'use client';

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

// Fix Leaflet default markers in Next.js
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 {
  collections: Collection[];
  onNavigate: (lat: number, lng: number, name: string) => void;
}

function MapBounds({ collections }: { collections: Collection[] }) {
  const map = useMap();

  useEffect(() => {
    const validPoints = collections
      .filter((c) => c.expand?.supplier?.latitude && c.expand?.supplier?.longitude)
      .map((c) => [c.expand!.supplier!.latitude!, c.expand!.supplier!.longitude!] as [number, number]);

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

  return null;
}

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

  useEffect(() => {
    if ('geolocation' in navigator) {
      navigator.geolocation.getCurrentPosition(
        (pos) => {
          setUserLocation([pos.coords.latitude, pos.coords.longitude]);
        },
        (error) => console.error('Could not get location:', error),
        { enableHighAccuracy: true, timeout: 10000 }
      );

      const watchId = navigator.geolocation.watchPosition(
        (pos) => {
          setUserLocation([pos.coords.latitude, pos.coords.longitude]);
        },
        (error) => console.error('Watch error:', error),
        { enableHighAccuracy: true }
      );

      return () => navigator.geolocation.clearWatch(watchId);
    }
  }, []);

  // Group collections by supplier
  const suppliers = useMemo(() => {
    const map = new Map<string, { supplier: Supplier; collections: Collection[] }>();

    collections.forEach((collection) => {
      if (!collection.expand?.supplier) return;
      const supplier = collection.expand.supplier;
      if (!supplier.latitude || !supplier.longitude) return;

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

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

  const defaultCenter: [number, number] = [-33.9249, 18.4241]; // Cape Town default
  const center = userLocation || defaultCenter;

  const getSupplierDistance = (supplier: Supplier) => {
    if (!userLocation || !supplier.latitude || !supplier.longitude) return null;
    return calculateDistance(
      userLocation[0],
      userLocation[1],
      supplier.latitude,
      supplier.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 collections={collections} />

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

        {suppliers.map(({ supplier, collections: supplierCollections }) => {
          const distance = getSupplierDistance(supplier);
          const hasProblem = supplierCollections.some((c) => c.status === 'problem');

          return (
            <Marker
              key={supplier.id}
              position={[supplier.latitude!, supplier.longitude!]}
              icon={defaultIcon}
              eventHandlers={{
                click: () => setSelectedSupplier(supplier.id),
              }}
            >
              <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.address}</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">
                    {supplierCollections.map((c) => (
                      <div
                        key={c.id}
                        className="text-xs p-1.5 bg-gray-50 rounded"
                      >
                        <div className="flex items-center gap-1">
                          {c.status === 'problem' && (
                            <AlertTriangle size={12} className="text-red-500" />
                          )}
                          <span className="font-medium truncate">
                            {c.is_manual
                              ? c.description
                              : c.expand?.order_item?.description || 'Unknown'}
                          </span>
                        </div>
                        <span className="text-gray-400">
                          Qty: {c.quantity} {c.unit || c.expand?.order_item?.unit || 'units'}
                        </span>
                      </div>
                    ))}
                  </div>

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

      {/* Legend overlay */}
      <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-blue-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-blue-500 rounded-sm rotate-45 transform origin-bottom" />
            </div>
            <span className="text-[10px] text-gray-600">Collection Stop</span>
          </div>
        </div>
      </div>
    </div>
  );
}