import { useEffect, useRef, useState } from 'react';
import {
  ClipboardList, Clock, CheckCircle, AlertTriangle,
  Database, ChevronRight,
  X, AlertCircle, Info, Bell
} from 'lucide-react';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { dbInstances, statusMap, statusColorMap, dbTypeColorMap, tickets, announcements } from '@/lib/mock';
import { useTheme } from '@/hooks/useTheme';
import { useAuth } from '@/hooks/useAuth';
import { dashboardApi } from '@/api/dashboard';
import type { DashboardStats } from '@/types';
import * as echarts from 'echarts';

const priorityStyle: Record<string, { border: string; bg: string; icon: React.ElementType; iconColor: string; badge: string }> = {
  urgent: { border: 'border-l-red-500', bg: 'bg-red-500/5', icon: AlertCircle, iconColor: 'text-red-400', badge: 'bg-red-500/15 text-red-400 border-red-500/30' },
  high: { border: 'border-l-orange-500', bg: 'bg-orange-500/5', icon: AlertTriangle, iconColor: 'text-orange-400', badge: 'bg-orange-500/15 text-orange-400 border-orange-500/30' },
  normal: { border: 'border-l-blue-500', bg: 'bg-blue-500/5', icon: Info, iconColor: 'text-blue-400', badge: 'bg-blue-500/15 text-blue-400 border-blue-500/30' },
  low: { border: 'border-l-gray-500', bg: 'bg-gray-500/5', icon: Bell, iconColor: 'text-gray-400', badge: 'bg-gray-500/15 text-gray-400 border-gray-500/30' },
};

const priorityLabel: Record<string, string> = { urgent: '紧急', high: '重要', normal: '通知', low: '一般' };

export default function Dashboard() {
  const chartRef = useRef<HTMLDivElement>(null);
  const { theme } = useTheme();
  const { user } = useAuth();
  const [dismissedIds, setDismissedIds] = useState<Set<string>>(new Set());
  const [expandedId, setExpandedId] = useState<string | null>(null);
  const [stats, setStats] = useState<DashboardStats | null>(null);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    dashboardApi.getStats()
      .then(data => setStats(data))
      .catch(() => {
        // fallback: keep stats null, show skeleton
      })
      .finally(() => setLoading(false));
  }, []);

  const visibleAnnouncements = announcements
    .filter(a => a.enabled && a.targetRoles.includes(user.role) && !dismissedIds.has(a.id))
    .sort((a, b) => {
      if (a.pinned !== b.pinned) return a.pinned ? -1 : 1;
      const po = { urgent: 0, high: 1, normal: 2, low: 3 };
      if (po[a.priority] !== po[b.priority]) return po[a.priority] - po[b.priority];
      return new Date(b.publishTime).getTime() - new Date(a.publishTime).getTime();
    });

  const dismiss = (id: string) => setDismissedIds(prev => new Set(prev).add(id));
  const toggleExpand = (id: string) => setExpandedId(prev => prev === id ? null : id);

