"use client";

import { useState, useMemo } from "react";
import { useSession } from "next-auth/react";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { Badge } from "@/components/ui/badge";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { Button } from "@/components/ui/button";
import { PLATFORM_MAP } from "@/lib/platforms";
import { Check, X, Quote, Filter, TrendingUp, MapPin, Hash, FileDown, FileText, Loader2 } from "lucide-react";
import { useApi } from "@/lib/hooks/use-api";
import { LoadingState } from "@/components/ui/api-states";
import { type CitationStats } from "@/lib/api/citations";
import { reportsApi } from "@/lib/api/reports";
import {
  PieChart,
  Pie,
  Cell,
  Tooltip as RechartsTooltip,
  ResponsiveContainer,
  LineChart,
  Line,
  XAxis,
  YAxis,
  CartesianGrid,
} from "recharts";

interface CitationItem {
  id: string;
  query_id: string;
  platform: string;
  cited: boolean;
  citation_position: number | null;
  citation_text: string | null;
  competitor_brands: string[];
  queried_at: string;
}

interface QueryOption {
  id: string;
  keyword: string;
}

const PIE_FALLBACK_COLORS = [
  "#3b82f6",
  "#10b981",
  "#f59e0b",
  "#ef4444",
  "#8b5cf6",
];

function getChartColor(index: number): string {
  if (typeof document !== "undefined") {
    const style = getComputedStyle(document.documentElement);
    const cssVar = style.getPropertyValue(`--chart-${index + 1}`).trim();
    if (cssVar) return `hsl(var(--chart-${index + 1}))`;
  }
  return PIE_FALLBACK_COLORS[index % PIE_FALLBACK_COLORS.length];
}

function StatCard({
  title,
  value,
  icon: Icon,
  suffix,
}: {
  title: string;
  value: string | number;
  icon: React.ElementType;
  suffix?: string;
}) {
  return (
    <Card>
      <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
        <CardTitle className="text-sm font-medium">{title}</CardTitle>
        <Icon className="h-4 w-4 text-muted-foreground" />
      </CardHeader>
      <CardContent>
        <div className="text-2xl font-bold">
          {value}
          {suffix && <span className="text-sm font-normal text-muted-foreground ml-1">{suffix}</span>}
        </div>
      </CardContent>
    </Card>
  );
}

function PlatformPieChart({ data }: { data: { platform: string; count: number }[] }) {
  const chartData = useMemo(
    () =>
      data.map((d) => ({
        name: PLATFORM_MAP[d.platform] || d.platform,
        value: d.count,
      })),
    [data]
  );

  return (
    <ResponsiveContainer width="100%" height={300}>
      <PieChart>
        <Pie
          data={chartData}
          cx="50%"
          cy="50%"
          innerRadius={60}
          outerRadius={100}
          paddingAngle={2}
          dataKey="value"
          nameKey="name"
        >
          {chartData.map((_, index) => (
            <Cell key={`cell-${index}`} fill={getChartColor(index)} />
          ))}
        </Pie>
        <RechartsTooltip
          contentStyle={{
            backgroundColor: "hsl(var(--card))",
            border: "1px solid hsl(var(--border))",
            borderRadius: "var(--radius)",
          }}
          formatter={(value: number) => [value, "引用数"]}
        />
      </PieChart>
    </ResponsiveContainer>
  );
}

function TrendLineChart({ data }: { data: { date: string; count: number }[] }) {
  return (
    <ResponsiveContainer width="100%" height={300}>
      <LineChart data={data} margin={{ top: 5, right: 20, left: 0, bottom: 5 }}>
        <CartesianGrid strokeDasharray="3 3" className="stroke-muted" />
        <XAxis
          dataKey="date"
          tick={{ fontSize: 12 }}
          tickFormatter={(value: string) => {
            const date = new Date(value);
            return `${date.getMonth() + 1}/${date.getDate()}`;
          }}
        />
        <YAxis tick={{ fontSize: 12 }} allowDecimals={false} />
        <RechartsTooltip
          contentStyle={{
            backgroundColor: "hsl(var(--card))",
            border: "1px solid hsl(var(--border))",
            borderRadius: "var(--radius)",
          }}
          labelFormatter={(value: string) => {
            const date = new Date(value);
            return `${date.getFullYear()}-${String(date.getMonth() + 1).padStart(2, "0")}-${String(date.getDate()).padStart(2, "0")}`;
          }}
          formatter={(value: number) => [`引用次数: ${value}`, ""]}
        />
        <Line
          type="monotone"
          dataKey="count"
          stroke="hsl(var(--primary))"
          strokeWidth={2}
          dot={{ r: 3 }}
          activeDot={{ r: 5 }}
        />
      </LineChart>
    </ResponsiveContainer>
  );
}

export default function CitationsPage() {
  const { data: session } = useSession();
  const token = (session as { accessToken?: string })?.accessToken;
  const [selectedQuery, setSelectedQuery] = useState<string>("all");
  const [selectedPlatform, setSelectedPlatform] = useState<string>("all");
  const [startDate, setStartDate] = useState<string>("");
  const [endDate, setEndDate] = useState<string>("");
  const [filterKey, setFilterKey] = useState(0);
  const [exporting, setExporting] = useState(false);

