// components/uiWidgets/baseMapPanel/BaseMapPanel.js , aus rechliche Grunde nur OSM, dieses Feature ist optional, aktuell nicht genutzt
import React, { useEffect, useMemo, useRef, useState } from "react";
import L from "leaflet";
import { Icon } from "@iconify/react";

// Minimal, safe defaults (no API key required). You can extend via config later.
const DEFAULT_BASE_LAYERS = [
  {
    id: "osm-standard",
    name: "Standard",
    url: "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
    attribution: "© OpenStreetMap contributors",
    minZoom: 0,
    maxZoom: 19,
  },
  {
    id: "osm-humanitarian",
    name: "Humanitarian",
    url: "https://{s}.tile.openstreetmap.fr/hot/{z}/{x}/{y}.png",
    attribution: "© OpenStreetMap contributors, Humanitarian OpenStreetMap Team",
    minZoom: 0,
    maxZoom: 19,
  },
  {
    id: "cyclosm",
    name: "CyclOSM",
    url: "https://{s}.tile-cyclosm.openstreetmap.fr/cyclosm/{z}/{x}/{y}.png",
    attribution: "© OpenStreetMap contributors, CyclOSM",
    minZoom: 0,
    maxZoom: 20,
  },
  {
    id: "carto-light",
    name: "Carto Light",
    url: "https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}{r}.png",
    attribution: "© OpenStreetMap contributors, © CARTO",
    subdomains: "abcd",
    minZoom: 0,
    maxZoom: 20,
  },
];

function getCurrentTileLayer(map) {
  let found = null;
  if (!map) return null;
  map.eachLayer(layer => {
    if (!found && layer instanceof L.TileLayer) {
      found = layer;
    }
  });
  return found;
}

export default function BaseMapPanel({ map, onSelect, onClose, initialId }) {
  const [activeId, setActiveId] = useState(initialId || null);
  const layerCacheRef = useRef({});
  const bases = useMemo(() => {
    try {
      if (typeof window !== "undefined") {
        const cfg = window.__leafletConfig;
        if (cfg && cfg.tileSources) {
          return Object.entries(cfg.tileSources).map(([key, ts]) => ({
            id: key,
            name: ts.name || key,
            url: ts.url,
            attribution: ts.attribution || "© OpenStreetMap contributors",
            minZoom: ts.minZoom ?? cfg.minZoom ?? 0,
            maxZoom: ts.maxZoom ?? cfg.maxZoom ?? 19,
            subdomains: ts.subdomains,
          }));
        }
      }
    } catch (_) {}
    return DEFAULT_BASE_LAYERS;
  }, []);

  const applyBase = id => {
    if (!map) return;
    const base = bases.find(b => b.id === id) || bases[0];
    if (!base) return;

    // Remove current tile layer
    const current = getCurrentTileLayer(map);
    if (current) {
      try {
        map.removeLayer(current);
      } catch (_) {}
    }

    // Get or create the new layer
    let nextLayer = layerCacheRef.current[id];
    if (!nextLayer) {
      nextLayer = L.tileLayer(base.url, {
        attribution: base.attribution,
        subdomains: base.subdomains || "abc",
        tileSize: 256,
        minZoom: base.minZoom ?? 0,
        maxZoom: base.maxZoom ?? 19,
        noWrap: true,
        // Ensure base tiles stay behind overlays
        zIndex: 1,
      });
      layerCacheRef.current[id] = nextLayer;
    }

    nextLayer.addTo(map);
    try {
      if (typeof map.setMinZoom === "function") map.setMinZoom(base.minZoom ?? 0);
      if (typeof map.setMaxZoom === "function") map.setMaxZoom(base.maxZoom ?? 19);
      if (typeof window !== "undefined") {
        window.__tileSourceMinZoom = base.minZoom ?? 0;
        window.__tileSourceMaxZoom = base.maxZoom ?? 19;
      }
    } catch (_) {}

    setActiveId(id);
    try {
      localStorage.setItem("baseMapId", id);
    } catch (_) {}
    onSelect && onSelect(id);
  };

  useEffect(() => {
    const saved = (() => {
      try {
        return localStorage.getItem("baseMapId");
      } catch (_) {
        return null;
      }
    })();
    const targetId = initialId || saved || bases[0]?.id;
    if (targetId) {
      applyBase(targetId);
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [map]);

  return (
    <div className="absolute top-16 right-3 z-50 w-64 bg-white rounded-lg shadow-lg p-3">
      <div className="flex items-center justify-between mb-2">
        <h3 className="text-sm font-semibold">Map Layers</h3>
        <button onClick={onClose} aria-label="Schließen" title="Schließen">
          <Icon icon="material-symbols:close-rounded" className="h-5 w-5 text-gray-700" />
        </button>
      </div>
      <div className="flex flex-col gap-2">
        {bases.map(b => (
          <button
            key={b.id}
            onClick={() => applyBase(b.id)}
            className={`text-left rounded-md border p-2 hover:bg-gray-50 ${
              activeId === b.id ? "ring-2 ring-blue-500" : ""
            }`}
            title={b.name}
          >
            <div className="font-medium text-sm">{b.name}</div>
            <div className="text-[10px] text-gray-500 truncate">{b.url}</div>
          </button>
        ))}
      </div>
    </div>
  );
}