'use client';

import { useState, useMemo } from 'react';
import Link from 'next/link';
import Image from 'next/image';
import { ArrowRight, ArrowLeft, Check, Thermometer, Home, Zap, ShoppingCart, Phone, RotateCcw } from 'lucide-react';
import { Product } from '@/content/products';
import { companyDetails } from '@/content/company';

interface Props {
  products: Product[];
}

// Oblicz wymaganą moc chłodniczą w kW
function calculatePower(m2: number, floor: string, sun: string, building: string): number {
  let power = m2 * 0.1; // baza: 1 kW na 10 m²

  // Korekta typu budynku i piętra
  if (building === 'apartment') {
    if (floor === 'top') power *= 1.2; // ostatnie piętro - więcej ciepła z dachu
    if (floor === 'ground') power *= 0.95;
  } else if (building === 'house') {
    if (floor === 'top') power *= 1.1; // poddasze - dodatkowe nagrzewanie
  }

  // Korekta nasłonecznienia
  if (sun === 'south') power *= 1.15; // południe - duże nasłonecznienie
  if (sun === 'west') power *= 1.1;
  if (sun === 'north') power *= 0.9;

  return Math.round(power * 10) / 10;
}

// Szacunkowy koszt montażu
function estimateInstall(pipes: string, rooms: number): { min: number; max: number } {
  const base = rooms === 1 ? 1200 : rooms === 2 ? 2800 : rooms === 3 ? 4200 : 5500;
  const pipeExtra = pipes === 'short' ? 0 : pipes === 'medium' ? 300 : pipes === 'long' ? 700 : 1200;
  return { min: base + pipeExtra, max: base + pipeExtra + 600 };
}

const STEPS = ['Pomieszczenie', 'Konfiguracja', 'Instalacja', 'Budżet'] as const;

export function KalkulatorClient({ products }: Props) {
  const [step, setStep] = useState(0);
  const [building, setBuilding] = useState('apartment');
  const [m2, setM2] = useState(25);
  const [floor, setFloor] = useState('middle'); // ground | middle | top
  const [sun, setSun] = useState('south'); // north | east | south | west
  const [rooms, setRooms] = useState(1);
  const [pipes, setPipes] = useState('medium'); // short(<3m) | medium(3-6m) | long(6-10m) | verylong(>10m)
  const [budget, setBudget] = useState(8000);
  const [showResults, setShowResults] = useState(false);

  const requiredPower = useMemo(() => calculatePower(m2, floor, sun, building), [m2, floor, sun, building]);
  const installCost = useMemo(() => estimateInstall(pipes, rooms), [pipes, rooms]);
  const category = rooms === 1 ? 'scienne' : 'multisplit';

  const results = useMemo(() => {
    if (!showResults) return [];
    const powerMin = requiredPower * 0.8;
    const powerMax = requiredPower * 1.4;
    const maxPrice = budget - installCost.min;

    return products
      .filter(p => {
        if (p.category !== category) return false;
        if (p.price === null || p.price > maxPrice) return false;
        const moc = parseFloat(String(p.specs?.['Moc chłodnicza'] || '0').replace(',', '.').split('–')[0]);
        return moc >= powerMin && moc <= powerMax;
      })
      .sort((a, b) => {
        // Sortuj po tym jak blisko jest moc do wymaganej
        const mocA = parseFloat(String(a.specs?.['Moc chłodnicza'] || '0').replace(',', '.').split('–')[0]);
        const mocB = parseFloat(String(b.specs?.['Moc chłodnicza'] || '0').replace(',', '.').split('–')[0]);
        return Math.abs(mocA - requiredPower) - Math.abs(mocB - requiredPower);
      })
      .slice(0, 6);
  }, [showResults, products, requiredPower, category, budget, installCost.min]);

  const handleFinish = () => setShowResults(true);
  const handleReset = () => { setShowResults(false); setStep(0); };

  if (showResults) {
    return (
      <main className="bg-slate-50 min-h-screen py-12">
        <div className="max-w-5xl mx-auto px-4 sm:px-6 lg:px-8">
          {/* Podsumowanie */}
          <div className="bg-white rounded-2xl border border-border p-6 mb-8">
            <h1 className="text-2xl font-extrabold text-primary font-heading mb-4">
              Dopasowane klimatyzatory
            </h1>
            <div className="grid grid-cols-2 sm:grid-cols-4 gap-4">
              {[
                { label: 'Wymagana moc', value: `${requiredPower} kW` },
                { label: 'Powierzchnia', value: `${m2} m²` },
                { label: 'Typ instalacji', value: rooms === 1 ? 'Split (1 pokój)' : `Multisplit (${rooms} pokoje)` },
                { label: 'Szac. montaż', value: `${installCost.min.toLocaleString('pl-PL')}–${installCost.max.toLocaleString('pl-PL')} zł` },
              ].map((s, i) => (
                <div key={i} className="bg-slate-50 rounded-xl p-3">
                  <p className="text-xs text-text-muted mb-1">{s.label}</p>
                  <p className="text-base font-bold text-primary font-heading">{s.value}</p>
                </div>
              ))}
            </div>
          </div>

