"use client";

import { useEffect, useState, useCallback } from "react";
import { authFetch } from "@/lib/auth";
import { useAuth } from "@/lib/auth";
import Link from "next/link";
import {
  ComposedChart, Area, Line, XAxis, YAxis, Tooltip, ResponsiveContainer,
  ReferenceLine, CartesianGrid, Legend
} from "recharts";

type Symbol = "BTC" | "ETH";

interface IndicatorRow {
  ts: number;
  cvd_fast: number;
  cvd_mid: number;
  cvd_day: number;
  atr_5m: number;
  vwap_30m: number;
  price: number;
  score: number;
  signal: string | null;
}

interface LatestIndicator {
  ts: number;
  cvd_fast: number;
  cvd_mid: number;
  cvd_day: number;
  cvd_fast_slope: number;
  atr_5m: number;
  atr_percentile: number;
  vwap_30m: number;
  price: number;
  p95_qty: number;
  p99_qty: number;
  score: number;
  signal: string | null;
}

const WINDOWS = [
  { label: "1h", value: 60 },
  { label: "4h", value: 240 },
  { label: "12h", value: 720 },
  { label: "24h", value: 1440 },
];

function bjtStr(ms: number) {
  const d = new Date(ms + 8 * 3600 * 1000);
  return `${String(d.getUTCHours()).padStart(2, "0")}:${String(d.getUTCMinutes()).padStart(2, "0")}`;
}

function fmt(v: number, decimals = 1): string {
  if (Math.abs(v) >= 1000000) return `${(v / 1000000).toFixed(1)}M`;
  if (Math.abs(v) >= 1000) return `${(v / 1000).toFixed(1)}K`;
  return v.toFixed(decimals);
}

// ─── 实时指标卡片 ────────────────────────────────────────────────

function IndicatorCards({ symbol }: { symbol: Symbol }) {
  const [data, setData] = useState<LatestIndicator | null>(null);

  useEffect(() => {
    const fetch = async () => {
      try {
        const res = await authFetch("/api/signals/latest");
        if (!res.ok) return;
        const json = await res.json();
        setData(json[symbol] || null);
      } catch {}
    };
    fetch();
    const iv = setInterval(fetch, 5000);
    return () => clearInterval(iv);
  }, [symbol]);

  if (!data) return <div className="text-center text-slate-400 text-sm py-4">等待指标数据...</div>;

  const cvdFastDir = data.cvd_fast > 0 ? "多" : "空";
  const cvdMidDir = data.cvd_mid > 0 ? "多" : "空";
  const priceVsVwap = data.price > data.vwap_30m ? "上方" : "下方";

  // 核心条件检查
  const core1 = data.cvd_fast > 0 && data.cvd_fast_slope > 0 ? "✅" : data.cvd_fast < 0 && data.cvd_fast_slope < 0 ? "✅空" : "⬜";
  const core2 = data.cvd_mid !== 0 ? "✅" : "⬜";
  const core3 = data.price !== data.vwap_30m ? "✅" : "⬜";

  return (
    <div className="space-y-3">
      {/* CVD三轨 */}
      <div className="grid grid-cols-3 gap-2">
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">CVD_fast (30m)</p>
          <p className={`font-mono font-bold text-lg ${data.cvd_fast >= 0 ? "text-emerald-600" : "text-red-500"}`}>
            {fmt(data.cvd_fast)}
          </p>
          <p className="text-xs text-slate-400 mt-0.5">
            斜率: <span className={data.cvd_fast_slope >= 0 ? "text-emerald-600" : "text-red-500"}>
              {data.cvd_fast_slope >= 0 ? "↑" : "↓"} {fmt(Math.abs(data.cvd_fast_slope))}
            </span>
          </p>
        </div>
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">CVD_mid (4h)</p>
          <p className={`font-mono font-bold text-lg ${data.cvd_mid >= 0 ? "text-emerald-600" : "text-red-500"}`}>
            {fmt(data.cvd_mid)}
          </p>
          <p className="text-xs text-slate-400 mt-0.5">大方向: {cvdMidDir}头占优</p>
        </div>
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">CVD_day (日内)</p>
          <p className={`font-mono font-bold text-lg ${data.cvd_day >= 0 ? "text-emerald-600" : "text-red-500"}`}>
            {fmt(data.cvd_day)}
          </p>
          <p className="text-xs text-slate-400 mt-0.5">盘中基线</p>
        </div>
      </div>

