package handler

import (
	"fmt"
	"net/http"
	"strconv"

	"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/util"
)

type PartnerHandler struct {
	db *gorm.DB
}

func NewPartnerHandler(db *gorm.DB) *PartnerHandler {
	return &PartnerHandler{db: db}
}

func (h *PartnerHandler) List(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	// 往来单位是有界的参考数据，下拉需一次取全部；放宽上限到 1000，
	// 避免前端请求大页被 ValidatePageSize 回退到默认 20（超上限即返回默认值，非截断）。
	pageSize = util.ValidatePageSize(pageSize, 20, 1000)

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

	if t := c.Query("type"); t != "" {
		query = query.Where("FIND_IN_SET(?, type)", t)
	}
	if kw := c.Query("keyword"); kw != "" {
		// 原型搜索口径：名称 / 拼音（全拼+首字母）/ 联系人；phone 保留兼容
		like := "%" + kw + "%"
		query = query.Where(
			"name LIKE ? OR contact LIKE ? OR phone LIKE ? OR name_pinyin LIKE ? OR name_initials LIKE ?",
			like, like, like, like, like)
	}

	var total int64
	query.Count(&total)

	partners := make([]model.Partner, 0)
	query.Offset((page - 1) * pageSize).Limit(pageSize).Order("id DESC").Find(&partners)

	c.JSON(http.StatusOK, gin.H{"data": partners, "total": total, "page": page, "page_size": pageSize})
}

func (h *PartnerHandler) Create(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	var p model.Partner
	if err := c.ShouldBindJSON(&p); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	p.ShopID = shopID
	p.NamePinyin, p.NameInitials = util.ToPinyin(p.Name)
	// 编码未提供时自动生成：供应商 S001/S002…，客户 C001/C002…
	if p.Code == "" {
		prefix := "S"
		if p.Type == "customer" {
			prefix = "C"
		}
		var count int64
		h.db.Model(&model.Partner{}).
			Where("shop_id = ? AND type = ? AND deleted_at IS NULL", shopID, p.Type).
			Count(&count)
		p.Code = fmt.Sprintf("%s%03d", prefix, count+1)
	}
	if err := h.db.Create(&p).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	util.RespondCreated(c, p)
}

func (h *PartnerHandler) Update(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	var p model.Partner
	if err := h.db.Where("id = ? AND shop_id = ? AND deleted_at IS NULL", c.Param("id"), shopID).
		First(&p).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
		return
	}
	var req struct {
		Name        string  `json:"name"`
		Type        string  `json:"type"`
		Code        string  `json:"code"`
		Contact     string  `json:"contact"`
		Phone       string  `json:"phone"`
		Address     string  `json:"address"`
		BankAccount string  `json:"bank_account"`
		CreditLimit float64 `json:"credit_limit"`
		// 期初余额：指针区分「未传」与 0，旧客户端不传时不清零
		Balance *float64 `json:"balance"`
		Status  string   `json:"status"`
		Remark  string   `json:"remark"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	pinyin, initials := util.ToPinyin(req.Name)
	updates := map[string]interface{}{
		"name":          req.Name,
		"name_pinyin":   pinyin,
		"name_initials": initials,
		"type":          req.Type,
		"code":          req.Code,
		"contact":       req.Contact,
		"phone":         req.Phone,
		"address":       req.Address,
		"bank_account":  req.BankAccount,
		"credit_limit":  req.CreditLimit,
		"status":        req.Status,
		"remark":        req.Remark,
	}
	if req.Balance != nil {
		updates["balance"] = *req.Balance
	}
	if err := h.db.Model(&p).Where("shop_id = ?", shopID).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	h.db.Where("id = ? AND shop_id = ?", p.ID, shopID).First(&p)
	util.RespondSuccess(c, p)
}

func (h *PartnerHandler) Delete(c *gin.Context) {
	shopID := middleware.GetShopID(c)
	now := timeNow()
	result := h.db.Model(&model.Partner{}).
		Where("id = ? AND shop_id = ? AND deleted_at IS NULL", c.Param("id"), shopID).
		Update("deleted_at", now)
	if result.RowsAffected == 0 {
		c.JSON(http.StatusNotFound, gin.H{"error": "not found"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "deleted"})
}