import { useEffect, useMemo, useState } from 'react';
import { useNavigate, useSearchParams } from 'react-router-dom';
import PageHeader from '@dukang/shared-ui/PageHeader';
import type { PartnerBillDto } from '@dukang/shared-types';
import { isLoggedIn, request } from '../lib/api';
import { toastError, toastSuccess } from '../lib/toast';

function fmtMoney(n: number) {
  return n.toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
}

function billStatusLabel(status: string) {
  switch (status) {
    case 'DRAFT': return '待确认';
    case 'CONFIRMED': return '审核中';
    case 'PAID': return '已结算';
    case 'REJECTED': return '已驳回';
    default: return status;
  }
}

function canApplyPayment(status: string) {
  return status === 'DRAFT' || status === 'REJECTED';
}

export default function BillsPage() {
  const navigate = useNavigate();
  const [searchParams] = useSearchParams();
  const [bills, setBills] = useState<PartnerBillDto[]>([]);
  const [confirmed, setConfirmed] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [loading, setLoading] = useState(true);

  async function loadBills() {
    setLoading(true);
    try {
      const list = await request<PartnerBillDto[]>('PARTNER_H5', '/partner/settlement/bills');
      setBills(Array.isArray(list) ? list : []);
    } catch {
      setBills([]);
    } finally {
      setLoading(false);
    }
  }

  useEffect(() => {
    if (!isLoggedIn()) { navigate('/login'); return; }
    void loadBills();
  }, [navigate]);

  const billId = searchParams.get('id');
  const actionable = useMemo(
    () => bills.filter((b) => canApplyPayment(b.status)),
    [bills],
  );
  const bill = billId
    ? bills.find((b) => String(b.id) === billId) ?? actionable[0] ?? bills[0]
    : actionable[0] ?? bills[0];

  const status = String(bill?.status || '');
  const showApplyForm = !!bill && canApplyPayment(status);
  const isReviewing = status === 'CONFIRMED';
  const isRejected = status === 'REJECTED';
  const isPaid = status === 'PAID';

  async function confirmBill() {
    if (!bill || !confirmed || !canApplyPayment(String(bill.status))) return;
    setSubmitting(true);
    try {
      await request('PARTNER_H5', `/partner/settlement/bills/${bill.id}/confirm`, {
        method: 'POST',
      });
      toastSuccess('申请已提交，请耐心等待总部打款审核');
      setConfirmed(false);
      await loadBills();
    } catch (e) {
      toastError(e instanceof Error ? e.message : '提交失败');
    } finally {
      setSubmitting(false);
    }
  }

  return (
    <div className="partner-bills-page">
      <PageHeader title="账单确认" onBack={() => navigate('/center/settlement')} />

      <div className="partner-bill-stepper">
        <div className="partner-stepper-inner">
          <div className="partner-stepper-line" aria-hidden>
            <div
              className="partner-stepper-line-fill"
              style={{ width: isPaid ? '100%' : isReviewing || isRejected ? '75%' : '50%' }}
            />
          </div>
          <div className="partner-step">
            <div className="partner-step-circle partner-step-circle--sm partner-step-circle--done">
              <span className="material-symbols-outlined" style={{ fontSize: 14, fontVariationSettings: "'FILL' 1" }}>check</span>
            </div>
            <span className="partner-step-label partner-step-label--active">数据核算</span>
          </div>
          <div className="partner-step">
            <div className={`partner-step-circle partner-step-circle--sm${showApplyForm || isReviewing || isRejected || isPaid ? ' partner-step-circle--done' : ' partner-step-circle--active'}`}>
              {showApplyForm && !confirmed ? '2' : (
                <span className="material-symbols-outlined" style={{ fontSize: 14, fontVariationSettings: "'FILL' 1" }}>check</span>
              )}
            </div>
            <span className="partner-step-label partner-step-label--active">账单确认</span>
          </div>
          <div className="partner-step">
            <div className={`partner-step-circle partner-step-circle--sm${isPaid ? ' partner-step-circle--done' : isReviewing || isRejected ? ' partner-step-circle--active' : ''}`}>
              {isPaid ? (
                <span className="material-symbols-outlined" style={{ fontSize: 14, fontVariationSettings: "'FILL' 1" }}>check</span>
              ) : '3'}
            </div>
            <span className={`partner-step-label${isReviewing || isRejected || isPaid ? ' partner-step-label--active' : ''}`}>
              {isRejected ? '已驳回' : isPaid ? '已打款' : '申请打款'}
            </span>
          </div>
        </div>
      </div>

      {loading && <div className="empty">加载中…</div>}
      {!loading && !bill && <div className="empty">暂无账单</div>}

