import React, { useState, useEffect } from 'react';
import {
  
  Search,
  Clock,
  Server,
  ArrowRight,
  ChevronRight,
  ChevronDown,
  Zap,
  AlertCircle,
  CheckCircle,
  XCircle,
  BarChart3,
  TrendingUp,
  RefreshCw,
  Eye,
  GitBranch,
  Code,
  Box,
} from 'lucide-react';

import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Badge } from '@/components/ui/badge';
import { Card, CardContent, CardHeader, CardTitle} from '@/components/ui/card';
import { StatStrip } from '@/components/ui/stat-strip';
import {
  Dialog, DialogContent, DialogHeader, DialogTitle, DialogDescription
} from '@/components/ui/dialog';
import {
  Select, SelectContent, SelectItem, SelectTrigger, SelectValue
} from '@/components/ui/select';
import { Label } from '@/components/ui/label';
import { Separator } from '@/components/ui/separator';
import { ScrollArea } from '@/components/ui/scroll-area';
import { toast } from 'sonner';
import { traceApi } from '@/api';
import { PageShell } from '@/components/layout/PageShell';
import { PageLoading } from '@/components/layout/PageLoading';
import { PageEmpty } from '@/components/layout/PageEmpty';
import type { JsonData } from '@/types/common';

interface Trace {
  id: string;
  traceId: string;
  serviceName: string;
  operationName: string;
  startTime: string;
  duration: number;
  status: 'success' | 'error' | 'pending';
  spanCount: number;
  tags: Record<string, string>;
  spans?: Span[];
}

interface Span {
  id: string;
  spanId: string;
  parentSpanId?: string;
  serviceName: string;
  operationName: string;
  startTime: string;
  duration: number;
  status: 'success' | 'error' | 'pending';
  kind: 'client' | 'server' | 'producer' | 'consumer' | 'internal';
  tags: Record<string, string>;
  logs: SpanLog[];
  children: Span[];
}

interface SpanLog {
  timestamp: string;
  fields: Record<string, string>;
}

interface ServiceMetrics {
  serviceName: string;
  requestCount: number;
  errorRate: number;
  avgDuration: number;
  p95Duration: number;
  p99Duration: number;
}

const TraceManager: React.FC = () => {
  const [traces, setTraces] = useState<Trace[]>([]);
  const [services, setServices] = useState<ServiceMetrics[]>([]);
  const [loading, setLoading] = useState(false);
  const [searchQuery, setSearchQuery] = useState('');
  const [serviceFilter, setServiceFilter] = useState<string>('all');
  const [statusFilter, setStatusFilter] = useState<string>('all');
  const [timeRange, setTimeRange] = useState<string>('1h');
  const [activeTab, setActiveTab] = useState('traces');
  const [selectedTrace, setSelectedTrace] = useState<Trace | null>(null);
  const [selectedSpan, setSelectedSpan] = useState<Span | null>(null);
  const [traceDetailOpen, setTraceDetailOpen] = useState(false);
  const [spanDetailOpen, setSpanDetailOpen] = useState(false);

  useEffect(() => {
    fetchData();
  }, [timeRange]);

  const fetchData = async () => {
    await Promise.all([fetchTraces(), fetchServices()]);
  };

  const fetchTraces = async () => {
    setLoading(true);
    try {
      const res = await traceApi.getTraces({ timeRange, service: serviceFilter, status: statusFilter });
      setTraces(res.data || []);
    } catch {
      toast.error('获取链路数据失败');
    } finally {
      setLoading(false);
    }
  };

  const fetchServices = async () => {
    try {
      const res = await traceApi.getServices(timeRange);
      setServices(res.data || []);
    } catch {
      toast.error('获取服务数据失败');
    }
  };

  const fetchTraceDetail = async (traceId: string) => {
    try {
      const res = await traceApi.getTraceDetail(traceId);
      return res.data;
    } catch {
      toast.error('获取链路详情失败');
      return null;
    }
  };

  const getStatusBadge = (status: string) => {
    switch (status) {
      case 'success':
        return <Badge variant="default" className="bg-green-500 gap-1"><CheckCircle className="w-3 h-3" />成功</Badge>;
      case 'error':
        return <Badge variant="destructive" className="gap-1"><XCircle className="w-3 h-3" />错误</Badge>;
      case 'pending':
        return <Badge variant="outline" className="gap-1"><Clock className="w-3 h-3" />进行中</Badge>;
      default:
        return <Badge variant="secondary">未知</Badge>;
    }
  };

