'use client';

import { useEffect, useMemo, useState } from 'react';
import { MapContainer, TileLayer, Marker, Popup, useMap } from 'react-leaflet';
import { OrderItem, Supplier } from '@/lib/types';
import { formatCurrency, calculateDistance, parseCoordinates } from '@/lib/utils';
import { Navigation, AlertTriangle } from 'lucide-react';
import L from 'leaflet';
import 'leaflet/dist/leaflet.css';

const defaultIcon = L.icon({
  iconUrl: 'https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.7.1/images/marker-icon.png',
  iconRetinaUrl: 'https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.7.1/images/marker-icon-2x.png',
  shadowUrl: 'https://cdnjs.cloudflare.com/ajax/libs/leaflet/1.7.1/images/marker-shadow.png',
  iconSize: [25, 41],
  iconAnchor: [12, 41],
  popupAnchor: [1, -34],
  shadowSize: [41, 41],
});

const currentLocationIcon = L.divIcon({
  className: 'custom-div-icon',
  html: `<div style="width:20px;height:20px;background:#ea580c;border:3px solid white;border-radius:50%;box-shadow:0 2px 6px rgba(0,0,0,0.3);"></div>`,
  iconSize: [20, 20],
  iconAnchor: [10, 10],
});

interface MapViewProps {
  items: OrderItem[];
  onNavigate: (lat: number, lng: number, name: string) => void;
}

function MapBounds({ items }: { items: OrderItem[] }) {
  const map = useMap();

  useEffect(() => {
    const validPoints = items
      .map((i) => {
        const coords = parseCoordinates(i.expand?.supplier?.coordinates);
        return coords ? [coords.latitude, coords.longitude] as [number, number] : null;
      })
      .filter((point): point is [number, number] => point !== null);

    if (validPoints.length > 0) {
      const bounds = L.latLngBounds(validPoints);
      map.fitBounds(bounds, { padding: [50, 50], maxZoom: 15 });
    }
  }, [map, items]);

  return null;
}

export default function CollectionMap({ items, onNavigate }: MapViewProps) {
  const [userLocation, setUserLocation] = useState<[number, number] | null>(null);

  useEffect(() => {
    if ('geolocation' in navigator) {
      navigator.geolocation.getCurrentPosition(
        (pos) => setUserLocation([pos.coords.latitude, pos.coords.longitude]),
        () => {},
        { enableHighAccuracy: false, timeout: 30000 }
      );
    }
  }, []);

  const suppliers = useMemo(() => {
    const map = new Map<string, { supplier: Supplier; items: OrderItem[]; coords: { latitude: number; longitude: number } }>();

    items.forEach((item) => {
      if (!item.expand?.supplier) return;
      const supplier = item.expand.supplier;
      const coords = parseCoordinates(supplier.coordinates);
      if (!coords) return;

      const key = supplier.id;
      if (!map.has(key)) {
        map.set(key, { supplier, items: [], coords });
      }
      map.get(key)!.items.push(item);
    });

    return Array.from(map.values());
  }, [items]);

  const defaultCenter: [number, number] = [-33.9249, 18.4241];
  const center = userLocation || defaultCenter;

  const getDistance = (coords: { latitude: number; longitude: number }) => {
    if (!userLocation) return null;
    return calculateDistance(userLocation[0], userLocation[1], coords.latitude, coords.longitude);
  };

  return (
    <div className="h-[calc(100vh-4rem)] w-full relative">
      <MapContainer center={center} zoom={12} className="h-full w-full" zoomControl={false}>
        <TileLayer attribution='&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a>' url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png" />
        <MapBounds items={items} />

        {userLocation && (
          <Marker position={userLocation} icon={currentLocationIcon}>
            <Popup><div className="text-sm font-medium">Your Location</div></Popup>
          </Marker>
        )}

        {suppliers.map(({ supplier, items: supplierItems, coords }) => {
          const distance = getDistance(coords);
          const hasProblem = supplierItems.some((i) => i.item_status === 'problem' || i.problem_flag);

          return (
            <Marker key={supplier.id} position={[coords.latitude, coords.longitude]} icon={defaultIcon}>
              <Popup>
                <div className="min-w-[200px] max-w-[250px]">
                  <h3 className="font-bold text-sm mb-1">{supplier.suppliername}</h3>
                  <p className="text-xs text-gray-500 mb-2">{supplier.supplieraddress}</p>
                  {distance && <p className="text-xs text-orange-600 mb-2 font-medium">{distance.toFixed(1)} km away</p>}

                  <div className="space-y-1.5 mb-3">
                    {supplierItems.map((i) => (
                      <div key={i.id} className="text-xs p-1.5 bg-gray-50 rounded">
                        <div className="flex items-center gap-1">
                          {(i.item_status === 'problem' || i.problem_flag) && <AlertTriangle size={12} className="text-red-500" />}
                          <span className="font-medium truncate">{i.description}</span>
                        </div>
                        <span className="text-gray-400">Qty: {i.order_qty || i.quantity || 0}</span>
                      </div>
                    ))}
                  </div>

                  <button
                    onClick={() => onNavigate(coords.latitude, coords.longitude, supplier.suppliername)}
                    className="w-full flex items-center justify-center gap-1.5 py-2 px-3 bg-orange-500 text-white rounded-lg text-sm font-medium active:bg-orange-600 transition-colors"
                  >
                    <Navigation size={14} /> Navigate
                  </button>
                </div>
              </Popup>
            </Marker>
          );
        })}
      </MapContainer>

      <div className="absolute top-4 right-4 bg-white/90 backdrop-blur-sm rounded-xl p-3 shadow-lg z-[400]">
        <p className="text-xs font-medium text-gray-700 mb-2">Legend</p>
        <div className="space-y-1.5">
          <div className="flex items-center gap-2">
            <div className="w-3 h-3 rounded-full bg-orange-500 border-2 border-white shadow-sm" />
            <span className="text-[10px] text-gray-600">Your Location</span>
          </div>
          <div className="flex items-center gap-2">
            <div className="w-4 h-4 relative">
              <div className="absolute inset-0 bg-orange-500 rounded-sm rotate-45 transform origin-bottom" />
            </div>
            <span className="text-[10px] text-gray-600">Collection Stop</span>
          </div>
        </div>
      </div>
    </div>
  );
}