package handler

import (
	"fmt"
	"net/http"
	"strings"

	"entgo.io/ent/dialect/sql"
	"bj_power_wms/ent"
	"bj_power_wms/ent/inventory"
	"bj_power_wms/ent/inventorylock"
	"bj_power_wms/ent/predicate"
	"bj_power_wms/internal/svc"
)

// queryStockHandler 库存查询（MES 查料 / 客户端查料）
// 统一查询 inventory 一张表：按 物料编码/区域/关键字/管理粒度(manageMode) 过滤。
// 返回单一 list（结构件与精密件同表），前端统一展示、统一导出。
func queryStockHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		materialCode := r.URL.Query().Get("materialCode")
		zoneCode := r.URL.Query().Get("zoneCode")
		manageMode := r.URL.Query().Get("manageMode") // 1/2/空=全部
		keyword := r.URL.Query().Get("keyword")
		page := atoi(r.URL.Query().Get("page"), 1)
		pageSize := atoi(r.URL.Query().Get("pageSize"), 50)

		q := ctx.EntClient.Inventory.Query()
		// 仅展示在库/锁定（出库/使用/报废不计入库存）
		q = q.Where(inventory.StatusIn("在库", "锁定"))
		// 结构件隐藏数量为 0 的行
		q = q.Where(inventory.Or(inventory.ManageModeEQ(2), inventory.QuantityGT(0)))
		if materialCode != "" {
			q = q.Where(inventory.MaterialCodeEQ(materialCode))
		}
		if zoneCode != "" {
			q = q.Where(inventory.ZoneCodeEQ(zoneCode))
		}
		if manageMode == "1" {
			q = q.Where(inventory.ManageModeEQ(1))
		} else if manageMode == "2" {
			q = q.Where(inventory.ManageModeEQ(2))
		}
		if keyword != "" {
			q = q.Where(inventory.Or(
				inventory.BatchNoContains(keyword),
				inventory.MaterialCodeContains(keyword),
				inventory.SnCodeContains(keyword),
				inventory.MaterialNameContains(keyword),
			))
		}
		total, err := q.Count(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, err.Error())
			return
		}
		list, err := q.Order(ent.Desc("id")).
			Offset((page - 1) * pageSize).Limit(pageSize).All(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, err.Error())
			return
		}
		ok(w, map[string]any{
			"list":     list,
			"total":    total,
			"page":     page,
			"pageSize": pageSize,
		})
	}
}

// zoneSummaryHandler 区域库存汇总（按 区域 + 质量状态 + 类型 聚合）
// GET /api/stock/zone-summary
// 返回 rows: [{zoneCode, zoneName, quality, type(批次/精密件), qty}]
// 仅按"区域(Z01~Z04)"维度聚合，不引入货架/层/格（业务决策：小货架高频取货无需精确货位索引）。
func zoneSummaryHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		zones, _ := ctx.EntClient.Zone.Query().All(ctx0())
		zoneNameMap := map[string]string{}
		for _, z := range zones {
			zoneNameMap[z.ZoneCode] = z.ZoneName
		}

		rows, _ := ctx.EntClient.Inventory.Query().
			Where(inventory.StatusIn("在库", "锁定")).All(ctx0())

		type summRow struct {
			ZoneCode string `json:"zoneCode"`
			ZoneName string `json:"zoneName"`
			Quality  string `json:"quality"`
			Type     string `json:"type"` // 批次/精密件
			Qty      int    `json:"qty"`
		}
		agg := map[string]int{} // key: zc|quality|type
		for _, inv := range rows {
			zc := inv.ZoneCode
			if zc == "" {
				zc = "未分区"
			}
			t := "批次"
			if inv.ManageMode == 2 {
				t = "精密件"
			}
			key := zc + "|" + inv.QualityStatus + "|" + t
			if inv.ManageMode == 1 {
				agg[key] += inv.Quantity
			} else {
				agg[key] += 1
			}
		}

		out := make([]summRow, 0, len(agg))
		for k, v := range agg {
			parts := strings.Split(k, "|")
			name := zoneNameMap[parts[0]]
			if name == "" {
				name = parts[0]
			}
			out = append(out, summRow{parts[0], name, parts[1], parts[2], v})
		}
		ok(w, map[string]any{"rows": out})
	}
}

