package com.kaidi.oa.web;

import com.kaidi.oa.common.ApiResp;
import com.kaidi.oa.common.Money;
import com.kaidi.oa.domain.ArApItem;
import com.kaidi.oa.domain.Contract;
import com.kaidi.oa.domain.Payment;
import com.kaidi.oa.domain.Voucher;
import com.kaidi.oa.repository.ArApItemRepository;
import com.kaidi.oa.repository.ContractRepository;
import com.kaidi.oa.repository.PaymentRepository;
import com.kaidi.oa.repository.VoucherRepository;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * 财务多维看板（只读聚合）。把财务四类台账客户端汇总成「合同 / 资金支付 / 往来 / 凭证」多维：
 *  - 合同维：合同额 / 已付 / 已开票 总额与回款率/开票率；按公司主体(companySubject)分维行；
 *  - 资金维：付款单按状态(已付/待付)汇总金额与笔数；
 *  - 往来维：ArApItem 应收/应付的总额、已核销、未核销；
 *  - 凭证维：Voucher 按状态(草稿/已审核/已过账)的金额与笔数。
 *
 * 不新建任何实体；结果走 {@link ApiResp} 信封。所有金额一律 {@link BigDecimal} +
 * {@link Money}（无裸 double 算钱），仅在出参边界 doubleValue() 落到 JSON。
 *
 * 该端点跨表读合同额/付款/往来/凭证等机密财务数据，必须登记进 AuthInterceptor 的
 * SENSITIVE_READ_PREFIXES（见 sharedFileSnippets），读侧收口到 ADMIN/APPROVER。
 */
@RestController
@RequestMapping("/api/oa/finance-dashboard")
public class FinanceDashboardController {

    private final ContractRepository contractRepo;
    private final PaymentRepository paymentRepo;
    private final ArApItemRepository arApRepo;
    private final VoucherRepository voucherRepo;

    public FinanceDashboardController(ContractRepository contractRepo,
                                      PaymentRepository paymentRepo,
                                      ArApItemRepository arApRepo,
                                      VoucherRepository voucherRepo) {
        this.contractRepo = contractRepo;
        this.paymentRepo = paymentRepo;
        this.arApRepo = arApRepo;
        this.voucherRepo = voucherRepo;
    }

    // ---------- 合同维 ----------

    public record SubjectRow(String subject, double amount, double paid, double invoiced,
                             double paidRate, double invoicedRate, long count) {
    }

    public record ContractKpi(double amountTotal, double paidTotal, double invoicedTotal,
                              double paidRate, double invoicedRate, long count,
                              List<SubjectRow> bySubject) {
    }

    // ---------- 资金维 ----------

    public record PaymentKpi(double paidTotal, long paidCount, double pendingTotal, long pendingCount,
                             Map<String, Double> byStatus) {
    }

    // ---------- 往来维 ----------

    public record ArApKpi(double arTotal, double arWrittenOff, double arOutstanding,
                          double apTotal, double apWrittenOff, double apOutstanding) {
    }

    // ---------- 凭证维 ----------

    public record VoucherKpi(long total, double amountTotal, Map<String, Double> amountByStatus,
                             Map<String, Long> countByStatus) {
    }

    public record FinanceDashboard(ContractKpi contract, PaymentKpi payment,
                                   ArApKpi arAp, VoucherKpi voucher) {
    }

    @GetMapping
    public ApiResp<FinanceDashboard> dashboard() {
        return ApiResp.ok(new FinanceDashboard(contractKpi(), paymentKpi(), arApKpi(), voucherKpi()));
    }

    private static final class SubjectAcc {
        BigDecimal amount = BigDecimal.ZERO;
        BigDecimal paid = BigDecimal.ZERO;
        BigDecimal invoiced = BigDecimal.ZERO;
        long count = 0;
    }

    private ContractKpi contractKpi() {
        BigDecimal amountTotal = BigDecimal.ZERO;
        BigDecimal paidTotal = BigDecimal.ZERO;
        BigDecimal invoicedTotal = BigDecimal.ZERO;
        long count = 0;
        Map<String, SubjectAcc> bySubject = new LinkedHashMap<>();

        for (Contract c : contractRepo.findAll()) {
            count++;
            amountTotal = Money.add(amountTotal, c.getAmount());
            paidTotal = Money.add(paidTotal, c.getPaidAmount());
            invoicedTotal = Money.add(invoicedTotal, c.getInvoicedAmount());
            String subject = c.getCompanySubject() == null || c.getCompanySubject().isBlank()
                    ? "未指定主体" : c.getCompanySubject();
            SubjectAcc acc = bySubject.computeIfAbsent(subject, k -> new SubjectAcc());
            acc.amount = Money.add(acc.amount, c.getAmount());
            acc.paid = Money.add(acc.paid, c.getPaidAmount());
            acc.invoiced = Money.add(acc.invoiced, c.getInvoicedAmount());
            acc.count++;
        }

