"use client";

import MapLibreGL, { type PopupOptions, type MarkerOptions } from "maplibre-gl";
import "maplibre-gl/dist/maplibre-gl.css";
import type * as GeoJSON from "geojson";
import {
  createContext,
  forwardRef,
  useCallback,
  useContext,
  useEffect,
  useId,
  useImperativeHandle,
  useMemo,
  useRef,
  useState,
  type ReactNode,
} from "react";
import { createPortal } from "react-dom";
import { X, Minus, Plus, Locate, Maximize, Loader2 } from "lucide-react";

import { cn } from "@/lib/utils";

const defaultStyles = {
  dark: "https://basemaps.cartocdn.com/gl/dark-matter-gl-style/style.json",
  light: "https://basemaps.cartocdn.com/gl/positron-gl-style/style.json",
};

// A tile-less, dependency-free style with a transparent background. Use it for
// data visualizations (choropleths, world arcs, dot maps) where you draw your
// own layers and don't need a street basemap. The easiest way to opt in is the
// `blank` prop:
//   <Map blank>...</Map>
// The transparent background lets the themed container show through.
const blankMapStyle: MapLibreGL.StyleSpecification = {
  version: 8,
  sources: {},
  layers: [
    {
      id: "background",
      type: "background",
      paint: { "background-color": "rgba(0, 0, 0, 0)" },
    },
  ],
};

function mergeHoverPaint<T extends Record<string, unknown>>(
  paint: T,
  hoverPaint: T | undefined,
): T {
  if (!hoverPaint) return paint;
  const merged: Record<string, unknown> = { ...paint };
  for (const [key, hoverValue] of Object.entries(hoverPaint)) {
    if (hoverValue === undefined) continue;
    const baseValue = merged[key];
    merged[key] =
      baseValue === undefined
        ? hoverValue
        : [
            "case",
            ["boolean", ["feature-state", "hover"], false],
            hoverValue,
            baseValue,
          ];
  }
  return merged as T;
}

type Theme = "light" | "dark";

// Check document class for theme (works with next-themes, etc.)
function getDocumentTheme(): Theme | null {
  if (typeof document === "undefined") return null;
  if (document.documentElement.classList.contains("dark")) return "dark";
  if (document.documentElement.classList.contains("light")) return "light";
  return null;
}

// Get system preference
function getSystemTheme(): Theme {
  if (typeof window === "undefined") return "light";
  return window.matchMedia("(prefers-color-scheme: dark)").matches
    ? "dark"
    : "light";
}

function useResolvedTheme(themeProp?: "light" | "dark"): Theme {
  const [detectedTheme, setDetectedTheme] = useState<Theme>(
    () => getDocumentTheme() ?? getSystemTheme(),
  );

  useEffect(() => {
    if (themeProp) return; // Skip detection if theme is provided via prop

    // Watch for document class changes (e.g., next-themes toggling dark class)
    const observer = new MutationObserver(() => {
      const docTheme = getDocumentTheme();
      if (docTheme) {
        setDetectedTheme(docTheme);
      }
    });
    observer.observe(document.documentElement, {
      attributes: true,
      attributeFilter: ["class"],
    });

    // Also watch for system preference changes
    const mediaQuery = window.matchMedia("(prefers-color-scheme: dark)");
    const handleSystemChange = (e: MediaQueryListEvent) => {
      // Only use system preference if no document class is set
      if (!getDocumentTheme()) {
        setDetectedTheme(e.matches ? "dark" : "light");
      }
    };
    mediaQuery.addEventListener("change", handleSystemChange);

    return () => {
      observer.disconnect();
      mediaQuery.removeEventListener("change", handleSystemChange);
    };
  }, [themeProp]);

  return themeProp ?? detectedTheme;
}

type MapContextValue = {
  map: MapLibreGL.Map | null;
  isLoaded: boolean;
  resolvedTheme: Theme;
};

const MapContext = createContext<MapContextValue | null>(null);

function useMap() {
  const context = useContext(MapContext);
  if (!context) {
    throw new Error("useMap must be used within a Map component");
  }
  return context;
}

/** Map viewport state */
type MapViewport = {
  /** Center coordinates [longitude, latitude] */
  center: [number, number];
  /** Zoom level */
  zoom: number;
  /** Bearing (rotation) in degrees */
  bearing: number;
  /** Pitch (tilt) in degrees */
  pitch: number;
};

type MapStyleOption = string | MapLibreGL.StyleSpecification;

type MapRef = MapLibreGL.Map;

type MapProps = {
  children?: ReactNode;
  /** Additional CSS classes for the map container */
  className?: string;
  /**
   * Theme for the map. If not provided, automatically detects system preference.
   * Pass your theme value here.
   */
  theme?: Theme;
  /** Custom map styles for light and dark themes. Overrides the default Carto styles. */
  styles?: {
    light?: MapStyleOption;
    dark?: MapStyleOption;
  };
  /**
   * Use a transparent, tile-less basemap instead of the default Carto street
   * basemap — a blank canvas. Used alone it renders nothing; add your own
   * layers on top (`<MapGeoJSON>`, `<MapArc>`, markers, etc.). Ideal for data
   * visualizations (choropleths, arcs, dot maps).
   * Ignored when an explicit `styles` prop is provided.
   */
  blank?: boolean;
  /** Map projection type. Use `{ type: "globe" }` for 3D globe view. */
  projection?: MapLibreGL.ProjectionSpecification;
  /**
   * Controlled viewport. When provided with onViewportChange,
   * the map becomes controlled and viewport is driven by this prop.
   */
  viewport?: Partial<MapViewport>;
  /**
   * Callback fired continuously as the viewport changes (pan, zoom, rotate, pitch).
   * Can be used standalone to observe changes, or with `viewport` prop
   * to enable controlled mode where the map viewport is driven by your state.
   */
  onViewportChange?: (viewport: MapViewport) => void;
  /** Show a loading indicator on the map */
  loading?: boolean;
} & Omit<MapLibreGL.MapOptions, "container" | "style">;

function DefaultLoader() {
  return (
    <div className="bg-background/50 absolute inset-0 z-10 flex items-center justify-center backdrop-blur-xs">
      <div className="flex gap-1">
        <span className="bg-muted-foreground/60 size-1.5 animate-pulse rounded-full" />
        <span className="bg-muted-foreground/60 size-1.5 animate-pulse rounded-full [animation-delay:150ms]" />
        <span className="bg-muted-foreground/60 size-1.5 animate-pulse rounded-full [animation-delay:300ms]" />
      </div>
    </div>
  );
}

function getViewport(map: MapLibreGL.Map): MapViewport {
  const center = map.getCenter();
  return {
    center: [center.lng, center.lat],
    zoom: map.getZoom(),
    bearing: map.getBearing(),
    pitch: map.getPitch(),
  };
}

const Map = forwardRef<MapRef, MapProps>(function Map(
  {
    children,
    className,
    theme: themeProp,
    styles,
    blank = false,
    projection,
    viewport,
    onViewportChange,
    loading = false,
    ...props
  },
  ref,
) {
  const containerRef = useRef<HTMLDivElement>(null);
  const [mapInstance, setMapInstance] = useState<MapLibreGL.Map | null>(null);
  const [isLoaded, setIsLoaded] = useState(false);
  const [isStyleLoaded, setIsStyleLoaded] = useState(false);
  const currentStyleRef = useRef<MapStyleOption | null>(null);
  const styleTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
  const internalUpdateRef = useRef(false);
  const resolvedTheme = useResolvedTheme(themeProp);

  const isControlled = viewport !== undefined && onViewportChange !== undefined;

  const onViewportChangeRef = useRef(onViewportChange);
  onViewportChangeRef.current = onViewportChange;

  const mapStyles = useMemo(() => {
    // Explicit styles win. Otherwise `blank` opts into the transparent
    // tile-less basemap; with neither, fall back to the Carto defaults.
    if (styles) {
      return {
        dark: styles.dark ?? defaultStyles.dark,
        light: styles.light ?? defaultStyles.light,
      };
    }
    if (blank) {
      return { dark: blankMapStyle, light: blankMapStyle };
    }
    return defaultStyles;
  }, [styles, blank]);

