'use client';

import * as React from 'react';
import { useCallback, useEffect, useRef, useState } from 'react';
import { toast } from 'sonner';
import {
  Activity,
  Cpu,
  Database,
  HardDrive,
  Layers,
  RefreshCw,
} from 'lucide-react';
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Switch } from '@/components/ui/switch';
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select';
import { Badge } from '@/components/ui/badge';
import { Progress } from '@/components/ui/progress';
import { Skeleton } from '@/components/ui/skeleton';
import type { SystemStatus } from '@/lib/services/admin';
import services from '@/lib/services';

/**
 * 格式化数字，每3位加逗号
 */
const formatNumber = (num: number | string) => {
  if (num === undefined || num === null) return '0';
  return num.toString().replace(/\B(?=(\d{3})+(?!\B))/g, ',');
};

/**
 * 运行时系统状态展示与管理组件
 */
export function SystemStatusManager() {
  const [status, setStatus] = useState<SystemStatus | null>(null);
  const [loading, setLoading] = useState(true);
  const [wavelet, setWavelet] = useState(false);
  const [autoRefresh, setAutoRefresh] = useState(true);
  const [intervalTime, setIntervalTime] = useState('5000'); // 默认5秒

  const intervalRef = useRef<NodeJS.Timeout | null>(null);
  const prevStatusRef = useRef<SystemStatus | null>(null);
  const [changedFields, setChangedFields] = useState<Record<string, boolean>>(
    {},
  );

  // 获取状态数据
  const fetchStatus = useCallback(async (isSilent = false) => {
    if (!isSilent) setWavelet(true);
    try {
      const data = await services.adminStatus.getSystemStatus();

      // 检测变化的字段用于微动画效果
      if (prevStatusRef.current) {
        const changes: Record<string, boolean> = {};
        Object.keys(data).forEach((key) => {
          const k = key as keyof SystemStatus;
          if (prevStatusRef.current && prevStatusRef.current[k] !== data[k]) {
            changes[k] = true;
          }
        });
        setChangedFields(changes);
        // 1秒后清除变化状态
        setTimeout(() => {
          setChangedFields({});
        }, 1000);
      }

      setStatus(data);
      prevStatusRef.current = data;
    } catch (err) {
      toast.error('获取系统状态失败', {
        description: err instanceof Error ? err.message : '请求时发生未知错误',
      });
    } finally {
      setLoading(false);
      setWavelet(false);
    }
  }, []);

  // 轮询逻辑
  useEffect(() => {
    // 首次加载
    fetchStatus();
  }, [fetchStatus]);

  useEffect(() => {
    if (intervalRef.current) {
      clearInterval(intervalRef.current);
    }

    if (autoRefresh) {
      const time = parseInt(intervalTime, 10);
      intervalRef.current = setInterval(() => {
        fetchStatus(true);
      }, time);
    }

    return () => {
      if (intervalRef.current) {
        clearInterval(intervalRef.current);
      }
    };
  }, [autoRefresh, intervalTime, fetchStatus]);

  // 计算内存分配百分比 (Alloc / Sys)
  const getMemoryUsagePercent = () => {
    if (!status) return 0;

    const parseSizeToBytes = (sizeStr: string): number => {
      const parts = sizeStr.split(' ');
      if (parts.length < 2) return 0;
      const value = parseFloat(parts[0]);
      const unit = parts[1].toLowerCase();

      if (unit.startsWith('gib')) return value * 1024 * 1024 * 1024;
      if (unit.startsWith('mib')) return value * 1024 * 1024;
      if (unit.startsWith('kib')) return value * 1024;
      return value;
    };

    const alloc = parseSizeToBytes(status.alloc);
    const sys = parseSizeToBytes(status.sys);
    if (sys === 0) return 0;
    return Math.min(Math.round((alloc / sys) * 100), 100);
  };

