/*
Copyright 2026 Arctel.net

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

"use client"

import {useCallback, useEffect, useState} from "react"
import {BarChart3, Globe, RefreshCw, TrendingUp, Users, XCircle} from "lucide-react"
import {Area, AreaChart, CartesianGrid, XAxis, YAxis} from "recharts"

import services from "@/lib/services"
import {ErrorInline} from "@/components/layout/error"
import {LoadingStateWithBorder} from "@/components/layout/loading"
import {EmptyStateWithBorder} from "@/components/layout/empty"
import {Badge} from "@/components/ui/badge"
import {Button} from "@/components/ui/button"
import {Card, CardContent, CardDescription, CardHeader, CardTitle} from "@/components/ui/card"
import {ChartConfig, ChartContainer, ChartTooltip, ChartTooltipContent} from "@/components/ui/chart"
import {Spinner} from "@/components/ui/spinner"

interface TrendData {
  date: string
  count: number
}

interface BrowserData {
  browser: string
  count: number
}

interface TopUserData {
  user_id: string
  username: string
  nickname: string
  count: number
}

const chartConfig = {
  count: {
    label: "请求量",
    color: "hsl(var(--primary))",
  },
} satisfies ChartConfig

// Format YYYY-MM-DD to MM/DD
function formatDateLabel(dateStr: string) {
  if (!dateStr || dateStr.length < 10) return dateStr
  const parts = dateStr.split("-")
  if (parts.length === 3) {
    return `${parts[1]}/${parts[2]}`
  }
  return dateStr
}

export function AccessAnalytics() {
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<Error | null>(null)
  const [clickhouseDisabled, setClickhouseDisabled] = useState(false)

  const [trend, setTrend] = useState<TrendData[]>([])
  const [browsers, setBrowsers] = useState<BrowserData[]>([])
  const [topUsers, setTopUsers] = useState<TopUserData[]>([])

  const fetchAnalytics = useCallback(async () => {
    try {
      setLoading(true)
      setError(null)
      const data = await services.adminLog.getLogsAnalytics()

      // Formats the date labels for the X-axis representation
      const formattedTrend = (data.trend || []).map(item => ({
        ...item,
        formattedDate: formatDateLabel(item.date)
      }))

      setTrend(formattedTrend)
      setBrowsers(data.browsers || [])
      setTopUsers(data.top_users || [])
      setClickhouseDisabled(false)
    } catch (err) {
      const errorInstance = err instanceof Error ? err : new Error("获取数据统计失败")
      const errMsg = errorInstance.message || ""
      if (errMsg.includes("ClickHouse") || errMsg.includes("未启用")) {
        setClickhouseDisabled(true)
      } else {
        setError(errorInstance)
      }
    } finally {
      setLoading(false)
    }
  }, [])

  useEffect(() => {
    fetchAnalytics()
  }, [fetchAnalytics])

  const totalBrowserRequests = browsers.reduce((sum, item) => sum + item.count, 0)
  const totalTrendRequests = trend.reduce((sum, item) => sum + item.count, 0)

  if (clickhouseDisabled) {
    return (
      <div className="flex flex-col items-center justify-center p-8 border border-dashed rounded-lg bg-card text-center my-6 min-h-[300px]">
        <XCircle className="size-10 text-muted-foreground mb-3" />
        <h3 className="text-base font-semibold">ClickHouse 未启用</h3>
        <p className="text-sm text-muted-foreground mt-1 max-w-[400px] mb-4">
          当前系统配置未启用 ClickHouse 存储，系统不会收集用户访问日志。如需使用此功能，请在后端 `config.yaml` 配置文件中配置并启用 ClickHouse。
        </p>
      </div>
    )
  }

  if (error) {
    return <ErrorInline error={error} onRetry={fetchAnalytics} />
  }

  if (loading) {
    return <LoadingStateWithBorder icon={BarChart3} description="加载访问统计指标中..." />
  }

  return (
    <div className="space-y-6">
      {/* Overview Cards */}
      <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
        <Card className="bg-card/25 border-border/40">
          <CardHeader className="flex flex-row items-center justify-between pb-2 space-y-0">
            <CardTitle className="text-sm font-semibold tracking-tight">近 7 天总请求数</CardTitle>
            <TrendingUp className="size-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold font-mono">{totalTrendRequests.toLocaleString()}</div>
            <p className="text-[10px] text-muted-foreground mt-1">系统记录的所有成功认证的访问总频次</p>
          </CardContent>
        </Card>
        <Card className="bg-card/25 border-border/40">
          <CardHeader className="flex flex-row items-center justify-between pb-2 space-y-0">
            <CardTitle className="text-sm font-semibold tracking-tight">活跃终端分类数</CardTitle>
            <Globe className="size-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold font-mono">{browsers.length}</div>
            <p className="text-[10px] text-muted-foreground mt-1">在一周内发起请求的浏览器代理大类统计</p>
          </CardContent>
        </Card>
        <Card className="bg-card/25 border-border/40 sm:col-span-2 lg:col-span-1">
          <CardHeader className="flex flex-row items-center justify-between pb-2 space-y-0">
            <CardTitle className="text-sm font-semibold tracking-tight">活跃独立用户数</CardTitle>
            <Users className="size-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold font-mono">{topUsers.length}</div>
            <p className="text-[10px] text-muted-foreground mt-1">一周内累计发起高频请求的注册账户总量</p>
          </CardContent>
        </Card>
      </div>