      {/* ATR + VWAP + 大单 */}
      <div className="grid grid-cols-2 md:grid-cols-4 gap-2">
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">ATR (5m×14)</p>
          <p className="font-mono font-semibold text-slate-800">${fmt(data.atr_5m, 2)}</p>
          <p className="text-xs text-slate-400 mt-0.5">
            分位: <span className={data.atr_percentile > 60 ? "text-amber-600 font-semibold" : "text-slate-500"}>
              {data.atr_percentile.toFixed(0)}%
            </span>
            {data.atr_percentile > 60 ? " 🔥扩张" : data.atr_percentile < 40 ? " 压缩" : ""}
          </p>
        </div>
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">VWAP (30m)</p>
          <p className="font-mono font-semibold text-slate-800">${data.vwap_30m.toLocaleString("en-US", { maximumFractionDigits: 1 })}</p>
          <p className="text-xs text-slate-400 mt-0.5">
            价格在VWAP<span className={data.price > data.vwap_30m ? "text-emerald-600" : "text-red-500"}>{priceVsVwap}</span>
          </p>
        </div>
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">大单阈值 P95</p>
          <p className="font-mono font-semibold text-slate-800">{data.p95_qty.toFixed(4)}</p>
          <p className="text-xs text-slate-400 mt-0.5">24h动态分位</p>
        </div>
        <div className="bg-white rounded-lg border border-slate-200 p-3">
          <p className="text-xs text-slate-400">大单阈值 P99</p>
          <p className="font-mono font-semibold text-amber-600">{data.p99_qty.toFixed(4)}</p>
          <p className="text-xs text-slate-400 mt-0.5">超大单门槛</p>
        </div>
      </div>

      {/* 信号状态 */}
      <div className={`rounded-lg border p-3 ${
        data.signal === "LONG" ? "border-emerald-300 bg-emerald-50" :
        data.signal === "SHORT" ? "border-red-300 bg-red-50" :
        "border-slate-200 bg-slate-50"
      }`}>
        <div className="flex items-center justify-between">
          <div>
            <p className="text-xs text-slate-500">当前信号</p>
            <p className={`font-bold text-lg ${
              data.signal === "LONG" ? "text-emerald-700" :
              data.signal === "SHORT" ? "text-red-600" :
              "text-slate-400"
            }`}>
              {data.signal === "LONG" ? "🟢 做多" : data.signal === "SHORT" ? "🔴 做空" : "⚪ 无信号"}
            </p>
          </div>
          <div className="text-right">
            <p className="text-xs text-slate-500">加分</p>
            <p className="font-mono font-bold text-slate-800">{data.score}/60</p>
          </div>
        </div>
        {data.signal && (
          <div className="mt-2 grid grid-cols-3 gap-2 text-xs">
            <span>{core1} CVD_fast方向</span>
            <span>{core2} CVD_mid方向</span>
            <span>{core3} VWAP位置</span>
          </div>
        )}
      </div>
    </div>
  );
}

// ─── CVD三轨图 ──────────────────────────────────────────────────

function CVDChart({ symbol, minutes }: { symbol: Symbol; minutes: number }) {
  const [data, setData] = useState<IndicatorRow[]>([]);
  const [loading, setLoading] = useState(true);

  const fetchData = useCallback(async (silent = false) => {
    try {
      const res = await authFetch(`/api/signals/indicators?symbol=${symbol}&minutes=${minutes}`);
      if (!res.ok) return;
      const json = await res.json();
      setData(json.data || []);
      if (!silent) setLoading(false);
    } catch {}
  }, [symbol, minutes]);

  useEffect(() => {
    setLoading(true);
    fetchData();
    const iv = setInterval(() => fetchData(true), 30000);
    return () => clearInterval(iv);
  }, [fetchData]);

  const chartData = data.map(d => ({
    time: bjtStr(d.ts),
    fast: parseFloat(d.cvd_fast?.toFixed(2) || "0"),
    mid: parseFloat(d.cvd_mid?.toFixed(2) || "0"),
    price: d.price,
  }));

  // 价格轴自适应
  const prices = chartData.map(d => d.price).filter(v => v > 0);
  const pMin = prices.length ? Math.min(...prices) : 0;
  const pMax = prices.length ? Math.max(...prices) : 0;
  const pPad = (pMax - pMin) * 0.3 || pMax * 0.001;

  if (loading) return <div className="flex items-center justify-center h-48 text-slate-400 text-sm">加载指标数据...</div>;
  if (data.length === 0) return <div className="flex items-center justify-center h-48 text-slate-400 text-sm">暂无指标数据，signal-engine需运行积累</div>;

