JSON(http.StatusForbidden, gin.H{"error": "无权确认售价"})
			return
		}
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "sale confirmed"})
}

// Get GET /api/v1/stock-out/orders/:id
func (h *StockOutHandler) Get(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	var order model.StockOutOrder
	if err := h.db.Preload("Items.Product", "shop_id = ?", shopID).
		Preload("Warehouse", "shop_id = ?", shopID).Preload("Partner", "shop_id = ?", shopID).
		Preload("Operator", "shop_id = ?", shopID).Preload("Reviewer", "shop_id = ?", shopID).
		Where("id = ? AND shop_id = ? AND deleted_at IS NULL", c.Param("id"), shopID).
		First(&order).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
		return
	}
	one := []model.StockOutOrder{order}
	stripStockOutCost(middleware.GetRole(c), one)
	util.RespondSuccess(c, one[0])
}

// Create POST /api/v1/stock-out/orders
// fillStockOutItemSnapshots 按 product_id 从商品主数据拷明细快照列（编码/名称/系列/规格/批次/生产日期）。
// 明细 = product 引用 + 快照（历史保真：商品日后改名/删除，单据仍能还原当时信息；搜索/退单提示读快照）。
// 入库建单在 createIndependentProduct 后即填快照，出库同样必须在建单/改单时填齐。
func fillStockOutItemSnapshots(db *gorm.DB, shopID uint64, items []model.StockOutItem) error {
	if len(items) == 0 {
		return nil
	}
	ids := make([]uint64, 0, len(items))
	for i := range items {
		ids = append(ids, items[i].ProductID)
	}
	var prods []model.Product
	if err := db.Where("shop_id = ? AND id IN ?", shopID, ids).Find(&prods).Error; err != nil {
		return err
	}
	byID := make(map[uint64]*model.Product, len(prods))
	for i := range prods {
		byID[prods[i].ID] = &prods[i]
	}
	for i := range items {
		p, ok := byID[items[i].ProductID]
		if !ok {
			return fmt.Errorf("明细第 %d 行商品不存在", i+1)
		}
		items[i].ProductCode = p.Code
		items[i].ProductName = p.Name
		items[i].Series = p.Series
		items[i].Spec = p.Spec
		if items[i].BatchNo == "" {
			items[i].BatchNo = p.BatchNo
		}
		if items[i].ProductionDate == nil {
			items[i].ProductionDate = p.ProductionDate
		}
	}
	return nil
}

func (h *StockOutHandler) Create(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	operatorID := middleware.GetUserID(c)

	var req model.StockOutOrder
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// SEC-001：外键必须属于当前店（防跨租户引用泄露）
	if err := ensureShopRef(h.db, "warehouses", req.WarehouseID, shopID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := ensureShopRefOpt(h.db, "partners", req.PartnerID, shopID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	req.ShopID = shopID
	req.OperatorID = operatorID

	// 状态只允许 draft 或 pending；直接提交审核时校验库存
	if req.Status == "pending" {
		if err := h.stockSvc.CheckInventoryAvailability(shopID, req.WarehouseID, req.Items); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
	} else {
		req.Status = "draft"
	}

	orderNo, err := h.stockSvc.GenerateOrderNo(shopID, "stock_out")
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	req.OrderNo = orderNo

	var total, profit float64
	for i := range req.Items {
		it := &req.Items[i]
		it.ShopID = shopID
		// 兼容旧客户端(≤1.0.87)：unit_price 回落为 cost_price（新 key 优先）
		if it.CostPrice == 0 && it.LegacyUnitPrice != nil {
			it.CostPrice = *it.LegacyUnitPrice
		}
		// 成本小计 / 售价小计分列；应收(SaleTotal)与总利润按售价口径
		it.CostAmount = it.Quantity * it.CostPrice
		it.SaleAmount = it.Quantity * it.SalePrice
		total += it.SaleAmount
		if it.SalePrice > 0 {
			profit += (it.SalePrice - it.CostPrice) * it.Quantity
		}
	}
	req.SaleTotal = total
	req.ProfitTotal = profit

	if err := fillStockOutItemSnapshots(h.db, shopID, req.Items); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if err := h.db.Create(&req).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	util.RespondCreated(c, req)
}

// Update PUT /api/v1/stock-out/orders/:id （只允许草稿状态）
func (h *StockOutHandler) Update(c *gin.Context) {
	shopID := middleware.GetShopID(c)

	var order model.StockOutOrder
	if err := h.db.Where("id = ? AND shop_id = ? AND status = 'draft' AND deleted_at IS NULL", c.Param("id"), shopID).
		First(&order).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "出库单不存在或不可修改"})
		return
	}