  useEffect(() => {
    if (!chartRef.current) return;
    const chart = echarts.init(chartRef.current);
    const isLight = theme === 'light';
    const colors = isLight
      ? { bg: 'rgba(255,255,255,0.95)', border: '#e2e5eb', text: '#1a1d23', muted: '#5c6370', grid: '#f0f1f5', blue: '#2563eb', green: '#16a34a', red: '#dc2626' }
      : { bg: 'rgba(22, 27, 34, 0.95)', border: '#30363d', text: '#f0f6fc', muted: '#8b949e', grid: '#21262d', blue: '#58a6ff', green: '#3fb950', red: '#f85149' };
    const option: any = {
      backgroundColor: 'transparent',
      tooltip: {
        trigger: 'axis' as const,
        backgroundColor: colors.bg,
        borderColor: colors.border,
        textStyle: { color: colors.text },
      },
      legend: {
        data: ['提交工单', '执行成功', '执行失败'],
        textStyle: { color: colors.muted },
        bottom: 0,
        itemWidth: 14,
        itemHeight: 8,
      },
      grid: { left: '2%', right: '3%', bottom: '18%', top: '8%', containLabel: true },
      xAxis: {
        type: 'category' as const,
        data: ['周一', '周二', '周三', '周四', '周五', '周六', '周日'],
        axisLine: { lineStyle: { color: colors.border } },
        axisLabel: { color: colors.muted, fontSize: 11 },
      },
      yAxis: {
        type: 'value' as const,
        axisLine: { show: false },
        splitLine: { lineStyle: { color: colors.grid } },
        axisLabel: { color: colors.muted, fontSize: 11 },
      },
      series: [
        {
          name: '提交工单', type: 'line', smooth: true,
          data: [120, 132, 101, 134, 90, 230, 210],
          itemStyle: { color: colors.blue },
          lineStyle: { width: 2 },
          areaStyle: {
            color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [
              { offset: 0, color: isLight ? 'rgba(37, 99, 235, 0.15)' : 'rgba(88, 166, 255, 0.3)' },
              { offset: 1, color: 'transparent' },
            ]),
          },
          symbol: 'none',
        },
        {
          name: '执行成功', type: 'line', smooth: true,
          data: [110, 125, 95, 128, 85, 215, 200],
          itemStyle: { color: colors.green },
          lineStyle: { width: 2 },
          areaStyle: {
            color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [
              { offset: 0, color: isLight ? 'rgba(22, 163, 74, 0.15)' : 'rgba(63, 185, 80, 0.3)' },
              { offset: 1, color: 'transparent' },
            ]),
          },
          symbol: 'none',
        },
        {
          name: '执行失败', type: 'line', smooth: true,
          data: [5, 3, 4, 2, 3, 8, 5],
          itemStyle: { color: colors.red },
          lineStyle: { width: 2 },
          symbol: 'none',
        },
      ],
    };
    chart.setOption(option);
    const handleResize = () => chart.resize();
    window.addEventListener('resize', handleResize);
    return () => { window.removeEventListener('resize', handleResize); chart.dispose(); };
  }, [theme]);

  const onlineInstances = dbInstances.filter(i => i.status === 'online').length;
  const warningInstances = dbInstances.filter(i => i.status === 'warning').length;
  const offlineInstances = dbInstances.filter(i => i.status === 'offline').length;
  const pendingTickets = tickets.filter(t => t.status === 'pending' || t.status === 'reviewing').slice(0, 4);

  // Stats cards - use real API data
  const statsCards = stats ? [
    { title: '工单总数', value: stats.ticket_total, icon: ClipboardList, color: 'text-blue-400', bg: 'bg-blue-400/10' },
    { title: '待审批', value: stats.ticket_pending, icon: Clock, color: 'text-orange-400', bg: 'bg-orange-400/10' },
    { title: '本月工单', value: stats.ticket_month, icon: CheckCircle, color: 'text-purple-400', bg: 'bg-purple-400/10' },
    { title: '今日查询', value: stats.queries_today.toLocaleString(), icon: AlertTriangle, color: 'text-red-400', bg: 'bg-red-400/10' },
  ] : [];

  return (
    <div className="space-y-6">
      {/* 公告通知栏 */}
      {visibleAnnouncements.length > 0 && (
        <div className="space-y-3">
          {visibleAnnouncements.slice(0, 3).map(ann => {
            const style = priorityStyle[ann.priority] || priorityStyle.normal;
            const PIcon = style.icon;
            const isExpanded = expandedId === ann.id;
            return (
              <div
                key={ann.id}
                className={`dg-card border-l-[3px] ${style.border} ${style.bg} overflow-hidden transition-all duration-300`}
              >
                <div className="px-5 py-3.5 flex items-start gap-3">
                  <div className={`w-8 h-8 rounded-lg flex items-center justify-center flex-shrink-0 mt-0.5 ${style.badge.split(' ').slice(1).join(' ')}`}>
                    <PIcon className="w-4 h-4" />
                  </div>
                  <div className="flex-1 min-w-0">
                    <div className="flex items-center gap-2 mb-1">
                      <span className={`text-[10px] px-2 py-0.5 rounded-full border font-medium ${style.badge}`}>
                        {priorityLabel[ann.priority]}
                      </span>
                      <span className="text-sm font-semibold truncate">{ann.title}</span>
                      {ann.pinned && <span className="text-[10px] text-purple-400 flex-shrink-0">置顶</span>}
                    </div>
                    <div className={`text-xs text-[var(--dg-text-secondary)] leading-relaxed ${isExpanded ? '' : 'line-clamp-1'}`}>
                      {ann.content}
                    </div>
                    {ann.content.includes('\n') && (
                      <button
                        onClick={() => toggleExpand(ann.id)}
                        className="text-[11px] text-blue-400 hover:text-blue-300 mt-1 flex items-center gap-0.5 transition-colors"
                      >
                        {isExpanded ? '收起' : '展开全文'}
                        <ChevronRight className={`w-3 h-3 transition-transform ${isExpanded ? 'rotate-90' : ''}`} />
                      </button>
                    )}
                  </div>
                  <div className="flex items-center gap-2 flex-shrink-0">
                    <span className="text-[11px] text-[var(--dg-text-muted)]">{ann.publishTime.slice(0, 10)}</span>
                    <button
                      onClick={() => dismiss(ann.id)}
                      className="w-6 h-6 rounded-md flex items-center justify-center text-[var(--dg-text-muted)] hover:text-[var(--dg-text-primary)] hover:bg-[var(--dg-bg-hover)] transition-colors"
                    >
                      <X className="w-3.5 h-3.5" />
                    </button>
                  </div>
                </div>
              </div>
            );
          })}
          {visibleAnnouncements.length > 3 && (
            <div className="text-center">
              <span className="text-xs text-[var(--dg-text-muted)]">
                还有 {visibleAnnouncements.length - 3} 条公告，可在「公告管理」中查看
              </span>
            </div>
          )}
        </div>
      )}

