# -*- coding: utf-8 -*-
# Copradiusight (c) 2014, Vispy Development Team.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.


"""
Simple ellipse visual based on PolygonVisual
"""

from __future__ import division

import numpy as np
from ..color import Color
from .polygon import PolygonVisual


class RectangleVisual(PolygonVisual):
    """
    Displays a 2D rectangle with optional rounded corners

    Parameters
    ----------
    pos :  array
        Center of the rectangle
    color : instance of Color
        The fill color to use.
    border_color : instance of Color
        The border color to use.
    height : float
        Length of the rectangle along y-axis
        Defaults to 1.0
    width : float
        Length of the rectangle along x-axis
        Defaults to 1.0
    radius : float | array
        Radii of curvatures of corners in clockwise order from top-left
        Defaults to 0.
    """
    def __init__(self, pos=None, color='black', border_color=None,
                 height=1.0, width=1.0, radius=[0., 0., 0., 0.], **kwargs):
        super(RectangleVisual, self).__init__()
        self.mesh.mode = 'triangle_fan'
        self._vertices = None
        self._pos = pos
        self._color = Color(color)
        self._border_color = Color(border_color)
        self._height = height
        self._width = width
        self.radius = radius
        self._update()

    def _generate_vertices(self, pos, radius, height, width):

        half_height = self._height / 2.
        half_width = self._width / 2.
        hw = min(half_height, half_width)

        num_segments = (radius / hw * 500.).astype(int)

        bias1 = np.full(4, half_width) - radius
        bias2 = np.full(4, half_height) - radius

        corner1 = np.empty([num_segments[0]+1, 3], dtype=np.float32)
        corner2 = np.empty([num_segments[1]+1, 3], dtype=np.float32)
        corner3 = np.empty([num_segments[2]+1, 3], dtype=np.float32)
        corner4 = np.empty([num_segments[3]+1, 3], dtype=np.float32)

        start_angle = 0.
        end_angle = np.pi / 2.

        theta = np.linspace(end_angle, start_angle, num_segments[0]+1)

        corner1[:, 0] = pos[0] - bias1[0] - radius[0] * np.sin(theta)
        corner1[:, 1] = pos[1] - bias2[0] - radius[0] * np.cos(theta)
        corner1[:, 2] = 0

        theta = np.linspace(start_angle, end_angle, num_segments[1]+1)

        corner2[:, 0] = pos[0] + bias1[1] + radius[1] * np.sin(theta)
        corner2[:, 1] = pos[1] - bias2[1] - radius[1] * np.cos(theta)
        corner2[:, 2] = 0

        theta = np.linspace(end_angle, start_angle, num_segments[2]+1)

        corner3[:, 0] = pos[0] + bias1[2] + radius[2] * np.sin(theta)
        corner3[:, 1] = pos[1] + bias2[2] + radius[2] * np.cos(theta)
        corner3[:, 2] = 0

        theta = np.linspace(start_angle, end_angle, num_segments[3]+1)

        corner4[:, 0] = pos[0] - bias1[3] - radius[3] * np.sin(theta)
        corner4[:, 1] = pos[1] + bias2[3] + radius[3] * np.cos(theta)
        corner4[:, 2] = 0

        output = np.concatenate(([[pos[0], pos[1], 0.]],
                                 [[pos[0] - half_width, pos[1], 0.]],
                                 corner1,
                                 [[pos[0], pos[1] - half_height, 0.]],
                                 corner2,
                                 [[pos[0] + half_width, pos[1], 0.]],
                                 corner3,
                                 [[pos[0], pos[1] + half_height, 0.]],
                                 corner4,
                                 [[pos[0] - half_width, pos[1], 0.]]))

        self._vertices = np.array(output, dtype=np.float32)

    @property
    def height(self):
        """ The height of the rectangle.
        """
        return self._height

    @height.setter
    def height(self, height):
        if height <= 0.:
            raise ValueError('Height must be positive')
        self._height = height
        self._update()

    @property
    def width(self):
        """ The width of the rectangle.
        """
        return self._width

    @width.setter
    def width(self, width):
        if width <= 0.:
            raise ValueError('Width must be positive')
        self._width = width
        self._update()

    @property
    def radius(self):
        """ The radius of curvature of rounded corners.
        """
        return self._radius

    @radius.setter
    def radius(self, radius):
        half_height = self._height / 2.
        half_width = self._width / 2.
        hw = min(half_height, half_width)

        if isinstance(radius, (list, tuple)):
            if len(radius) != 4:
                raise ValueError("radius must be float or 4 value tuple/list"
                                 " (got %s of length %d)" % (type(radius),
                                                             len(radius)))

            if (radius > np.full(4, hw)).all():
                raise ValueError('Radius of curvature cannot be greater than\
                                  half of min(width, height)')
            radius = np.array(radius, dtype=np.float32)

        else:
            if radius > hw:
                raise ValueError('Radius of curvature cannot be greater than\
                                  half of min(width, height)')
            radius = np.full(4, radius)

        self._radius = radius
        self._update()

    def _update(self):
        if self._pos is None:
            return
        self._generate_vertices(pos=self._pos, radius=self._radius,
                                height=self._height, width=self._width)
        
        if not self._color.is_blank:
            self.mesh.set_data(vertices=self._vertices, 
                               color=self._color.rgba)
        if not self._border_color.is_blank:
            self.border.set_data(pos=self._vertices[1:, ..., :2],
                                 color=self._border_color.rgba)

        self.update()