  // Expose the map instance to the parent component
  useImperativeHandle(ref, () => mapInstance as MapLibreGL.Map, [mapInstance]);

  const clearStyleTimeout = useCallback(() => {
    if (styleTimeoutRef.current) {
      clearTimeout(styleTimeoutRef.current);
      styleTimeoutRef.current = null;
    }
  }, []);

  // Initialize the map
  useEffect(() => {
    if (!containerRef.current) return;

    const initialStyle =
      resolvedTheme === "dark" ? mapStyles.dark : mapStyles.light;
    currentStyleRef.current = initialStyle;

    const map = new MapLibreGL.Map({
      container: containerRef.current,
      style: initialStyle,
      renderWorldCopies: false,
      attributionControl: {
        compact: true,
      },
      ...props,
      ...viewport,
    });

    const styleDataHandler = () => {
      clearStyleTimeout();
      // Delay to ensure style is fully processed before allowing layer operations
      // This is a workaround to avoid race conditions with the style loading
      // else we have to force update every layer on setStyle change
      styleTimeoutRef.current = setTimeout(() => {
        setIsStyleLoaded(true);
        if (projection) {
          map.setProjection(projection);
        }
      }, 100);
    };
    const loadHandler = () => setIsLoaded(true);

    // Viewport change handler - skip if triggered by internal update
    const handleMove = () => {
      if (internalUpdateRef.current) return;
      onViewportChangeRef.current?.(getViewport(map));
    };

    map.on("load", loadHandler);
    map.on("styledata", styleDataHandler);
    map.on("move", handleMove);
    setMapInstance(map);

    return () => {
      clearStyleTimeout();
      map.off("load", loadHandler);
      map.off("styledata", styleDataHandler);
      map.off("move", handleMove);
      map.remove();
      setIsLoaded(false);
      setIsStyleLoaded(false);
      setMapInstance(null);
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  // Sync controlled viewport to map
  useEffect(() => {
    if (!mapInstance || !isControlled || !viewport) return;
    if (mapInstance.isMoving()) return;

    const current = getViewport(mapInstance);
    const next = {
      center: viewport.center ?? current.center,
      zoom: viewport.zoom ?? current.zoom,
      bearing: viewport.bearing ?? current.bearing,
      pitch: viewport.pitch ?? current.pitch,
    };

    if (
      next.center[0] === current.center[0] &&
      next.center[1] === current.center[1] &&
      next.zoom === current.zoom &&
      next.bearing === current.bearing &&
      next.pitch === current.pitch
    ) {
      return;
    }

    internalUpdateRef.current = true;
    mapInstance.jumpTo(next);
    internalUpdateRef.current = false;
  }, [mapInstance, isControlled, viewport]);

  // Handle style change
  useEffect(() => {
    if (!mapInstance || !resolvedTheme) return;

    const newStyle =
      resolvedTheme === "dark" ? mapStyles.dark : mapStyles.light;

    if (currentStyleRef.current === newStyle) return;

    clearStyleTimeout();
    currentStyleRef.current = newStyle;
    setIsStyleLoaded(false);

    mapInstance.setStyle(newStyle, { diff: true });
  }, [mapInstance, resolvedTheme, mapStyles, clearStyleTimeout]);

  // Sync projection when the prop changes after mount.
  useEffect(() => {
    if (!mapInstance || !isStyleLoaded || !projection) return;
    mapInstance.setProjection(projection);
  }, [mapInstance, isStyleLoaded, projection]);

  const contextValue = useMemo(
    () => ({
      map: mapInstance,
      isLoaded: isLoaded && isStyleLoaded,
      resolvedTheme,
    }),
    [mapInstance, isLoaded, isStyleLoaded, resolvedTheme],
  );

  return (
    <MapContext.Provider value={contextValue}>
      <div
        ref={containerRef}
        className={cn("relative h-full w-full", className)}
      >
        {(!isLoaded || loading) && <DefaultLoader />}
        {/* SSR-safe: children render only when map is loaded on client */}
        {mapInstance && children}
      </div>
    </MapContext.Provider>
  );
});

type MarkerContextValue = {
  marker: MapLibreGL.Marker;
  map: MapLibreGL.Map | null;
};

const MarkerContext = createContext<MarkerContextValue | null>(null);

function useMarkerContext() {
  const context = useContext(MarkerContext);
  if (!context) {
    throw new Error("Marker components must be used within MapMarker");
  }
  return context;
}

type MapMarkerProps = {
  /** Longitude coordinate for marker position */
  longitude: number;
  /** Latitude coordinate for marker position */
  latitude: number;
  /** Marker subcomponents (MarkerContent, MarkerPopup, MarkerTooltip, MarkerLabel) */
  children: ReactNode;
  /** Callback when marker is clicked */
  onClick?: (e: MouseEvent) => void;
  /** Callback when mouse enters marker */
  onMouseEnter?: (e: MouseEvent) => void;
  /** Callback when mouse leaves marker */
  onMouseLeave?: (e: MouseEvent) => void;
  /** Callback when marker drag starts (requires draggable: true) */
  onDragStart?: (lngLat: { lng: number; lat: number }) => void;
  /** Callback during marker drag (requires draggable: true) */
  onDrag?: (lngLat: { lng: number; lat: number }) => void;
  /** Callback when marker drag ends (requires draggable: true) */
  onDragEnd?: (lngLat: { lng: number; lat: number }) => void;
} & Omit<MarkerOptions, "element">;

function MapMarker({
  longitude,
  latitude,
  children,
  onClick,
  onMouseEnter,
  onMouseLeave,
  onDragStart,
  onDrag,
  onDragEnd,
  draggable = false,
  ...markerOptions
}: MapMarkerProps) {
  const { map } = useMap();

  const callbacksRef = useRef({
    onClick,
    onMouseEnter,
    onMouseLeave,
    onDragStart,
    onDrag,
    onDragEnd,
  });
  callbacksRef.current = {
    onClick,
    onMouseEnter,
    onMouseLeave,
    onDragStart,
    onDrag,
    onDragEnd,
  };

  const marker = useMemo(() => {
    const markerInstance = new MapLibreGL.Marker({
      ...markerOptions,
      element: document.createElement("div"),
      draggable,
    }).setLngLat([longitude, latitude]);

    const handleClick = (e: MouseEvent) => callbacksRef.current.onClick?.(e);
    const handleMouseEnter = (e: MouseEvent) =>
      callbacksRef.current.onMouseEnter?.(e);
    const handleMouseLeave = (e: MouseEvent) =>
      callbacksRef.current.onMouseLeave?.(e);

    markerInstance.getElement()?.addEventListener("click", handleClick);
    markerInstance
      .getElement()
      ?.addEventListener("mouseenter", handleMouseEnter);
    markerInstance
      .getElement()
      ?.addEventListener("mouseleave", handleMouseLeave);

    const handleDragStart = () => {
      const lngLat = markerInstance.getLngLat();
      callbacksRef.current.onDragStart?.({ lng: lngLat.lng, lat: lngLat.lat });
    };
    const handleDrag = () => {
      const lngLat = markerInstance.getLngLat();
      callbacksRef.current.onDrag?.({ lng: lngLat.lng, lat: lngLat.lat });
    };
    const handleDragEnd = () => {
      const lngLat = markerInstance.getLngLat();
      callbacksRef.current.onDragEnd?.({ lng: lngLat.lng, lat: lngLat.lat });
    };

    markerInstance.on("dragstart", handleDragStart);
    markerInstance.on("drag", handleDrag);
    markerInstance.on("dragend", handleDragEnd);

    return markerInstance;

    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    if (!map) return;

    marker.addTo(map);

    return () => {
      marker.remove();
    };