      {/* 统计卡片 */}
      <div className="grid grid-cols-4 gap-5">
        {loading ? (
          Array.from({ length: 4 }).map((_, i) => (
            <Card key={i} className="dg-card">
              <CardContent className="p-5">
                <div className="h-20 animate-pulse bg-[var(--dg-bg-tertiary)] rounded" />
              </CardContent>
            </Card>
          ))
        ) : (
          statsCards.map((s, i) => (
            <Card key={i} className="dg-card dg-card-hover">
              <CardContent className="p-5">
                <div className="flex items-center justify-between mb-4">
                  <span className="text-sm text-[var(--dg-text-secondary)] font-medium">{s.title}</span>
                  <div className={`w-10 h-10 rounded-xl ${s.bg} flex items-center justify-center`}>
                    <s.icon className={`w-5 h-5 ${s.color}`} />
                  </div>
                </div>
                <div className="text-3xl font-bold text-[var(--dg-text-primary)]">{s.value}</div>
                <div className="flex items-center gap-2 text-sm mt-2">
                  <span className="text-[var(--dg-text-muted)]">
                    实例 {stats?.instance_online}/{stats?.instance_total} 在线 · {stats?.user_total} 用户
                  </span>
                </div>
              </CardContent>
            </Card>
          ))
        )}
      </div>

      {/* 图表 + 实例状态 */}
      <div className="grid grid-cols-3 gap-5">
        {/* 工单趋势图 */}
        <Card className="dg-card col-span-2">
          <CardHeader className="pb-2 border-b border-[var(--dg-border)]">
            <div className="flex items-center justify-between">
              <CardTitle className="text-[15px] font-semibold">工单趋势</CardTitle>
              <div className="flex gap-1.5">
                {['近7天', '近30天', '近90天'].map((p, i) => (
                  <button key={p} className={`px-3 py-1.5 text-xs rounded-md transition-colors ${i === 0 ? 'bg-blue-500/15 text-blue-400 border border-blue-500/30' : 'bg-[var(--dg-bg-tertiary)] text-[var(--dg-text-secondary)] border border-[var(--dg-border)] hover:border-[var(--dg-text-muted)]'}`}>
                    {p}
                  </button>
                ))}
              </div>
            </div>
          </CardHeader>
          <CardContent className="p-5">
            <div ref={chartRef} style={{ height: 300 }} />
          </CardContent>
        </Card>

