package erp

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	"server/models"

	"github.com/beego/beego/v2/client/orm"
)

// Settings 从租户「ERP基础设置」读取的运行时参数。
type Settings struct {
	NegativeAllowed    bool   // negative_stock_allowed
	AutoDocNo          bool   // auto_generate_doc_no
	DefaultWarehouseID uint64 // default_warehouse（存的是名称，按名称匹配）
	SalesPriceType     string // sales_price_type：sale/wholesale/member
}

func GetSettings(tenantID string) *Settings {
	s := &Settings{AutoDocNo: true, SalesPriceType: "sale"}
	if v := models.GetErpNormalSettingByKey(tenantID, "negative_stock_allowed"); v != nil {
		s.NegativeAllowed = strings.TrimSpace(v.ConfigValue) == "1"
	}
	if v := models.GetErpNormalSettingByKey(tenantID, "auto_generate_doc_no"); v != nil {
		s.AutoDocNo = strings.TrimSpace(v.ConfigValue) != "0"
	}
	if v := models.GetErpNormalSettingByKey(tenantID, "sales_price_type"); v != nil {
		if t := strings.TrimSpace(v.ConfigValue); t != "" {
			s.SalesPriceType = t
		}
	}
	if v := models.GetErpNormalSettingByKey(tenantID, "default_warehouse"); v != nil {
		name := strings.TrimSpace(v.ConfigValue)
		if name != "" {
			var wh models.ErpWarehouse
			if err := models.Orm.QueryTable(new(models.ErpWarehouse)).
				Filter("tenant_id", tenantID).
				Filter("warehouse_name", name).
				Filter("delete_time__isnull", true).One(&wh); err == nil {
				s.DefaultWarehouseID = wh.ID
			}
		}
	}
	if s.DefaultWarehouseID == 0 {
		var wh models.ErpWarehouse
		if err := models.Orm.QueryTable(new(models.ErpWarehouse)).
			Filter("tenant_id", tenantID).
			Filter("is_default", 1).
			Filter("status", 1).
			Filter("delete_time__isnull", true).One(&wh); err == nil {
			s.DefaultWarehouseID = wh.ID
		}
	}
	return s
}

// erpDocPrefixDefaults 各单据类型的取号前缀默认值（也是基础设置里可改的初值）。
// 必须一型一前缀：共用前缀会让采购入库/其他入库、采购退货/销售退货同号段，
// 单据号无法反推类型，日次序号也会互相穿插。
var erpDocPrefixDefaults = map[string]string{
	models.ErpDocPurchaseOrder:  "CGDD",
	models.ErpDocPurchaseIn:     "CGRK",
	models.ErpDocPurchaseReturn: "CGTH",
	models.ErpDocSalesOrder:     "XSDD",
	models.ErpDocSalesOut:       "XSCK",
	models.ErpDocSalesReturn:    "XSTH",
	models.ErpDocOtherIn:        "QTRK",
	models.ErpDocOtherOut:       "QTCK",
	models.ErpDocTransfer:       "DB",
	models.ErpDocStockTake:      "PD",
}

// ErpDocPrefixKey 单据类型 → 基础设置键（document 分组，每型独立）
func ErpDocPrefixKey(docType string) string {
	if _, ok := erpDocPrefixDefaults[docType]; !ok {
		return ""
	}
	return "doc_prefix_" + docType
}

// ErpDocPrefixDefaults 供基础设置接口登记默认前缀
func ErpDocPrefixDefaults() map[string]string {
	return erpDocPrefixDefaults
}

// ErpDocPrefixField 基础设置「单据设置」里一条可编辑的单据前缀
type ErpDocPrefixField struct {
	Key     string
	Name    string
	Default string
}

// 表单展示顺序：按采购→销售→其他→调拨/盘点
var erpDocPrefixLabels = []struct {
	docType string
	name    string
}{
	{models.ErpDocPurchaseOrder, "采购订单前缀"},
	{models.ErpDocPurchaseIn, "采购入库前缀"},
	{models.ErpDocPurchaseReturn, "采购退货前缀"},
	{models.ErpDocSalesOrder, "销售订单前缀"},
	{models.ErpDocSalesOut, "销售出库前缀"},
	{models.ErpDocSalesReturn, "销售退货前缀"},
	{models.ErpDocOtherIn, "其他入库前缀"},
	{models.ErpDocOtherOut, "其他出库前缀"},
	{models.ErpDocTransfer, "调拨单前缀"},
	{models.ErpDocStockTake, "盘点单前缀"},
}

