package handler

import (
	"net/http"
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/xuri/excelize/v2"
	"gorm.io/gorm"

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

type ImportHandler struct {
	db *gorm.DB
}

func NewImportHandler(db *gorm.DB) *ImportHandler {
	return &ImportHandler{db: db}
}

// ImportProducts POST /api/v1/import/products
// 支持 .xlsx / .csv，列顺序：名称,系列,规格,单位,品牌,最低库存,备注
func (h *ImportHandler) ImportProducts(c *gin.Context) {
	shopID := middleware.GetShopID(c)

	file, err := c.FormFile("file")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "file required"})
		return
	}

	f, err := file.Open()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	defer f.Close()

	xl, err := excelize.OpenReader(f)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid excel file: " + err.Error()})
		return
	}

	sheetName := xl.GetSheetName(0)
	rows, err := xl.GetRows(sheetName)
	if err != nil || len(rows) < 2 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "empty or invalid sheet"})
		return
	}

	var products []model.Product
	var errRows []map[string]interface{}

	for i, row := range rows[1:] { // 跳过表头
		if len(row) < 1 || strings.TrimSpace(row[0]) == "" {
			continue
		}
		p := model.Product{
			TenantBase: model.TenantBase{ShopID: shopID},
		}
		p.Name = cell(row, 0)
		p.Series = cell(row, 1)
		p.Spec = cell(row, 2)
		p.Unit = cell(row, 3)
		p.Brand = cell(row, 4)
		p.Remark = cell(row, 6)

		if p.Name == "" {
			errRows = append(errRows, map[string]interface{}{"row": i + 2, "error": "name is empty"})
			continue
		}
		products = append(products, p)
	}

	if len(products) == 0 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "no valid rows", "errors": errRows})
		return
	}

	if err := h.db.CreateInBatches(&products, 100).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"imported": len(products),
		"errors":   errRows,
	})
}

// ImportPartners POST /api/v1/import/partners
// 列顺序：名称,类型(supplier/customer),联系人,电话,地址,备注
func (h *ImportHandler) ImportPartners(c *gin.Context) {
	shopID := middleware.GetShopID(c)

	file, err := c.FormFile("file")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "file required"})
		return
	}

	f, err := file.Open()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	defer f.Close()

	xl, err := excelize.OpenReader(f)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid excel file"})
		return
	}

	rows, err := xl.GetRows(xl.GetSheetName(0))
	if err != nil || len(rows) < 2 {
		c.JSON(http.StatusBadRequest, gin.H{"error": "empty sheet"})
		return
	}

	var partners []model.Partner
	for _, row := range rows[1:] {
		if len(row) < 1 || strings.TrimSpace(row[0]) == "" {
			continue
		}
		t := cell(row, 1)
		if t == "" {
			t = "supplier"
		}
		partners = append(partners, model.Partner{
			TenantBase: model.TenantBase{ShopID: shopID},
			Name:       cell(row, 0),
			Type:       t,
			Contact:    cell(row, 2),
			Phone:      cell(row, 3),
			Address:    cell(row, 4),
			Remark:     cell(row, 5),
		})
	}

	if err := h.db.CreateInBatches(&partners, 100).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"imported": len(partners)})
}

func cell(row []string, idx int) string {
	if idx >= len(row) {
		return ""
	}
	return strings.TrimSpace(row[idx])
}