        {/* 实例状态 */}
        <Card className="dg-card">
          <CardHeader className="pb-2 border-b border-[var(--dg-border)]">
            <CardTitle className="text-[15px] font-semibold">实例状态</CardTitle>
          </CardHeader>
          <CardContent className="p-0">
            <div className="p-4 border-b border-[var(--dg-border-light)]">
              <div className="grid grid-cols-3 gap-3 text-center">
                <div>
                  <div className="text-2xl font-bold text-green-400">{onlineInstances}</div>
                  <div className="text-xs text-[var(--dg-text-muted)] mt-1">在线</div>
                </div>
                <div>
                  <div className="text-2xl font-bold text-yellow-400">{warningInstances}</div>
                  <div className="text-xs text-[var(--dg-text-muted)] mt-1">告警</div>
                </div>
                <div>
                  <div className="text-2xl font-bold text-red-400">{offlineInstances}</div>
                  <div className="text-xs text-[var(--dg-text-muted)] mt-1">离线</div>
                </div>
              </div>
            </div>
            {dbInstances.slice(0, 4).map(inst => (
              <div key={inst.id} className="flex items-center px-5 py-3.5 border-b border-[var(--dg-border-light)] last:border-0 hover:bg-[var(--dg-bg-hover)] transition-colors cursor-pointer">
                <div className={`w-9 h-9 rounded-lg flex items-center justify-center mr-3.5 ${inst.dbType === 'mysql' ? 'bg-[rgba(0,117,143,0.2)] text-[#26a69a]' : inst.dbType === 'redis' ? 'bg-[rgba(220,50,32,0.2)] text-[#ef5350]' : inst.dbType === 'postgres' ? 'bg-[rgba(51,103,145,0.2)] text-[#42a5f5]' : 'bg-[rgba(71,162,72,0.2)] text-[#66bb6a]'}`}>
                  <Database className="w-4.5 h-4.5" />
                </div>
                <div className="flex-1 min-w-0">
                  <div className="text-sm font-medium truncate">{inst.name}</div>
                  <div className="text-xs text-[var(--dg-text-muted)]">{inst.host}:{inst.port}</div>
                </div>
                <span className={`px-2.5 py-1 rounded-full text-[11px] font-medium ${inst.status === 'online' ? 'bg-green-500/15 text-green-400' : inst.status === 'warning' ? 'bg-yellow-500/15 text-yellow-400' : 'bg-red-500/15 text-red-400'}`}>
                  {inst.status === 'online' ? '在线' : inst.status === 'warning' ? '告警' : '离线'}
                </span>
              </div>
            ))}
          </CardContent>
        </Card>
      </div>

      {/* 待处理工单 */}
      <Card className="dg-card">
        <CardHeader className="pb-2 border-b border-[var(--dg-border)]">
          <CardTitle className="text-[15px] font-semibold">待处理工单</CardTitle>
        </CardHeader>
        <CardContent className="p-0">
          <div className="overflow-x-auto">
            <table className="w-full text-sm">
              <thead>
                <tr className="border-b border-[var(--dg-border)] bg-[var(--dg-bg-tertiary)]">
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">工单号</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">标题</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">数据库</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">申请人</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">状态</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">创建时间</th>
                  <th className="text-left px-5 py-3 font-semibold text-[var(--dg-text-primary)]">操作</th>
                </tr>
              </thead>
              <tbody>
                {pendingTickets.map(ticket => (
                  <tr key={ticket.id} className="border-b border-[var(--dg-border-light)] hover:bg-[var(--dg-bg-hover)] transition-colors">
                    <td className="px-5 py-3.5 font-mono text-xs">{ticket.id}</td>
                    <td className="px-5 py-3.5 max-w-xs truncate">{ticket.title}</td>
                    <td className="px-5 py-3.5">
                      <span className={`inline-flex items-center gap-1 px-2.5 py-1 rounded-md text-xs font-medium ${dbTypeColorMap[ticket.dbType] || ''}`}>
                        {ticket.dbType.toUpperCase()}
                      </span>
                    </td>
                    <td className="px-5 py-3.5">{ticket.applicant}</td>
                    <td className="px-5 py-3.5">
                      <span className={`inline-flex items-center gap-1.5 px-2.5 py-1 rounded-full text-xs font-medium ${statusColorMap[ticket.status] || ''}`}>
                        <span className={`w-1.5 h-1.5 rounded-full ${ticket.status === 'reviewing' ? 'bg-blue-400 animate-pulse' : ticket.status === 'pending' ? 'bg-yellow-400' : ''}`} />
                        {statusMap[ticket.status]}
                      </span>
                    </td>
                    <td className="px-5 py-3.5 text-[var(--dg-text-secondary)]">{ticket.createTime}</td>
                    <td className="px-5 py-3.5">
                      <div className="flex gap-2">
                        <button className="text-blue-400 hover:text-blue-300 text-xs font-medium transition-colors">查看</button>
                        <button className="text-green-400 hover:text-green-300 text-xs font-medium transition-colors">审批</button>
                      </div>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        </CardContent>
      </Card>
    </div>
  );
}