    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [map]);

  const { offset, rotation, rotationAlignment, pitchAlignment } = markerOptions;

  useEffect(() => {
    const current = marker.getLngLat();
    if (current.lng !== longitude || current.lat !== latitude) {
      marker.setLngLat([longitude, latitude]);
    }

    if (marker.isDraggable() !== draggable) {
      marker.setDraggable(draggable);
    }

    const currentOffset = marker.getOffset();
    const newOffset = offset ?? [0, 0];
    const [newOffsetX, newOffsetY] = Array.isArray(newOffset)
      ? newOffset
      : [newOffset.x, newOffset.y];
    if (currentOffset.x !== newOffsetX || currentOffset.y !== newOffsetY) {
      marker.setOffset(newOffset);
    }

    if (marker.getRotation() !== (rotation ?? 0)) {
      marker.setRotation(rotation ?? 0);
    }
    if (marker.getRotationAlignment() !== (rotationAlignment ?? "auto")) {
      marker.setRotationAlignment(rotationAlignment ?? "auto");
    }
    if (marker.getPitchAlignment() !== (pitchAlignment ?? "auto")) {
      marker.setPitchAlignment(pitchAlignment ?? "auto");
    }
  }, [
    marker,
    longitude,
    latitude,
    draggable,
    offset,
    rotation,
    rotationAlignment,
    pitchAlignment,
  ]);

  return (
    <MarkerContext.Provider value={{ marker, map }}>
      {children}
    </MarkerContext.Provider>
  );
}

type MarkerContentProps = {
  /** Custom marker content. Defaults to a blue dot if not provided */
  children?: ReactNode;
  /** Additional CSS classes for the marker container */
  className?: string;
};

function MarkerContent({ children, className }: MarkerContentProps) {
  const { marker } = useMarkerContext();

  return createPortal(
    <div className={cn("relative cursor-pointer", className)}>
      {children || <DefaultMarkerIcon />}
    </div>,
    marker.getElement(),
  );
}

function DefaultMarkerIcon() {
  return (
    <div className="relative h-4 w-4 rounded-full border-2 border-white bg-blue-500 shadow-lg" />
  );
}

function PopupCloseButton({ onClick }: { onClick: () => void }) {
  return (
    <button
      type="button"
      onClick={onClick}
      aria-label="Close popup"
      className="focus-visible:ring-ring hover:bg-muted text-foreground absolute top-1 right-1 z-10 inline-flex size-5 cursor-pointer items-center justify-center rounded-sm transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-inset"
    >
      <X className="size-3.5" />
    </button>
  );
}

type MarkerPopupProps = {
  /** Popup content */
  children: ReactNode;
  /** Additional CSS classes for the popup container */
  className?: string;
  /** Show a close button in the popup (default: false) */
  closeButton?: boolean;
} & Omit<PopupOptions, "className" | "closeButton">;

function MarkerPopup({
  children,
  className,
  closeButton = false,
  ...popupOptions
}: MarkerPopupProps) {
  const { marker, map } = useMarkerContext();
  const container = useMemo(() => document.createElement("div"), []);
  const { offset, maxWidth } = popupOptions;

  const popup = useMemo(() => {
    const popupInstance = new MapLibreGL.Popup({
      offset: 16,
      ...popupOptions,
      closeButton: false,
    })
      .setMaxWidth("none")
      .setDOMContent(container);

    return popupInstance;
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    if (!map) return;

    popup.setDOMContent(container);
    marker.setPopup(popup);

    return () => {
      marker.setPopup(null);
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [map]);

  // Sync popup options when they change.
  useEffect(() => {
    popup.setOffset(offset ?? 16);
    if (maxWidth) {
      popup.setMaxWidth(maxWidth);
    }
  }, [popup, offset, maxWidth]);

  const handleClose = () => popup.remove();

  return createPortal(
    <div
      className={cn(
        "bg-popover text-popover-foreground relative max-w-62 rounded-md border p-3 shadow-md",
        "animate-in fade-in-0 zoom-in-95 duration-200 ease-out",
        className,
      )}
    >
      {closeButton && <PopupCloseButton onClick={handleClose} />}
      {children}
    </div>,
    container,
  );
}

type MarkerTooltipProps = {
  /** Tooltip content */
  children: ReactNode;
  /** Additional CSS classes for the tooltip container */
  className?: string;
} & Omit<PopupOptions, "className" | "closeButton" | "closeOnClick">;

function MarkerTooltip({
  children,
  className,
  ...popupOptions
}: MarkerTooltipProps) {
  const { marker, map } = useMarkerContext();
  const container = useMemo(() => document.createElement("div"), []);
  const { offset, maxWidth } = popupOptions;

  const tooltip = useMemo(() => {
    const tooltipInstance = new MapLibreGL.Popup({
      offset: 16,
      ...popupOptions,
      closeOnClick: true,
      closeButton: false,
    }).setMaxWidth("none");

    return tooltipInstance;
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    if (!map) return;

    tooltip.setDOMContent(container);

    const handleMouseEnter = () => {
      tooltip.setLngLat(marker.getLngLat()).addTo(map);
    };
    const handleMouseLeave = () => tooltip.remove();

    marker.getElement()?.addEventListener("mouseenter", handleMouseEnter);
    marker.getElement()?.addEventListener("mouseleave", handleMouseLeave);

    return () => {
      marker.getElement()?.removeEventListener("mouseenter", handleMouseEnter);
      marker.getElement()?.removeEventListener("mouseleave", handleMouseLeave);
      tooltip.remove();
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [map]);

  // Sync tooltip options when they change.
  useEffect(() => {
    tooltip.setOffset(offset ?? 16);
    if (maxWidth) {
      tooltip.setMaxWidth(maxWidth);
    }
  }, [tooltip, offset, maxWidth]);

  return createPortal(
    <div
      className={cn(
        "bg-foreground text-background pointer-events-none rounded-md px-2 py-1 text-xs text-balance shadow-md",
        "animate-in fade-in-0 zoom-in-95 duration-200 ease-out",
        className,
      )}
    >
      {children}
    </div>,
    container,
  );
}

type MarkerLabelProps = {
  /** Label text content */
  children: ReactNode;
  /** Additional CSS classes for the label */
  className?: string;
  /** Position of the label relative to the marker (default: "top") */
  position?: "top" | "bottom";
};

function MarkerLabel({
  children,
  className,
  position = "top",
}: MarkerLabelProps) {
  const positionClasses = {
    top: "bottom-full mb-1",
    bottom: "top-full mt-1",
  };

  return (
    <div
      className={cn(
        "absolute left-1/2 -translate-x-1/2 whitespace-nowrap",
        "text-foreground text-[10px] font-medium",
        positionClasses[position],
        className,
      )}
    >
      {children}
    </div>
  );
}

type MapControlsProps = {
  /** Position of the controls on the map (default: "bottom-right") */
  position?: "top-left" | "top-right" | "bottom-left" | "bottom-right";
  /** Show zoom in/out buttons (default: true) */
  showZoom?: boolean;
  /** Show compass button to reset bearing (default: false) */
  showCompass?: boolean;
  /** Show locate button to find user's location (default: false) */
  showLocate?: boolean;
  /** Show fullscreen toggle button (default: false) */
  showFullscreen?: boolean;
  /** Additional CSS classes for the controls container */
  className?: string;
  /** Callback with user coordinates when located */
  onLocate?: (coords: { longitude: number; latitude: number }) => void;
};

const positionClasses = {
  "top-left": "top-2 left-2",
  "top-right": "top-2 right-2",
  "bottom-left": "bottom-2 left-2",
  "bottom-right": "bottom-10 right-2",
};

function ControlGroup({ children }: { children: React.ReactNode }) {
  return (
    <div className="border-border bg-background [&>button:not(:last-child)]:border-border flex flex-col overflow-hidden rounded-md border shadow-sm [&>button:not(:last-child)]:border-b">
      {children}
    </div>
  );
}

function ControlButton({
  onClick,
  label,
  children,
  disabled = false,
}: {
  onClick: () => void;
  label: string;
  children: React.ReactNode;
  disabled?: boolean;
}) {
  return (
    <button
      onClick={onClick}
      aria-label={label}
      type="button"
      className={cn(
        "flex size-8 items-center justify-center transition-all",
        "first:rounded-t-md last:rounded-b-md",
        "hover:bg-accent dark:hover:bg-accent/40",
        "focus-visible:ring-ring focus-visible:ring-2 focus-visible:outline-none focus-visible:ring-inset",
        "disabled:pointer-events-none disabled:opacity-50",
      )}
      disabled={disabled}
    >
      {children}
    </button>
  );
}

