import { useEffect, useState } from 'react';
import { useParams, Link, useOutletContext } from 'react-router-dom';
import { ArrowLeft, Package, DollarSign } from 'lucide-react';
import { AreaChart, Area, XAxis, YAxis, CartesianGrid, Tooltip, ResponsiveContainer } from 'recharts';
import DateRangePicker from '../components/DateRangePicker';
import RefreshStatus from '../components/RefreshStatus';
import type { DateRange, ProductDetailsAnalytics } from '../types';
import { fetchProductDetailsAnalytics } from '../dataService';

const CHART_GRID_COLOR = 'var(--chart-grid)';
const CHART_AXIS_COLOR = 'var(--chart-axis)';
const CHART_CURSOR_COLOR = 'var(--chart-cursor)';
const CHART_DETAIL_BAR_COLOR = 'var(--chart-detail-bar)';

const formatDateKey = (date: Date) => {
  const year = date.getFullYear();
  const month = String(date.getMonth() + 1).padStart(2, '0');
  const day = String(date.getDate()).padStart(2, '0');
  return `${year}-${month}-${day}`;
};

type CustomTooltipProps = {
  active?: boolean;
  payload?: Array<{ value: number }>;
  label?: string;
};

const CustomTooltip = ({ active, payload, label }: CustomTooltipProps) => {
  if (active && payload && payload.length) {
    return (
      <div
        className="rounded-xl border p-3 shadow-lg"
        style={{ backgroundColor: 'var(--chart-tooltip-bg)', borderColor: 'var(--chart-tooltip-border)' }}
      >
        <p className="font-bold mb-1" style={{ color: CHART_DETAIL_BAR_COLOR }}>{label}</p>
        <p className="m-0" style={{ color: 'var(--chart-tooltip-text)' }}>Vendas: {payload[0].value}</p>
      </div>
    );
  }
  return null;
};

const ProductDetailsSkeleton = () => (
  <div className="space-y-6" aria-label="Carregando produto">
    <div className="flex flex-col md:flex-row md:items-center justify-between gap-4">
      <div className="flex flex-col gap-4">
        <div className="skeleton h-4 w-20" />
        <div className="flex items-center gap-4">
          <div className="skeleton h-16 w-16 rounded-2xl" />
          <div>
            <div className="skeleton h-3 w-24" />
            <div className="skeleton mt-3 h-7 w-80 max-w-[70vw]" />
          </div>
        </div>
      </div>
      <div className="skeleton h-10 w-64" />
    </div>

    <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
      {[0, 1].map(item => (
        <div key={`product-details-kpi-skeleton-${item}`} className="bg-dark-card p-6 rounded-2xl border border-dark-border shadow-sm">
          <div className="flex justify-between gap-6">
            <div className="w-full">
              <div className="skeleton h-3 w-36" />
              <div className="skeleton mt-3 h-8 w-32" />
            </div>
            <div className="skeleton h-12 w-12 shrink-0 rounded-xl" />
          </div>
        </div>
      ))}
    </div>

    <div className="bg-white dark:bg-dark-card border border-zinc-200 dark:border-dark-border rounded-2xl p-6 shadow-sm">
      <div className="skeleton h-5 w-56" />
      <div className="mt-8 skeleton h-[400px] w-full" />
    </div>
  </div>
);

const ProductDetails = () => {
  const { id } = useParams<{ id: string }>();
  const { dateRange, setDateRange } = useOutletContext<{ 
    dateRange: DateRange, 
    setDateRange: (range: DateRange) => void
  }>();
  const [details, setDetails] = useState<ProductDetailsAnalytics | null>(null);
  const [isLoading, setIsLoading] = useState(true);

  useEffect(() => {
    let isMounted = true;

    const loadProductDetails = async () => {
      if (!id) {
        if (isMounted) {
          setDetails(null);
          setIsLoading(false);
        }
        return;
      }

      setIsLoading(true);
      const productDetails = await fetchProductDetailsAnalytics(id, dateRange);

      if (isMounted) {
        setDetails(productDetails);
        setIsLoading(false);
      }
    };

    void loadProductDetails();

    return () => {
      isMounted = false;
    };
  }, [dateRange, id]);

  const formatCurrency = (value: number) => {
    return new Intl.NumberFormat('pt-BR', { style: 'currency', currency: 'BRL' }).format(value);
  };

  if (isLoading && !details) {
    return <ProductDetailsSkeleton />;
  }

  if (!details?.productInfo) {
    return (
      <div className="text-center py-12">
        <p className="text-zinc-500 dark:text-dark-muted font-medium">Produto não encontrado.</p>
        <Link to="/products" className="text-brand-primary hover:underline mt-4 inline-block font-bold">Voltar para produtos</Link>
      </div>
    );
  }

  const { productInfo, chartData, totalSold, totalRevenue } = details;
  const isRefreshing = isLoading && Boolean(details);
  const isSingleDayRange = formatDateKey(dateRange.start) === formatDateKey(dateRange.end);

  return (
    <div className="space-y-6">
      <div className="flex flex-col md:flex-row md:items-center justify-between gap-4">
        <div className="flex flex-col gap-4">
          <Link to="/products" className="inline-flex items-center text-sm font-bold text-zinc-400 dark:text-dark-muted hover:text-zinc-900 dark:hover:text-dark-text transition-colors w-fit">
            <ArrowLeft className="w-4 h-4 mr-2" />
            Voltar
          </Link>
          
