package controllers

import (
	"strconv"
	"strings"
	"time"

	erp "server/services/erp"
)

// BackendErpFinanceController 往来账（应收/应付）、收付款与核销
//
// 往来账由单据生效时自动生成，不开放手工新增/修改，保证「业务单据 → 往来账 → 收付款」
// 三段可追溯；收付款单可以手工开草稿，确认后按单核销（显式指定或按到期日 FIFO）。
// 查询与核销口径统一在 erp_finance_core.go，与移动端 /api/erp/finance* 共用。
type BackendErpFinanceController struct {
	BackendErpBaseController
}

// BillList GET /backend/erp/finance/bill/list 往来账列表
func (c *BackendErpFinanceController) BillList() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	page, pageSize := c.pageArgs()

	f := erpBillFilter{
		BillType:    strings.TrimSpace(c.GetString("bill_type")),
		PartnerID:   erpUintParam(c.GetString("partner_id")),
		PartnerType: strings.TrimSpace(c.GetString("partner_type")),
		SourceDocID: erpUintParam(c.GetString("source_doc_id")),
		SettleState: strings.TrimSpace(c.GetString("settle_state")),
		Keyword:     strings.TrimSpace(c.GetString("keyword")),
		DateFrom:    strings.TrimSpace(c.GetString("date_from")),
		DateTo:      strings.TrimSpace(c.GetString("date_to")),
	}
	list, total, summary, code, msg := erpBillListCore(erpNewActor(cl), f, page, pageSize)
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(map[string]interface{}{
		"list": list, "total": total, "page": page, "pageSize": pageSize,
		"summary": summary,
	})
}

// BillDetail GET /backend/erp/finance/bill/:id 往来账详情（含核销记录与原单据）
func (c *BackendErpFinanceController) BillDetail() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	data, code, msg := erpBillDetailCore(erpNewActor(cl), c.pathID())
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(data)
}

// Aging GET /backend/erp/finance/aging 账龄分析（按未结余额分桶）
func (c *BackendErpFinanceController) Aging() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	data, code, msg := erpAgingCore(erpNewActor(cl))
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(data)
}

// FundList GET /backend/erp/finance/fund/list 收付款单列表
func (c *BackendErpFinanceController) FundList() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	page, pageSize := c.pageArgs()

	f := erpFundFilter{
		FundType:  strings.TrimSpace(c.GetString("fund_type")),
		Status:    strings.TrimSpace(c.GetString("status")),
		PartnerID: erpUintParam(c.GetString("partner_id")),
		Keyword:   strings.TrimSpace(c.GetString("keyword")),
		DateFrom:  strings.TrimSpace(c.GetString("date_from")),
		DateTo:    strings.TrimSpace(c.GetString("date_to")),
	}
	rows, total, code, msg := erpFundListCore(erpNewActor(cl), f, page, pageSize)
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.listOK(rows, total, page, pageSize)
}

// FundDetail GET /backend/erp/finance/fund/:id
func (c *BackendErpFinanceController) FundDetail() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	data, code, msg := erpFundDetailCore(erpNewActor(cl), c.pathID())
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(data)
}

type erpFundPayload struct {
	ID         uint64  `json:"id"`
	FundType   int8    `json:"fund_type"`
	PartnerID  uint64  `json:"partner_id"`
	Amount     float64 `json:"amount"`
	PayMethod  string  `json:"pay_method"`
	PayAccount string  `json:"pay_account"`
	BizDate    string  `json:"biz_date"`
	Remark     string  `json:"remark"`
}

// FundSave POST /backend/erp/finance/fund 新建/修改收付款草稿
func (c *BackendErpFinanceController) FundSave() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	var p erpFundPayload
	if !c.bindJSON(&p) {
		return
	}
	id, fundNo, code, msg := erpFundSaveCore(erpNewActor(cl), p)
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(map[string]interface{}{"id": id, "fund_no": fundNo})
}

// FundConfirm POST /backend/erp/finance/fund/:id/confirm
// 确认收付款并核销；body 可选 settles=[{partner_bill_id,amount}]，不传则按到期日自动 FIFO。
func (c *BackendErpFinanceController) FundConfirm() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	var body struct {
		Settles []erp.SettleItem `json:"settles"`
	}
	// 允许空 body（自动核销）
	_ = c.bindJSON(&body)
	code, msg := erpFundConfirmCore(erpNewActor(cl), c.pathID(), body.Settles)
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(nil)
}

// FundVoid POST /backend/erp/finance/fund/:id/void
func (c *BackendErpFinanceController) FundVoid() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	code, msg := erpFundVoidCore(erpNewActor(cl), c.pathID())
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(nil)
}

// FundDelete DELETE /backend/erp/finance/fund/:id 仅草稿可删
func (c *BackendErpFinanceController) FundDelete() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	code, msg := erpFundDeleteCore(erpNewActor(cl), c.pathID())
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(nil)
}

// FundOpenBills GET /backend/erp/finance/fund/openBills?fund_type=&partner_id=
// 收款/付款时列出可核销的往来账，前端据此勾选。
func (c *BackendErpFinanceController) FundOpenBills() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	ft, _ := erpInt8Query(c.GetString("fund_type"))
	list, code, msg := erpFundOpenBillsCore(erpNewActor(cl), ft, erpUintParam(c.GetString("partner_id")))
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(map[string]interface{}{"list": list})
}

// CashFlow GET /backend/erp/finance/cashflow 资金流水（含单据生成的往来账不在此列，只统计实际收付）
func (c *BackendErpFinanceController) CashFlow() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	from := time.Now().AddDate(0, 0, -30)
	if d := strings.TrimSpace(c.GetString("date_from")); d != "" {
		if t, e := time.ParseInLocation("2006-01-02", d, time.Local); e == nil {
			from = t
		}
	}
	to := time.Now()
	if d := strings.TrimSpace(c.GetString("date_to")); d != "" {
		if t, e := time.ParseInLocation("2006-01-02", d, time.Local); e == nil {
			to = t
		}
	}
	data, code, msg := erpCashFlowCore(erpNewActor(cl), from, to)
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(data)
}

// PartnerSummary GET /backend/erp/finance/partner 往来单位对账汇总
func (c *BackendErpFinanceController) PartnerSummary() {
	cl, err := c.claims()
	if c.denied(err) {
		return
	}
	data, code, msg := erpPartnerSummaryCore(erpNewActor(cl), strings.TrimSpace(c.GetString("partner_type")))
	if msg != "" {
		c.fail(code, code, msg)
		return
	}
	c.ok(data)
}

func erpBillStatusLabel(s int8) string {
	switch s {
	case 1:
		return "部分核销"
	case 2:
		return "已结清"
	default:
		return "未核销"
	}
}

func erpInt8Query(v string) (int8, bool) {
	n, err := strconv.Atoi(strings.TrimSpace(v))
	if err != nil {
		return 0, false
	}
	return int8(n), true
}