  // 闪烁动画类
  const getPulseClass = (field: string) => {
    return changedFields[field]
      ? 'animate-pulse text-primary font-bold transition-all duration-300 scale-105 inline-block'
      : 'transition-all duration-300';
  };

  const RenderMetricRow = ({
    label,
    value,
    field,
  }: {
    label: string;
    value: string | number;
    field?: string;
  }) => (
    <div className='flex items-center justify-between py-2 border-b border-dashed border-border/40 last:border-b-0 hover:bg-muted/30 px-2 rounded-sm transition-colors duration-150'>
      <span className='text-xs font-medium text-muted-foreground'>{label}</span>
      <span
        className={`text-xs font-mono font-medium ${field ? getPulseClass(field) : ''}`}
      >
        {typeof value === 'number' ? formatNumber(value) : value}
      </span>
    </div>
  );

  if (loading) {
    return (
      <div className='space-y-6 p-1'>
        <div className='flex items-center justify-between border-b border-border/40 pb-4'>
          <div className='space-y-1'>
            <Skeleton className='h-6 w-32' />
            <Skeleton className='h-4 w-48' />
          </div>
          <div className='flex items-center gap-3'>
            <Skeleton className='h-8 w-24' />
            <Skeleton className='h-8 w-16' />
            <Skeleton className='h-8 w-8' />
          </div>
        </div>
        <div className='grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6'>
          <Skeleton className='h-48 w-full' />
          <Skeleton className='h-48 w-full' />
          <Skeleton className='h-48 w-full' />
          <Skeleton className='h-48 w-full' />
          <Skeleton className='h-48 w-full' />
        </div>
      </div>
    );
  }

  return (
    <div className='py-6 px-1 space-y-6'>
      {/* 顶部控制栏 */}
      <div className='flex flex-col sm:flex-row sm:items-center sm:justify-between pb-4 gap-4'>
        <div className='flex items-center gap-2'>
          <Activity className='size-5 text-primary' />
          <div>
            <h1 className='text-2xl font-semibold tracking-tight'>系统状态</h1>
          </div>
        </div>

        <div className='flex items-center flex-wrap gap-4 bg-muted/30 p-1.5 rounded-lg border border-border/40 backdrop-blur-sm'>
          <div className='flex items-center gap-2 px-1'>
            <Switch
              id='auto-refresh'
              checked={autoRefresh}
              onCheckedChange={setAutoRefresh}
            />
            <label
              htmlFor='auto-refresh'
              className='text-xs font-medium cursor-pointer select-none'
            >
              自动刷新
            </label>
          </div>

          {autoRefresh && (
            <Select value={intervalTime} onValueChange={setIntervalTime}>
              <SelectTrigger className='h-7 w-20 text-[11px] bg-background border-border/40'>
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value='1000'>1s</SelectItem>
                <SelectItem value='2000'>2s</SelectItem>
                <SelectItem value='5000'>5s</SelectItem>
                <SelectItem value='10000'>10s</SelectItem>
              </SelectContent>
            </Select>
          )}

          <Button
            size='sm'
            variant='secondary'
            className='h-7 text-[11px] gap-1.5'
            onClick={() => fetchStatus()}
            disabled={wavelet}
          >
            <RefreshCw className={`size-3 ${wavelet ? 'animate-spin' : ''}`} />
            刷新
          </Button>
        </div>
      </div>

      {status && (
        <>
          {/* 主网格排版 */}
          <div className='grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6'>
            {/* 1. 服务概览 */}
            <Card className='shadow-sm border-border/40 bg-card/50 backdrop-blur-md hover:border-primary/20 transition-all duration-300'>
              <CardHeader className='flex flex-row items-center justify-between pb-2 space-y-0'>
                <div className='space-y-0.5'>
                  <CardTitle className='text-sm font-semibold'>
                    服务概览
                  </CardTitle>
                  <CardDescription className='text-[10px]'>
                    服务的基础生命指标
                  </CardDescription>
                </div>
                <Badge
                  variant='secondary'
                  className='p-1 rounded-full bg-primary/10 text-primary border-none'
                >
                  <Activity className='size-4' />
                </Badge>
              </CardHeader>
              <CardContent className='space-y-1'>
                <RenderMetricRow
                  label='服务运行时间'
                  value={status.uptime}
                  field='uptime'
                />
                <RenderMetricRow
                  label='当前 Goroutines 数量'
                  value={status.num_goroutine}
                  field='num_goroutine'
                />
                <RenderMetricRow
                  label='Heap 对象数量'
                  value={status.heap_objects}
                  field='heap_objects'
                />
              </CardContent>
            </Card>

