import React, { useEffect, useRef, useState } from "react";
import L from "leaflet";
import "leaflet/dist/leaflet.css";
import "leaflet.heat";
import "./MapView.css";

// Fix Leaflet default marker icons
delete L.Icon.Default.prototype._getIconUrl;
L.Icon.Default.mergeOptions({
  iconRetinaUrl: "https://unpkg.com/leaflet@1.9.4/dist/images/marker-icon-2x.png",
  iconUrl: "https://unpkg.com/leaflet@1.9.4/dist/images/marker-icon.png",
  shadowUrl: "https://unpkg.com/leaflet@1.9.4/dist/images/marker-shadow.png",
});

const MapView = ({ 
  tnpLat, 
  tnpLon, 
  zones = [], 
  direction = null,
  heatmapData = [],
  showHeatmap = false 
}) => {
  const mapRef = useRef(null);
  const mapInstanceRef = useRef(null);
  const zonesLayerRef = useRef(null);
  const heatmapLayerRef = useRef(null);
  const tnpMarkerRef = useRef(null);
  const directionArrowRef = useRef(null);

  const [heatmapVisible, setHeatmapVisible] = useState(showHeatmap);

  // Цвета зон из §5 ЦОУ палитры
  const ZONE_COLORS = {
    0: "#ff4d00", // Зона 1 (0-500м) - красный
    1: "#ff9f1a", // Зона 2 (500-1500м) - оранжевый
    2: "#ffd166", // Зона 3 (1500-2500м) - желтый
  };

  // Направления в градусы
  const DIRECTION_ANGLES = {
    N: 0,
    NE: 45,
    E: 90,
    SE: 135,
    S: 180,
    SW: 225,
    W: 270,
    NW: 315,
  };

  useEffect(() => {
    if (!mapRef.current || mapInstanceRef.current) return;

    // Инициализация карты
    const map = L.map(mapRef.current).setView([tnpLat || 53.9, tnpLon || 27.56], 13);

    L.tileLayer("https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png", {
      attribution: "© OpenStreetMap contributors",
      maxZoom: 19,
    }).addTo(map);

    mapInstanceRef.current = map;

    return () => {
      if (mapInstanceRef.current) {
        mapInstanceRef.current.remove();
        mapInstanceRef.current = null;
      }
    };
  }, []);

  // Обновление ТНП маркера
  useEffect(() => {
    if (!mapInstanceRef.current || !tnpLat || !tnpLon) return;

    // Удаляем старый маркер
    if (tnpMarkerRef.current) {
      mapInstanceRef.current.removeLayer(tnpMarkerRef.current);
    }

    // Создаем красный маркер ТНП
    const tnpIcon = L.divIcon({
      className: "tnp-marker",
      html: "<div class=\"tnp-marker-inner\">ТНП</div>",
      iconSize: [40, 40],
      iconAnchor: [20, 20],
    });

    const marker = L.marker([tnpLat, tnpLon], { icon: tnpIcon }).addTo(mapInstanceRef.current);
    marker.bindPopup("<b>Точка начала поиска</b><br>" + tnpLat.toFixed(6) + ", " + tnpLon.toFixed(6));
    tnpMarkerRef.current = marker;

    // Центрируем карту
    mapInstanceRef.current.setView([tnpLat, tnpLon], 13);
  }, [tnpLat, tnpLon]);

  // Обновление стрелки направления
  useEffect(() => {
    if (!mapInstanceRef.current || !tnpLat || !tnpLon || !direction || direction === "unknown") {
      if (directionArrowRef.current) {
        mapInstanceRef.current.removeLayer(directionArrowRef.current);
        directionArrowRef.current = null;
      }
      return;
    }

    // Удаляем старую стрелку
    if (directionArrowRef.current) {
      mapInstanceRef.current.removeLayer(directionArrowRef.current);
    }

    const angle = DIRECTION_ANGLES[direction];
    if (angle === undefined) return;

    // Создаем стрелку (линия 1км в направлении)
    const distance = 1000; // метров
    const endPoint = calculateDestination(tnpLat, tnpLon, angle, distance);

    const arrow = L.polyline(
      [[tnpLat, tnpLon], endPoint],
      {
        color: "#ff4d00",
        weight: 3,
        opacity: 0.8,
        dashArray: "10, 5",
      }
    ).addTo(mapInstanceRef.current);

    // Добавляем стрелку на конце
    const arrowHead = L.marker(endPoint, {
      icon: L.divIcon({
        className: "direction-arrow",
        html: "<div style=\"transform: rotate(" + angle + "deg)\">➤</div>",
        iconSize: [30, 30],
        iconAnchor: [15, 15],
      }),
    }).addTo(mapInstanceRef.current);

    directionArrowRef.current = L.layerGroup([arrow, arrowHead]).addTo(mapInstanceRef.current);
  }, [tnpLat, tnpLon, direction]);

