import { useCallback, useEffect, useState } from 'react';
import { AlertTriangle, ReceiptText, RefreshCw, RotateCcw } from 'lucide-react';
import type { BillingSettlement } from '@easyai-ai-gateway/contracts';
import { listBillingSettlements, retryBillingSettlement } from '../../api';
import { Badge, Button, Card, CardContent, CardHeader, CardTitle, ConfirmDialog, Select, Table, TableCell, TableHead, TableRow } from '../../components/ui';

export function BillingSettlementsPanel(props: { token: string }) {
  const [items, setItems] = useState<BillingSettlement[]>([]);
  const [status, setStatus] = useState('');
  const [loading, setLoading] = useState(false);
  const [retrying, setRetrying] = useState('');
  const [confirming, setConfirming] = useState<BillingSettlement | null>(null);
  const [message, setMessage] = useState('');

  const load = useCallback(async (signal?: AbortSignal) => {
    setLoading(true);
    setMessage('');
    try {
      const result = await listBillingSettlements(props.token, { status, pageSize: 100, signal });
      setItems(result.items);
    } catch (error) {
      if (signal?.aborted) return;
      setMessage(error instanceof Error ? error.message : '结算队列加载失败');
    } finally {
      if (!signal?.aborted) setLoading(false);
    }
  }, [props.token, status]);

  useEffect(() => {
    const controller = new AbortController();
    void load(controller.signal);
    return () => controller.abort();
  }, [load]);

  async function retry(item: BillingSettlement) {
    setRetrying(item.id);
    setMessage('');
    try {
      await retryBillingSettlement(props.token, item.id);
      setMessage(`结算 ${shortId(item.id)} 已重新进入队列`);
      await load();
    } catch (error) {
      setMessage(error instanceof Error ? error.message : '结算重试失败');
    } finally {
      setRetrying('');
    }
  }

  const exceptions = items.filter((item) => item.status === 'retryable_failed' || item.status === 'manual_review').length;
  return (
    <div className="pageStack">
      <Card>
        <CardHeader>
          <div className="identityHeaderTitle">
            <div className="iconBox"><ReceiptText size={17} /></div>
            <div>
              <CardTitle>计费结算</CardTitle>
              <p className="mutedText">任务结果与账务状态相互独立；异常记录可审计重试，不会重新调用上游。</p>
            </div>
            <Badge variant={exceptions ? 'warning' : 'secondary'}>{exceptions ? `${exceptions} 条异常` : `${items.length} 条`}</Badge>
          </div>
        </CardHeader>
        <CardContent>
          <div className="tableActions">
            <Select size="sm" aria-label="结算状态" value={status} onChange={(event) => setStatus(event.target.value)}>
              <option value="">全部状态</option>
              <option value="pending">待处理</option>
              <option value="processing">处理中</option>
              <option value="retryable_failed">等待重试</option>
              <option value="manual_review">人工复核</option>
              <option value="completed">已完成</option>
            </Select>
            <Button type="button" size="sm" variant="outline" disabled={loading} onClick={() => void load()}>
              <RefreshCw size={14} />{loading ? '刷新中' : '刷新'}
            </Button>
          </div>
          {message && <p className="formMessage">{message}</p>}
        </CardContent>
      </Card>
      {items.length ? (
        <Table density="compact" className="identityDataTable">
          <TableRow>
            <TableHead>任务 / 动作</TableHead>
            <TableHead>状态</TableHead>
            <TableHead>金额</TableHead>
            <TableHead>尝试</TableHead>
            <TableHead>异常分类</TableHead>
            <TableHead>操作</TableHead>
          </TableRow>
          {items.map((item) => (
            <TableRow key={item.id}>
              <TableCell><span className="identityTableName"><strong>{shortId(item.taskId)}</strong><small>{item.action === 'settle' ? '扣费' : '释放冻结'} · {shortId(item.id)}</small></span></TableCell>
              <TableCell><Badge variant={statusVariant(item.status)}>{statusLabel(item.status)}</Badge></TableCell>
              <TableCell>{formatAmount(item.amount)} {item.currency}</TableCell>
              <TableCell>{item.attempts} / 20</TableCell>
              <TableCell>{item.lastErrorCode || item.manualReviewReason || '-'}</TableCell>
              <TableCell>
                {(item.status === 'retryable_failed' || item.status === 'manual_review') ? (
                  <Button type="button" size="xs" variant="outline" disabled={retrying === item.id} onClick={() => setConfirming(item)}>
                    <RotateCcw size={13} />{retrying === item.id ? '提交中' : retryActionLabel(item)}
                  </Button>
                ) : '-'}
              </TableCell>
            </TableRow>
          ))}
        </Table>
      ) : (
        <Card><CardContent className="emptyState"><AlertTriangle size={18} /><strong>{loading ? '正在加载结算队列' : '暂无结算记录'}</strong><span>可切换状态筛选，查看待处理与人工复核记录。</span></CardContent></Card>
      )}
      <ConfirmDialog
        open={Boolean(confirming)}
        loading={Boolean(confirming && retrying === confirming.id)}
        title={confirming ? `${retryActionLabel(confirming)}这条计费记录？` : '处理计费记录？'}
        description={confirming ? retryActionDescription(confirming) : ''}
        confirmLabel={confirming ? retryActionLabel(confirming) : '确认'}
        onCancel={() => setConfirming(null)}
        onConfirm={() => {
          if (!confirming) return;
          const item = confirming;
          void retry(item).finally(() => setConfirming(null));
        }}
      />
    </div>
  );
}

function statusLabel(status: string) {
  return ({ pending: '待处理', processing: '处理中', retryable_failed: '等待重试', manual_review: '人工复核', completed: '已完成' } as Record<string, string>)[status] ?? status;
}

function statusVariant(status: string): 'secondary' | 'warning' | 'destructive' | 'success' | 'outline' {
  if (status === 'completed') return 'success';
  if (status === 'manual_review') return 'destructive';
  if (status === 'retryable_failed') return 'warning';
  if (status === 'processing') return 'outline';
  return 'secondary';
}

function formatAmount(value: number) {
  return new Intl.NumberFormat('zh-CN', { minimumFractionDigits: 0, maximumFractionDigits: 9 }).format(value);
}

function retryActionLabel(item: BillingSettlement) {
  if (item.status !== 'manual_review') return '重试';
  if (item.manualReviewReason === 'upstream_submission_unknown' && item.action === 'release') return '确认释放';
  if (item.manualReviewReason === 'historical_success_without_charge' && item.action === 'settle') return '确认结算';
  return '重新入队';
}

function retryActionDescription(item: BillingSettlement) {
  if (item.manualReviewReason === 'upstream_submission_unknown' && item.action === 'release') {
    return '上游提交结果不明。确认后只会释放当前冻结，不会再次调用上游；请先完成外部核查。';
  }
  if (item.manualReviewReason === 'historical_success_without_charge' && item.action === 'settle') {
    return `确认后将按历史快照结算 ${formatAmount(item.amount)} ${item.currency}，不会重新调用上游。`;
  }
  return '确认后会将该记录重新放入结算队列，不会重新调用上游。';
}

function shortId(value: string) {
  return value.length > 12 ? `${value.slice(0, 8)}…${value.slice(-4)}` : value;
}