// 操作审计 Tab — 增强版审计日志列表，含筛选/导出/统计/清除
// v2: 虚拟滚动渲染，支持万级日志流畅查看
import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
import { cn } from '@/lib/utils';
import { useTranslation } from 'react-i18next';
import { useVirtualizer } from '@tanstack/react-virtual';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Badge } from '@/components/ui/badge';
import {
  Search,
  RefreshCw,
  Download,
  Eye,
  X,
  ClipboardList,
} from 'lucide-react';
import { PageShell } from '@/components/layout/PageShell';
import { ContentPanel } from '@/components/layout/ContentPanel';
import { PageEmpty } from '@/components/layout/PageEmpty';
import { StatStrip } from '@/components/ui/stat-strip';
import { auditApi } from '@/api';
import { useAuditLogs } from '@/hooks/api';
import { useConfirm } from '@/components/ui/confirm-dialog';
import type { OperationLog, OptionItem } from '@/types';

// Normalize backend log to frontend type
function normalizeLog(raw: Record<string, unknown>): OperationLog {
  return {
    id: String(raw.id ?? ''),
    userId: String(raw.user_id ?? raw.userId ?? ''),
    username: String(raw.username ?? ''),
    module: String(raw.module ?? raw.resource ?? ''),
    action: String(raw.action ?? ''),
    resource: String(raw.resource ?? ''),
    ip: String(raw.ip ?? ''),
    userAgent: String(raw.user_agent ?? raw.userAgent ?? ''),
    result: raw.result === 'failure' ? 'failure' : 'success',
    message: String(raw.message ?? raw.detail ?? ''),
    createdAt: String(raw.createdAt ?? raw.created_at ?? ''),
  };
}

interface AuditStatistics {
  total_logs?: number;
  success_count?: number;
  failure_count?: number;
  today_count?: number;
  top_modules?: { module: string; count: number }[];
  top_actions?: { action: string; count: number }[];
  top_users?: { username: string; count: number }[];
}

export function AuditOperationsTab() {
  const { t } = useTranslation();
  const _confirm = useConfirm();
  // Filters
  const [keyword, setKeyword] = useState('');
  const [moduleFilter, setModuleFilter] = useState('');
  const [actionFilter, setActionFilter] = useState('');

  const auditParams = useMemo(() => ({
    page: 1,
    page_size: 100,
    ...(moduleFilter ? { module: moduleFilter } : {}),
    ...(actionFilter ? { action: actionFilter } : {}),
  }), [moduleFilter, actionFilter]);

  const { data: auditData, isLoading: loading, isFetching, refetch: refetchLogs } = useAuditLogs(auditParams);
  const logs = useMemo(
    () => (auditData?.list || []).map((raw) => normalizeLog(raw)),
    [auditData],
  );
  const [modules, setModules] = useState<OptionItem[]>([]);
  const [actions, setActions] = useState<OptionItem[]>([]);

  // Detail modal
  const [detailLog, setDetailLog] = useState<OperationLog | null>(null);

  // Statistics modal
  const [statsOpen, setStatsOpen] = useState(false);
  const [statistics, setStatistics] = useState<AuditStatistics | null>(null);
  const [statsLoading, setStatsLoading] = useState(false);

  const fetchOptions = useCallback(async () => {
    try {
      const [modRes, actRes] = await Promise.all([auditApi.getModules(), auditApi.getActions()]);
      const modData = modRes as { list?: OptionItem[] } | OptionItem[];
      const actData = actRes as { list?: OptionItem[] } | OptionItem[];
      setModules(Array.isArray(modData) ? modData : (modData?.list ?? []));
      setActions(Array.isArray(actData) ? actData : (actData?.list ?? []));
    } catch {
      /* noop */
    }
  }, []);

  useEffect(() => {
    fetchOptions();
  }, [fetchOptions]);

  const filteredLogs = logs.filter((log) => {
    const kw = keyword.toLowerCase();
    return (
      !kw ||
      log.username.toLowerCase().includes(kw) ||
      log.module.toLowerCase().includes(kw) ||
      log.action.toLowerCase().includes(kw) ||
      log.resource.toLowerCase().includes(kw)
    );
  });

  const getLogResultBadge = (result: OperationLog['result']) => {
    return result === 'success' ? (
      <Badge variant="outline" className="border-emerald-500/30 dg-text-green bg-emerald-500/10">
        {t('common.success')}
      </Badge>
    ) : (
      <Badge variant="outline" className="border-red-500/30 dg-text-red bg-red-500/10">
        {t('common.failed')}
      </Badge>
    );
  };

  const handleExport = async () => {
    try {
      const params: Record<string, string> = {};
      if (moduleFilter) params.module = moduleFilter;
      if (actionFilter) params.action = actionFilter;
      await auditApi.exportLogs(params);
    } catch {
      // noop
    }
  };

  const _handleShowStats = async () => {
    setStatsOpen(true);
    setStatsLoading(true);
    try {
      const data = (await auditApi.getStatistics()) as AuditStatistics;
      setStatistics(data);
    } catch {
      setStatistics(null);
    } finally {
      setStatsLoading(false);
    }
  };

  const viewDetail = (log: OperationLog) => {
    setDetailLog(log);
  };