          {results.length > 0 ? (
            <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-5">
              {results.map(product => (
                <div key={product.slug} className="bg-white rounded-2xl border border-border overflow-hidden hover:border-accent hover:shadow-md transition-all">
                  <div className="relative aspect-[4/3] bg-slate-50">
                    <Image
                      src={product.image}
                      alt={product.name}
                      fill
                      className="object-contain p-6"
                      unoptimized={product.image.startsWith('http')}
                    />
                    {product.specs?.['Klasa energetyczna'] && (
                      <span className="absolute top-2 left-2 px-2 py-0.5 bg-green-500 text-white text-xs font-bold rounded">
                        {product.specs['Klasa energetyczna'].split('/')[0]}
                      </span>
                    )}
                  </div>
                  <div className="p-4">
                    <p className="text-xs text-accent font-bold uppercase mb-1">{product.brand}</p>
                    <h3 className="text-sm font-bold text-primary font-heading leading-snug mb-3 line-clamp-2">
                      {product.name}
                    </h3>
                    <div className="flex flex-wrap gap-1.5 mb-3">
                      {product.specs?.['Moc chłodnicza'] && (
                        <span className="px-2 py-0.5 bg-blue-50 text-blue-700 text-xs rounded border border-blue-100">
                          {product.specs['Moc chłodnicza']} kW
                        </span>
                      )}
                      {product.specs?.['Hałas wewnątrz (dB)'] && (
                        <span className="px-2 py-0.5 bg-slate-50 text-text-muted text-xs rounded border border-border">
                          {product.specs['Hałas wewnątrz (dB)']} dB
                        </span>
                      )}
                    </div>
                    <div className="flex items-end justify-between">
                      <div>
                        <p className="text-lg font-extrabold text-primary font-heading leading-none">
                          {product.price?.toLocaleString('pl-PL')} zł
                        </p>
                        <p className="text-xs text-text-muted mt-0.5">+ montaż od {installCost.min.toLocaleString('pl-PL')} zł</p>
                      </div>
                      <Link href={`/sklep/${product.slug}`}>
                        <button className="flex items-center gap-1.5 px-3 py-2 bg-accent text-white rounded-xl text-xs font-bold hover:bg-accent/90 transition-colors">
                          Zobacz <ArrowRight className="size-3.5" />
                        </button>
                      </Link>
                    </div>
                  </div>
                </div>
              ))}
            </div>
          ) : (
            <div className="bg-white rounded-2xl border border-border p-12 text-center">
              <p className="text-text-muted mb-4">
                Nie znaleziono produktów dla podanych kryteriów. Spróbuj zwiększyć budżet lub zadzwoń do nas — dobierzemy ofertę indywidualnie.
              </p>
              <a href={`tel:${companyDetails.phoneRaw}`}>
                <button className="flex items-center gap-2 px-6 py-3 bg-accent text-white rounded-xl font-bold mx-auto hover:bg-accent/90 transition-colors">
                  <Phone className="size-4" /> {companyDetails.phone}
                </button>
              </a>
            </div>
          )}

          <div className="mt-8 flex gap-4">
            <button onClick={handleReset} className="flex items-center gap-2 px-5 py-3 bg-white border border-border rounded-xl text-sm font-semibold text-primary hover:border-accent transition-colors">
              <RotateCcw className="size-4" /> Zacznij od nowa
            </button>
            <Link href="/sklep">
              <button className="flex items-center gap-2 px-5 py-3 bg-white border border-border rounded-xl text-sm font-semibold text-primary hover:border-accent transition-colors">
                Przeglądaj cały sklep <ArrowRight className="size-4" />
              </button>
            </Link>
          </div>
        </div>
      </main>
    );
  }

  return (
    <main className="bg-slate-50 min-h-screen py-12">
      <div className="max-w-2xl mx-auto px-4 sm:px-6">
        {/* Header */}
        <div className="text-center mb-8">
          <h1 className="text-3xl font-extrabold text-primary font-heading mb-2">
            Dobierz klimatyzator
          </h1>
          <p className="text-text-muted">Odpowiedz na 4 pytania — pokażemy Ci najlepsze opcje z naszej oferty</p>
        </div>

