import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { Building2, ChevronRight, Fuel, Plug, ReceiptText, TrendingUp, Truck, UserRound, X } 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';
import {
  buildHydrogenDrillUrl,
  parseHydrogenDrillContext,
  type HydrogenDrillContext,
} from './hydrogen-drill-context';
import HydrogenOrders from './HydrogenOrders';
import AnalysisDateFilters from './AnalysisDateFilters';
import AnalysisScopeSwitch, { type AnalysisScopeOption } from './AnalysisScopeSwitch';
import { activateDrillOnKeyDown } from './drill-interaction';
import {
  dateRangeModeLabel,
  getQuickDateRange,
  inferDateRangeMode,
  normalizeDateRange,
  type DateRangeMode,
} from './date-range';

const VEHICLE_SCOPE_OPTIONS: readonly AnalysisScopeOption<CustomerType>[] = [
  { id: 'lingniu', label: '羚牛车辆' },
  { id: 'external', label: '外部车辆' },
];

const HYDROGEN_ORDERS_ID = 'hydrogen-orders';

export default function HydrogenDaily() {
  const [drillContext, setDrillContext] = useState<HydrogenDrillContext>(() => (
    parseHydrogenDrillContext(window.location.search)
  ));
  const [pick, setPick] = useState<DateRangeMode>(() => (
    drillContext.startDate && drillContext.endDate
      ? inferDateRangeMode(drillContext.startDate, drillContext.endDate)
      : 'last15'
  ));
  const [dateRange, setDateRange] = useState(() => (
    drillContext.startDate && drillContext.endDate
      ? normalizeDateRange(drillContext.startDate, drillContext.endDate)
      : getQuickDateRange('last15')
  ));
  const [vehicleScope, setVehicleScope] = useState<CustomerType>(drillContext.vehicleScope);
  const [expanded, setExpanded] = useState<Set<string>>(new Set());
  const [rows, setRows] = useState<HydrogenDailyRow[] | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [retryKey, setRetryKey] = useState(0);
  const orderTriggerRef = useRef<HTMLElement | SVGElement | null>(null);

  const effectiveRange = useMemo(() => normalizeDateRange(dateRange.start, dateRange.end), [dateRange.start, dateRange.end]);
  const selectedStationId = drillContext.level === 'station' ? drillContext.stationId : undefined;
  const selectedStationName = drillContext.level === 'station'
    ? drillContext.stationName || `站点 #${drillContext.stationId}`
    : undefined;
  const selectedCustomerName = drillContext.level === 'customer'
    ? drillContext.customerName
    : undefined;
  const selectedDate = drillContext.selectedDate;
  const selectedDailyRow = rows?.find(row => row.date === selectedDate);

  const commitDrillContext = useCallback((next: HydrogenDrillContext, mode: 'push' | 'replace') => {
    const url = buildHydrogenDrillUrl(window.location, next);
    window.history[mode === 'push' ? 'pushState' : 'replaceState'](null, '', url);
    setDrillContext(next);
  }, []);

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

  // 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 ids = new Set<number>();
    (rows ?? []).forEach(r => r.stations.forEach(s => ids.add(s.stationId)));
    return ids.size;
  }, [rows]);
  const avgKg = activeDays > 0 ? totalKg / activeDays : 0;
  const scopeLabel = dateRangeModeLabel(pick);
  const rangeText = `${effectiveRange.start} 至 ${effectiveRange.end}`;
  const orderScopeLabel = selectedCustomerName
    ? `客户 ${selectedCustomerName}`
    : selectedStationName
      ? `站点 ${selectedStationName}`
      : vehicleScope === 'external' ? '外部车辆' : '羚牛车辆';
  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) => {
    const nextRange = getQuickDateRange(nextPick);
    setPick(nextPick);
    setDateRange(nextRange);
    commitDrillContext({
      ...drillContext,
      vehicleScope,
      startDate: nextRange.start,
      endDate: nextRange.end,
      selectedDate: undefined,
      orderPage: undefined,
    }, 'replace');
  };

  const updateDateRange = (field: 'start' | 'end', value: string) => {
    if (!value) return;
    const nextRange = { ...dateRange, [field]: value };
    setPick('custom');
    const normalized = normalizeDateRange(nextRange.start, nextRange.end);
    setDateRange(normalized);
    commitDrillContext({
      ...drillContext,
      vehicleScope,
      startDate: normalized.start,
      endDate: normalized.end,
      selectedDate: undefined,
      orderPage: undefined,
    }, 'replace');
  };

  const updateVehicleScope = (next: CustomerType) => {
    setVehicleScope(next);
    commitDrillContext({
      ...drillContext,
      vehicleScope: next,
      startDate: effectiveRange.start,
      endDate: effectiveRange.end,
      orderPage: undefined,
    }, 'replace');
  };