        List<SubjectRow> rows = new ArrayList<>();
        for (Map.Entry<String, SubjectAcc> e : bySubject.entrySet()) {
            SubjectAcc a = e.getValue();
            rows.add(new SubjectRow(e.getKey(), a.amount.doubleValue(), a.paid.doubleValue(),
                    a.invoiced.doubleValue(), pct(a.paid, a.amount), pct(a.invoiced, a.amount), a.count));
        }
        return new ContractKpi(amountTotal.doubleValue(), paidTotal.doubleValue(),
                invoicedTotal.doubleValue(), pct(paidTotal, amountTotal),
                pct(invoicedTotal, amountTotal), count, rows);
    }

    private PaymentKpi paymentKpi() {
        BigDecimal paidTotal = BigDecimal.ZERO;
        BigDecimal pendingTotal = BigDecimal.ZERO;
        long paidCount = 0, pendingCount = 0;
        Map<String, BigDecimal> byStatus = new LinkedHashMap<>();

        for (Payment p : paymentRepo.findAll()) {
            String status = p.getStatus() == null || p.getStatus().isBlank() ? "未知" : p.getStatus();
            byStatus.merge(status, Money.nz(p.getAmount()), Money::add);
            if ("已付".equals(status)) {
                paidTotal = Money.add(paidTotal, p.getAmount());
                paidCount++;
            } else if ("待付".equals(status)) {
                pendingTotal = Money.add(pendingTotal, p.getAmount());
                pendingCount++;
            }
        }
        return new PaymentKpi(paidTotal.doubleValue(), paidCount, pendingTotal.doubleValue(),
                pendingCount, toDoubleMap(byStatus));
    }

    private ArApKpi arApKpi() {
        BigDecimal arTotal = BigDecimal.ZERO, arOff = BigDecimal.ZERO, arOut = BigDecimal.ZERO;
        BigDecimal apTotal = BigDecimal.ZERO, apOff = BigDecimal.ZERO, apOut = BigDecimal.ZERO;
        for (ArApItem it : arApRepo.findAll()) {
            boolean ar = ArApItem.T_AR.equals(it.getArApType());
            if (ar) {
                arTotal = Money.add(arTotal, it.getAmount());
                arOff = Money.add(arOff, it.getWrittenOff());
                arOut = Money.add(arOut, it.getUnwrittenOff());
            } else {
                apTotal = Money.add(apTotal, it.getAmount());
                apOff = Money.add(apOff, it.getWrittenOff());
                apOut = Money.add(apOut, it.getUnwrittenOff());
            }
        }
        return new ArApKpi(arTotal.doubleValue(), arOff.doubleValue(), arOut.doubleValue(),
                apTotal.doubleValue(), apOff.doubleValue(), apOut.doubleValue());
    }

    private VoucherKpi voucherKpi() {
        long total = 0;
        BigDecimal amountTotal = BigDecimal.ZERO;
        Map<String, BigDecimal> amountByStatus = new LinkedHashMap<>();
        Map<String, Long> countByStatus = new LinkedHashMap<>();
        for (Voucher v : voucherRepo.findAll()) {
            total++;
            amountTotal = Money.add(amountTotal, v.getAmount());
            String status = normalizeVoucherStatus(v.getStatus());
            amountByStatus.merge(status, Money.nz(v.getAmount()), Money::add);
            countByStatus.merge(status, 1L, Long::sum);
        }
        return new VoucherKpi(total, amountTotal.doubleValue(), toDoubleMap(amountByStatus), countByStatus);
    }

    // ---------- helpers ----------

    /** 兼容历史旧值：暂存→草稿、已记账→已过账（与 VoucherController.normalizeStatus 同口径）。 */
    private static String normalizeVoucherStatus(String raw) {
        if (raw == null || raw.isBlank()) {
            return Voucher.S_DRAFT;
        }
        if ("暂存".equals(raw)) {
            return Voucher.S_DRAFT;
        }
        if ("已记账".equals(raw)) {
            return Voucher.S_POSTED;
        }
        return raw;
    }

    /** a/b 百分比（保留 1 位），b 为 0 返回 0；全程 BigDecimal 不裸 double 算比率。 */
    private static double pct(BigDecimal a, BigDecimal b) {
        BigDecimal denom = Money.nz(b);
        if (denom.signum() == 0) {
            return 0;
        }
        return Money.nz(a).divide(denom, 4, RoundingMode.HALF_UP)
                .multiply(BigDecimal.valueOf(100))
                .setScale(1, RoundingMode.HALF_UP)
                .doubleValue();
    }

    private static Map<String, Double> toDoubleMap(Map<String, BigDecimal> src) {
        Map<String, Double> out = new LinkedHashMap<>();
        for (Map.Entry<String, BigDecimal> e : src.entrySet()) {
            out.put(e.getKey(), e.getValue().doubleValue());
        }
        return out;
    }
}