            {/* 2. 内存统计 */}
            <Card className='shadow-sm border-border/40 bg-card/50 backdrop-blur-md hover:border-primary/20 transition-all duration-300'>
              <CardHeader className='flex flex-row items-center justify-between pb-2 space-y-0'>
                <div className='space-y-0.5'>
                  <CardTitle className='text-sm font-semibold'>
                    内存统计
                  </CardTitle>
                  <CardDescription className='text-[10px]'>
                    主内存消耗概览
                  </CardDescription>
                </div>
                <Badge
                  variant='secondary'
                  className='p-1 rounded-full bg-primary/10 text-primary border-none'
                >
                  <Cpu className='size-4' />
                </Badge>
              </CardHeader>
              <CardContent className='space-y-3'>
                <div className='space-y-1'>
                  <RenderMetricRow
                    label='当前内存使用量'
                    value={status.alloc}
                    field='alloc'
                  />
                  <RenderMetricRow
                    label='所有已分配的内存'
                    value={status.total_alloc}
                    field='total_alloc'
                  />
                  <RenderMetricRow
                    label='内存占用量'
                    value={status.sys}
                    field='sys'
                  />
                  <RenderMetricRow
                    label='下次 GC 内存回收量'
                    value={status.next_gc}
                    field='next_gc'
                  />
                </div>
                {/* 物理内存水位比例 */}
                <div className='space-y-1 px-1 pt-1'>
                  <div className='flex justify-between text-[10px] text-muted-foreground'>
                    <span>当前使用率 (Alloc / Sys)</span>
                    <span className='font-mono'>
                      {getMemoryUsagePercent()}%
                    </span>
                  </div>
                  <Progress value={getMemoryUsagePercent()} className='h-1.5' />
                </div>
              </CardContent>
            </Card>

            {/* 3. 堆/栈详情 */}
            <Card className='shadow-sm border-border/40 bg-card/50 backdrop-blur-md hover:border-primary/20 transition-all duration-300'>
              <CardHeader className='flex flex-row items-center justify-between pb-2 space-y-0'>
                <div className='space-y-0.5'>
                  <CardTitle className='text-sm font-semibold'>
                    堆/栈详情
                  </CardTitle>
                  <CardDescription className='text-[10px]'>
                    运行时堆栈内存空间细节
                  </CardDescription>
                </div>
                <Badge
                  variant='secondary'
                  className='p-1 rounded-full bg-primary/10 text-primary border-none'
                >
                  <Database className='size-4' />
                </Badge>
              </CardHeader>
              <CardContent className='space-y-1'>
                <RenderMetricRow
                  label='当前 Heap 内存使用量'
                  value={status.heap_alloc}
                  field='heap_alloc'
                />
                <RenderMetricRow
                  label='Heap 内存占用量'
                  value={status.heap_sys}
                  field='heap_sys'
                />
                <RenderMetricRow
                  label='Heap 内存空闲量'
                  value={status.heap_idle}
                  field='heap_idle'
                />
                <RenderMetricRow
                  label='正在使用的 Heap 内存'
                  value={status.heap_inuse}
                  field='heap_inuse'
                />
                <RenderMetricRow
                  label='已释放的 Heap 内存'
                  value={status.heap_released}
                  field='heap_released'
                />
                <RenderMetricRow
                  label='启动 Stack 使用量'
                  value={status.stack_inuse}
                  field='stack_inuse'
                />
                <RenderMetricRow
                  label='已分配的 Stack 内存'
                  value={status.stack_sys}
                  field='stack_sys'
                />
              </CardContent>
            </Card>