  const citationsUrl = (() => {
    const params = new URLSearchParams();
    if (selectedQuery && selectedQuery !== "all") params.append("query_id", selectedQuery);
    if (selectedPlatform && selectedPlatform !== "all") params.append("platform", selectedPlatform);
    if (startDate) params.append("start_date", startDate);
    if (endDate) params.append("end_date", endDate);
    const qs = params.toString();
    return `/api/v1/citations/${qs ? `?${qs}&_k=${filterKey}` : `?_k=${filterKey}`}`;
  })();

  const statsUrl = useMemo(() => {
    const params = new URLSearchParams();
    if (selectedQuery && selectedQuery !== "all") params.append("query_id", selectedQuery);
    if (startDate) params.append("start_date", startDate);
    if (endDate) params.append("end_date", endDate);
    const qs = params.toString();
    return `/api/v1/citations/stats${qs ? `?${qs}&_k=${filterKey}` : `?_k=${filterKey}`}`;
  }, [selectedQuery, startDate, endDate, filterKey]);

  const {
    data: citationsData,
    isLoading,
    error: citationsError,
    refresh: refreshCitations,
  } = useApi<{ items: CitationItem[] }>(
    citationsUrl,
    { dedupingInterval: 0 }
  );

  const {
    data: queriesData,
  } = useApi<{ items: QueryOption[] }>("/api/v1/queries/");

  const {
    data: statsData,
    isLoading: statsLoading,
    error: statsError,
  } = useApi<CitationStats>(statsUrl, { dedupingInterval: 0 });

  const citations: CitationItem[] = citationsData?.items ?? [];
  const queries: QueryOption[] = queriesData?.items ?? [];

  function handleFilter() {
    setFilterKey((k) => k + 1);
  }

  function handleReset() {
    setSelectedQuery("all");
    setSelectedPlatform("all");
    setStartDate("");
    setEndDate("");
    setFilterKey((k) => k + 1);
  }

  async function handleExport(format: "csv" | "pdf") {
    if (!token) return;
    const queryId = selectedQuery !== "all" ? selectedQuery : undefined;
    try {
      setExporting(true);
      let blob: Blob;
      let filename: string;
      if (format === "csv") {
        blob = await reportsApi.exportCSV(token, queryId) as unknown as Blob;
        filename = `citations_${new Date().toISOString().split("T")[0]}.csv`;
      } else {
        blob = await reportsApi.exportPDF(token, queryId) as unknown as Blob;
        filename = `citations_${new Date().toISOString().split("T")[0]}.pdf`;
      }
      const url = window.URL.createObjectURL(blob);
      const a = document.createElement("a");
      a.href = url;
      a.download = filename;
      document.body.appendChild(a);
      a.click();
      a.remove();
      window.URL.revokeObjectURL(url);
    } catch (err) {
      console.error("导出失败:", err);
    } finally {
      setExporting(false);
    }
  }

  if (isLoading && citations.length === 0) {
    return (
      <div className="space-y-4">
        <div>
          <h2 className="text-2xl font-bold tracking-tight">引用记录</h2>
          <p className="text-muted-foreground">查看各平台的引用检测结果</p>
        </div>
        <LoadingState rows={4} rowHeight="h-12" />
      </div>
    );
  }

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <div>
          <h2 className="text-2xl font-bold tracking-tight">引用记录</h2>
          <p className="text-muted-foreground">查看各平台的引用检测结果</p>
        </div>
        <div className="flex gap-2">
          <Button
            variant="outline"
            size="sm"
            onClick={() => handleExport("csv")}
            disabled={exporting || !token}
          >
            {exporting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <FileDown className="mr-2 h-4 w-4" />}
            导出 CSV
          </Button>
          <Button
            variant="outline"
            size="sm"
            onClick={() => handleExport("pdf")}
            disabled={exporting || !token}
          >
            {exporting ? <Loader2 className="mr-2 h-4 w-4 animate-spin" /> : <FileText className="mr-2 h-4 w-4" />}
            导出 PDF
          </Button>
        </div>
      </div>

      {!statsError && (
        <div className="space-y-4">
          {statsLoading ? (
            <LoadingState rows={2} rowHeight="h-32" />
          ) : statsData ? (
            <>
              <div className="grid gap-4 sm:grid-cols-3">
                <StatCard
                  title="引用率"
                  value={statsData.citation_rate != null ? `${(statsData.citation_rate * 100).toFixed(1)}` : "—"}
                  icon={TrendingUp}
                  suffix={statsData.citation_rate != null ? "%" : undefined}
                />
                <StatCard
                  title="平均位置"
                  value={statsData.avg_position != null ? statsData.avg_position.toFixed(1) : "—"}
                  icon={MapPin}
                />
                <StatCard
                  title="总引用数"
                  value={statsData.total_citations ?? 0}
                  icon={Hash}
                />
              </div>
              <div className="grid gap-4 md:grid-cols-2">
                <Card>
                  <CardHeader>
                    <CardTitle className="text-base">平台分布</CardTitle>
                  </CardHeader>
                  <CardContent>
                    {statsData.platform_distribution?.length > 0 ? (
                      <PlatformPieChart data={statsData.platform_distribution} />
                    ) : (
                      <div className="flex items-center justify-center h-[300px] text-muted-foreground">
                        暂无平台分布数据
                      </div>
                    )}
                  </CardContent>
                </Card>
                <Card>
                  <CardHeader>
                    <CardTitle className="text-base">30天趋势</CardTitle>
                  </CardHeader>
                  <CardContent>
                    {statsData.trend?.length > 0 ? (
                      <TrendLineChart data={statsData.trend} />
                    ) : (
                      <div className="flex items-center justify-center h-[300px] text-muted-foreground">
                        暂无趋势数据
                      </div>
                    )}
                  </CardContent>
                </Card>
              </div>
            </>
          ) : null}
        </div>
      )}

