import svg
from typing import Iterator, NamedTuple

import numpy as np

RGen = np.random.default_rng()


class Point(NamedTuple):
    x: float
    y: float


def iter_body_points(size: int) -> Iterator[Point]:
    n_points = RGen.integers(3, 12)  # how many points do we want?
    angle_step = (
        np.pi * 2 / n_points
    )  # step used to place each point at equal distances
    for point_number in range(1, n_points + 1):
        pull = 0.75 * RGen.random() * 0.25
        angle = point_number * angle_step
        x = size + np.cos(angle) * size * pull
        y = size + np.sin(angle) * size * pull
        yield Point(x, y)


def spline(points: list[Point], body_tension: int) -> Iterator[svg.PathData]:
    """
    https://github.com/georgedoescode/splinejs
    """
    yield svg.MoveTo(*points[-1])
    first_point = points[0]
    second_point = points[1]
    points.insert(0, points[-1])
    points.insert(0, points[-2])
    points.append(first_point)
    points.append(second_point)
    for p0, p1, p2, p3 in zip(points, points[1:], points[2:], points[3:]):
        yield svg.CubicBezier(
            x1=p1.x + (p2.x - p0.x) / 6 * body_tension,
            y1=p1.y + (p2.y - p0.y) / 6 * body_tension,
            x2=p2.x - (p3.x - p1.x) / 6 * body_tension,
            y2=p2.y - (p3.y - p1.y) / 6 * body_tension,
            x=p2.x,
            y=p2.y,
        )


def blob(x, y, c, s, body_tension: int = 1) -> svg.Path:
    points = list(iter_body_points(s))
    return svg.Path(
        d=list(spline(points, body_tension)),
        fill=c,
        stroke="#000000",
        stroke_width=2,
        transform=[svg.Translate(x-s, y-s)],
    )