      {bill && (
        <section className="partner-bill-card">
          <div className="partner-bill-card-bar" />
          <div style={{ padding: 16 }}>
            <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'flex-start', marginBottom: 24 }}>
              <div>
                <p className="label-md text-muted" style={{ textTransform: 'uppercase', letterSpacing: '0.1em', marginBottom: 4 }}>SETTLEMENT PERIOD</p>
                <h2 className="headline-lg" style={{ fontSize: 20 }}>{String(bill.billNo || '月度结算账单')}</h2>
              </div>
              <span className={`partner-status-pill${isRejected ? ' partner-status-pill--closed' : isReviewing ? ' partner-status-pill--paused' : isPaid ? ' partner-status-pill--open' : ' partner-status-pill--paused'}`}>
                {billStatusLabel(status)}
              </span>
            </div>

            {isRejected && bill.rejectReason && (
              <div className="partner-info-banner" style={{ marginBottom: 16, background: 'rgba(166,29,36,0.06)' }}>
                <span className="material-symbols-outlined text-primary" style={{ fontVariationSettings: "'FILL' 1" }}>error</span>
                <div>
                  <p className="body-md text-primary" style={{ fontWeight: 600, marginBottom: 4 }}>打款申请已驳回</p>
                  <p className="body-md text-variant" style={{ lineHeight: 1.5 }}>{bill.rejectReason}</p>
                </div>
              </div>
            )}

            {isReviewing && (
              <div className="partner-info-banner" style={{ marginBottom: 16 }}>
                <span className="material-symbols-outlined text-primary" style={{ fontVariationSettings: "'FILL' 1" }}>hourglass_top</span>
                <p className="body-md text-variant" style={{ lineHeight: 1.5 }}>
                  您已提交打款申请，总部审核中，请耐心等待。
                </p>
              </div>
            )}

            <div className="partner-bill-amount">
              <p className="text-muted body-md" style={{ marginBottom: 8 }}>应结总金额</p>
              <div style={{ display: 'flex', alignItems: 'baseline', justifyContent: 'center', gap: 4 }}>
                <span className="text-primary" style={{ fontWeight: 700, fontSize: 20 }}>¥</span>
                <span className="amount-xl">{fmtMoney(Number(bill.totalAmount || 0))}</span>
              </div>
            </div>

            <div style={{ display: 'flex', flexDirection: 'column', gap: 16 }}>
              <div className="partner-info-row">
                <span className="text-variant body-md">订单分佣收入</span>
                <span className="body-md" style={{ fontWeight: 700 }}>¥ {fmtMoney(Number(bill.orderCommission || 0))}</span>
              </div>
              <div className="partner-info-row">
                <span className="text-variant body-md">核销权益分佣</span>
                <span className="body-md" style={{ fontWeight: 700 }}>¥ {fmtMoney(Number(bill.redeemCommission || 0))}</span>
              </div>
            </div>
          </div>
        </section>
      )}

      {bills.length > 1 && (
        <div style={{ padding: '0 20px' }}>
          <h3 className="headline-md" style={{ marginBottom: 12 }}>全部账单</h3>
          {bills.map((b) => (
            <button
              key={String(b.id)}
              type="button"
              className="partner-store-card"
              style={{ margin: '0 0 12px', width: '100%', textAlign: 'left', cursor: 'pointer' }}
              onClick={() => navigate(`/center/bills?id=${b.id}`)}
            >
              <div className="partner-store-card-header" style={{ marginBottom: 0 }}>
                <div>
                  <p className="body-md">{b.billNo}</p>
                  <p className="label-md text-muted">{billStatusLabel(b.status)}</p>
                  {b.status === 'REJECTED' && b.rejectReason ? (
                    <p className="label-md text-primary" style={{ marginTop: 4 }}>驳回：{b.rejectReason}</p>
                  ) : null}
                </div>
                <span className="amount-lg" style={{ fontSize: 18 }}>¥{Number(b.totalAmount).toFixed(2)}</span>
              </div>
            </button>
          ))}
        </div>
      )}

      {showApplyForm && (
        <>
          <div className="partner-info-banner" style={{ marginTop: 16 }}>
            <span className="material-symbols-outlined text-primary" style={{ fontVariationSettings: "'FILL' 1" }}>info</span>
            <p className="body-md text-variant" style={{ lineHeight: 1.5 }}>
              {isRejected
                ? '请根据驳回理由核对后重新确认并申请打款。'
                : '账单确认后将正式进入打款审核。如有异议，请在确认前联系城市运营经理核实数据。'}
            </p>
          </div>

          <footer className="partner-bill-footer">
            <label className="partner-checkbox-row" style={{ marginBottom: 16 }}>
              <input type="checkbox" checked={confirmed} onChange={(e) => setConfirmed(e.target.checked)} />
              <span>我已核对数据无误，同意根据此账单进行结算</span>
            </label>
            <button
              type="button"
              className="partner-btn-primary"
              disabled={!confirmed || submitting}
              style={{ opacity: confirmed ? 1 : 0.5 }}
              onClick={() => void confirmBill()}
            >
              {submitting ? '正在提交...' : isRejected ? '重新申请打款' : '确认并申请打款'}
              {!submitting && <span className="material-symbols-outlined">payments</span>}
            </button>
          </footer>
        </>
      )}
    </div>
  );
}