// invAvailGTE 自定义谓词：可用量(quantity - locked_qty) >= need
// 用于锁库存时的原子条件校验，避免并发超锁。
func invAvailGTE(need int) predicate.Inventory {
	return predicate.Inventory(func(s *sql.Selector) {
		s.Where(sql.ExprP(
			fmt.Sprintf("%s.%s - %s.%s >= ?",
				inventory.Table, inventory.FieldQuantity,
				inventory.Table, inventory.FieldLockedQty),
			need,
		))
	})
}

// lockStockHandler 工单锁定库存（库存占用）
// body: { orderNo, items: [{ materialCode, batchNo?, sn?, qty }] }
// 锁定为"增量"操作：结构件 locked_qty += qty；精密件状态置 锁定。绝不覆盖终值。
// 锁批次用原子增量 + 可用量条件校验；锁 SN 用状态条件原子更新，杜绝超锁与并发冲突。
func lockStockHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req struct {
			OrderNo string `json:"orderNo"`
			Items   []struct {
				MaterialCode string `json:"materialCode"`
				BatchNo      string `json:"batchNo"`
				Sn           string `json:"sn"`
				Qty          int    `json:"qty"`
			} `json:"items"`
		}
		if err := parseJSON(r, &req); err != nil {
			fail(w, http.StatusBadRequest, "参数错误: "+err.Error())
			return
		}
		if req.OrderNo == "" || len(req.Items) == 0 {
			fail(w, http.StatusBadRequest, "orderNo 和 items 必填")
			return
		}

		locked := 0
		for _, item := range req.Items {
			if item.MaterialCode == "" {
				continue
			}
			// 精密件：锁 SN（原子：仅 在库 才能锁）
			if item.Sn != "" {
				aff, err := ctx.EntClient.Inventory.Update().
					Where(inventory.ManageModeEQ(2), inventory.SnCodeEQ(item.Sn), inventory.StatusEQ("在库")).
					SetStatus("锁定").SetLockedQty(1).
					Save(ctx0())
				if err != nil {
					fail(w, http.StatusInternalServerError, "锁定 SN 失败: "+err.Error())
					return
				}
				if aff == 0 {
					fail(w, http.StatusBadRequest, "SN 不在库或不存在: "+item.Sn)
					return
				}
				ctx.EntClient.InventoryLock.Create().
					SetTargetType("SN").
					SetTargetID(item.Sn).
					SetMaterialCode(item.MaterialCode).
					SetLockedQty(1).
					SetOrderNo(req.OrderNo).
					SetStatus("ACTIVE").
					SaveX(ctx0())
				locked++
				continue
			}

			// 结构件：锁批次数量（原子增量 + 可用量校验）
			qty := item.Qty
			if qty <= 0 {
				qty = 1
			}
			b, err := ctx.EntClient.Inventory.Query().
				Where(inventory.ManageModeEQ(1), inventory.BatchNoEQ(item.BatchNo)).Only(ctx0())
			if err != nil {
				fail(w, http.StatusBadRequest, "批次不存在: "+item.BatchNo)
				return
			}
			avail := b.Quantity - b.LockedQty
			if avail < qty {
				fail(w, http.StatusConflict, "批次库存不足: "+item.BatchNo+" 可用 "+itoa(avail))
				return
			}
			aff, err := ctx.EntClient.Inventory.Update().
				Where(inventory.ID(b.ID), invAvailGTE(qty)).
				AddLockedQty(qty).
				Save(ctx0())
			if err != nil || aff == 0 {
				fail(w, http.StatusConflict, "锁定失败(库存不足或并发冲突): "+item.BatchNo)
				return
			}
			ctx.EntClient.InventoryLock.Create().
				SetTargetType("BATCH").
				SetTargetID(item.BatchNo).
				SetMaterialCode(item.MaterialCode).
				SetLockedQty(qty).
				SetOrderNo(req.OrderNo).
				SetStatus("ACTIVE").
				SaveX(ctx0())
			locked += qty
		}

