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

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

function billStatusLabel(status: string) {
  switch (status) {
    case 'AWAITING_CONFIRM': return '待确认';
    case 'UNPAID': return '未打款';
    case 'PAID': return '已打款';
    case 'REJECTED': return '已驳回';
    default: return status;
  }
}

function canConfirm(status: string) {
  return status === 'AWAITING_CONFIRM';
}

export default function BillsPage() {
  usePartnerPageView('partner_bills_view');
  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);
  const [selectedIds, setSelectedIds] = useState<string[]>([]);

  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) => canConfirm(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 && canConfirm(status);
  const isUnpaid = status === 'UNPAID';
  const isRejected = status === 'REJECTED';
  const isPaid = status === 'PAID';

  function askConfirm(ids: string[]) {
    if (!window.confirm(`确认 ${ids.length} 笔账单无误并提交？确认后状态将变为「未打款」，等待总部打款。`)) {
      return;
    }
    void doConfirm(ids);
  }

  async function doConfirm(ids: string[]) {
    setSubmitting(true);
    try {
      if (ids.length === 1) {
        await request('PARTNER_H5', `/partner/settlement/bills/${ids[0]}/confirm`, { method: 'POST' });
      } else {
        await request('PARTNER_H5', '/partner/settlement/bills/batch-confirm', {
          method: 'POST',
          body: JSON.stringify({ ids }),
        });
      }
      toastSuccess('已确认，等待总部打款');
      setConfirmed(false);
      setSelectedIds([]);
      await loadBills();
    } catch (e) {
      toastError(e instanceof Error ? e.message : '提交失败');
    } finally {
      setSubmitting(false);
    }
  }

  function toggleSelect(id: string) {
    setSelectedIds((prev) => (prev.includes(id) ? prev.filter((x) => x !== id) : [...prev, id]));
  }

  return (
    <PullToRefresh onRefresh={loadBills} 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%' : isUnpaid || 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${showApplyForm || isUnpaid || isRejected || isPaid ? ' partner-step-circle--done' : ' partner-step-circle--active'}`}>
              {showApplyForm && !confirmed ? '2' : (
                <span className="material-symbols-outlined" style={{ fontSize: 14, fontVariationSettings: "'FILL' 1" }}>check</span>
              )}
            </div>
            <span className="partner-step-label partner-step-label--active">账单确认</span>
          </div>
          <div className="partner-step">
            <div className={`partner-step-circle partner-step-circle--sm${isPaid ? ' partner-step-circle--done' : isUnpaid || 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${isUnpaid || isRejected || isPaid ? ' partner-step-label--active' : ''}`}>
              {isRejected ? '已驳回' : isPaid ? '已打款' : '总部打款'}
            </span>
          </div>
        </div>
      </div>

      {loading && <div className="empty">加载中…</div>}
      {!loading && !bill && <div className="empty">暂无待确认账单</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' : isUnpaid ? ' 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 }}>账单已驳回</p>
                  <p className="body-md text-variant" style={{ lineHeight: 1.5 }}>{bill.rejectReason}</p>
                </div>
              </div>
            )}

            {isUnpaid && (
              <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 }}>
                  您已确认账单，总部打款中，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 > 0 && (
        <div style={{ padding: '0 20px' }}>
          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 12 }}>
            <h3 className="headline-md" style={{ margin: 0 }}>全部账单</h3>
            {actionable.length > 1 && (
              <button
                type="button"
                className="partner-fill-max"
                style={{ fontSize: 13 }}
                disabled={!selectedIds.length || submitting}
                onClick={() => askConfirm(selectedIds)}
              >
                批量确认 ({selectedIds.length})
              </button>
            )}
          </div>
          {bills.map((b) => {
            const id = String(b.id);
            const selectable = canConfirm(b.status);
            return (
              <div
                key={id}
                className="partner-store-card"
                style={{ margin: '0 0 12px', display: 'flex', gap: 10, alignItems: 'flex-start' }}
              >
                {selectable ? (
                  <input
                    type="checkbox"
                    checked={selectedIds.includes(id)}
                    onChange={() => toggleSelect(id)}
                    style={{ marginTop: 4 }}
                  />
                ) : (
                  <span style={{ width: 16 }} />
                )}
                <button
                  type="button"
                  style={{ flex: 1, textAlign: 'left', background: 'none', border: 'none', padding: 0, cursor: 'pointer' }}
                  onClick={() => navigate(`/center/bills?id=${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>
            );
          })}
        </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 }}>
              确认后账单变为「未打款」，由总部完成打款。如有异议请先联系城市运营经理。
            </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={() => askConfirm([String(bill!.id)])}
            >
              {submitting ? '正在提交...' : '确认账单'}
              {!submitting && <span className="material-symbols-outlined">payments</span>}
            </button>
          </footer>
        </>
      )}
    </PullToRefresh>
  );
}