  // 虚拟滚动
  const scrollRef = useRef<HTMLDivElement>(null);
  const GRID_COLS = 'minmax(140px,1fr) minmax(80px,1fr) minmax(100px,1fr) minmax(100px,1fr) minmax(140px,1fr) minmax(100px,1fr) minmax(80px,0.8fr) 48px';

  const virtualizer = useVirtualizer({
    count: filteredLogs.length,
    getScrollElement: () => scrollRef.current,
    estimateSize: () => 52,
    overscan: 10,
  });

  const virtualRows = virtualizer.getVirtualItems();
  const totalHeight = virtualizer.getTotalSize();

  const successCount = filteredLogs.filter(l => l.result === 'success').length;
  const failCount = filteredLogs.filter(l => l.result === 'failure').length;

  const toolbar = (
    <div className="flex items-center gap-3 flex-wrap">
      <div className="relative w-64">
        <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 dg-text-muted" />
        <Input
          placeholder={t('audit.operations.searchPlaceholder')}
          value={keyword}
          onChange={(e) => setKeyword(e.target.value)}
          className="pl-9 h-9 dg-input"
        />
      </div>
      <select
        value={moduleFilter}
        onChange={(e) => setModuleFilter(e.target.value)}
        className="h-9 px-3 text-sm rounded-md dg-input"
      >
        <option value="">{t('audit.operations.allModules')}</option>
        {modules.map((m) => (
          <option key={m.value} value={m.value}>{m.label}</option>
        ))}
      </select>
      <select
        value={actionFilter}
        onChange={(e) => setActionFilter(e.target.value)}
        className="h-9 px-3 text-sm rounded-md dg-input"
      >
        <option value="">{t('audit.operations.allActions')}</option>
        {actions.map((a) => (
          <option key={a.value} value={a.value}>{a.label}</option>
        ))}
      </select>
    </div>
  );

  return (
    <PageShell
      variant="list"
      title={t('audit.operations.title', { defaultValue: '操作审计' })}
      subtitle={t('audit.operations.subtitle', { defaultValue: '系统操作日志筛选、导出与详情查看' })}
      icon={<ClipboardList className="h-5 w-5" />}
      loading={loading}
      metrics={(
        <StatStrip
          items={[
            { label: t('audit.operations.allModules'), value: filteredLogs.length, color: 'blue' },
            { label: t('common.success'), value: successCount, color: 'emerald' },
            { label: t('common.failed'), value: failCount, color: 'red' },
          ]}
        />
      )}
      toolbar={toolbar}
      actions={(
        <>
          <Button variant="outline" className="dg-btn-secondary" onClick={() => refetchLogs()} disabled={isFetching}>
            <RefreshCw className={cn('h-4 w-4 mr-2', isFetching && 'animate-spin')} />{t('common.refresh')}
          </Button>
          <Button variant="outline" className="dg-btn-secondary" onClick={handleExport}>
            <Download className="h-4 w-4 mr-2" />{t('common.export')}
          </Button>
        </>
      )}
    >
      <ContentPanel noPadding>
          <div>
            {!loading && filteredLogs.length === 0 ? (
              <PageEmpty icon={<Search className="h-8 w-8" />} title={t('audit.operations.noData')} />
            ) : (
              <>
                {/* 表头 */}
                <div
                  className="grid gap-2 px-4 py-2 border-b border-[var(--dg-border)] bg-[var(--dg-bg-secondary)] text-xs font-medium dg-text-secondary sticky top-0 z-10"
                  style={{ gridTemplateColumns: GRID_COLS }}
                >
                  <span>{t('audit.operations.col.time')}</span>
                  <span>{t('audit.operations.col.user')}</span>
                  <span>{t('audit.operations.col.module')}</span>
                  <span>{t('audit.operations.col.actionType')}</span>
                  <span>{t('audit.operations.col.resource')}</span>
                  <span>{t('audit.operations.col.ip')}</span>
                  <span>{t('audit.operations.col.result')}</span>
                  <span className="text-right">{t('audit.operations.col.detail')}</span>
                </div>