  const getKindIcon = (kind: string) => {
    switch (kind) {
      case 'client': return <ArrowRight className="w-4 h-4" />;
      case 'server': return <Server className="w-4 h-4" />;
      case 'producer': return <Zap className="w-4 h-4" />;
      case 'consumer': return <Box className="w-4 h-4" />;
      default: return <Code className="w-4 h-4" />;
    }
  };

  const getStatusColor = (status: string) => {
    switch (status) {
      case 'success': return 'bg-green-500';
      case 'error': return 'bg-red-500';
      case 'pending': return 'bg-yellow-500';
      default: return 'bg-[var(--dg-bg-active)]';
    }
  };

  const formatDuration = (ms: number) => {
    if (ms < 1) return `${(ms * 1000).toFixed(2)}μs`;
    if (ms < 1000) return `${ms.toFixed(2)}ms`;
    return `${(ms / 1000).toFixed(2)}s`;
  };

  const filteredTraces = traces.filter(trace => {
    const matchSearch = trace.traceId.toLowerCase().includes(searchQuery.toLowerCase()) ||
                       trace.operationName.toLowerCase().includes(searchQuery.toLowerCase());
    const matchService = serviceFilter === 'all' || trace.serviceName === serviceFilter;
    const matchStatus = statusFilter === 'all' || trace.status === statusFilter;
    return matchSearch && matchService && matchStatus;
  });

  const serviceNames = Array.from(new Set(traces.map(t => t.serviceName)));

  // 构建Span树
  const buildSpanTree = (spans: Span[]): Span[] => {
    const spanMap = new Map<string, Span>();
    const roots: Span[] = [];
    
    spans.forEach(span => {
      spanMap.set(span.spanId, { ...span, children: [] });
    });
    
    spans.forEach(span => {
      const node = spanMap.get(span.spanId)!;
      if (span.parentSpanId && spanMap.has(span.parentSpanId)) {
        const parent = spanMap.get(span.parentSpanId)!;
        parent.children = parent.children || [];
        parent.children.push(node);
      } else {
        roots.push(node);
      }
    });
    
    return roots;
  };

  // 渲染Span树
  const SpanTreeNode: React.FC<{ span: Span; level: number; totalDuration: number }> = ({ span, level, totalDuration }) => {
    const [expanded, setExpanded] = useState(true);
    const widthPercent = totalDuration > 0 ? (span.duration / totalDuration) * 100 : 0;
    const _offsetPercent = 0; // Simplified

    return (
      <div className="select-none">
        <div
          className="flex items-center py-2 hover:bg-muted/50 cursor-pointer border-l-2 border-transparent hover:border-blue-500"
          style={{ paddingLeft: `${level * 24 + 12}px` }}
          onClick={() => { setSelectedSpan(span); setSpanDetailOpen(true); }}
        >
          {span.children?.length > 0 && (
            <Button
              variant="ghost"
              size="sm"
              className="h-4 w-4 p-0 mr-1"
              onClick={(e) => { e.stopPropagation(); setExpanded(!expanded); }}
            >
              {expanded ? <ChevronDown className="w-3 h-3" /> : <ChevronRight className="w-3 h-3" />}
            </Button>
          )}
          {!span.children?.length && <span className="w-5" />}
          
          <div className="flex items-center gap-2 flex-1 min-w-0">
            {getKindIcon(span.kind)}
            <span className="font-medium truncate">{span.operationName}</span>
            <span className="text-xs text-muted-foreground">{span.serviceName}</span>
          </div>
          
          <div className="flex items-center gap-4">
            <div className="w-32 h-4 bg-muted rounded overflow-hidden">
              <div
                className={`h-full ${getStatusColor(span.status)}`}
                style={{ width: `${Math.max(widthPercent, 1)}%` }}
              />
            </div>
            <span className="text-sm text-muted-foreground w-20 text-right">
              {formatDuration(span.duration)}
            </span>
            {span.status === 'error' && <AlertCircle className="w-4 h-4 text-red-500" />}
          </div>
        </div>
        