            {/* 4. 底层组件与结构体 */}
            <Card className='shadow-sm border-border/40 bg-card/50 backdrop-blur-md hover:border-primary/20 transition-all duration-300'>
              <CardHeader className='flex flex-row items-center justify-between pb-2 space-y-0'>
                <div className='space-y-0.5'>
                  <CardTitle className='text-sm font-semibold'>
                    底层及结构体内存
                  </CardTitle>
                  <CardDescription className='text-[10px]'>
                    运行时底层管理结构体开销
                  </CardDescription>
                </div>
                <Badge
                  variant='secondary'
                  className='p-1 rounded-full bg-primary/10 text-primary border-none'
                >
                  <HardDrive className='size-4' />
                </Badge>
              </CardHeader>
              <CardContent className='space-y-1'>
                <RenderMetricRow
                  label='MSpan 结构内存使用量'
                  value={status.mspan_inuse}
                  field='mspan_inuse'
                />
                <RenderMetricRow
                  label='已分配的 MSpan 结构内存'
                  value={status.mspan_sys}
                  field='mspan_sys'
                />
                <RenderMetricRow
                  label='MCache 结构内存使用量'
                  value={status.mcache_inuse}
                  field='mcache_inuse'
                />
                <RenderMetricRow
                  label='已分配的 MCache 结构内存'
                  value={status.mcache_sys}
                  field='mcache_sys'
                />
                <RenderMetricRow
                  label='已分配的剖析哈希表内存'
                  value={status.buck_hash_sys}
                  field='buck_hash_sys'
                />
                <RenderMetricRow
                  label='已分配的 GC 元数据内存'
                  value={status.gc_sys}
                  field='gc_sys'
                />
                <RenderMetricRow
                  label='其它已分配的系统内存'
                  value={status.other_sys}
                  field='other_sys'
                />
              </CardContent>
            </Card>

            {/* 5. 垃圾回收与分配计数 */}
            <Card className='shadow-sm border-border/40 bg-card/50 backdrop-blur-md hover:border-primary/20 transition-all duration-300 md:col-span-2'>
              <CardHeader className='flex flex-row items-center justify-between pb-2 space-y-0'>
                <div className='space-y-0.5'>
                  <CardTitle className='text-sm font-semibold'>
                    垃圾回收与分配计数
                  </CardTitle>
                  <CardDescription className='text-[10px]'>
                    GC 历史数据与分配频次
                  </CardDescription>
                </div>
                <Badge
                  variant='secondary'
                  className='p-1 rounded-full bg-primary/10 text-primary border-none'
                >
                  <Layers className='size-4' />
                </Badge>
              </CardHeader>
              <CardContent>
                <div className='grid grid-cols-1 sm:grid-cols-2 gap-x-6'>
                  <div>
                    <RenderMetricRow
                      label='GC 执行次数'
                      value={status.num_gc}
                      field='num_gc'
                    />
                    <RenderMetricRow
                      label='距离上次 GC 时间'
                      value={status.last_gc_time}
                      field='last_gc_time'
                    />
                    <RenderMetricRow
                      label='GC 暂停时间总量'
                      value={status.pause_total_ns}
                      field='pause_total_ns'
                    />
                    <RenderMetricRow
                      label='上次 GC 暂停时间'
                      value={status.last_pause}
                      field='last_pause'
                    />
                  </div>
                  <div>
                    <RenderMetricRow
                      label='内存分配次数'
                      value={status.mallocs}
                      field='mallocs'
                    />
                    <RenderMetricRow
                      label='内存释放次数'
                      value={status.frees}
                      field='frees'
                    />
                    <RenderMetricRow
                      label='指针查找次数'
                      value={status.lookups}
                      field='lookups'
                    />
                  </div>
                </div>
              </CardContent>
            </Card>
          </div>
        </>
      )}
    </div>
  );
}