package handler

import (
	"net/http"

	"silk-server-go/internal/middleware"
	"silk-server-go/internal/model"

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

// RegisterConsumableRoutes 注册耗材路由
func RegisterConsumableRoutes(rg *gin.RouterGroup, db *gorm.DB) {
	read := middleware.RequirePermission(db, "consumable:read")
	write := middleware.RequirePermission(db, "consumable:write")
	rg.GET("/consumables", read, listConsumables(db))
	rg.POST("/consumables", write, createConsumable(db))
	rg.PATCH("/consumables/:id", write, updateConsumable(db))
	rg.DELETE("/consumables/:id", write, deleteConsumable(db))
	rg.GET("/consumables/alerts", read, consumableAlerts(db))
	rg.GET("/consumables/purchase-suggestions", read, purchaseSuggestions(db))
}

// listConsumables 耗材列表（category 过滤）
func listConsumables(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		q := db.Model(&model.Consumable{})
		if cat := c.Query("category"); cat != "" {
			q = q.Where("category = ?", cat)
		}
		var list []model.Consumable
		q.Order("name ASC").Find(&list)
		c.JSON(http.StatusOK, list)
	}
}

func createConsumable(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var item model.Consumable
		if err := c.ShouldBindJSON(&item); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		item.ID = ""
		if item.Name == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": "耗材名称不能为空"})
			return
		}
		if item.Category == "" {
			item.Category = "other"
		}
		if err := db.Create(&item).Error; err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "创建失败"})
			return
		}
		c.JSON(http.StatusCreated, item)
	}
}

func updateConsumable(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id := c.Param("id")
		var item model.Consumable
		if db.Where("id = ?", id).First(&item).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consumable not found"})
			return
		}
		updates, err := bindUpdates(c)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		if len(updates) > 0 {
			db.Model(&model.Consumable{}).Where("id = ?", id).Updates(updates)
		}
		db.Where("id = ?", id).First(&item)
		c.JSON(http.StatusOK, item)
	}
}

func deleteConsumable(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id := c.Param("id")
		var item model.Consumable
		if db.Where("id = ?", id).First(&item).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "consumable not found"})
			return
		}
		db.Where("id = ?", id).Delete(&model.Consumable{})
		c.JSON(http.StatusOK, gin.H{"id": id})
	}
}

// consumableAlerts 低库存 + 临期/过期预警（30 天窗口）
func consumableAlerts(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var list []model.Consumable
		db.Find(&list)
		result := make([]gin.H, 0)
		for _, item := range list {
			alertType := ""
			if item.LowStockAlert() {
				alertType = "low_stock"
			}
			if item.ExpiringAlert(30) {
				alertType = "expiring"
			}
			if alertType != "" {
				result = append(result, gin.H{
					"id":          item.ID,
					"name":        item.Name,
					"category":    item.Category,
					"quantity":    item.Quantity,
					"unit":        item.Unit,
					"minQuantity": item.MinQuantity,
					"expiryDate":  item.ExpiryDate,
					"alertType":   alertType,
				})
			}
		}
		c.JSON(http.StatusOK, result)
	}
}

// purchaseSuggestions 低于安全阈值的采购建议
func purchaseSuggestions(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var list []model.Consumable
		db.Find(&list)
		result := make([]gin.H, 0)
		for _, item := range list {
			if s := item.PurchaseSuggestion(); s > 0 {
				result = append(result, gin.H{
					"id":          item.ID,
					"name":        item.Name,
					"category":    item.Category,
					"quantity":    item.Quantity,
					"unit":        item.Unit,
					"minQuantity": item.MinQuantity,
					"suggest":     s,
				})
			}
		}
		c.JSON(http.StatusOK, result)
	}
}