                {/* 虚拟滚动列表 */}
                <div ref={scrollRef} style={{ height: 'min(600px, calc(100vh - 340px))', overflow: 'auto' }}>
                  <div style={{ height: totalHeight, position: 'relative' }}>
                    {virtualRows.map((vr) => {
                      const log = filteredLogs[vr.index];
                      if (!log) return null;
                      return (
                        <div
                          key={log.id}
                          data-index={vr.index}
                          ref={virtualizer.measureElement}
                          style={{
                            position: 'absolute',
                            top: 0,
                            left: 0,
                            width: '100%',
                            transform: `translateY(${vr.start}px)`,
                            display: 'grid',
                            gridTemplateColumns: GRID_COLS,
                            gap: '0.5rem',
                          }}
                          className="px-4 py-2.5 border-b border-[var(--dg-border)] hover:bg-[var(--dg-bg-hover)]"
                        >
                          <span className="text-sm dg-text-secondary truncate">
                            {log.createdAt ? new Date(log.createdAt).toLocaleString() : '--'}
                          </span>
                          <span className="text-sm text-[var(--dg-text-primary)] truncate">{log.username || '--'}</span>
                          <span className="text-sm text-[var(--dg-text-secondary)] truncate">{log.module || '--'}</span>
                          <div>
                            <Badge variant="outline" className="border-blue-500/30 dg-text-blue bg-blue-500/10">
                              {log.action || '--'}
                            </Badge>
                          </div>
                          <code className="text-xs dg-text-secondary bg-[var(--dg-bg-tertiary)] px-2 py-0.5 rounded truncate">
                            {log.resource || '--'}
                          </code>
                          <span className="text-sm dg-text-secondary truncate">{log.ip || '--'}</span>
                          <div>{getLogResultBadge(log.result)}</div>
                          <div className="flex items-center justify-end">
                            <Button
                              variant="ghost"
                              size="icon"
                              className="h-8 w-8 dg-text-secondary hover:dg-text-blue hover:bg-[var(--dg-bg-hover)]"
                              onClick={() => viewDetail(log)}
                              title={t('audit.operations.viewDetail')}
                            >
                              <Eye className="h-4 w-4" />
                            </Button>
                          </div>
                        </div>
                      );
                    })}
                  </div>
                </div>

                {/* 行数统计 */}
                <div className="text-center py-2 text-xs dg-text-muted border-t border-[var(--dg-border)]">
                  {t('audit.operations.totalLogs', { count: filteredLogs.length })} {filteredLogs.length > 200 && `· ${t('audit.operations.virtualScroll')}`}
                </div>
              </>
            )}
          </div>
      </ContentPanel>

      {/* Detail Modal */}
      <LogDetailDialog log={detailLog} onClose={() => setDetailLog(null)} />

      {/* Statistics Modal */}
      <StatisticsDialog
        open={statsOpen}
        onClose={() => setStatsOpen(false)}
        loading={statsLoading}
        stats={statistics}
      />
    </PageShell>
  );
}

// =========================================================================
//  Log Detail Dialog
// =========================================================================

function LogDetailDialog({ log, onClose }: { log: OperationLog | null; onClose: () => void }) {
  const { t } = useTranslation();
  if (!log) return null;

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center">
      <div className="absolute inset-0 bg-black/60" onClick={onClose} />
      <div className="relative dg-card rounded-lg p-6 max-w-lg w-full mx-4 shadow-2xl">
        <div className="flex items-center justify-between mb-4">
          <h3 className="text-lg font-semibold text-[var(--dg-text-primary)]">{t('audit.operations.detailTitle')}</h3>
          <Button
            variant="ghost"
            size="icon"
            className="h-7 w-7 dg-text-secondary hover:text-[var(--dg-text-primary)]"
            onClick={onClose}
          >
            <X className="h-4 w-4" />
          </Button>
        </div>

        <div className="space-y-3 text-sm">
          <DetailRow label="ID" value={log.id} />
          <DetailRow label={t('audit.operations.col.time')} value={log.createdAt ? new Date(log.createdAt).toLocaleString() : '--'} />
          <DetailRow label={t('audit.operations.col.user')} value={log.username || '--'} />
          <DetailRow label={t('audit.operations.detailCol.userId')} value={log.userId || '--'} />
          <DetailRow label={t('audit.operations.col.module')} value={log.module || '--'} />
          <DetailRow label={t('audit.operations.col.actionType')} value={log.action || '--'} />
          <DetailRow label={t('audit.operations.col.resource')} value={log.resource || '--'} />
          <DetailRow label={t('audit.operations.detailCol.ipAddress')} value={log.ip || '--'} />
          <DetailRow label={t('audit.operations.detailCol.userAgent')} value={log.userAgent || '--'} />
          <DetailRow
            label={t('audit.operations.col.result')}
            value={
              <Badge
                variant="outline"
                className={
                  log.result === 'success'
                    ? 'border-emerald-500/30 dg-text-green bg-emerald-500/10'
                    : 'border-red-500/30 dg-text-red bg-red-500/10'
                }
              >
                {log.result === 'success' ? t('common.success') : t('common.failed')}
              </Badge>
            }
          />
          {log.message && <DetailRow label={t('audit.operations.detailCol.message')} value={log.message} mono />}
        </div>

