"""Lightweight MapVisualizer: minimal display helper using OpenCV if available."""
from typing import Optional, Callable

try:
    import cv2
    CV2_AVAILABLE = True
except Exception:
    cv2 = None
    CV2_AVAILABLE = False

class MapVisualizer:
    def __init__(self, engine):
        self.engine = engine
        self.callback_on_click: Optional[Callable[[float, float], None]] = None

    def set_click_callback(self, callback: Callable[[float, float], None]):
        self.callback_on_click = callback

    def show_pil_image(self, pil_image):
        if pil_image is None:
            return
        if CV2_AVAILABLE:
            import numpy as np
            img = pil_image.convert('RGB')
            arr = cv2.cvtColor(np.array(img), cv2.COLOR_RGB2BGR)
            cv2.imshow('Map', arr)
            cv2.waitKey(0)
            cv2.destroyAllWindows()
        else:
            # Fallback: save temp file and open with default image viewer
            import tempfile, os
            tmp = tempfile.NamedTemporaryFile(delete=False, suffix='.png')
            pil_image.save(tmp.name)
            tmp.close()
            if os.name == 'nt':
                os.startfile(tmp.name)  # type: ignore
            else:
                try:
                    import webbrowser
                    webbrowser.open('file://' + tmp.name)
                except Exception:
                    pass

    def show_point(self, lat: float, lon: float, zoom: int = 12, tiles_radius: int = 1):
        img = self.engine.get_image_for_point(lat, lon, zoom, tiles_radius=tiles_radius)
        self.show_pil_image(img)