        {/* Pasek postępu */}
        <div className="flex items-center gap-2 mb-8">
          {STEPS.map((s, i) => (
            <div key={s} className="flex-1 flex items-center gap-2">
              <div className={`size-7 rounded-full flex items-center justify-center text-xs font-bold shrink-0 transition-all ${
                i < step ? 'bg-green-500 text-white' : i === step ? 'bg-accent text-white' : 'bg-slate-200 text-text-muted'
              }`}>
                {i < step ? <Check className="size-3.5" /> : i + 1}
              </div>
              <span className={`text-xs font-medium hidden sm:block ${i === step ? 'text-accent' : 'text-text-muted'}`}>{s}</span>
              {i < STEPS.length - 1 && <div className={`flex-1 h-0.5 ${i < step ? 'bg-green-500' : 'bg-slate-200'}`} />}
            </div>
          ))}
        </div>

        {/* Karty kroków */}
        <div className="bg-white rounded-2xl border border-border p-6 md:p-8">

          {/* Krok 0: Pomieszczenie */}
          {step === 0 && (
            <div className="flex flex-col gap-6">
              <div className="flex items-center gap-3 mb-2">
                <div className="size-10 rounded-xl bg-blue-50 flex items-center justify-center">
                  <Home className="size-5 text-blue-600" />
                </div>
                <div>
                  <h2 className="text-lg font-bold text-primary font-heading">Pomieszczenie</h2>
                  <p className="text-xs text-text-muted">Metraż i warunki</p>
                </div>
              </div>

              <div>
                <label className="text-sm font-semibold text-primary mb-3 block">
                  Powierzchnia pomieszczenia: <span className="text-accent">{m2} m²</span>
                </label>
                <input
                  type="range" min={10} max={100} step={5} value={m2}
                  onChange={e => setM2(Number(e.target.value))}
                  className="w-full accent-accent"
                />
                <div className="flex justify-between text-xs text-text-muted mt-1">
                  <span>10 m²</span><span>100 m²</span>
                </div>
                <div className="mt-3 p-3 bg-blue-50 rounded-xl text-sm text-blue-700 font-medium">
                  Wymagana moc: ok. <strong>{requiredPower} kW</strong>
                  <span className="text-xs font-normal ml-2">(dla {m2} m²)</span>
                </div>
              </div>

              <div>
                <label className="text-sm font-semibold text-primary mb-3 block">Typ budynku</label>
                <div className="grid grid-cols-2 gap-2">
                  {[
                    { value: 'apartment', label: '🏢 Mieszkanie w bloku', sub: 'Kamienica, wieżowiec, blok' },
                    { value: 'house', label: '🏠 Dom jednorodzinny', sub: 'Wolnostojący, szeregowiec, bliźniak' },
                  ].map(o => (
                    <button key={o.value} onClick={() => setBuilding(o.value)}
                      className={`p-4 rounded-xl border-2 text-left transition-all ${building === o.value ? 'border-accent bg-accent/5' : 'border-border hover:border-accent'}`}>
                      <p className="text-sm font-bold text-primary">{o.label}</p>
                      <p className="text-xs text-text-muted">{o.sub}</p>
                    </button>
                  ))}
                </div>
              </div>

              {building === 'house' && (
                <div>
                  <label className="text-sm font-semibold text-primary mb-3 block">Typ przestrzeni</label>
                  <div className="grid grid-cols-2 gap-2">
                    {[
                      { value: 'ground', label: '🏠 Parter' },
                      { value: 'top', label: '🏠 Piętro / poddasze' },
                    ].map(o => (
                      <button key={o.value} onClick={() => setFloor(o.value)}
                        className={`py-2.5 px-3 rounded-xl text-sm font-semibold border-2 transition-all ${floor === o.value ? 'border-accent bg-accent text-white' : 'border-border bg-white text-primary hover:border-accent'}`}>
                        {o.label}
                      </button>
                    ))}
                  </div>
                </div>
              )}

