import numpy as np

from vedo import merge
from vedo.shapes import Line, Sphere, Text
from vedo.utils import precision, mag

from brainrender.actor import Actor


def ruler(p1, p2, unit_scale=1, units=None, s=50):
    """ 
        Creates a ruler showing the distance between two points.
        The ruler is composed of a line between the points and 
        a text indicating the distance.

        :param p1: list, np.ndarray with coordinates of first point
        :param p2: list, np.ndarray with coordinates of second point
        :param unit_scale: float. To scale the units (e.g. show mm instead of µm)
        :param units: str, name of unit (e.g. 'mm')
        :param s: float size of text

    """
    actors = []

    # Make two line segments
    midpoint = np.array([(x + y) / 2 for x, y in zip(p1, p2)])
    gap1 = ((midpoint - p1) * 0.8) + p1
    gap2 = ((midpoint - p2) * 0.8) + p2

    actors.append(Line(p1, gap1, lw=200))
    actors.append(Line(gap2, p2, lw=200))

    # Add label
    if units is None:  # pragma: no cover
        units = ""  # pragma: no cover
    dist = mag(p2 - p1) * unit_scale
    label = precision(dist, 3) + " " + units
    lbl = Text(label, pos=midpoint, s=s + 100, justify="center")
    lbl.SetOrientation([0, 0, 180])
    actors.append(lbl)

    # Add spheres add end
    actors.append(Sphere(p1, r=s, c=[0.3, 0.3, 0.3]))
    actors.append(Sphere(p2, r=s, c=[0.3, 0.3, 0.3]))

    act = Actor(merge(*actors), name="Ruler", br_class="Ruler")
    act.c((0.3, 0.3, 0.3)).alpha(1).lw(2)
    return act


def ruler_from_surface(
    p1, root, unit_scale=1, axis=1, units=None, s=50
) -> Actor:
    """
        Creates a ruler between a point and the brain's surface
        :param p1: list, np.ndarray with coordinates of  point
        :param root: mesh or actor with brain's root
        :param axis: int, index of axis along which distance is computed
        :param unit_scale: float. To scale the units (e.g. show mm instead of µm)
        :param units: str, name of unit (e.g. 'mm')
        :param s: float size of text
    """
    # Get point on brain surface
    p2 = p1.copy()
    p2[axis] = 0  # zero the choosen coordinate

    pts = root.mesh.intersectWithLine(p1, p2)
    surface_point = pts[0]

    return ruler(p1, surface_point, unit_scale=unit_scale, units=units, s=s)
