# The MIT License (MIT)
#
# Copyright (c) 2019-2020 Roy Hooper
# Copyright (c) 2020 Kattni Rembor for Adafruit Industries
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`adafruit_led_animation.animation.comet`
================================================================================

Comet animation for CircuitPython helper library for LED animations.

* Author(s): Roy Hooper, Kattni Rembor

Implementation Notes
--------------------

**Hardware:**

* `Adafruit NeoPixels <https://www.adafruit.com/category/168>`_
* `Adafruit DotStars <https://www.adafruit.com/category/885>`_

**Software and Dependencies:**

* Adafruit CircuitPython firmware for the supported boards:
  https://circuitpython.org/downloads


"""

from adafruit_led_animation.animation import Animation
from adafruit_led_animation.color import BLACK


class Comet(Animation):
    """
    A comet animation.

    :param pixel_object: The initialised LED object.
    :param float speed: Animation speed in seconds, e.g. ``0.1``.
    :param color: Animation color in ``(r, g, b)`` tuple, or ``0x000000`` hex format.
    :param int tail_length: The length of the comet. Defaults to 25% of the length of the
                            ``pixel_object``. Automatically compensates for a minimum of 2 and a
                            maximum of the length of the ``pixel_object``.
    :param bool reverse: Animates the comet in the reverse order. Defaults to ``False``.
    :param bool bounce: Comet will bounce back and forth. Defaults to ``True``.
    """

    # pylint: disable=too-many-arguments
    def __init__(
        self,
        pixel_object,
        speed,
        color,
        tail_length=0,
        reverse=False,
        bounce=False,
        name=None,
    ):
        if tail_length == 0:
            tail_length = len(pixel_object) // 4
        else:
            tail_length = max(2, min(tail_length, len(pixel_object)))
        self._tail_length = tail_length
        self._color_step = 0.9 / tail_length
        self._color_offset = 0.1
        self._comet_colors = None
        self._reverse_comet_colors = None
        self._initial_reverse = reverse
        self.reverse = reverse
        self.bounce = bounce
        self._computed_color = color
        self._generator = self._comet_generator()
        super().__init__(pixel_object, speed, color, name=name)

    on_cycle_complete_supported = True

    def _recompute_color(self, color):
        pass

    def __recompute_color(self, color):
        self._comet_colors = [BLACK] + [
            [
                int(color[rgb] * ((n * self._color_step) + self._color_offset))
                for rgb in range(len(color))
            ]
            for n in range(self._tail_length - 1)
        ]
        self._reverse_comet_colors = list(reversed(self._comet_colors))
        self._computed_color = color

    def _get_range(self, num_pixels):
        if self.reverse:
            return range(num_pixels, -self._tail_length - 1, -1)
        return range(-self._tail_length, num_pixels + 1)

    def _comet_generator(self):
        num_pixels = len(self.pixel_object)
        cycle_passes = 0
        while True:
            if self._color != self._computed_color or not self._comet_colors:
                self.__recompute_color(self._color)
            colors = self._reverse_comet_colors if self.reverse else self._comet_colors
            for start in self._get_range(num_pixels):

                if start + self._tail_length < num_pixels:
                    end = self._tail_length
                else:
                    end = num_pixels - start
                if start <= 0:
                    num_visible = self._tail_length + start
                    self.pixel_object[0:num_visible] = colors[
                        self._tail_length - num_visible :
                    ]
                else:
                    self.pixel_object[start : start + end] = colors[0:end]
                yield
            cycle_passes += 1
            if self.bounce:
                self.reverse = not self.reverse
            if not self.bounce or cycle_passes == 2:
                self.cycle_complete = True
                cycle_passes = 0

    def draw(self):
        next(self._generator)

    def reset(self):
        """
        Resets to the first color.
        """
        self._generator = self._comet_generator()
        self.reverse = self._initial_reverse