              {building === 'apartment' && (
                <div>
                  <label className="text-sm font-semibold text-primary mb-3 block">Piętro</label>
                  <div className="flex flex-wrap gap-2">
                    {[
                      { value: 'ground', label: 'Parter' },
                      { value: 'low', label: '1-3 piętro' },
                      { value: 'middle', label: '4-8 piętro' },
                      { value: 'high', label: '9+ piętro' },
                      { value: 'top', label: 'Ostatnie' },
                    ].map(o => (
                      <button key={o.value} onClick={() => setFloor(o.value)}
                        className={`py-2 px-4 rounded-xl text-sm font-semibold border-2 transition-all ${floor === o.value ? 'border-accent bg-accent text-white' : 'border-border bg-white text-primary hover:border-accent'}`}>
                        {o.label}
                      </button>
                    ))}
                  </div>
                </div>
              )}

              <div>
                <label className="text-sm font-semibold text-primary mb-3 block">Ekspozycja okien</label>
                <div className="grid grid-cols-2 gap-2">
                  {[
                    { value: 'north', label: '🧭 Północ (chłodna)' },
                    { value: 'east', label: '🧭 Wschód' },
                    { value: 'west', label: '🧭 Zachód' },
                    { value: 'south', label: '🧭 Południe (mocne słońce)' },
                  ].map(o => (
                    <button key={o.value} onClick={() => setSun(o.value)}
                      className={`py-2.5 px-3 rounded-xl text-sm font-semibold border-2 transition-all ${sun === o.value ? 'border-accent bg-accent text-white' : 'border-border bg-white text-primary hover:border-accent'}`}>
                      {o.label}
                    </button>
                  ))}
                </div>
              </div>
            </div>
          )}

          {/* Krok 1: Konfiguracja */}
          {step === 1 && (
            <div className="flex flex-col gap-6">
              <div className="flex items-center gap-3 mb-2">
                <div className="size-10 rounded-xl bg-purple-50 flex items-center justify-center">
                  <Thermometer className="size-5 text-purple-600" />
                </div>
                <div>
                  <h2 className="text-lg font-bold text-primary font-heading">Ile pomieszczeń?</h2>
                  <p className="text-xs text-text-muted">1 pomieszczenie = split, więcej = multisplit</p>
                </div>
              </div>

              <div className="grid grid-cols-2 gap-3">
                {[
                  { value: 1, label: '1 pomieszczenie', sub: 'Klimatyzator split', icon: '🏠' },
                  { value: 2, label: '2 pomieszczenia', sub: 'System multisplit 2+1', icon: '🏡' },
                  { value: 3, label: '3 pomieszczenia', sub: 'System multisplit 3+1', icon: '🏘️' },
                  { value: 4, label: '4-5 pomieszczeń', sub: 'System multisplit 4+1', icon: '🏗️' },
                ].map(o => (
                  <button key={o.value} onClick={() => setRooms(o.value)}
                    className={`p-4 rounded-xl border-2 text-left transition-all ${rooms === o.value ? 'border-accent bg-accent/5' : 'border-border hover:border-accent'}`}>
                    <span className="text-2xl mb-2 block">{o.icon}</span>
                    <p className="text-sm font-bold text-primary">{o.label}</p>
                    <p className="text-xs text-text-muted">{o.sub}</p>
                  </button>
                ))}
              </div>

              <div className="p-3 bg-slate-50 rounded-xl text-xs text-text-muted">
                {rooms === 1
                  ? '✅ Klimatyzator split — jedna jednostka wewnętrzna + jedna zewnętrzna. Idealne do pojedynczego pomieszczenia.'
                  : `✅ System multisplit — jedna jednostka zewnętrzna obsługuje ${rooms} jednostki wewnętrzne. Ekonomiczne i estetyczne rozwiązanie dla całego domu.`}
              </div>
            </div>
          )}

          {/* Krok 2: Instalacja */}
          {step === 2 && (
            <div className="flex flex-col gap-6">
              <div className="flex items-center gap-3 mb-2">
                <div className="size-10 rounded-xl bg-orange-50 flex items-center justify-center">
                  <Zap className="size-5 text-orange-600" />
                </div>
                <div>
                  <h2 className="text-lg font-bold text-primary font-heading">Długość instalacji</h2>
                  <p className="text-xs text-text-muted">Rury i kable między jednostkami</p>
                </div>
              </div>