function MapControls({
  position = "bottom-right",
  showZoom = true,
  showCompass = false,
  showLocate = false,
  showFullscreen = false,
  className,
  onLocate,
}: MapControlsProps) {
  const { map } = useMap();
  const [waitingForLocation, setWaitingForLocation] = useState(false);

  const handleZoomIn = useCallback(() => {
    map?.zoomTo(map.getZoom() + 1, { duration: 300 });
  }, [map]);

  const handleZoomOut = useCallback(() => {
    map?.zoomTo(map.getZoom() - 1, { duration: 300 });
  }, [map]);

  const handleResetBearing = useCallback(() => {
    map?.resetNorthPitch({ duration: 300 });
  }, [map]);

  const handleLocate = useCallback(() => {
    setWaitingForLocation(true);
    if ("geolocation" in navigator) {
      navigator.geolocation.getCurrentPosition(
        (pos) => {
          const coords = {
            longitude: pos.coords.longitude,
            latitude: pos.coords.latitude,
          };
          map?.flyTo({
            center: [coords.longitude, coords.latitude],
            zoom: 14,
            duration: 1500,
          });
          onLocate?.(coords);
          setWaitingForLocation(false);
        },
        (error) => {
          console.error("Error getting location:", error);
          setWaitingForLocation(false);
        },
      );
    }
  }, [map, onLocate]);

  const handleFullscreen = useCallback(() => {
    const container = map?.getContainer();
    if (!container) return;
    if (document.fullscreenElement) {
      document.exitFullscreen();
    } else {
      container.requestFullscreen();
    }
  }, [map]);

  return (
    <div
      className={cn(
        "absolute z-10 flex flex-col gap-1.5",
        positionClasses[position],
        className,
      )}
    >
      {showZoom && (
        <ControlGroup>
          <ControlButton onClick={handleZoomIn} label="Zoom in">
            <Plus className="size-4" />
          </ControlButton>
          <ControlButton onClick={handleZoomOut} label="Zoom out">
            <Minus className="size-4" />
          </ControlButton>
        </ControlGroup>
      )}
      {showCompass && (
        <ControlGroup>
          <CompassButton onClick={handleResetBearing} />
        </ControlGroup>
      )}
      {showLocate && (
        <ControlGroup>
          <ControlButton
            onClick={handleLocate}
            label="Find my location"
            disabled={waitingForLocation}
          >
            {waitingForLocation ? (
              <Loader2 className="size-4 animate-spin" />
            ) : (
              <Locate className="size-4" />
            )}
          </ControlButton>
        </ControlGroup>
      )}
      {showFullscreen && (
        <ControlGroup>
          <ControlButton onClick={handleFullscreen} label="Toggle fullscreen">
            <Maximize className="size-4" />
          </ControlButton>
        </ControlGroup>
      )}
    </div>
  );
}

function CompassButton({ onClick }: { onClick: () => void }) {
  const { map } = useMap();
  const compassRef = useRef<SVGSVGElement>(null);

  useEffect(() => {
    if (!map || !compassRef.current) return;

    const compass = compassRef.current;

    const updateRotation = () => {
      const bearing = map.getBearing();
      const pitch = map.getPitch();
      compass.style.transform = `rotateX(${pitch}deg) rotateZ(${-bearing}deg)`;
    };

    map.on("rotate", updateRotation);
    map.on("pitch", updateRotation);
    updateRotation();

    return () => {
      map.off("rotate", updateRotation);
      map.off("pitch", updateRotation);
    };
  }, [map]);

  return (
    <ControlButton onClick={onClick} label="Reset bearing to north">
      <svg
        ref={compassRef}
        viewBox="0 0 24 24"
        className="size-5 transition-transform duration-200"
        style={{ transformStyle: "preserve-3d" }}
      >
        <path d="M12 2L16 12H12V2Z" className="fill-red-500" />
        <path d="M12 2L8 12H12V2Z" className="fill-red-300" />
        <path d="M12 22L16 12H12V22Z" className="fill-muted-foreground/60" />
        <path d="M12 22L8 12H12V22Z" className="fill-muted-foreground/30" />
      </svg>
    </ControlButton>
  );
}

type MapPopupProps = {
  /** Longitude coordinate for popup position */
  longitude: number;
  /** Latitude coordinate for popup position */
  latitude: number;
  /** Callback when popup is closed */
  onClose?: () => void;
  /** Popup content */
  children: ReactNode;
  /** Additional CSS classes for the popup container */
  className?: string;
  /** Show a close button in the popup (default: false) */
  closeButton?: boolean;
} & Omit<PopupOptions, "className" | "closeButton">;

function MapPopup({
  longitude,
  latitude,
  onClose,
  children,
  className,
  closeButton = false,
  ...popupOptions
}: MapPopupProps) {
  const { map } = useMap();
  const onCloseRef = useRef(onClose);
  onCloseRef.current = onClose;
  const container = useMemo(() => document.createElement("div"), []);
  const { offset, maxWidth } = popupOptions;

  const popup = useMemo(() => {
    const popupInstance = new MapLibreGL.Popup({
      offset: 16,
      ...popupOptions,
      closeButton: false,
    })
      .setMaxWidth("none")
      .setLngLat([longitude, latitude]);

    return popupInstance;
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  useEffect(() => {
    if (!map) return;

    const onCloseProp = () => onCloseRef.current?.();

    popup.on("close", onCloseProp);

    popup.setDOMContent(container);
    popup.addTo(map);

    return () => {
      popup.off("close", onCloseProp);
      if (popup.isOpen()) {
        popup.remove();
      }
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [map]);

  // Sync popup position and options when they change.
  useEffect(() => {
    const current = popup.getLngLat();
    if (!current || current.lng !== longitude || current.lat !== latitude) {
      popup.setLngLat([longitude, latitude]);
    }
    popup.setOffset(offset ?? 16);
    if (maxWidth) {
      popup.setMaxWidth(maxWidth);
    }
  }, [popup, longitude, latitude, offset, maxWidth]);

  const handleClose = () => {
    popup.remove();
  };

  return createPortal(
    <div
      className={cn(
        "bg-popover text-popover-foreground relative max-w-62 rounded-md border p-3 shadow-md",
        "animate-in fade-in-0 zoom-in-95 duration-200 ease-out",
        className,
      )}
    >
      {closeButton && <PopupCloseButton onClick={handleClose} />}
      {children}
    </div>,
    container,
  );
}

type MapRouteProps = {
  /** Optional unique identifier for the route layer */
  id?: string;
  /** Array of [longitude, latitude] coordinate pairs defining the route */
  coordinates: [number, number][];
  /** Line color as CSS color value (default: "#4285F4") */
  color?: string;
  /** Line width in pixels (default: 3) */
  width?: number;
  /** Line opacity from 0 to 1 (default: 0.8) */
  opacity?: number;
  /** Dash pattern [dash length, gap length] for dashed lines */
  dashArray?: [number, number];
  /** Callback when the route line is clicked */
  onClick?: () => void;
  /** Callback when mouse enters the route line */
  onMouseEnter?: () => void;
  /** Callback when mouse leaves the route line */
  onMouseLeave?: () => void;
  /** Whether the route is interactive - shows pointer cursor on hover (default: true) */
  interactive?: boolean;
};

function MapRoute({
  id: propId,
  coordinates,
  color = "#4285F4",
  width = 3,
  opacity = 0.8,
  dashArray,
  onClick,
  onMouseEnter,
  onMouseLeave,
  interactive = true,
}: MapRouteProps) {
  const { map, isLoaded } = useMap();
  const autoId = useId();
  const id = propId ?? autoId;
  const sourceId = `route-source-${id}`;
  const layerId = `route-layer-${id}`;

  // Add source and layer on mount
  useEffect(() => {
    if (!isLoaded || !map) return;

    map.addSource(sourceId, {
      type: "geojson",
      data: {
        type: "Feature",
        properties: {},
        geometry: { type: "LineString", coordinates: [] },
      },
    });

    map.addLayer({
      id: layerId,
      type: "line",
      source: sourceId,
      layout: { "line-join": "round", "line-cap": "round" },
      paint: {
        "line-color": color,
        "line-width": width,
        "line-opacity": opacity,
        ...(dashArray && { "line-dasharray": dashArray }),
      },
    });

    return () => {
      try {
        if (map.getLayer(layerId)) map.removeLayer(layerId);
        if (map.getSource(sourceId)) map.removeSource(sourceId);
      } catch {
        // ignore
      }
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [isLoaded, map]);