        <div className="mt-5 flex justify-end">
          <Button
            variant="outline"
            className="dg-btn-secondary"
            onClick={onClose}
          >
            {t('common.close')}
          </Button>
        </div>
      </div>
    </div>
  );
}

function DetailRow({ label, value, mono }: { label: string; value: React.ReactNode; mono?: boolean }) {
  return (
    <div className="flex items-start gap-4">
      <span className="dg-text-muted w-20 flex-shrink-0">{label}</span>
      <span className={mono ? 'text-[var(--dg-text-secondary)] font-mono text-xs break-all' : 'text-[var(--dg-text-primary)] break-all'}>
        {value}
      </span>
    </div>
  );
}

// =========================================================================
//  Statistics Dialog
// =========================================================================

function StatisticsDialog({
  open,
  onClose,
  loading,
  stats,
}: {
  open: boolean;
  onClose: () => void;
  loading: boolean;
  stats: AuditStatistics | null;
}) {
  const { t } = useTranslation();
  if (!open) return null;

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center">
      <div className="absolute inset-0 bg-black/60" onClick={onClose} />
      <div className="relative dg-card rounded-lg p-6 max-w-md w-full mx-4 shadow-2xl">
        <div className="flex items-center justify-between mb-4">
          <h3 className="text-lg font-semibold text-[var(--dg-text-primary)]">{t('audit.operations.statsTitle')}</h3>
          <Button
            variant="ghost"
            size="icon"
            className="h-7 w-7 dg-text-secondary hover:text-[var(--dg-text-primary)]"
            onClick={onClose}
          >
            <X className="h-4 w-4" />
          </Button>
        </div>

        {loading ? (
          <div className="flex items-center justify-center py-10">
            <div className="w-8 h-8 border-2 border-blue-500 border-t-transparent rounded-full animate-spin" />
          </div>
        ) : stats ? (
          <div className="space-y-4">
            <div className="grid grid-cols-2 gap-3">
              <StatCard label={t('audit.operations.stats.totalLogs')} value={String(stats.total_logs ?? '--')} color="blue" />
              <StatCard label={t('audit.operations.stats.todayLogs')} value={String(stats.today_count ?? '--')} color="emerald" />
              <StatCard label={t('audit.operations.stats.successCount')} value={String(stats.success_count ?? '--')} color="emerald" />
              <StatCard label={t('audit.operations.stats.failureCount')} value={String(stats.failure_count ?? '--')} color="red" />
            </div>

            {stats.top_modules && stats.top_modules.length > 0 && (
              <div>
                <h4 className="text-xs font-semibold dg-text-secondary mb-2">{t('audit.operations.topModules')}</h4>
                <div className="space-y-1">
                  {stats.top_modules.slice(0, 5).map((m, i) => (
                    <div key={i} className="flex justify-between text-xs">
                      <span className="text-[var(--dg-text-secondary)]">{m.module}</span>
                      <span className="dg-text-muted">{m.count}</span>
                    </div>
                  ))}
                </div>
              </div>
            )}

            {stats.top_users && stats.top_users.length > 0 && (
              <div>
                <h4 className="text-xs font-semibold dg-text-secondary mb-2">{t('audit.operations.topUsers')}</h4>
                <div className="space-y-1">
                  {stats.top_users.slice(0, 5).map((u, i) => (
                    <div key={i} className="flex justify-between text-xs">
                      <span className="text-[var(--dg-text-secondary)]">{u.username}</span>
                      <span className="dg-text-muted">{u.count}</span>
                    </div>
                  ))}
                </div>
              </div>
            )}
          </div>
        ) : (
          <p className="dg-text-muted text-center py-10 text-sm">{t('audit.operations.noStats')}</p>
        )}

        <div className="mt-5 flex justify-end">
          <Button
            variant="outline"
            className="dg-btn-secondary"
            onClick={onClose}
          >
            {t('common.close')}
          </Button>
        </div>
      </div>
    </div>
  );
}

function StatCard({ label, value, color }: { label: string; value: string; color: 'blue' | 'emerald' | 'red' }) {
  const colorMap = {
    blue: 'border-blue-500/20 bg-blue-500/5 dg-text-blue',
    emerald: 'border-emerald-500/20 bg-emerald-500/5 dg-text-green',
    red: 'border-red-500/20 bg-red-500/5 dg-text-red',
  };
  return (
    <div className={`rounded-lg border p-3 ${colorMap[color]}`}>
      <div className="text-xs dg-text-muted">{label}</div>
      <div className="text-xl font-bold mt-0.5">{value}</div>
    </div>
  );
}