        {expanded && span.children?.map(child => (
          <SpanTreeNode key={child.spanId} span={child} level={level + 1} totalDuration={totalDuration} />
        ))}
      </div>
    );
  };

  const pageTabs = [
    { id: 'traces', label: '链路追踪' },
    { id: 'services', label: '服务拓扑' },
    { id: 'metrics', label: '性能指标' },
  ];

  const tracesToolbar = activeTab === 'traces' ? (
    <div className="flex flex-wrap items-center justify-between gap-4 w-full">
            <div className="flex items-center gap-2 flex-1 min-w-[400px]">
              <div className="relative flex-1">
                <Search className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-muted-foreground" />
                <Input
                  placeholder="搜索Trace ID、操作名..."
                  value={searchQuery}
                  onChange={(e) => setSearchQuery(e.target.value)}
                  className="pl-10"
                />
              </div>
              <Select value={serviceFilter} onValueChange={setServiceFilter}>
                <SelectTrigger className="w-[150px]">
                  <SelectValue placeholder="服务" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">全部服务</SelectItem>
                  {serviceNames.map(s => (
                    <SelectItem key={s} value={s}>{s}</SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <Select value={statusFilter} onValueChange={setStatusFilter}>
                <SelectTrigger className="w-[120px]">
                  <SelectValue placeholder="状态" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">全部状态</SelectItem>
                  <SelectItem value="success">成功</SelectItem>
                  <SelectItem value="error">错误</SelectItem>
                  <SelectItem value="pending">进行中</SelectItem>
                </SelectContent>
              </Select>
              <Select value={timeRange} onValueChange={setTimeRange}>
                <SelectTrigger className="w-[120px]">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="15m">15分钟</SelectItem>
                  <SelectItem value="1h">1小时</SelectItem>
                  <SelectItem value="6h">6小时</SelectItem>
                  <SelectItem value="24h">24小时</SelectItem>
                  <SelectItem value="7d">7天</SelectItem>
                </SelectContent>
              </Select>
            </div>
      <div className="flex items-center gap-2">
        <Button variant="outline" className="dg-btn-secondary" onClick={fetchTraces}>
          <RefreshCw className="w-4 h-4 mr-2" />
          刷新
        </Button>
      </div>
    </div>
  ) : undefined;

  return (
    <PageShell
      variant="list"
      title="链路追踪"
      subtitle="分布式链路查询与服务性能分析"
      icon={<GitBranch className="h-5 w-5" />}
      tabs={pageTabs}
      activeTab={activeTab}
      onTabChange={setActiveTab}
      toolbar={tracesToolbar}
      metrics={(
        <StatStrip
          items={[
            { label: '总请求', value: services.reduce((sum, s) => sum + s.requestCount, 0).toLocaleString(), color: 'blue' },
            { label: '错误率', value: `${(services.reduce((sum, s) => sum + s.errorRate, 0) / (services.length || 1)).toFixed(2)}%`, color: 'red' },
            { label: '平均延迟', value: formatDuration(services.reduce((sum, s) => sum + s.avgDuration, 0) / (services.length || 1)), color: 'amber' },
            { label: '服务数', value: services.length, color: 'purple' },
          ]}
        />
      )}
      actions={activeTab === 'traces' ? undefined : (
        <Button variant="outline" className="dg-btn-secondary" onClick={fetchData}>
          <RefreshCw className="w-4 h-4 mr-2" />
          刷新
        </Button>
      )}
    >
      {activeTab === 'traces' && (
        <Card>
            <CardContent className="p-0">
              <div className="overflow-x-auto">
                <table className="w-full">
                  <thead className="bg-muted/50">
                    <tr>
                      <th className="px-4 py-3 text-left text-sm font-medium">Trace ID</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">服务 / 操作</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">状态</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">耗时</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">Span数</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">时间</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">操作</th>
                    </tr>
                  </thead>
                  <tbody className="divide-y">
                    {loading ? (
                      <tr>
                        <td colSpan={7} className="px-4 py-2"><PageLoading label="加载链路数据..." /></td>
                      </tr>
                    ) : filteredTraces.length === 0 ? (
                      <tr>
                        <td colSpan={7} className="px-4 py-2"><PageEmpty title="暂无链路数据" className="py-8" /></td>
                      </tr>
                    ) : (
                      filteredTraces.map((trace) => (
                        <tr key={trace.id} className="hover:bg-muted/50">
                          <td className="px-4 py-3">
                            <span className="font-mono text-sm dg-text-blue">{trace.traceId.slice(0, 16)}...</span>
                          </td>
                          <td className="px-4 py-3">
                            <div className="font-medium">{trace.operationName}</div>
                            <div className="text-sm text-muted-foreground">{trace.serviceName}</div>
                          </td>
                          <td className="px-4 py-3">{getStatusBadge(trace.status)}</td>
                          <td className="px-4 py-3 text-sm">{formatDuration(trace.duration)}</td>
                          <td className="px-4 py-3 text-sm">{trace.spanCount}</td>
                          <td className="px-4 py-3 text-sm text-muted-foreground">{trace.startTime}</td>
                          <td className="px-4 py-3">
                            <Button
                              variant="ghost"
                              size="sm"
                              onClick={async () => {
                                const detail = await fetchTraceDetail(trace.traceId);
                                if (detail) {
                                  setSelectedTrace({ ...trace, spans: detail.spans });
                                  setTraceDetailOpen(true);
                                }
                              }}
                            >
                              <Eye className="w-4 h-4" />
                            </Button>
                          </td>
                        </tr>
                      ))
                    )}
                  </tbody>
                </table>
              </div>
            </CardContent>
          </Card>
      )}

