import { useEffect, useMemo, useState } from 'react';
import { ChevronRight, Fuel, Plug, TrendingUp, Truck } from 'lucide-react';
import { motion, AnimatePresence } from 'motion/react';
import { BarChart, Bar, XAxis, YAxis, ResponsiveContainer, Cell, Tooltip, ReferenceLine } from 'recharts';
import TrendBadge from './TrendBadge';
import { fetchHydrogenDaily } from './api';
import type { CustomerType, DateQuickPick, HydrogenDailyRow } from './types';
import RotatingFooterHint from '../../components/RotatingFooterHint';
import { EmptyState, ErrorState, LoadingState, MetricTile, SurfaceCard } from '../../components/ui/surface';

const QUICK_PICK_OPTIONS: Array<{ id: DateQuickPick; label: string }> = [
  { id: 'thisWeek',  label: '本周'    },
  { id: 'thisMonth', label: '本月'    },
  { id: 'last15',    label: '近 15 天' },
];

type RangeMode = DateQuickPick | 'custom';

function fmtYmd(d: Date): string {
  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
}

function addDays(d: Date, days: number): Date {
  const next = new Date(d);
  next.setDate(next.getDate() + days);
  return next;
}

function getQuickRange(pick: DateQuickPick): { start: string; end: string } {
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  if (pick === 'thisWeek') {
    const day = today.getDay() || 7;
    return { start: fmtYmd(addDays(today, -(day - 1))), end: fmtYmd(today) };
  }
  if (pick === 'thisMonth') {
    return { start: fmtYmd(new Date(today.getFullYear(), today.getMonth(), 1)), end: fmtYmd(today) };
  }
  return { start: fmtYmd(addDays(today, -14)), end: fmtYmd(today) };
}

function normalizeRange(start: string, end: string): { start: string; end: string } {
  return start <= end ? { start, end } : { start: end, end: start };
}

export default function HydrogenDaily() {
  const [pick, setPick] = useState<RangeMode>('last15');
  const [dateRange, setDateRange] = useState(() => getQuickRange('last15'));
  const [customer, setCustomer] = useState<CustomerType>('lingniu');
  const [expanded, setExpanded] = useState<Set<string>>(new Set());
  const [rows, setRows] = useState<HydrogenDailyRow[] | null>(null);
  const [error, setError] = useState<string | null>(null);

  const effectiveRange = useMemo(() => normalizeRange(dateRange.start, dateRange.end), [dateRange.start, dateRange.end]);

  useEffect(() => {
    let cancelled = false;
    setError(null);
    const query = pick === 'custom'
      ? { startDate: effectiveRange.start, endDate: effectiveRange.end }
      : { range: pick };
    fetchHydrogenDaily(query, customer)
      .then(r => { if (!cancelled) setRows(r); })
      .catch(e => { if (!cancelled) setError(e instanceof Error ? e.message : String(e)); });
    return () => { cancelled = true; };
  }, [pick, customer, effectiveRange.start, effectiveRange.end]);

  // 柱图：按日期升序，用于"从左到右时间流"
  const trendData = useMemo(() => (rows ? [...rows].sort((a, b) => a.date.localeCompare(b.date)) : []), [rows]);
  const totalKg = (rows ?? []).reduce((a, r) => a + r.totalKg, 0);
  const activeDays = (rows ?? []).filter(r => r.totalKg > 0).length;
  const stationCount = useMemo(() => {
    const names = new Set<string>();
    (rows ?? []).forEach(r => r.stations.forEach(s => names.add(s.name)));
    return names.size;
  }, [rows]);
  const avgKg = activeDays > 0 ? totalKg / activeDays : 0;
  const scopeLabel = pick === 'custom'
    ? '自定义区间'
    : QUICK_PICK_OPTIONS.find(item => item.id === pick)?.label ?? '当前时段';
  const rangeText = `${effectiveRange.start} 至 ${effectiveRange.end}`;
  const peakDay = trendData.reduce<HydrogenDailyRow | null>((best, item) => (!best || item.totalKg > best.totalKg ? item : best), null);
  const lowDay = trendData
    .filter(item => item.totalKg > 0)
    .reduce<HydrogenDailyRow | null>((low, item) => (!low || item.totalKg < low.totalKg ? item : low), null);
  const zeroDays = (rows ?? []).filter(r => r.totalKg === 0).length;

  const toggle = (date: string) => setExpanded(prev => {
    const next = new Set(prev);
    next.has(date) ? next.delete(date) : next.add(date);
    return next;
  });