  // When coordinates change, update the source data
  useEffect(() => {
    if (!isLoaded || !map || coordinates.length < 2) return;

    const source = map.getSource(sourceId) as MapLibreGL.GeoJSONSource;
    if (source) {
      source.setData({
        type: "Feature",
        properties: {},
        geometry: { type: "LineString", coordinates },
      });
    }
  }, [isLoaded, map, coordinates, sourceId]);

  useEffect(() => {
    if (!isLoaded || !map || !map.getLayer(layerId)) return;

    map.setPaintProperty(layerId, "line-color", color);
    map.setPaintProperty(layerId, "line-width", width);
    map.setPaintProperty(layerId, "line-opacity", opacity);
    map.setPaintProperty(layerId, "line-dasharray", dashArray);
  }, [isLoaded, map, layerId, color, width, opacity, dashArray]);

  // Handle click and hover events
  useEffect(() => {
    if (!isLoaded || !map || !interactive) return;

    const handleClick = () => {
      onClick?.();
    };
    const handleMouseEnter = () => {
      map.getCanvas().style.cursor = "pointer";
      onMouseEnter?.();
    };
    const handleMouseLeave = () => {
      map.getCanvas().style.cursor = "";
      onMouseLeave?.();
    };

    map.on("click", layerId, handleClick);
    map.on("mouseenter", layerId, handleMouseEnter);
    map.on("mouseleave", layerId, handleMouseLeave);

    return () => {
      map.off("click", layerId, handleClick);
      map.off("mouseenter", layerId, handleMouseEnter);
      map.off("mouseleave", layerId, handleMouseLeave);
    };
  }, [
    isLoaded,
    map,
    layerId,
    onClick,
    onMouseEnter,
    onMouseLeave,
    interactive,
  ]);

  return null;
}

type MapGeoJSONData<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
> =
  | GeoJSON.FeatureCollection<GeoJSON.Geometry, P>
  | GeoJSON.Feature<GeoJSON.Geometry, P>
  | GeoJSON.Geometry
  | string;

type MapFillPaint = NonNullable<MapLibreGL.FillLayerSpecification["paint"]>;
type MapLinePaint = NonNullable<MapLibreGL.LineLayerSpecification["paint"]>;

/** A rendered feature with strongly-typed `properties`. */
type MapGeoJSONFeature<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
> = Omit<MapLibreGL.MapGeoJSONFeature, "properties"> & { properties: P };

/** Event payload passed to MapGeoJSON interaction callbacks. */
type MapGeoJSONEvent<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
> = {
  /** The feature under the cursor, with its typed GeoJSON properties. */
  feature: MapGeoJSONFeature<P>;
  /** Longitude of the cursor at the time of the event. */
  longitude: number;
  /** Latitude of the cursor at the time of the event. */
  latitude: number;
  /** The underlying MapLibre mouse event for advanced use cases. */
  originalEvent: MapLibreGL.MapLayerMouseEvent;
};

type MapGeoJSONProps<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
> = {
  /** GeoJSON data (FeatureCollection, Feature, Geometry) or a URL to fetch it from. */
  data: MapGeoJSONData<P>;
  /** Optional unique identifier prefix for the source/layers. Auto-generated if not provided. */
  id?: string;
  /**
   * Feature property to promote to the feature `id`. Required for hover
   * feature-state (`fillHoverPaint`) and stable `onHover`/`onClick` payloads.
   */
  promoteId?: string;
  /**
   * Paint for the polygon fill layer. Merged on top of a theme-aware monochrome
   * surface tone (`fill-color`). Pass `false` to omit the fill layer entirely
   * (e.g. outlines only).
   */
  fillPaint?: MapFillPaint | false;
  /**
   * Paint for the outline layer. Merged on top of a hairline default
   * (`line-color` = a near-surface neutral, `line-width` = 0.5) for thin
   * separators. Override `line-color` if your container differs, or pass
   * `false` to omit the layer.
   */
  linePaint?: MapLinePaint | false;
  /**
   * Paint merged onto the fill layer for the feature under the cursor, applied
   * as a `case` expression keyed on hover feature-state. Requires `promoteId`.
   */
  fillHoverPaint?: MapFillPaint;
  /** Callback when a feature is clicked. */
  onClick?: (e: MapGeoJSONEvent<P>) => void;
  /** Callback fired when the hovered feature changes; `null` when the cursor leaves. */
  onHover?: (e: MapGeoJSONEvent<P> | null) => void;
  /** Whether features respond to mouse events (default: false). */
  interactive?: boolean;
  /** Optional MapLibre layer id to insert the layers before (z-order control). */
  beforeId?: string;
};

// Monochrome defaults: a neutral-gray fill (hex of the grayscale chart tokens)
// with a fixed near-surface line for thin separators. Colors are hardcoded (not
// theme tokens), tuned for a typical light/dark surface. Override via
// `fillPaint` / `linePaint`.
const GEOJSON_DEFAULT_COLORS = {
  light: { fill: "#d4d4d4", line: "#ffffff" },
  dark: { fill: "#404040", line: "#171717" },
} satisfies Record<Theme, { fill: string; line: string }>;

/**
 * Renders arbitrary GeoJSON as fill + outline layers on the map. Composes like
 * `MapRoute` / `MapArc` — drop it inside `<Map>` (typically with `blank`) for
 * choropleths and region/data maps. For full control over expressions and
 * multiple layers, manage layers directly via `useMap()` instead.
 */
function MapGeoJSON<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
>({
  data,
  id: propId,
  promoteId,
  fillPaint,
  linePaint,
  fillHoverPaint,
  onClick,
  onHover,
  interactive = false,
  beforeId,
}: MapGeoJSONProps<P>) {
  const { map, isLoaded, resolvedTheme } = useMap();
  const autoId = useId();
  const id = propId ?? autoId;
  const sourceId = `geojson-source-${id}`;
  const fillLayerId = `geojson-fill-${id}`;
  const lineLayerId = `geojson-line-${id}`;

  const defaults = GEOJSON_DEFAULT_COLORS[resolvedTheme];

  const showFill = fillPaint !== false;
  const showLine = linePaint !== false;

  const mergedFillPaint = useMemo(
    () =>
      mergeHoverPaint(
        { "fill-color": defaults.fill, ...(fillPaint || {}) },
        fillHoverPaint,
      ),
    [defaults.fill, fillPaint, fillHoverPaint],
  );
  const mergedLinePaint = useMemo(
    () => ({
      "line-color": defaults.line,
      "line-width": 0.5,
      ...(linePaint || {}),
    }),
    [defaults.line, linePaint],
  );
  const latestRef = useRef({ onClick, onHover });
  latestRef.current = { onClick, onHover };

  // Add source on mount.
  useEffect(() => {
    if (!isLoaded || !map) return;

    map.addSource(sourceId, {
      type: "geojson",
      data,
      ...(promoteId ? { promoteId } : {}),
    });

    return () => {
      try {
        if (map.getLayer(lineLayerId)) map.removeLayer(lineLayerId);
        if (map.getLayer(fillLayerId)) map.removeLayer(fillLayerId);
        if (map.getSource(sourceId)) map.removeSource(sourceId);
      } catch {
        // style may be mid-reload
      }
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [isLoaded, map]);

  // Sync data when it changes.
  useEffect(() => {
    if (!isLoaded || !map) return;
    const source = map.getSource(sourceId) as
      | MapLibreGL.GeoJSONSource
      | undefined;
    source?.setData(data as never);
  }, [isLoaded, map, data, sourceId]);