  // Обновление зон (секторные полигоны)
  useEffect(() => {
    if (!mapInstanceRef.current || !tnpLat || !tnpLon || zones.length === 0) {
      if (zonesLayerRef.current) {
        mapInstanceRef.current.removeLayer(zonesLayerRef.current);
        zonesLayerRef.current = null;
      }
      return;
    }

    // Удаляем старые зоны
    if (zonesLayerRef.current) {
      mapInstanceRef.current.removeLayer(zonesLayerRef.current);
    }

    const zonePolygons = [];

    zones.forEach((zone, index) => {
      const color = ZONE_COLORS[index] || "#cccccc";
      const directionAngle = DIRECTION_ANGLES[zone.direction] || 0;

      // Создаем секторный полигон (угол ±45° от направления)
      const sectorAngle = 90; // ширина сектора
      const startAngle = directionAngle - sectorAngle / 2;
      const endAngle = directionAngle + sectorAngle / 2;
      const radiusMeters = zone.distance_km * 1000;

      const sectorPoints = [[tnpLat, tnpLon]]; // Начало в ТНП

      // Генерируем точки по дуге
      for (let angle = startAngle; angle <= endAngle; angle += 5) {
        const point = calculateDestination(tnpLat, tnpLon, angle, radiusMeters);
        sectorPoints.push(point);
      }

      sectorPoints.push([tnpLat, tnpLon]); // Замыкаем полигон

      const polygon = L.polygon(sectorPoints, {
        color: color,
        fillColor: color,
        fillOpacity: 0.2,
        weight: 2,
        opacity: 0.6,
      });

      polygon.bindPopup(
        "<b>" + zone.name + "</b><br>" +
        "Приоритет: " + zone.priority + "<br>" +
        "Оценка: " + zone.score + "<br>" +
        "Расстояние: " + zone.distance_km.toFixed(2) + " км<br>" +
        "<small>" + zone.reasoning + "</small>"
      );

      zonePolygons.push(polygon);
    });

    zonesLayerRef.current = L.layerGroup(zonePolygons).addTo(mapInstanceRef.current);
  }, [tnpLat, tnpLon, zones]);

  // Обновление тепловой карты
  useEffect(() => {
    if (!mapInstanceRef.current) return;

    // Удаляем старый слой
    if (heatmapLayerRef.current) {
      mapInstanceRef.current.removeLayer(heatmapLayerRef.current);
      heatmapLayerRef.current = null;
    }

    if (!heatmapVisible || heatmapData.length === 0) return;

    // Создаем heatmap слой
    const heatPoints = heatmapData.map(point => [
      point.lat,
      point.lon,
      point.intensity || 1.0
    ]);

    const heatLayer = L.heatLayer(heatPoints, {
      radius: 25,
      blur: 15,
      maxZoom: 17,
      max: 1.0,
      gradient: {
        0.0: "#0d1117",
        0.3: "#238636",
        0.5: "#ffd166",
        0.7: "#ff9f1a",
        1.0: "#ff4d00"
      }
    }).addTo(mapInstanceRef.current);

    heatmapLayerRef.current = heatLayer;
  }, [heatmapVisible, heatmapData]);

  // Вычисление точки назначения (lat, lon, angle, distance)
  const calculateDestination = (lat, lon, bearing, distance) => {
    const R = 6371000; // Радиус Земли в метрах
    const φ1 = (lat * Math.PI) / 180;
    const λ1 = (lon * Math.PI) / 180;
    const θ = (bearing * Math.PI) / 180;

    const φ2 = Math.asin(
      Math.sin(φ1) * Math.cos(distance / R) +
      Math.cos(φ1) * Math.sin(distance / R) * Math.cos(θ)
    );

    const λ2 = λ1 + Math.atan2(
      Math.sin(θ) * Math.sin(distance / R) * Math.cos(φ1),
      Math.cos(distance / R) - Math.sin(φ1) * Math.sin(φ2)
    );

    return [(φ2 * 180) / Math.PI, (λ2 * 180) / Math.PI];
  };

  return (
    <div className="map-view-container">
      <div className="map-controls">
        <button
          className={heatmapVisible ? "control-btn active" : "control-btn"}
          onClick={() => setHeatmapVisible(!heatmapVisible)}
          disabled={heatmapData.length === 0}
        >
          {heatmapVisible ? "🔥 Скрыть тепловую карту" : "🔥 Показать тепловую карту"}
        </button>
      </div>
      <div ref={mapRef} className="map-view" />
    </div>
  );
};

export default MapView;