          <div className="flex items-center gap-4">
            <div className="w-16 h-16 rounded-2xl bg-white dark:bg-dark-card border border-zinc-200 dark:border-dark-border flex items-center justify-center shadow-sm text-brand-primary">
              <Package className="w-8 h-8" />
            </div>
            <div>
              <div className="text-[10px] font-bold text-zinc-400 dark:text-dark-muted uppercase tracking-widest">ID: #{productInfo.id}</div>
              <h1 className="text-2xl font-bold text-zinc-900 dark:text-dark-text">{productInfo.name}</h1>
            </div>
          </div>
        </div>

        <DateRangePicker 
          dateRange={dateRange} 
          onChange={setDateRange} 
        />      </div>

      <RefreshStatus isRefreshing={isRefreshing} />

      <div className={isRefreshing ? 'refreshing-content space-y-6' : 'space-y-6'} aria-busy={isRefreshing}>
      <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
        <div className="bg-dark-card p-6 rounded-2xl border border-dark-border flex items-center justify-between shadow-sm">
          <div>
            <p className="text-xs font-bold text-dark-muted uppercase tracking-widest mb-1">Unidades Vendidas</p>
            <p className="text-3xl font-bold text-dark-text">{totalSold}</p>
          </div>
          <div className="p-3 bg-brand-primary/10 rounded-xl text-brand-primary">
            <Package size={24} />
          </div>
        </div>
        <div className="bg-dark-card p-6 rounded-2xl border border-dark-border flex items-center justify-between shadow-sm">
          <div>
            <p className="text-xs font-bold text-dark-muted uppercase tracking-widest mb-1">Receita Total</p>
            <p className="text-3xl font-bold text-brand-primary">{formatCurrency(totalRevenue)}</p>
          </div>
          <div className="p-3 bg-emerald-500/10 rounded-xl text-emerald-500">
            <DollarSign size={24} />
          </div>
        </div>
      </div>

      <div className="bg-white dark:bg-dark-card border border-zinc-200 dark:border-dark-border rounded-2xl p-6 shadow-sm">
        <h3 className="text-lg font-bold mb-8 text-zinc-900 dark:text-dark-text">
          Volume de Vendas por {isSingleDayRange ? 'Horário' : 'Data'}
        </h3>
        <div className="h-[400px] w-full">
          <ResponsiveContainer width="100%" height="100%">
            <AreaChart data={chartData} margin={{ top: 5, right: 30, left: 20, bottom: isSingleDayRange ? 24 : 80 }}>
              <defs>
                <linearGradient id="productVolumeGradient" x1="0" y1="0" x2="0" y2="1">
                  <stop offset="5%" stopColor={CHART_DETAIL_BAR_COLOR} stopOpacity={0.38} />
                  <stop offset="95%" stopColor={CHART_DETAIL_BAR_COLOR} stopOpacity={0.04} />
                </linearGradient>
              </defs>
              <CartesianGrid strokeDasharray="3 3" stroke={CHART_GRID_COLOR} vertical={false} />
              <XAxis 
                dataKey="date" stroke={CHART_AXIS_COLOR} fontSize={10} tickLine={false} axisLine={false}
                interval={isSingleDayRange ? 2 : 0}
                angle={isSingleDayRange ? 0 : -45}
                textAnchor={isSingleDayRange ? 'middle' : 'end'}
                height={isSingleDayRange ? 24 : 80}
              />
              <YAxis stroke={CHART_AXIS_COLOR} fontSize={12} tickLine={false} axisLine={false} />
              <Tooltip content={<CustomTooltip />} cursor={{ fill: CHART_CURSOR_COLOR }} />
              <Area
                type="monotone"
                dataKey="value"
                stroke={CHART_DETAIL_BAR_COLOR}
                strokeWidth={2.25}
                fill="url(#productVolumeGradient)"
                dot={{ r: 3, strokeWidth: 2, fill: 'var(--color-dark-card)', stroke: CHART_DETAIL_BAR_COLOR }}
                activeDot={{ r: 5, strokeWidth: 2, fill: CHART_DETAIL_BAR_COLOR, stroke: 'var(--color-dark-card)' }}
              />
            </AreaChart>
          </ResponsiveContainer>
        </div>
      </div>
      </div>
    </div>
  );
};

export default ProductDetails;