  // Sync layers and paint when visibility or styling changes.
  useEffect(() => {
    if (!isLoaded || !map) return;

    const source = map.getSource(sourceId);
    if (!source) return;

    if (showFill && !map.getLayer(fillLayerId)) {
      map.addLayer(
        {
          id: fillLayerId,
          type: "fill",
          source: sourceId,
          paint: mergedFillPaint,
        },
        beforeId,
      );
    } else if (!showFill && map.getLayer(fillLayerId)) {
      map.removeLayer(fillLayerId);
    }

    if (showLine && !map.getLayer(lineLayerId)) {
      map.addLayer(
        {
          id: lineLayerId,
          type: "line",
          source: sourceId,
          paint: mergedLinePaint,
        },
        beforeId,
      );
    } else if (!showLine && map.getLayer(lineLayerId)) {
      map.removeLayer(lineLayerId);
    }

    if (showFill && map.getLayer(fillLayerId)) {
      for (const [key, value] of Object.entries(mergedFillPaint)) {
        map.setPaintProperty(
          fillLayerId,
          key as keyof MapFillPaint,
          value as never,
        );
      }
    }
    if (showLine && map.getLayer(lineLayerId)) {
      for (const [key, value] of Object.entries(mergedLinePaint)) {
        map.setPaintProperty(
          lineLayerId,
          key as keyof MapLinePaint,
          value as never,
        );
      }
    }
  }, [
    isLoaded,
    map,
    sourceId,
    fillLayerId,
    lineLayerId,
    showFill,
    showLine,
    mergedFillPaint,
    mergedLinePaint,
    beforeId,
  ]);

  // Interaction handlers (bound to the fill layer).
  useEffect(() => {
    if (!isLoaded || !map || !interactive || !showFill) return;

    let hoveredId: string | number | null = null;

    const setHover = (next: string | number | null) => {
      if (next === hoveredId) return;
      const sourceExists = !!map.getSource(sourceId);
      if (hoveredId != null && sourceExists) {
        map.setFeatureState(
          { source: sourceId, id: hoveredId },
          { hover: false },
        );
      }
      hoveredId = next;
      if (next != null && sourceExists) {
        map.setFeatureState({ source: sourceId, id: next }, { hover: true });
      }
    };

    const handleMouseMove = (e: MapLibreGL.MapLayerMouseEvent) => {
      const feature = e.features?.[0];
      if (!feature) return;
      map.getCanvas().style.cursor = "pointer";

      const featureId = feature.id;
      if (featureId === hoveredId) return;
      setHover(featureId ?? null);
      latestRef.current.onHover?.({
        feature: feature as unknown as MapGeoJSONFeature<P>,
        longitude: e.lngLat.lng,
        latitude: e.lngLat.lat,
        originalEvent: e,
      });
    };

    const handleMouseLeave = () => {
      setHover(null);
      map.getCanvas().style.cursor = "";
      latestRef.current.onHover?.(null);
    };

    const handleClick = (e: MapLibreGL.MapLayerMouseEvent) => {
      const feature = e.features?.[0];
      if (!feature) return;
      latestRef.current.onClick?.({
        feature: feature as unknown as MapGeoJSONFeature<P>,
        longitude: e.lngLat.lng,
        latitude: e.lngLat.lat,
        originalEvent: e,
      });
    };

    map.on("mousemove", fillLayerId, handleMouseMove);
    map.on("mouseleave", fillLayerId, handleMouseLeave);
    map.on("click", fillLayerId, handleClick);

    return () => {
      map.off("mousemove", fillLayerId, handleMouseMove);
      map.off("mouseleave", fillLayerId, handleMouseLeave);
      map.off("click", fillLayerId, handleClick);
      setHover(null);
      map.getCanvas().style.cursor = "";
    };
  }, [isLoaded, map, fillLayerId, sourceId, interactive, showFill]);

  return null;
}

/** A single arc to render inside <MapArc data={...}>. */
type MapArcDatum = {
  /** Unique identifier for this arc. Required for hover state tracking and event payloads. */
  id: string | number;
  /** Start coordinate as [longitude, latitude]. */
  from: [number, number];
  /** End coordinate as [longitude, latitude]. */
  to: [number, number];
};

/** Event payload passed to MapArc interaction callbacks. */
type MapArcEvent<T extends MapArcDatum = MapArcDatum> = {
  /** The arc datum that was hovered or clicked. */
  arc: T;
  /** Longitude of the cursor at the time of the event. */
  longitude: number;
  /** Latitude of the cursor at the time of the event. */
  latitude: number;
  /** The underlying MapLibre mouse event for advanced use cases. */
  originalEvent: MapLibreGL.MapMouseEvent;
};

type MapArcLinePaint = NonNullable<MapLibreGL.LineLayerSpecification["paint"]>;
type MapArcLineLayout = NonNullable<
  MapLibreGL.LineLayerSpecification["layout"]
>;

type MapArcProps<T extends MapArcDatum = MapArcDatum> = {
  /** Array of arcs to render. Each arc must have a unique `id`. */
  data: T[];
  /** Optional unique identifier prefix for the arc source/layers. Auto-generated if not provided. */
  id?: string;
  /**
   * How far each arc bows away from a straight line. `0` renders straight
   * lines; higher values bend further. Negative values bend to the opposite
   * side. Arcs are computed as a quadratic Bézier in lng/lat space; the
   * destination longitude is unwrapped relative to the origin so that arcs
   * cross the antimeridian via the shorter great-circle direction. (default: 0.2)
   */
  curvature?: number;
  /** Number of samples used to render each curve. Higher = smoother. (default: 64) */
  samples?: number;
  /**
   * MapLibre paint properties for the arc layer. Merged on top of sensible
   * defaults (`line-color: #4285F4`, `line-width: 2`, `line-opacity: 0.85`).
   * Any value can be a MapLibre expression for per-feature styling, every
   * field on each arc datum (besides `from`/`to`) is exposed via `["get", ...]`.
   */
  paint?: MapArcLinePaint;
  /** MapLibre layout properties for the arc layer. Defaults to rounded joins/caps. */
  layout?: MapArcLineLayout;
  /**
   * Paint properties applied to the arc currently under the cursor. Each key
   * is merged into `paint` as a `case` expression keyed on per-feature hover
   * state, so only the hovered arc changes appearance.
   */
  hoverPaint?: MapArcLinePaint;
  /** Callback when an arc is clicked. */
  onClick?: (e: MapArcEvent<T>) => void;
  /**
   * Callback fired when the hovered arc changes. Receives the cursor's
   * lng/lat at the moment of entry, and `null` when the cursor leaves the
   * last hovered arc.
   */
  onHover?: (e: MapArcEvent<T> | null) => void;
  /** Whether arcs respond to mouse events (default: true). */
  interactive?: boolean;
  /** Optional MapLibre layer id to insert the arc layers before (z-order control). */
  beforeId?: string;
};

const DEFAULT_ARC_CURVATURE = 0.2;
const DEFAULT_ARC_SAMPLES = 64;
const ARC_HIT_MIN_WIDTH = 12;
const ARC_HIT_PADDING = 6;

const DEFAULT_ARC_PAINT: MapArcLinePaint = {
  "line-color": "#4285F4",
  "line-width": 2,
  "line-opacity": 0.85,
};

const DEFAULT_ARC_LAYOUT: MapArcLineLayout = {
  "line-join": "round",
  "line-cap": "round",
};

function buildArcCoordinates(
  from: [number, number],
  to: [number, number],
  curvature: number,
  samples: number,
): [number, number][] {
  const [x0, y0] = from;
  const [xTo, y2] = to;
  // Unwrap the destination longitude so |dx| <= 180. This makes arcs that
  // straddle the antimeridian (e.g. Tokyo -> San Francisco) bow the short way
  // across the Pacific instead of the long way around the globe. Resulting
  // longitudes may fall outside [-180, 180]; MapLibre renders them correctly
  // on the globe projection, and on mercator when world copies are enabled.
  const rawDx = xTo - x0;
  const x2 = rawDx > 180 ? xTo - 360 : rawDx < -180 ? xTo + 360 : xTo;
  const dx = x2 - x0;
  const dy = y2 - y0;
  const distance = Math.hypot(dx, dy);

  if (distance === 0 || curvature === 0) return [from, [x2, y2]];

  const mx = (x0 + x2) / 2;
  const my = (y0 + y2) / 2;
  const nx = -dy / distance;
  const ny = dx / distance;
  const offset = distance * curvature;
  const cx = mx + nx * offset;
  const cy = my + ny * offset;