  const clearEntity = () => {
    commitDrillContext({
      level: 'overview',
      year: drillContext.year,
      vehicleScope,
      startDate: effectiveRange.start,
      endDate: effectiveRange.end,
    }, 'replace');
  };

  const openOrders = (date: string) => {
    const activeElement = document.activeElement;
    if (activeElement instanceof HTMLElement || activeElement instanceof SVGElement) {
      orderTriggerRef.current = activeElement;
    }
    commitDrillContext({
      ...drillContext,
      vehicleScope,
      startDate: effectiveRange.start,
      endDate: effectiveRange.end,
      selectedDate: date,
      orderPage: undefined,
    }, selectedDate === date ? 'replace' : 'push');
    window.requestAnimationFrame(() => {
      const orders = document.getElementById(HYDROGEN_ORDERS_ID);
      orders?.focus({ preventScroll: true });
      orders?.scrollIntoView({
        behavior: window.matchMedia('(prefers-reduced-motion: reduce)').matches ? 'auto' : 'smooth',
        block: 'start',
      });
    });
  };

  const closeOrders = () => {
    commitDrillContext({
      ...drillContext,
      vehicleScope,
      startDate: effectiveRange.start,
      endDate: effectiveRange.end,
      selectedDate: undefined,
      orderPage: undefined,
    }, 'replace');
    window.requestAnimationFrame(() => orderTriggerRef.current?.focus());
  };

  const changeOrderPage = useCallback((page: number, mode: 'push' | 'replace') => {
    commitDrillContext({
      ...drillContext,
      orderPage: page > 1 ? page : undefined,
    }, mode);
  }, [commitDrillContext, drillContext]);

  const retryLoad = () => {
    setRows(null);
    setError(null);
    setRetryKey(key => key + 1);
  };

  useEffect(() => {
    const handlePopState = () => {
      const next = parseHydrogenDrillContext(window.location.search);
      setDrillContext(next);
      setVehicleScope(next.vehicleScope);
      if (next.startDate && next.endDate) {
        const normalized = normalizeDateRange(next.startDate, next.endDate);
        setPick(inferDateRangeMode(normalized.start, normalized.end));
        setDateRange(normalized);
      }
    };
    window.addEventListener('popstate', handlePopState);
    return () => window.removeEventListener('popstate', handlePopState);
  }, []);

  return (
    <div className="flex flex-col gap-3">
      <SurfaceCard className="p-2 md:p-3">
        <AnalysisDateFilters
          idPrefix="hydrogen"
          mode={pick}
          startDate={dateRange.start}
          endDate={dateRange.end}
          onQuickPick={applyQuickPick}
          onCustom={() => setPick('custom')}
          onDateChange={updateDateRange}
        />

        <AnalysisScopeSwitch
          ariaLabel="氢能车辆范围"
          value={vehicleScope}
          options={VEHICLE_SCOPE_OPTIONS}
          onChange={updateVehicleScope}
          icon={Truck}
          className="mt-2"
        />
      </SurfaceCard>

      {selectedStationName && (
        <section className="flex items-center gap-3 rounded-xl border border-blue-100 bg-blue-50 px-4 py-3 text-blue-700 shadow-sm">
          <Building2 size={16} className="shrink-0" />
          <div className="min-w-0 flex-1">
            <div className="truncate text-xs font-black">{selectedStationName}</div>
            <div className="mt-0.5 text-[10px] font-bold text-blue-500">站点每日明细 · {rangeText}</div>
          </div>
          <button
            type="button"
            onClick={clearEntity}
            className="flex h-8 w-8 shrink-0 items-center justify-center rounded-lg bg-white text-blue-500 shadow-sm ring-1 ring-blue-100 hover:text-blue-700"
            aria-label="清除站点筛选"
            title="清除站点筛选"
          >
            <X size={14} />
          </button>
        </section>
      )}

      {selectedCustomerName && (
        <section className="flex items-center gap-3 rounded-xl border border-emerald-100 bg-emerald-50 px-4 py-3 text-emerald-700 shadow-sm">
          <UserRound size={16} className="shrink-0" />
          <div className="min-w-0 flex-1">
            <div className="truncate text-xs font-black">{selectedCustomerName}</div>
            <div className="mt-0.5 text-[10px] font-bold text-emerald-600">客户每日明细 · {rangeText}</div>
          </div>
          <button
            type="button"
            onClick={clearEntity}
            className="flex h-8 w-8 shrink-0 items-center justify-center rounded-lg bg-white text-emerald-600 shadow-sm ring-1 ring-emerald-100 hover:text-emerald-800"
            aria-label="清除客户筛选"
            title="清除客户筛选"
          >
            <X size={14} />
          </button>
        </section>
      )}

      {error && (
        <ErrorState
          title="氢能数据源暂不可用"
          message={error}
          onRetry={retryLoad}
        />
      )}