      {/* Access Trend Chart */}
      <Card className="bg-card/20 border-border/40">
        <CardHeader className="flex flex-row items-center justify-between">
          <div>
            <CardTitle className="text-base font-bold">一周访问量趋势</CardTitle>
            <CardDescription className="text-xs">
              展现系统最近 7 天内的每日 API 请求曲线
            </CardDescription>
          </div>
          <Button variant="ghost" size="icon" className="size-8" onClick={fetchAnalytics} disabled={loading}>
            {loading ? <Spinner className="size-4" /> : <RefreshCw className="size-4 text-muted-foreground" />}
          </Button>
        </CardHeader>
        <CardContent className="pl-2 pr-4 pt-2">
          {trend.length === 0 ? (
            <EmptyStateWithBorder icon={TrendingUp} description="暂无趋势数据" />
          ) : (
            <div className="h-[280px] w-full">
              <ChartContainer config={chartConfig} className="w-full h-full aspect-auto">
                <AreaChart
                  data={trend}
                  margin={{ top: 10, right: 10, left: -20, bottom: 0 }}
                >
                  <defs>
                    <linearGradient id="colorCount" x1="0" y1="0" x2="0" y2="1">
                      <stop offset="5%" stopColor="var(--color-count)" stopOpacity={0.3} />
                      <stop offset="95%" stopColor="var(--color-count)" stopOpacity={0.01} />
                    </linearGradient>
                  </defs>
                  <CartesianGrid strokeDasharray="3 3" vertical={false} />
                  <XAxis
                    dataKey="formattedDate"
                    tickLine={false}
                    axisLine={false}
                    dy={10}
                    className="font-mono"
                  />
                  <YAxis
                    tickLine={false}
                    axisLine={false}
                    dx={-10}
                    className="font-mono"
                  />
                  <ChartTooltip content={<ChartTooltipContent />} />
                  <Area
                    type="monotone"
                    dataKey="count"
                    stroke="var(--color-count)"
                    strokeWidth={2}
                    fillOpacity={1}
                    fill="url(#colorCount)"
                    name="请求次数"
                  />
                </AreaChart>
              </ChartContainer>
            </div>
          )}
        </CardContent>
      </Card>

      {/* Two Columns for Ranking Statistics */}
      <div className="grid gap-6 md:grid-cols-2">
        {/* Browser Rankings */}
        <Card className="bg-card/20 border-border/40 flex flex-col h-full">
          <CardHeader>
            <CardTitle className="text-base font-bold flex items-center gap-1.5">
              <Globe className="size-4.5 text-muted-foreground" />
              使用的浏览器排行
            </CardTitle>
            <CardDescription className="text-xs">
              基于请求头 User-Agent 智能分类的一周占比统计
            </CardDescription>
          </CardHeader>
          <CardContent className="flex-1">
            {browsers.length === 0 ? (
              <EmptyStateWithBorder icon={Globe} description="暂无浏览器排行数据" />
            ) : (
              <div className="space-y-4">
                {browsers.map((item, index) => {
                  const percent = totalBrowserRequests > 0 ? (item.count / totalBrowserRequests) * 100 : 0
                  return (
                    <div key={item.browser} className="space-y-1.5">
                      <div className="flex items-center justify-between text-xs font-medium">
                        <span className="flex items-center gap-2">
                          <Badge variant="outline" className="px-1.5 py-0 h-5 font-mono text-[10px] select-none">
                            {index + 1}
                          </Badge>
                          <span className="font-semibold">{item.browser}</span>
                        </span>
                        <span className="text-muted-foreground font-mono text-xs">
                          {item.count.toLocaleString()} 次 ({percent.toFixed(1)}%)
                        </span>
                      </div>
                      <div className="h-2 w-full rounded-full bg-muted overflow-hidden">
                        <div
                          className="h-full bg-primary rounded-full transition-all duration-500"
                          style={{ width: `${percent}%` }}
                        />
                      </div>
                    </div>
                  )
                })}
              </div>
            )}
          </CardContent>
        </Card>

        {/* Top Users */}
        <Card className="bg-card/20 border-border/40 flex flex-col h-full">
          <CardHeader>
            <CardTitle className="text-base font-bold flex items-center gap-1.5">
              <Users className="size-4.5 text-muted-foreground" />
              最活跃的用户排行 (Top 10)
            </CardTitle>
            <CardDescription className="text-xs">
              统计最近一周发起接口访问请求数量最多的账户
            </CardDescription>
          </CardHeader>
          <CardContent className="flex-1">
            {topUsers.length === 0 ? (
              <EmptyStateWithBorder icon={Users} description="暂无活跃用户数据" />
            ) : (
              <div className="divide-y divide-border/40">
                {topUsers.map((user) => (
                  <div key={user.user_id} className="flex items-center justify-between py-2.5 first:pt-0 last:pb-0">
                    <div className="flex items-center gap-3">
                      <div className="flex size-8 shrink-0 items-center justify-center rounded-full bg-primary/10 text-primary font-bold text-xs select-none">
                        {(user.username || "U").slice(0, 1).toUpperCase()}
                      </div>
                      <div className="truncate max-w-[180px] sm:max-w-xs">
                        <div className="text-xs font-bold leading-tight truncate">
                          {user.username || "未知"}
                        </div>
                        <div className="text-[10px] text-muted-foreground leading-normal truncate">
                          {user.nickname ? `(${user.nickname})` : "(无昵称)"} | ID: {user.user_id}
                        </div>
                      </div>
                    </div>
                    <div className="text-right shrink-0">
                      <div className="text-xs font-bold font-mono">{user.count.toLocaleString()}</div>
                      <div className="text-[9px] text-muted-foreground uppercase font-bold tracking-wider">次请求</div>
                    </div>
                  </div>
                ))}
              </div>
            )}
          </CardContent>
        </Card>
      </div>
    </div>
  )
}