  const points: [number, number][] = [];
  const segments = Math.max(2, Math.floor(samples));
  for (let i = 0; i <= segments; i += 1) {
    const t = i / segments;
    const inv = 1 - t;
    const x = inv * inv * x0 + 2 * inv * t * cx + t * t * x2;
    const y = inv * inv * y0 + 2 * inv * t * cy + t * t * y2;
    points.push([x, y]);
  }
  return points;
}

function MapArc<T extends MapArcDatum = MapArcDatum>({
  data,
  id: propId,
  curvature = DEFAULT_ARC_CURVATURE,
  samples = DEFAULT_ARC_SAMPLES,
  paint,
  layout,
  hoverPaint,
  onClick,
  onHover,
  interactive = true,
  beforeId,
}: MapArcProps<T>) {
  const { map, isLoaded } = useMap();
  const autoId = useId();
  const id = propId ?? autoId;
  const sourceId = `arc-source-${id}`;
  const layerId = `arc-layer-${id}`;
  const hitLayerId = `arc-hit-layer-${id}`;

  const mergedPaint = useMemo(
    () => mergeHoverPaint({ ...DEFAULT_ARC_PAINT, ...paint }, hoverPaint),
    [paint, hoverPaint],
  );
  const mergedLayout = useMemo(
    () => ({ ...DEFAULT_ARC_LAYOUT, ...layout }),
    [layout],
  );

  const hitWidth = useMemo(() => {
    const w = paint?.["line-width"] ?? DEFAULT_ARC_PAINT["line-width"];
    const base = typeof w === "number" ? w : ARC_HIT_MIN_WIDTH;
    return Math.max(base + ARC_HIT_PADDING, ARC_HIT_MIN_WIDTH);
  }, [paint]);

  const geoJSON = useMemo<GeoJSON.FeatureCollection<GeoJSON.LineString>>(
    () => ({
      type: "FeatureCollection",
      features: data.map((arc) => {
        const { from, to, ...properties } = arc;
        return {
          type: "Feature",
          properties,
          geometry: {
            type: "LineString",
            coordinates: buildArcCoordinates(from, to, curvature, samples),
          },
        };
      }),
    }),
    [data, curvature, samples],
  );

  const latestRef = useRef({ data, onClick, onHover });
  latestRef.current = { data, onClick, onHover };

  // Add source and layers on mount.
  useEffect(() => {
    if (!isLoaded || !map) return;

    map.addSource(sourceId, {
      type: "geojson",
      data: geoJSON,
      promoteId: "id",
    });

    map.addLayer(
      {
        id: hitLayerId,
        type: "line",
        source: sourceId,
        layout: DEFAULT_ARC_LAYOUT,
        paint: {
          "line-color": "rgba(0, 0, 0, 0)",
          "line-width": hitWidth,
          "line-opacity": 1,
        },
      },
      beforeId,
    );

    map.addLayer(
      {
        id: layerId,
        type: "line",
        source: sourceId,
        layout: mergedLayout,
        paint: mergedPaint,
      },
      beforeId,
    );

    return () => {
      try {
        if (map.getLayer(layerId)) map.removeLayer(layerId);
        if (map.getLayer(hitLayerId)) map.removeLayer(hitLayerId);
        if (map.getSource(sourceId)) map.removeSource(sourceId);
      } catch {
        // ignore
      }
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [isLoaded, map]);

  // Sync features when data / curvature / samples change.
  useEffect(() => {
    if (!isLoaded || !map) return;
    const source = map.getSource(sourceId) as
      | MapLibreGL.GeoJSONSource
      | undefined;
    source?.setData(geoJSON);
  }, [isLoaded, map, geoJSON, sourceId]);

  // Sync paint/layout when they change.
  useEffect(() => {
    if (!isLoaded || !map || !map.getLayer(layerId)) return;
    for (const [key, value] of Object.entries(mergedPaint)) {
      map.setPaintProperty(
        layerId,
        key as keyof MapArcLinePaint,
        value as never,
      );
    }
    for (const [key, value] of Object.entries(mergedLayout)) {
      map.setLayoutProperty(
        layerId,
        key as keyof MapArcLineLayout,
        value as never,
      );
    }
    if (map.getLayer(hitLayerId)) {
      map.setPaintProperty(hitLayerId, "line-width", hitWidth);
    }
  }, [isLoaded, map, layerId, hitLayerId, mergedPaint, mergedLayout, hitWidth]);

  // Interaction handlers
  useEffect(() => {
    if (!isLoaded || !map || !interactive) return;

    let hoveredId: string | number | null = null;

    const setHover = (next: string | number | null) => {
      if (next === hoveredId) return;
      const sourceExists = !!map.getSource(sourceId);
      if (hoveredId != null && sourceExists) {
        map.setFeatureState(
          { source: sourceId, id: hoveredId },
          { hover: false },
        );
      }
      hoveredId = next;
      if (next != null && sourceExists) {
        map.setFeatureState({ source: sourceId, id: next }, { hover: true });
      }
    };

    const findArc = (featureId: string | number | undefined) =>
      featureId == null
        ? undefined
        : latestRef.current.data.find(
            (arc) => String(arc.id) === String(featureId),
          );

    const handleMouseMove = (e: MapLibreGL.MapLayerMouseEvent) => {
      const featureId = e.features?.[0]?.id as string | number | undefined;
      if (featureId == null || featureId === hoveredId) return;

      setHover(featureId);
      map.getCanvas().style.cursor = "pointer";

      const arc = findArc(featureId);
      if (arc) {
        latestRef.current.onHover?.({
          arc: arc as T,
          longitude: e.lngLat.lng,
          latitude: e.lngLat.lat,
          originalEvent: e,
        });
      }
    };

    const handleMouseLeave = () => {
      setHover(null);
      map.getCanvas().style.cursor = "";
      latestRef.current.onHover?.(null);
    };

    const handleClick = (e: MapLibreGL.MapLayerMouseEvent) => {
      const arc = findArc(e.features?.[0]?.id as string | number | undefined);
      if (!arc) return;
      latestRef.current.onClick?.({
        arc: arc as T,
        longitude: e.lngLat.lng,
        latitude: e.lngLat.lat,
        originalEvent: e,
      });
    };

    map.on("mousemove", hitLayerId, handleMouseMove);
    map.on("mouseleave", hitLayerId, handleMouseLeave);
    map.on("click", hitLayerId, handleClick);

    return () => {
      map.off("mousemove", hitLayerId, handleMouseMove);
      map.off("mouseleave", hitLayerId, handleMouseLeave);
      map.off("click", hitLayerId, handleClick);
      setHover(null);
      map.getCanvas().style.cursor = "";
    };
  }, [isLoaded, map, hitLayerId, sourceId, interactive]);

  return null;
}

type MapClusterLayerProps<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
> = {
  /** GeoJSON FeatureCollection data or URL to fetch GeoJSON from */
  data: string | GeoJSON.FeatureCollection<GeoJSON.Point, P>;
  /** Maximum zoom level to cluster points on (default: 14) */
  clusterMaxZoom?: number;
  /** Radius of each cluster when clustering points in pixels (default: 50) */
  clusterRadius?: number;
  /** Colors for cluster circles: [small, medium, large] based on point count (default: ["#22c55e", "#eab308", "#ef4444"]) */
  clusterColors?: [string, string, string];
  /** Point count thresholds for color/size steps: [medium, large] (default: [100, 750]) */
  clusterThresholds?: [number, number];
  /** Color for unclustered individual points (default: "#3b82f6") */
  pointColor?: string;
  /** Callback when an unclustered point is clicked */
  onPointClick?: (
    feature: GeoJSON.Feature<GeoJSON.Point, P>,
    coordinates: [number, number],
  ) => void;
  /** Callback when a cluster is clicked. If not provided, zooms into the cluster */
  onClusterClick?: (
    clusterId: number,
    coordinates: [number, number],
    pointCount: number,
  ) => void;
};

const DEFAULT_CLUSTER_COLORS: [string, string, string] = [
  "#22c55e",
  "#eab308",
  "#ef4444",
];
const DEFAULT_CLUSTER_THRESHOLDS: [number, number] = [100, 750];

function MapClusterLayer<
  P extends GeoJSON.GeoJsonProperties = GeoJSON.GeoJsonProperties,
>({
  data,
  clusterMaxZoom = 14,
  clusterRadius = 50,
  clusterColors = DEFAULT_CLUSTER_COLORS,
  clusterThresholds = DEFAULT_CLUSTER_THRESHOLDS,
  pointColor = "#3b82f6",
  onPointClick,
  onClusterClick,
}: MapClusterLayerProps<P>) {
  const { map, isLoaded } = useMap();
  const id = useId();
  const sourceId = `cluster-source-${id}`;
  const clusterLayerId = `clusters-${id}`;
  const clusterCountLayerId = `cluster-count-${id}`;
  const unclusteredLayerId = `unclustered-point-${id}`;

  const stylePropsRef = useRef({
    clusterColors,
    clusterThresholds,
    pointColor,
  });