// ErpDocPrefixFields 返回全部单据前缀配置项，供基础设置接口注册默认值
func ErpDocPrefixFields() []ErpDocPrefixField {
	out := make([]ErpDocPrefixField, 0, len(erpDocPrefixLabels))
	for _, l := range erpDocPrefixLabels {
		out = append(out, ErpDocPrefixField{
			Key:     ErpDocPrefixKey(l.docType),
			Name:    l.name,
			Default: erpDocPrefixDefaults[l.docType],
		})
	}
	return out
}

// docNoPrefix 按单据类型取号前缀（基础设置 document 分组），缺省用类型缩写。
func docNoPrefix(tenantID, docType string) string {
	if key := ErpDocPrefixKey(docType); key != "" {
		if v := models.GetErpNormalSettingByKey(tenantID, key); v != nil {
			if p := strings.ToUpper(strings.TrimSpace(v.ConfigValue)); p != "" {
				return p
			}
		}
	}
	if p, ok := erpDocPrefixDefaults[docType]; ok {
		return p
	}
	return "ERP"
}

// GenerateDocNo 生成单据号：前缀+YYYYMMDD+当日3位序号（按租户+类型+日期计数）。
// 依赖 yz_backend_erp_document 的 uk_tenant_docno 唯一索引兜底，调用方需处理重号重试。
func GenerateDocNo(o orm.QueryExecutor, tenantID, docType string) (string, error) {
	prefix := docNoPrefix(tenantID, docType)
	day := time.Now().Format("20060102")
	var count int64
	var err error
	if o != nil {
		count, err = o.QueryTable(new(models.ErpDocument)).
			Filter("tenant_id", tenantID).Filter("doc_no__startswith", prefix+day).Count()
	} else {
		count, err = models.Orm.QueryTable(new(models.ErpDocument)).
			Filter("tenant_id", tenantID).Filter("doc_no__startswith", prefix+day).Count()
	}
	if err != nil && err != orm.ErrNoRows {
		return "", err
	}
	seq := count + 1
	if seq > 999 {
		return "", fmt.Errorf("当日单据编号已超过999，请先归档")
	}
	return fmt.Sprintf("%s%s%03d", prefix, day, seq), nil
}

// GenerateFundNo 收付款单号：前缀(SK/FK/QR/ZC)+日期+序号。
func GenerateFundNo(tenantID string, fundType int8) (string, error) {
	prefixMap := map[int8]string{
		models.ErpFundReceive: "SK", models.ErpFundPay: "FK",
		models.ErpFundOtherIn: "QR", models.ErpFundExpense: "FY",
	}
	p, ok := prefixMap[fundType]
	if !ok {
		p = "ZJ"
	}
	day := time.Now().Format("20060102")
	count, err := models.Orm.QueryTable(new(models.ErpFundBill)).
		Filter("tenant_id", tenantID).Filter("fund_no__startswith", p+day).Count()
	if err != nil && err != orm.ErrNoRows {
		return "", err
	}
	return fmt.Sprintf("%s%s%03d", p, day, count+1), nil
}

// GenerateProductCode 商品编号：SP+日期+当日序号（租户内唯一由 uk_tenant_code 兜底）。
func GenerateProductCode(tenantID string) string {
	day := time.Now().Format("20060102")
	count, _ := models.Orm.QueryTable(new(models.ErpProduct)).
		Filter("tenant_id", tenantID).Filter("product_code__startswith", "SP"+day).Count()
	return fmt.Sprintf("SP%s%03d", day, count+1)
}

// GetPartnerPaymentDays 取往来单位账期天数（应收到期日计算）。
func GetPartnerPaymentDays(partnerType string, partnerID uint64) int {
	if partnerID == 0 {
		return 0
	}
	switch partnerType {
	case "customer":
		var row models.TenantCrmCustomer
		if err := models.Orm.QueryTable(new(models.TenantCrmCustomer)).
			Filter("id", partnerID).One(&row); err == nil {
			return row.PaymentDays
		}
	case "supplier":
		var row models.TenantCrmSupplier
		if err := models.Orm.QueryTable(new(models.TenantCrmSupplier)).
			Filter("id", partnerID).One(&row); err == nil {
			return row.PaymentDays
		}
	}
	return 0
}

// GetCustomerCreditLimit 客户信用额度，0=不限。
func GetCustomerCreditLimit(customerID uint64) float64 {
	var row models.TenantCrmCustomer
	if err := models.Orm.QueryTable(new(models.TenantCrmCustomer)).
		Filter("id", customerID).One(&row); err != nil {
		return 0
	}
	return row.CreditLimit
}

// 内部工具
func itoa(v uint64) string { return strconv.FormatUint(v, 10) }