		ok(w, map[string]any{"locked": locked})
	}
}

// unlockStockHandler 释放库存锁定（取消锁定/返工）
func unlockStockHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req struct {
			OrderNo string `json:"orderNo"`
			LockIDs []int  `json:"lockIds"`
		}
		if err := parseJSON(r, &req); err != nil {
			fail(w, http.StatusBadRequest, "参数错误")
			return
		}

		q := ctx.EntClient.InventoryLock.Query().
			Where(inventorylock.StatusEQ("ACTIVE"))
		if req.OrderNo != "" {
			q = q.Where(inventorylock.OrderNoEQ(req.OrderNo))
		}
		if len(req.LockIDs) > 0 {
			q = q.Where(inventorylock.IDIn(req.LockIDs...))
		}
		locks, err := q.All(ctx0())
		if err != nil {
			fail(w, http.StatusInternalServerError, err.Error())
			return
		}

		released := 0
		for _, l := range locks {
			// 还原批次锁定数 / SN 状态
			if l.TargetType == "BATCH" {
				ctx.EntClient.Inventory.Update().
					Where(inventory.BatchNoEQ(l.TargetID)).
					AddLockedQty(-l.LockedQty).
					SaveX(ctx0())
				// 防止并发下锁定数为负
				ctx.EntClient.Inventory.Update().
					Where(inventory.BatchNoEQ(l.TargetID), inventory.LockedQtyLT(0)).
					SetLockedQty(0).
					SaveX(ctx0())
			} else if l.TargetType == "SN" {
				ctx.EntClient.Inventory.Update().
					Where(inventory.SnCodeEQ(l.TargetID), inventory.StatusEQ("锁定")).
					SetStatus("在库").SetLockedQty(0).
					SaveX(ctx0())
			}
			ctx.EntClient.InventoryLock.UpdateOneID(l.ID).
				SetStatus("RELEASED").ExecX(ctx0())
			released++
		}

		ok(w, map[string]any{"released": released})
	}
}

// checkStockHandler 校验库存是否满足需求（锁库前检查）
func checkStockHandler(ctx *svc.ServiceContext) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var req struct {
			Items []struct {
				MaterialCode string `json:"materialCode"`
				Qty          int    `json:"qty"`
			} `json:"items"`
		}
		if err := parseJSON(r, &req); err != nil {
			fail(w, http.StatusBadRequest, "参数错误")
			return
		}

		results := make([]map[string]any, 0, len(req.Items))
		allOk := true
		for _, item := range req.Items {
			// 汇总可用量：结构件 quantity-locked_qty；精密件 在库数量
			rows, _ := ctx.EntClient.Inventory.Query().
				Where(inventory.MaterialCodeEQ(item.MaterialCode)).All(ctx0())
			availBatch := 0
			availSerial := 0
			for _, row := range rows {
				if row.ManageMode == 1 {
					availBatch += row.Quantity - row.LockedQty
				} else if row.Status == "在库" {
					availSerial++
				}
			}
			enough := availBatch+availSerial >= item.Qty
			if !enough {
				allOk = false
			}
			results = append(results, map[string]any{
				"materialCode": item.MaterialCode,
				"requireQty":   item.Qty,
				"availQty":     availBatch + availSerial,
				"batchAvail":   availBatch,
				"serialAvail":  availSerial,
				"enough":       enough,
			})
		}

		ok(w, map[string]any{"allOk": allOk, "items": results})
	}
}

func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	neg := n < 0
	if neg {
		n = -n
	}
	var b [20]byte
	i := len(b)
	for n > 0 {
		i--
		b[i] = byte('0' + n%10)
		n /= 10
	}
	if neg {
		i--
		b[i] = '-'
	}
	return string(b[i:])
}