      {!error && rows !== null && <div className="grid grid-cols-2 gap-3 md:grid-cols-4">
        <MetricTile icon={Fuel} label={`${scopeLabel}加氢量`} value={totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 1 })} unit="Kg" helper={rangeText} />
        <MetricTile icon={Truck} label="车辆归属" value={vehicleScope === 'external' ? '外部' : '羚牛'} helper="当前筛选口径" tone="emerald" />
        <MetricTile icon={TrendingUp} label="有效天数" value={`${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 */}
      {!error && vehicleScope === '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） */}
      {!error && !(vehicleScope === '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 ${d}`}
                contentStyle={{ borderRadius: 12, fontSize: 12 }}
                cursor={{ fill: 'rgba(34, 211, 238, 0.06)' }}
              />
              {avgKg > 0 && (
                <ReferenceLine
                  y={avgKg}
                  stroke="#f59e0b"
                  strokeDasharray="4 4"
                  label={{ value: '均值', position: 'right', fill: '#d97706', fontSize: 10, fontWeight: 700 }}
                />
              )}
              <Bar dataKey="totalKg" radius={[4, 4, 0, 0]}>
                {trendData.map(item => (
                  <Cell
                    key={item.date}
                    fill="url(#hydrogenBarGrad)"
                    stroke={selectedDate === item.date ? '#1d4ed8' : undefined}
                    strokeWidth={selectedDate === item.date ? 2 : undefined}
                    className={item.totalKg > 0 ? 'cursor-pointer outline-none focus:stroke-blue-700 focus:stroke-2' : undefined}
                    role={item.totalKg > 0 ? 'button' : undefined}
                    tabIndex={item.totalKg > 0 ? 0 : -1}
                    aria-expanded={item.totalKg > 0 ? selectedDate === item.date : undefined}
                    aria-controls={item.totalKg > 0 ? HYDROGEN_ORDERS_ID : undefined}
                    aria-label={`${item.date}，加氢量 ${item.totalKg.toLocaleString('zh-CN', { maximumFractionDigits: 2 })} Kg${item.totalKg > 0 ? `，查看${orderScopeLabel}加氢订单` : '，无可下钻订单'}`}
                    onClick={item.totalKg > 0 ? () => openOrders(item.date) : undefined}
                    onKeyDown={item.totalKg > 0
                      ? event => activateDrillOnKeyDown(event, () => openOrders(item.date))
                      : undefined}
                  />
                ))}
              </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>
      )}

      {selectedDate && (
        <HydrogenOrders
          date={selectedDate}
          dailyRow={selectedDailyRow}
          page={drillContext.orderPage ?? 1}
          vehicleScope={vehicleScope}
          stationId={selectedStationId}
          customerName={selectedCustomerName}
          onPageChange={changeOrderPage}
          onClose={closeOrders}
        />
      )}

      {/* 表格（外部车辆 + 全 0 时不渲染，由上方友好空状态替代） */}
      {!error && !(vehicleScope === '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)_72px_64px] 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)_72px_64px] 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 */}
        {rows === null ? (
          <LoadingState label="正在加载加氢明细" variant="inline" />
        ) : rows.length === 0 ? (
          <EmptyState title="暂无加氢数据" description="请切换时间范围或车辆归属" variant="inline" />
        ) : 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}`}>
              <div className={`grid w-full grid-cols-[minmax(0,1fr)_72px_64px] gap-2 px-3 py-2.5 text-left transition-colors hover:bg-slate-50/60 md:grid-cols-[minmax(0,1fr)_140px_120px_104px] md:gap-3 ${selectedDate === r.date ? 'bg-blue-50/70' : ''}`}>
                <span className="flex min-w-0 items-center gap-1">
                  <button
                    type="button"
                    onClick={() => toggle(r.date)}
                    className="flex min-w-0 items-center gap-1 text-[12px] font-bold text-slate-700"
                    aria-expanded={open}
                    aria-label={`${open ? '收起' : '展开'} ${r.date} 加氢站明细`}
                  >
                    <ChevronRight size={14} className={`shrink-0 transition-transform ${open ? 'rotate-90' : ''} text-slate-400`} />
                    <span className="truncate">{r.date}</span>
                  </button>
                  <button
                    type="button"
                    onClick={() => openOrders(r.date)}
                    disabled={r.totalKg <= 0}
                    className="ml-1 flex h-7 w-7 shrink-0 items-center justify-center rounded-lg text-slate-400 hover:bg-blue-100 hover:text-blue-700 disabled:cursor-not-allowed disabled:opacity-25"
                    aria-label={`查看 ${r.date} 加氢订单`}
                    aria-expanded={selectedDate === r.date}
                    aria-controls={HYDROGEN_ORDERS_ID}
                    title="查看当日订单"
                  >
                    <ReceiptText size={13} />
                  </button>
                </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>
              </div>
              <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)_72px_64px] 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>
      )}
      {!error && <RotatingFooterHint />}
    </div>
  );
}