import { useEffect, useRef, useState } from "react";
import maplibregl from "maplibre-gl";
import { LAST_VIEW_KEY } from "./mapConfig";
import { getViewFromMap } from "./mapGeo";
import { clearAllMarkers, applyOcclusionForExpanded } from "./markerManager";

// MapLibre base style by theme
function getBaseStyle(theme) {
  const t = theme || "dark";
  let tiles;

  switch (t) {
    case "light":
      tiles = ["https://a.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png"];
      break;
    case "blue":
      tiles = ["https://a.basemaps.cartocdn.com/rastertiles/voyager/{z}/{x}/{y}.png"];
      break;
    case "dark":
    default:
      tiles = ["https://a.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}.png"];
      break;
  }

  return {
    version: 8,
    sources: {
      "carto-base": {
        type: "raster",
        tiles,
        tileSize: 256,
        attribution: "© OpenStreetMap contributors © CARTO",
      },
    },
    layers: [
      {
        id: "carto-base-layer",
        type: "raster",
        source: "carto-base",
      },
    ],
  };
}

export function useMapCore(theme) {
  const containerRef = useRef(null);
  const mapRef = useRef(null);

  const markersRef = useRef([]);
  const expandedElRef = useRef(null);

  // default large radius
  const [viewParams, setViewParams] = useState({
    center: null,
    radiusKm: 750,
  });

  const [hasLastView, setHasLastView] = useState(false);

  function closeExpandedIfAny() {
    const el = expandedElRef.current;
    if (el && el.__renderCompact) el.__renderCompact();
    expandedElRef.current = null;
  }

  function safeUpdateViewParams(map) {
    try {
      const vp = getViewFromMap(map);
      if (vp && Array.isArray(vp.center) && vp.center.length === 2) {
        setViewParams(vp);
      }
    } catch {
      // ignore
    }
  }

  useEffect(() => {
    if (!containerRef.current) return;

    const map = new maplibregl.Map({
      container: containerRef.current,
      style: getBaseStyle(theme || "dark"),
      center: [-95, 40],
      zoom: 3.5,
      pitch: 0,
      bearing: 0,
      antialias: true,
    });

    // Restore last view if available
    let hadLastView = false;
    try {
      const raw = localStorage.getItem(LAST_VIEW_KEY);
      if (raw) {
        const v = JSON.parse(raw);
        if (
          typeof v.lat === "number" &&
          typeof v.lon === "number" &&
          typeof v.zoom === "number"
        ) {
          map.setCenter([v.lon, v.lat]);
          map.setZoom(v.zoom);
          hadLastView = true;
        }
      }
    } catch {}
    setHasLastView(hadLastView);

    map.addControl(new maplibregl.NavigationControl(), "top-right");
    mapRef.current = map;

    // Re-occlude markers when post expanded
    const reOcclude = () => {
      const el = expandedElRef.current;
      if (el) applyOcclusionForExpanded(markersRef, el);
    };
    map.on("move", reOcclude);
    map.on("zoom", reOcclude);

    // Close expanded when clicking/dragging map
    map.on("click", () => closeExpandedIfAny());
    map.on("dragstart", () => closeExpandedIfAny());

    // ✅ CRITICAL FIX:
    // Set view params ASAP and also on load/idle/moveend.
    // On some devices/prod, relying on 'load' only can miss initial fetch triggers.
    const update = () => safeUpdateViewParams(map);

    map.on("load", update);
    map.on("idle", update);
    map.on("moveend", () => {
      update();
      try {
        const vp = getViewFromMap(map);
        const center = vp.center;
        localStorage.setItem(
          LAST_VIEW_KEY,
          JSON.stringify({
            lat: center[1],
            lon: center[0],
            zoom: map.getZoom(),
          })
        );
      } catch {}
    });

    // Also do an early update next frame (helps first load)
    requestAnimationFrame(update);

    return () => {
      clearAllMarkers(markersRef, expandedElRef);
      map.remove();
      mapRef.current = null;
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  // Theme style switch
  useEffect(() => {
    const map = mapRef.current;
    if (!map) return;

    // setStyle triggers style reload; we still want viewParams updated after
    map.setStyle(getBaseStyle(theme || "dark"));

    // update view params after style swap (next frame)
    requestAnimationFrame(() => {
      try {
        safeUpdateViewParams(map);
      } catch {}
    });
  }, [theme]);

  return {
    containerRef,
    mapRef,
    markersRef,
    expandedElRef,
    viewParams,
    hasLastView,
  };
}