  const applyQuickPick = (nextPick: DateQuickPick) => {
    setPick(nextPick);
    setDateRange(getQuickRange(nextPick));
  };

  const updateDateRange = (field: 'start' | 'end', value: string) => {
    if (!value) return;
    setPick('custom');
    setDateRange(prev => ({ ...prev, [field]: value }));
  };

  return (
    <div className="flex flex-col gap-3">
      <SurfaceCard className="p-2 md:p-3">
        <div className="flex items-center gap-2 overflow-x-auto pb-1">
          {QUICK_PICK_OPTIONS.map(opt => (
            <button
              key={opt.id}
              onClick={() => applyQuickPick(opt.id)}
              className={`min-h-9 shrink-0 rounded-xl border px-3 text-[12px] font-black transition-colors ${
                pick === opt.id
                  ? 'border-blue-200 bg-blue-50 text-blue-600 shadow-sm'
                  : 'border-slate-100 bg-white text-slate-500 hover:bg-slate-50'
              }`}
            >
              {opt.label}
            </button>
          ))}
          <button
            onClick={() => setPick('custom')}
            className={`min-h-9 shrink-0 rounded-xl border px-3 text-[12px] font-black transition-colors ${
              pick === 'custom'
                ? 'border-blue-200 bg-blue-50 text-blue-600 shadow-sm'
                : 'border-slate-100 bg-white text-slate-500 hover:bg-slate-50'
            }`}
          >
            自定义
          </button>
        </div>

        <div className="mt-2 grid grid-cols-2 gap-2">
          <label className="min-w-0 rounded-xl border border-slate-100 bg-slate-50 px-3 py-2">
            <span className="block text-[10px] font-black text-slate-400">开始日期</span>
            <input
              type="date"
              value={dateRange.start}
              onChange={e => updateDateRange('start', e.target.value)}
              onInput={e => updateDateRange('start', e.currentTarget.value)}
              className="mt-1 h-6 w-full bg-transparent text-[12px] font-black text-slate-800 outline-none"
            />
          </label>
          <label className="min-w-0 rounded-xl border border-slate-100 bg-slate-50 px-3 py-2">
            <span className="block text-[10px] font-black text-slate-400">结束日期</span>
            <input
              type="date"
              value={dateRange.end}
              onChange={e => updateDateRange('end', e.target.value)}
              onInput={e => updateDateRange('end', e.currentTarget.value)}
              className="mt-1 h-6 w-full bg-transparent text-[12px] font-black text-slate-800 outline-none"
            />
          </label>
        </div>

        <div className="mt-2 grid grid-cols-2 gap-1 rounded-xl bg-slate-100 p-1">
          {(['lingniu', 'external'] as const).map(c => (
            <button
              key={c}
              onClick={() => setCustomer(c)}
              className={`flex min-h-9 items-center justify-center gap-1.5 rounded-lg text-[12px] font-black transition-all ${
                customer === c ? 'bg-white text-slate-900 shadow-sm' : 'text-slate-500 hover:text-slate-700'
              }`}
            >
              <Truck size={14} />
              {c === 'external' ? '外部车辆' : '羚牛车辆'}
            </button>
          ))}
        </div>
      </SurfaceCard>

      <div className="grid grid-cols-2 gap-3 md:grid-cols-4">
        <MetricTile icon={Fuel} label={`${scopeLabel}加氢量`} value={totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 1 })} unit="Kg" helper={rangeText} />
        <MetricTile icon={Truck} label="车辆归属" value={customer === 'external' ? '外部' : '羚牛'} helper="当前筛选口径" tone="emerald" />
        <MetricTile icon={TrendingUp} label="有效天数" value={`${activeDays}/${rows?.length ?? 0}`} helper={`日均 ${avgKg.toLocaleString('zh-CN', { maximumFractionDigits: 1 })} Kg`} tone="amber" />
        <MetricTile icon={Plug} label="涉及加氢站" value={stationCount} unit="站" helper="按明细站点去重" tone="slate" />
      </div>

