from typing import Optional

import pygame

from path import Path
from vec import Vec2


class MapDisplay:
    PATH_WIDTH = 5
    SEGMENT_SIZE = 20
    MIN_SEGMENT_LENGTH = 5

    def __init__(self,
                 surf: pygame.Surface,
                 min_lon: float,
                 max_lon: float,
                 min_lat: float,
                 max_lat: float):
        self.surf: pygame.Surface = surf
        self.min_lon: float = min_lon
        self.max_lon: float = max_lon
        self.min_lat: float = min_lat
        self.max_lat: float = max_lat

    def real_to_screen(self, lon: float, lat: float) -> tuple[float, float]:
        x = (lon - self.min_lon) / (self.max_lon - self.min_lon)
        y = (lat - self.min_lat) / (self.max_lat - self.min_lat)

        w, h = self.surf.get_size()
        return x * w, h - y * h

    def draw_path(self, path: Path) -> None:
        self.draw_colored_path(path, None)

    def draw_colored_path(self, path: Path, colors: Optional[list[tuple[int, int, int]]] = None) -> None:
        for i, pt in enumerate(path.points):
            lon = pt.x
            lat = pt.y
            x, y = self.real_to_screen(lon, lat)
            col = (255, 255, 255) if colors is None else colors[i]
            pygame.draw.circle(self.surf, col, (x, y), self.PATH_WIDTH)

    def draw_segment(self, path: Path, start_i: int, end_i: int) -> None:
        if end_i - start_i < self.MIN_SEGMENT_LENGTH:
            return

        points = []
        for i in range(start_i, end_i):
            pt = path.points[i]
            pt = Vec2(*self.real_to_screen(pt.x, pt.y))
            n = path.normals[i]
            n = Vec2(n.x, -n.y)
            pt1 = pt + n * self.SEGMENT_SIZE
            pt2 = pt - n * self.SEGMENT_SIZE
            points.insert(0, (pt1.x, pt1.y))
            points.append((pt2.x, pt2.y))

        pygame.draw.lines(self.surf, (255, 255, 255), True, points)