	var req model.StockOutOrder
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// SEC-001：外键必须属于当前店（防跨租户引用泄露）
	if err := ensureShopRef(h.db, "warehouses", req.WarehouseID, shopID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := ensureShopRefOpt(h.db, "partners", req.PartnerID, shopID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	err := h.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Where("order_id = ?", order.ID).Delete(&model.StockOutItem{}).Error; err != nil {
			return err
		}
		var total float64
		var profit float64
		for i := range req.Items {
			it := &req.Items[i]
			it.ShopID = shopID
			it.OrderID = order.ID
			if it.CostPrice == 0 && it.LegacyUnitPrice != nil {
				it.CostPrice = *it.LegacyUnitPrice
			}
			it.CostAmount = it.Quantity * it.CostPrice
			it.SaleAmount = it.Quantity * it.SalePrice
			total += it.SaleAmount
			if it.SalePrice > 0 {
				profit += (it.SalePrice - it.CostPrice) * it.Quantity
			}
		}
		if err := fillStockOutItemSnapshots(tx, shopID, req.Items); err != nil {
			return err
		}
		updates := map[string]interface{}{
			"warehouse_id": req.WarehouseID,
			"partner_id":   req.PartnerID,
			"order_date":   req.OrderDate,
			"remark":       req.Remark,
			"sale_total": total,
			"profit_total": profit,
		}
		if err := tx.Model(&order).Updates(updates).Error; err != nil {
			return err
		}
		if len(req.Items) > 0 {
			if err := tx.Create(&req.Items).Error; err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "updated"})
}

// Delete DELETE /api/v1/stock-out/orders/:id （只允许草稿状态）
func (h *StockOutHandler) Delete(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	now := timeNow()
	result := h.db.Model(&model.StockOutOrder{}).
		Where("id = ? AND shop_id = ? AND status = 'draft' AND deleted_at IS NULL", c.Param("id"), shopID).
		Update("deleted_at", now)
	if result.RowsAffected == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "出库单不存在或不可删除"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
}

// Submit PUT /api/v1/stock-out/orders/:id/submit
func (h *StockOutHandler) Submit(c *gin.Context) {
	shopID := middleware.GetShopID(c)

	// 加载订单及明细，校验库存后再改状态
	var order model.StockOutOrder
	if err := h.db.Preload("Items").
		Where("id = ? AND shop_id = ? AND status = 'draft'", c.Param("id"), shopID).
		First(&order).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "order not found or not in draft status"})
		return
	}
	if err := h.stockSvc.CheckInventoryAvailability(shopID, order.WarehouseID, order.Items); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	h.db.Model(&order).Update("status", "pending")
	c.JSON(http.StatusOK, gin.H{"message": "submitted"})
}

// Approve PUT /api/v1/stock-out/orders/:id/approve
func (h *StockOutHandler) Approve(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	reviewerID := middleware.GetUserID(c)

	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
	if err := h.stockSvc.ApproveStockOut(shopID, id, reviewerID); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "approved"})
}

// Reject PUT /api/v1/stock-out/orders/:id/reject
func (h *StockOutHandler) Reject(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	reviewerID := middleware.GetUserID(c)
	now := timeNow()

	result := h.db.Model(&model.StockOutOrder{}).
		Where("id = ? AND shop_id = ? AND status = 'pending'", c.Param("id"), shopID).
		Updates(map[string]interface{}{
			"status":      "rejected",
			"reviewer_id": reviewerID,
			"reviewed_at": now,
		})
	if result.RowsAffected == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "order not found or not in pending status"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "rejected"})
}

// Withdraw PUT /api/v1/stock-out/orders/:id/withdraw
// 审核中(pending)撤回为草稿(draft)，修改后可重新提交。仅 pending 可撤回；
// 已审核(approved)单据只读、库存已变动，不可撤回。
// 权限：管理员/超管可撤回任意单；普通操作员只能撤回本人提交的单（operator_id 为本人）。
func (h *StockOutHandler) Withdraw(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	userID := middleware.GetUserID(c)
	role := middleware.GetRole(c)

	var order model.StockOutOrder
	if err := h.db.Where("id = ? AND shop_id = ? AND status = 'pending'", c.Param("id"), shopID).
		First(&order).Error; err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "order not found or not in pending status"})
		return
	}

	isAdmin := role == "admin" || role == "superadmin"
	if !isAdmin && order.OperatorID != userID {
		c.JSON(http.StatusForbidden, gin.H{"error": "只能撤回本人提交的单据"})
		return
	}

	h.db.Model(&model.StockOutOrder{}).
		Where("id = ? AND shop_id = ?", order.ID, shopID).
		Update("status", "draft")
	c.JSON(http.StatusOK, gin.H{"message": "withdrawn"})
}

// Return POST /api/v1/stock-out/orders/:id/return
// 出库退单：退掉指定明细，数量加回库存、冲减应收。仅 approved 单；管理员/超管 或 本人。
func (h *StockOutHandler) Return(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	userID := middleware.GetUserID(c)
	role := middleware.GetRole(c)
	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)

	var req struct {
		ItemIDs []uint64 `json:"item_ids"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if len(req.ItemIDs) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "未选择退单明细"})
		return
	}
	if err := h.stockSvc.ReturnStockOut(shopID, id, userID, role, req.ItemIDs); err != nil {
		if errors.Is(err, service.ErrForbidden) {
			c.JSON(http.StatusForbidden, gin.H{"error": "无权退单"})
			return
		}
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "returned"})
}