      {/* 外部车辆：新系统数据还没准备好 */}
      {customer === 'external' && rows !== null && totalKg === 0 && (
        <motion.div
          initial={{ opacity: 0, y: 8 }}
          animate={{ opacity: 1, y: 0 }}
          className="bg-white rounded-2xl border border-slate-100 shadow-sm px-6 py-14 flex flex-col items-center text-center"
        >
          <div className="w-14 h-14 rounded-2xl bg-blue-50 flex items-center justify-center mb-3 relative">
            <Plug size={22} className="text-blue-500" />
            <span className="absolute -top-0.5 -right-0.5 w-3 h-3 rounded-full bg-blue-400 animate-ping" />
            <span className="absolute -top-0.5 -right-0.5 w-3 h-3 rounded-full bg-blue-500" />
          </div>
          <div className="text-sm font-bold text-slate-700 mb-1">外部车辆 · 数据未就绪</div>
          <div className="text-[11px] text-slate-400 max-w-[280px] leading-relaxed">
            新系统的外部车辆加氢数据还在准备中
            <br />
            上线后此处将展示完整明细
          </div>
        </motion.div>
      )}

      {/* 时段加氢量柱图（外部车辆无数据时不渲染） */}
      {!(customer === 'external' && totalKg === 0) && trendData.length > 0 && (
        <SurfaceCard>
          <div className="flex items-center justify-between px-4 pt-4 mb-2">
            <span className="text-sm font-bold text-slate-700">每日加氢量</span>
            <span className="text-[11px] text-slate-400 font-bold">时间单位：日 · 单位 Kg</span>
          </div>
          <div className="mx-4 mb-2 grid grid-cols-3 gap-2 rounded-xl bg-slate-50 p-2">
            <div>
              <div className="text-[10px] font-black text-slate-400">峰值日</div>
              <div className="mt-0.5 truncate text-[11px] font-black text-slate-800">
                {peakDay ? `${peakDay.date.slice(5)} · ${peakDay.totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 0 })}` : '—'}
              </div>
            </div>
            <div>
              <div className="text-[10px] font-black text-slate-400">低谷日</div>
              <div className="mt-0.5 truncate text-[11px] font-black text-slate-800">
                {lowDay ? `${lowDay.date.slice(5)} · ${lowDay.totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 0 })}` : '—'}
              </div>
            </div>
            <div>
              <div className="text-[10px] font-black text-slate-400">零数据日</div>
              <div className={`mt-0.5 text-[11px] font-black ${zeroDays > 0 ? 'text-amber-600' : 'text-emerald-600'}`}>
                {zeroDays} 天
              </div>
            </div>
          </div>
          <div className="h-[180px] min-w-0 px-2 pb-2">
          <ResponsiveContainer width="100%" height={180} minWidth={0}>
            <BarChart data={trendData} margin={{ top: 8, right: 8, bottom: 0, left: -16 }}>
              <XAxis
                dataKey="date"
                tickFormatter={(v: string) => v.slice(5)}
                tick={{ fontSize: 10, fill: '#94a3b8' }}
                tickLine={false}
                axisLine={false}
                interval="preserveStartEnd"
                minTickGap={8}
              />
              <YAxis
                width={42}
                axisLine={false}
                tickLine={false}
                tick={{ fontSize: 9, fill: '#94a3b8' }}
                tickFormatter={(v: number) => v >= 1000 ? `${Math.round(v / 1000)}k` : `${Math.round(v)}`}
              />
              <Tooltip
                formatter={(v) => [`${Number(v ?? 0).toLocaleString('zh-CN', { maximumFractionDigits: 2 })} Kg`, '加氢量']}
                labelFormatter={(d) => `日期 ${d}`}
                contentStyle={{ borderRadius: 12, fontSize: 12 }}
                cursor={{ fill: 'rgba(34, 211, 238, 0.06)' }}
              />
              {avgKg > 0 && (
                <ReferenceLine
                  y={avgKg}
                  stroke="#f59e0b"
                  strokeDasharray="4 4"
                  label={{ value: '均值', position: 'right', fill: '#d97706', fontSize: 10, fontWeight: 700 }}
                />
              )}
              <Bar dataKey="totalKg" radius={[4, 4, 0, 0]}>
                {trendData.map((_, i) => (
                  <Cell key={i} fill="url(#hydrogenBarGrad)" />
                ))}
              </Bar>
              <defs>
                <linearGradient id="hydrogenBarGrad" x1="0" x2="0" y1="0" y2="1">
                  <stop offset="0%" stopColor="#22d3ee" />
                  <stop offset="100%" stopColor="#3b82f6" />
                </linearGradient>
              </defs>
            </BarChart>
          </ResponsiveContainer>
          </div>
        </SurfaceCard>
      )}