      {activeTab === 'services' && (
          <Card>
            <CardHeader>
              <CardTitle>服务性能概览</CardTitle>
            </CardHeader>
            <CardContent>
              <div className="overflow-x-auto">
                <table className="w-full">
                  <thead className="bg-muted/50">
                    <tr>
                      <th className="px-4 py-3 text-left text-sm font-medium">服务名称</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">请求数</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">错误率</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">平均延迟</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">P95延迟</th>
                      <th className="px-4 py-3 text-left text-sm font-medium">P99延迟</th>
                    </tr>
                  </thead>
                  <tbody className="divide-y">
                    {services.map((service) => (
                      <tr key={service.serviceName} className="hover:bg-muted/50">
                        <td className="px-4 py-3 font-medium">{service.serviceName}</td>
                        <td className="px-4 py-3">{service.requestCount.toLocaleString()}</td>
                        <td className="px-4 py-3">
                          <span className={service.errorRate > 1 ? 'text-red-500' : 'dg-text-green'}>
                            {service.errorRate.toFixed(2)}%
                          </span>
                        </td>
                        <td className="px-4 py-3">{formatDuration(service.avgDuration)}</td>
                        <td className="px-4 py-3">{formatDuration(service.p95Duration)}</td>
                        <td className="px-4 py-3">{formatDuration(service.p99Duration)}</td>
                      </tr>
                    ))}
                  </tbody>
                </table>
              </div>
            </CardContent>
          </Card>
      )}

      {activeTab === 'metrics' && (
          <div className="grid grid-cols-2 gap-4">
            <Card>
              <CardHeader>
                <CardTitle>延迟分布</CardTitle>
              </CardHeader>
              <CardContent className="h-[300px] flex items-center justify-center text-muted-foreground">
                <BarChart3 className="w-16 h-16 mr-4" />
                延迟分布图表（集成图表库后显示）
              </CardContent>
            </Card>
            <Card>
              <CardHeader>
                <CardTitle>错误率趋势</CardTitle>
              </CardHeader>
              <CardContent className="h-[300px] flex items-center justify-center text-muted-foreground">
                <TrendingUp className="w-16 h-16 mr-4" />
                错误率趋势图表（集成图表库后显示）
              </CardContent>
            </Card>
          </div>
      )}