  return (
    <ResponsiveContainer width="100%" height={220}>
      <ComposedChart data={chartData} margin={{ top: 4, right: 60, bottom: 0, left: 8 }}>
        <CartesianGrid strokeDasharray="3 3" stroke="#f1f5f9" />
        <XAxis dataKey="time" tick={{ fill: "#94a3b8", fontSize: 10 }} tickLine={false} interval="preserveStartEnd" />
        <YAxis yAxisId="cvd" tick={{ fill: "#94a3b8", fontSize: 10 }} tickLine={false} axisLine={false} width={55} />
        <YAxis yAxisId="price" orientation="right" tick={{ fill: "#f59e0b", fontSize: 10 }} tickLine={false} axisLine={false} width={65}
          domain={[Math.floor(pMin - pPad), Math.ceil(pMax + pPad)]}
          tickFormatter={(v: number) => v >= 1000 ? `$${(v / 1000).toFixed(1)}k` : `$${v.toFixed(0)}`}
        />
        <Tooltip
          // eslint-disable-next-line @typescript-eslint/no-explicit-any
          formatter={(v: any, name: any) => {
            if (name === "price") return [`$${Number(v).toLocaleString()}`, "币价"];
            if (name === "fast") return [fmt(Number(v)), "CVD_fast(30m)"];
            return [fmt(Number(v)), "CVD_mid(4h)"];
          }}
          contentStyle={{ background: "#fff", border: "1px solid #e2e8f0", borderRadius: 8, fontSize: 11 }}
        />
        <Legend wrapperStyle={{ fontSize: 11 }} />
        <ReferenceLine yAxisId="cvd" y={0} stroke="#94a3b8" strokeDasharray="4 2" />
        <Area yAxisId="cvd" type="monotone" dataKey="fast" name="fast" stroke="#2563eb" fill="#eff6ff" strokeWidth={1.5} dot={false} connectNulls />
        <Line yAxisId="cvd" type="monotone" dataKey="mid" name="mid" stroke="#7c3aed" strokeWidth={1.5} dot={false} connectNulls strokeDasharray="6 3" />
        <Line yAxisId="price" type="monotone" dataKey="price" name="price" stroke="#f59e0b" strokeWidth={1.5} dot={false} connectNulls strokeDasharray="4 2" />
      </ComposedChart>
    </ResponsiveContainer>
  );
}

// ─── 主页面 ──────────────────────────────────────────────────────

export default function SignalsPage() {
  const { isLoggedIn, loading } = useAuth();
  const [symbol, setSymbol] = useState<Symbol>("BTC");
  const [minutes, setMinutes] = useState(240);

  if (loading) return <div className="flex items-center justify-center h-64 text-slate-400">加载中...</div>;
  if (!isLoggedIn) return (
    <div className="flex flex-col items-center justify-center h-64 gap-4">
      <div className="text-5xl">🔒</div>
      <p className="text-slate-600 font-medium">请先登录查看信号数据</p>
      <div className="flex gap-2">
        <Link href="/login" className="bg-blue-600 text-white px-4 py-2 rounded-lg text-sm">登录</Link>
        <Link href="/register" className="border border-slate-300 text-slate-600 px-4 py-2 rounded-lg text-sm">注册</Link>
      </div>
    </div>
  );

  return (
    <div className="space-y-5">
      {/* 标题 */}
      <div className="flex items-center justify-between flex-wrap gap-2">
        <div>
          <h1 className="text-xl font-bold text-slate-900">V5 信号引擎</h1>
          <p className="text-slate-500 text-xs mt-0.5">CVD三轨 + ATR + VWAP + 大单阈值 → 做多/做空信号</p>
        </div>
        <div className="flex gap-1.5">
          {(["BTC", "ETH"] as Symbol[]).map(s => (
            <button key={s} onClick={() => setSymbol(s)}
              className={`px-4 py-1.5 rounded-lg border text-sm font-medium transition-colors ${symbol === s ? "bg-blue-600 text-white border-blue-600" : "border-slate-200 text-slate-600 hover:border-blue-400"}`}>
              {s}
            </button>
          ))}
        </div>
      </div>

      {/* 实时指标卡片 */}
      <IndicatorCards symbol={symbol} />

      {/* CVD三轨图 */}
      <div className="rounded-xl border border-slate-200 bg-white shadow-sm overflow-hidden">
        <div className="px-4 py-3 border-b border-slate-100 flex items-center justify-between flex-wrap gap-2">
          <div>
            <h3 className="font-semibold text-slate-800 text-sm">CVD三轨 + 币价</h3>
            <p className="text-xs text-slate-400 mt-0.5">蓝色面积=CVD_fast(30m) · 紫色虚线=CVD_mid(4h) · 橙色虚线=币价</p>
          </div>
          <div className="flex gap-1">
            {WINDOWS.map(w => (
              <button key={w.value} onClick={() => setMinutes(w.value)}
                className={`px-2 py-1 rounded border text-xs transition-colors ${minutes === w.value ? "bg-slate-800 text-white border-slate-800" : "border-slate-200 text-slate-500 hover:border-slate-400"}`}>
                {w.label}
              </button>
            ))}
          </div>
        </div>
        <div className="p-4">
          <CVDChart symbol={symbol} minutes={minutes} />
        </div>
      </div>

      {/* 说明 */}
      <div className="rounded-lg border border-blue-100 bg-blue-50 px-4 py-3 text-xs text-slate-600 space-y-1">
        <p><span className="text-blue-600 font-medium">信号逻辑：</span>CVD_fast方向 + CVD_mid方向 + VWAP位置 = 核心3条件。加分：ATR扩张(+25) + 无反向大单(+20) + 资金费率(+15)。</p>
        <p><span className="text-blue-600 font-medium">仓位：</span>0-15分→2%仓 / 20-40分→5%仓 / 45-60分→8%仓。冷却10分钟，时间止损30分钟。</p>
      </div>
    </div>
  );
}