      {/* 表格（外部车辆 + 全 0 时不渲染，由上方友好空状态替代） */}
      {!(customer === 'external' && rows !== null && totalKg === 0) && (
      <div className="bg-white rounded-2xl border border-slate-100 shadow-sm overflow-hidden">
        {/* 表头 */}
        <div className="grid grid-cols-[minmax(0,1fr)_84px_80px] md:grid-cols-[minmax(0,1fr)_140px_120px_104px] gap-2 md:gap-3 px-3 py-2 bg-slate-50 text-[11px] font-bold text-slate-500">
          <span>日期 / 加氢站</span>
          <span className="hidden md:block text-right">单价 (元/Kg)</span>
          <span className="text-right">加氢量 (Kg)</span>
          <span className="text-right">环比</span>
        </div>
        {/* 合计行 */}
        <div className="grid grid-cols-[minmax(0,1fr)_84px_80px] md:grid-cols-[minmax(0,1fr)_140px_120px_104px] gap-2 md:gap-3 px-3 py-2 bg-blue-50/50 text-[12px] text-blue-600 font-bold">
          <span>合计</span>
          <span className="hidden md:block" />
          <span className="text-right">{totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 2 })}</span>
          <span />
        </div>
        {/* 主行 + 子行 */}
        {error ? (
          <div className="p-3"><ErrorState message={error} /></div>
        ) : rows === null ? (
          <div className="p-3"><LoadingState label="正在加载加氢明细" /></div>
        ) : rows.length === 0 ? (
          <div className="p-3"><EmptyState title="暂无加氢数据" description="请切换时间范围或车辆归属" /></div>
        ) : rows.map(r => {
          const open = expanded.has(r.date);
          const isAbnormal = Math.abs(r.chainPct) >= 0.3;
          const abnormalBg = isAbnormal
            ? r.chainPct > 0 ? 'bg-emerald-50/40' : 'bg-red-50/40'
            : '';
          return (
            <div key={r.date} className={`border-t border-slate-100 ${abnormalBg}`}>
              <button
                onClick={() => toggle(r.date)}
                className="w-full grid grid-cols-[minmax(0,1fr)_84px_80px] md:grid-cols-[minmax(0,1fr)_140px_120px_104px] gap-2 md:gap-3 px-3 py-2.5 text-left hover:bg-slate-50/60 transition-colors"
              >
                <span className="flex items-center gap-1 text-[12px] text-slate-700 font-bold">
                  <ChevronRight size={14} className={`transition-transform ${open ? 'rotate-90' : ''} text-slate-400`} />
                  {r.date}
                </span>
                <span className="hidden md:block text-right text-[12px] text-slate-300">—</span>
                <span className="text-right text-[12px] text-slate-700 font-bold tabular-nums">
                  {r.totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 2 })}
                </span>
                <span className="text-right"><TrendBadge value={r.chainPct} /></span>
              </button>
              <AnimatePresence initial={false}>
                {open && (
                  <motion.div
                    initial={{ height: 0, opacity: 0 }}
                    animate={{ height: 'auto', opacity: 1 }}
                    exit={{ height: 0, opacity: 0 }}
                    transition={{ duration: 0.15 }}
                    className="overflow-hidden bg-slate-50/50"
                  >
                    {r.stations.map(s => (
                      <div
                        key={s.name}
                        className="grid grid-cols-[minmax(0,1fr)_84px_80px] md:grid-cols-[minmax(0,1fr)_140px_120px_104px] gap-2 md:gap-3 px-3 py-2 pl-6 md:pl-9 border-t border-slate-100 first:border-t-0 items-start"
                      >
                        <div className="min-w-0">
                          <div className="text-[12px] text-slate-700 font-medium whitespace-nowrap leading-snug">
                            {s.name}
                          </div>
                          {s.pricePerKg > 0 && (
                            <div className="md:hidden mt-1">
                              <span className="inline-flex items-center text-[10px] text-amber-600 bg-amber-50 px-1.5 py-0.5 rounded font-bold whitespace-nowrap">
                                单价 {s.pricePerKg} 元/Kg
                              </span>
                            </div>
                          )}
                        </div>
                        <span className="hidden md:block text-right text-[12px] text-slate-500 font-bold tabular-nums">{s.pricePerKg > 0 ? s.pricePerKg : '—'}</span>
                        <span className="text-right text-[12px] text-slate-700 font-bold tabular-nums">
                          {s.kg.toLocaleString('zh-CN', { maximumFractionDigits: 2 })}
                        </span>
                        <span className="text-right"><TrendBadge value={s.chainPct} /></span>
                      </div>
                    ))}
                  </motion.div>
                )}
              </AnimatePresence>
            </div>
          );
        })}
      </div>
      )}
      <RotatingFooterHint />
    </div>
  );
}