              <div className="flex flex-col gap-3">
                {[
                  { value: 'short', label: 'Do 3 metrów', sub: 'Jednostka zewnętrzna tuż obok (balkon, taras)' },
                  { value: 'medium', label: '3–6 metrów', sub: 'Typowa instalacja w bloku lub domu' },
                  { value: 'long', label: '6–10 metrów', sub: 'Dłuższa trasa, np. przez kilka pomieszczeń' },
                  { value: 'verylong', label: 'Powyżej 10 metrów', sub: 'Bardzo długa trasa, wymaga dodatkowych materiałów' },
                ].map(o => (
                  <button key={o.value} onClick={() => setPipes(o.value)}
                    className={`p-4 rounded-xl border-2 text-left transition-all ${pipes === o.value ? 'border-accent bg-accent/5' : 'border-border hover:border-accent'}`}>
                    <p className="text-sm font-bold text-primary">{o.label}</p>
                    <p className="text-xs text-text-muted">{o.sub}</p>
                  </button>
                ))}
              </div>

              <div className="p-3 bg-orange-50 rounded-xl text-xs text-orange-700">
                Szacowany koszt montażu dla Twojej konfiguracji:
                <strong className="ml-1">{installCost.min.toLocaleString('pl-PL')}–{installCost.max.toLocaleString('pl-PL')} zł</strong>
              </div>
            </div>
          )}

          {/* Krok 3: Budżet */}
          {step === 3 && (
            <div className="flex flex-col gap-6">
              <div className="flex items-center gap-3 mb-2">
                <div className="size-10 rounded-xl bg-green-50 flex items-center justify-center">
                  <ShoppingCart className="size-5 text-green-600" />
                </div>
                <div>
                  <h2 className="text-lg font-bold text-primary font-heading">Całkowity budżet</h2>
                  <p className="text-xs text-text-muted">Urządzenie + montaż łącznie</p>
                </div>
              </div>

              <div>
                <div className="flex justify-between items-center mb-3">
                  <label className="text-sm font-semibold text-primary">Budżet całkowity</label>
                  <span className="text-lg font-extrabold text-accent font-heading">{budget.toLocaleString('pl-PL')} zł</span>
                </div>
                <input
                  type="range" min={3000} max={25000} step={500} value={budget}
                  onChange={e => setBudget(Number(e.target.value))}
                  className="w-full accent-accent"
                />
                <div className="flex justify-between text-xs text-text-muted mt-1">
                  <span>3 000 zł</span><span>25 000 zł</span>
                </div>
              </div>

              <div className="grid grid-cols-2 gap-3">
                <div className="bg-slate-50 rounded-xl p-3">
                  <p className="text-xs text-text-muted mb-1">Na urządzenie zostaje</p>
                  <p className="text-base font-bold text-primary font-heading">
                    ok. {Math.max(0, budget - installCost.min).toLocaleString('pl-PL')} zł
                  </p>
                </div>
                <div className="bg-orange-50 rounded-xl p-3">
                  <p className="text-xs text-orange-700 mb-1">Szac. koszt montażu</p>
                  <p className="text-base font-bold text-orange-700 font-heading">
                    {installCost.min.toLocaleString('pl-PL')}–{installCost.max.toLocaleString('pl-PL')} zł
                  </p>
                </div>
              </div>

              <div className="p-3 bg-blue-50 rounded-xl text-xs text-blue-700">
                💡 Podsumowanie: szukamy klimatyzatora <strong>{category === 'scienne' ? 'split ściennego' : 'multisplit'}</strong> o mocy ok. <strong>{requiredPower} kW</strong> w cenie do <strong>{Math.max(0, budget - installCost.min).toLocaleString('pl-PL')} zł</strong>
              </div>
            </div>
          )}

          {/* Nawigacja */}
          <div className="flex justify-between mt-8 pt-6 border-t border-border">
            {step > 0 ? (
              <button onClick={() => setStep(s => s - 1)}
                className="flex items-center gap-2 px-4 py-2.5 border border-border rounded-xl text-sm font-semibold text-primary hover:border-accent transition-colors">
                <ArrowLeft className="size-4" /> Wstecz
              </button>
            ) : <div />}

            {step < 3 ? (
              <button onClick={() => setStep(s => s + 1)}
                className="flex items-center gap-2 px-6 py-2.5 bg-accent text-white rounded-xl text-sm font-bold hover:bg-accent/90 transition-colors">
                Dalej <ArrowRight className="size-4" />
              </button>
            ) : (
              <button onClick={handleFinish}
                className="flex items-center gap-2 px-6 py-2.5 bg-accent text-white rounded-xl text-sm font-bold hover:bg-accent/90 transition-colors">
                Pokaż dopasowane produkty <ArrowRight className="size-4" />
              </button>
            )}
          </div>
        </div>
      </div>
    </main>
  );
}