  // Add source and layers on mount
  useEffect(() => {
    if (!isLoaded || !map) return;

    // Add clustered GeoJSON source
    map.addSource(sourceId, {
      type: "geojson",
      data,
      cluster: true,
      clusterMaxZoom,
      clusterRadius,
    });

    // Add cluster circles layer
    map.addLayer({
      id: clusterLayerId,
      type: "circle",
      source: sourceId,
      filter: ["has", "point_count"],
      paint: {
        "circle-color": [
          "step",
          ["get", "point_count"],
          clusterColors[0],
          clusterThresholds[0],
          clusterColors[1],
          clusterThresholds[1],
          clusterColors[2],
        ],
        "circle-radius": [
          "step",
          ["get", "point_count"],
          20,
          clusterThresholds[0],
          30,
          clusterThresholds[1],
          40,
        ],
        "circle-stroke-width": 1,
        "circle-stroke-color": "#fff",
        "circle-opacity": 0.85,
      },
    });

    // Add cluster count text layer
    map.addLayer({
      id: clusterCountLayerId,
      type: "symbol",
      source: sourceId,
      filter: ["has", "point_count"],
      layout: {
        "text-field": "{point_count_abbreviated}",
        "text-font": ["Open Sans"],
        "text-size": 12,
      },
      paint: {
        "text-color": "#fff",
      },
    });

    // Add unclustered point layer
    map.addLayer({
      id: unclusteredLayerId,
      type: "circle",
      source: sourceId,
      filter: ["!", ["has", "point_count"]],
      paint: {
        "circle-color": pointColor,
        "circle-radius": 5,
        "circle-stroke-width": 2,
        "circle-stroke-color": "#fff",
      },
    });

    return () => {
      try {
        if (map.getLayer(clusterCountLayerId))
          map.removeLayer(clusterCountLayerId);
        if (map.getLayer(unclusteredLayerId))
          map.removeLayer(unclusteredLayerId);
        if (map.getLayer(clusterLayerId)) map.removeLayer(clusterLayerId);
        if (map.getSource(sourceId)) map.removeSource(sourceId);
      } catch {
        // ignore
      }
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [isLoaded, map, sourceId]);

  // Update source data when data prop changes (only for non-URL data)
  useEffect(() => {
    if (!isLoaded || !map || typeof data === "string") return;

    const source = map.getSource(sourceId) as MapLibreGL.GeoJSONSource;
    if (source) {
      source.setData(data);
    }
  }, [isLoaded, map, data, sourceId]);

  // Update layer styles when props change
  useEffect(() => {
    if (!isLoaded || !map) return;

    const prev = stylePropsRef.current;
    const colorsChanged =
      prev.clusterColors !== clusterColors ||
      prev.clusterThresholds !== clusterThresholds;

    // Update cluster layer colors and sizes
    if (map.getLayer(clusterLayerId) && colorsChanged) {
      map.setPaintProperty(clusterLayerId, "circle-color", [
        "step",
        ["get", "point_count"],
        clusterColors[0],
        clusterThresholds[0],
        clusterColors[1],
        clusterThresholds[1],
        clusterColors[2],
      ]);
      map.setPaintProperty(clusterLayerId, "circle-radius", [
        "step",
        ["get", "point_count"],
        20,
        clusterThresholds[0],
        30,
        clusterThresholds[1],
        40,
      ]);
    }

    // Update unclustered point layer color
    if (map.getLayer(unclusteredLayerId) && prev.pointColor !== pointColor) {
      map.setPaintProperty(unclusteredLayerId, "circle-color", pointColor);
    }

    stylePropsRef.current = { clusterColors, clusterThresholds, pointColor };
  }, [
    isLoaded,
    map,
    clusterLayerId,
    unclusteredLayerId,
    clusterColors,
    clusterThresholds,
    pointColor,
  ]);

  // Handle click events
  useEffect(() => {
    if (!isLoaded || !map) return;

    // Cluster click handler - zoom into cluster
    const handleClusterClick = async (
      e: MapLibreGL.MapMouseEvent & {
        features?: MapLibreGL.MapGeoJSONFeature[];
      },
    ) => {
      const features = map.queryRenderedFeatures(e.point, {
        layers: [clusterLayerId],
      });
      if (!features.length) return;

      const feature = features[0];
      const clusterId = feature.properties?.cluster_id as number;
      const pointCount = feature.properties?.point_count as number;
      const coordinates = (feature.geometry as GeoJSON.Point).coordinates as [
        number,
        number,
      ];

      if (onClusterClick) {
        onClusterClick(clusterId, coordinates, pointCount);
      } else {
        // Default behavior: zoom to cluster expansion zoom
        const source = map.getSource(sourceId) as MapLibreGL.GeoJSONSource;
        const zoom = await source.getClusterExpansionZoom(clusterId);
        map.easeTo({
          center: coordinates,
          zoom,
        });
      }
    };

    // Unclustered point click handler
    const handlePointClick = (
      e: MapLibreGL.MapMouseEvent & {
        features?: MapLibreGL.MapGeoJSONFeature[];
      },
    ) => {
      if (!onPointClick || !e.features?.length) return;

      const feature = e.features[0];
      const coordinates = (
        feature.geometry as GeoJSON.Point
      ).coordinates.slice() as [number, number];

      // Handle world copies
      while (Math.abs(e.lngLat.lng - coordinates[0]) > 180) {
        coordinates[0] += e.lngLat.lng > coordinates[0] ? 360 : -360;
      }

      onPointClick(
        feature as unknown as GeoJSON.Feature<GeoJSON.Point, P>,
        coordinates,
      );
    };

    // Cursor style handlers
    const handleMouseEnterCluster = () => {
      map.getCanvas().style.cursor = "pointer";
    };
    const handleMouseLeaveCluster = () => {
      map.getCanvas().style.cursor = "";
    };
    const handleMouseEnterPoint = () => {
      if (onPointClick) {
        map.getCanvas().style.cursor = "pointer";
      }
    };
    const handleMouseLeavePoint = () => {
      map.getCanvas().style.cursor = "";
    };

    map.on("click", clusterLayerId, handleClusterClick);
    map.on("click", unclusteredLayerId, handlePointClick);
    map.on("mouseenter", clusterLayerId, handleMouseEnterCluster);
    map.on("mouseleave", clusterLayerId, handleMouseLeaveCluster);
    map.on("mouseenter", unclusteredLayerId, handleMouseEnterPoint);
    map.on("mouseleave", unclusteredLayerId, handleMouseLeavePoint);

    return () => {
      map.off("click", clusterLayerId, handleClusterClick);
      map.off("click", unclusteredLayerId, handlePointClick);
      map.off("mouseenter", clusterLayerId, handleMouseEnterCluster);
      map.off("mouseleave", clusterLayerId, handleMouseLeaveCluster);
      map.off("mouseenter", unclusteredLayerId, handleMouseEnterPoint);
      map.off("mouseleave", unclusteredLayerId, handleMouseLeavePoint);
    };
  }, [
    isLoaded,
    map,
    clusterLayerId,
    unclusteredLayerId,
    sourceId,
    onClusterClick,
    onPointClick,
  ]);

  return null;
}

export {
  Map,
  useMap,
  MapMarker,
  MarkerContent,
  MarkerPopup,
  MarkerTooltip,
  MarkerLabel,
  MapPopup,
  MapControls,
  MapRoute,
  MapArc,
  MapGeoJSON,
  MapClusterLayer,
};

export type { MapRef, MapViewport, MapArcDatum, MapArcEvent, MapGeoJSONEvent };