      {/* Trace详情对话框 */}
      <Dialog open={traceDetailOpen} onOpenChange={setTraceDetailOpen}>
        <DialogContent className="max-w-6xl max-h-[90vh]">
          <DialogHeader>
            <DialogTitle className="flex items-center gap-2">
              <GitBranch className="w-5 h-5" />
              Trace详情
              <span className="font-mono text-sm text-muted-foreground">{selectedTrace?.traceId}</span>
            </DialogTitle>
            <DialogDescription className="sr-only">描述</DialogDescription>
          </DialogHeader>
          {selectedTrace && (
            <div className="space-y-4">
              <div className="flex items-center gap-4 p-3 bg-muted rounded-lg">
                <div>
                  <Label className="text-xs text-muted-foreground">服务</Label>
                  <p className="font-medium">{selectedTrace.serviceName}</p>
                </div>
                <Separator orientation="vertical" className="h-8" />
                <div>
                  <Label className="text-xs text-muted-foreground">操作</Label>
                  <p className="font-medium">{selectedTrace.operationName}</p>
                </div>
                <Separator orientation="vertical" className="h-8" />
                <div>
                  <Label className="text-xs text-muted-foreground">总耗时</Label>
                  <p className="font-medium">{formatDuration(selectedTrace.duration)}</p>
                </div>
                <Separator orientation="vertical" className="h-8" />
                <div>
                  <Label className="text-xs text-muted-foreground">状态</Label>
                  <p>{getStatusBadge(selectedTrace.status)}</p>
                </div>
              </div>
              
              <ScrollArea className="h-[500px]">
                <div className="border rounded-lg">
                  <div className="flex items-center px-4 py-2 bg-muted/50 border-b text-sm font-medium">
                    <span className="flex-1">Span名称</span>
                    <span className="w-32">时间线</span>
                    <span className="w-20 text-right">耗时</span>
                  </div>
                  {/* Span树渲染 */}
                  {(selectedTrace as JsonData).spans && buildSpanTree((selectedTrace as JsonData).spans).map(span => (
                    <SpanTreeNode key={span.spanId} span={span} level={0} totalDuration={selectedTrace.duration} />
                  ))}
                </div>
              </ScrollArea>
            </div>
          )}
        </DialogContent>
      </Dialog>

      {/* Span详情对话框 */}
      <Dialog open={spanDetailOpen} onOpenChange={setSpanDetailOpen}>
        <DialogContent className="max-w-2xl">
          <DialogHeader>
            <DialogTitle>Span详情</DialogTitle>
            <DialogDescription className="sr-only">描述</DialogDescription>
          </DialogHeader>
          {selectedSpan && (
            <div className="space-y-4">
              <div className="grid grid-cols-2 gap-4">
                <div>
                  <Label className="text-muted-foreground">Span ID</Label>
                  <p className="font-mono text-sm">{selectedSpan.spanId}</p>
                </div>
                <div>
                  <Label className="text-muted-foreground">类型</Label>
                  <p className="capitalize">{selectedSpan.kind}</p>
                </div>
                <div>
                  <Label className="text-muted-foreground">服务</Label>
                  <p className="font-medium">{selectedSpan.serviceName}</p>
                </div>
                <div>
                  <Label className="text-muted-foreground">操作</Label>
                  <p className="font-medium">{selectedSpan.operationName}</p>
                </div>
                <div>
                  <Label className="text-muted-foreground">状态</Label>
                  <p>{getStatusBadge(selectedSpan.status)}</p>
                </div>
                <div>
                  <Label className="text-muted-foreground">耗时</Label>
                  <p className="font-medium">{formatDuration(selectedSpan.duration)}</p>
                </div>
              </div>
              
              {Object.keys(selectedSpan.tags).length > 0 && (
                <div>
                  <Label className="text-muted-foreground">标签</Label>
                  <div className="mt-1 p-3 bg-muted rounded-lg">
                    {Object.entries(selectedSpan.tags).map(([k, v]) => (
                      <div key={k} className="flex justify-between text-sm py-1">
                        <span className="text-muted-foreground">{k}</span>
                        <span className="font-mono">{v}</span>
                      </div>
                    ))}
                  </div>
                </div>
              )}
              
              {selectedSpan.logs?.length > 0 && (
                <div>
                  <Label className="text-muted-foreground">日志</Label>
                  <div className="mt-1 space-y-2">
                    {selectedSpan.logs.map((log, idx) => (
                      <div key={idx} className="p-2 bg-muted rounded text-sm">
                        <span className="text-muted-foreground">{log.timestamp}</span>
                        <pre className="mt-1 text-xs">{JSON.stringify(log.fields, null, 2)}</pre>
                      </div>
                    ))}
                  </div>
                </div>
              )}
            </div>
          )}
        </DialogContent>
      </Dialog>
    </PageShell>
  );
};

export default TraceManager;