      <Card>
        <CardHeader>
          <CardTitle className="flex items-center gap-2 text-base">
            <Filter className="h-4 w-4" />
            筛选条件
          </CardTitle>
        </CardHeader>
        <CardContent>
          <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-5">
            <div className="space-y-2">
              <Label htmlFor="query-filter">查询词</Label>
              <Select value={selectedQuery} onValueChange={setSelectedQuery}>
                <SelectTrigger id="query-filter">
                  <SelectValue placeholder="全部查询词" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">全部查询词</SelectItem>
                  {queries.map((q) => (
                    <SelectItem key={q.id} value={q.id}>
                      {q.keyword}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="space-y-2">
              <Label htmlFor="platform-filter">平台</Label>
              <Select value={selectedPlatform} onValueChange={setSelectedPlatform}>
                <SelectTrigger id="platform-filter">
                  <SelectValue placeholder="全部平台" />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="all">全部平台</SelectItem>
                  {Object.entries(PLATFORM_MAP).map(([key, label]) => (
                    <SelectItem key={key} value={key}>
                      {label}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="space-y-2">
              <Label htmlFor="start-date">开始日期</Label>
              <Input
                id="start-date"
                type="date"
                value={startDate}
                onChange={(e) => setStartDate(e.target.value)}
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="end-date">结束日期</Label>
              <Input
                id="end-date"
                type="date"
                value={endDate}
                onChange={(e) => setEndDate(e.target.value)}
              />
            </div>
            <div className="flex items-end gap-2">
              <Button onClick={handleFilter} className="flex-1">
                筛选
              </Button>
              <Button variant="outline" onClick={handleReset} className="flex-1">
                重置
              </Button>
            </div>
          </div>
        </CardContent>
      </Card>

      {citationsError && (
        <div className="rounded-md bg-destructive/10 px-4 py-3 text-sm text-destructive">
          {citationsError.message}
        </div>
      )}

      <Card>
        <CardHeader>
          <CardTitle className="text-base">引用记录列表</CardTitle>
        </CardHeader>
        <CardContent>
          {citations.length === 0 ? (
            <div className="flex flex-col items-center justify-center py-12 text-muted-foreground">
              <Quote className="mb-4 h-12 w-12 opacity-20" />
              <p>暂无引用记录</p>
              <p className="text-sm">添加查询词并执行查询后将在此显示结果</p>
            </div>
          ) : (
            <div className="overflow-x-auto">
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>平台</TableHead>
                    <TableHead>是否引用</TableHead>
                    <TableHead>引用位置</TableHead>
                    <TableHead>引用文本片段</TableHead>
                    <TableHead>竞争品牌</TableHead>
                    <TableHead>查询时间</TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {citations.map((item) => (
                    <TableRow key={item.id}>
                      <TableCell className="font-medium">
                        {PLATFORM_MAP[item.platform] || item.platform}
                      </TableCell>
                      <TableCell>
                        {item.cited ? (
                          <div className="flex items-center gap-1 text-emerald-600">
                            <Check className="h-4 w-4" />
                            <span className="text-sm">已引用</span>
                          </div>
                        ) : (
                          <div className="flex items-center gap-1 text-red-500">
                            <X className="h-4 w-4" />
                            <span className="text-sm">未引用</span>
                          </div>
                        )}
                      </TableCell>
                      <TableCell>
                        {item.citation_position !== null
                          ? `第 ${item.citation_position} 位`
                          : "—"}
                      </TableCell>
                      <TableCell className="max-w-xs truncate">
                        {item.citation_text || "—"}
                      </TableCell>
                      <TableCell>
                        <div className="flex flex-wrap gap-1">
                          {item.competitor_brands?.length > 0 ? (
                            item.competitor_brands.map((brand) => (
                              <Badge key={brand} variant="secondary" className="text-xs">
                                {brand}
                              </Badge>
                            ))
                          ) : (
                            <span className="text-muted-foreground">—</span>
                          )}
                        </div>
                      </TableCell>
                      <TableCell className="text-muted-foreground">
                        {new Date(item.queried_at).toLocaleString("zh-CN")}
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            </div>
          )}
        </CardContent>
      </Card>
    </div>
  );
}