"""PR11 Drawing."""


# TODO: You should create the exception classes here.


class FigureDoesNotExistError(Exception):
    """IF figure does not exist"""

    pass


class DrawingFullError(Exception):
    """IF drawing figures are full."""

    pass


class DrawingCanvas:
    """A drawing canvas where one can draw some simple figures."""

    def __init__(self, max_figures: int, author: str):
        """
        Initialize the canvas.

        You should initialize your variables (properties) here.

        :param max_figures: The maxim amount of figures on the drawing.
        :param author: The author of the drawing.
        """
        self.max_figures = max_figures
        self.author = author
        self.figures = []
        self.figures_count = 0

    def draw_figure(self, figure: str) -> str or None:
        """
        Draw a new figure.

        If the drawing has already reached maximum amount of figures
        don't add this figure and throw a DrawingFullError with the
        message "The drawing is full".

        There can be only unique figures on the drawing.
        This means that there is no way that, for example, two or more
        circles are on the drawing.
        In this case method does nothing and returns None.

        :param figure: A figure to draw.
        :return: The newly drawn figure.
        """
        self.figures_count += 1
        if self.figures_count > self.max_figures:
            self.figures_count -= 1
            raise DrawingFullError("The drawing is full")
        for i in self.figures:
            if i == figure:
                self.figures_count =- 1
                return None
        return figure

    def erase_figure(self, figure: str) -> str:
        """
        Erase the figure.

        If there is no such figure throw a FigureDoesNotExistError
        with the message "There is no such figure on the drawing".

        :return: The erased figure.
        """
        try:
            self.figures.index(figure)
        except ValueError:
            raise FigureDoesNotExistError("There is no such figure on the drawing")
        self.figures.remove(figure)
        self.figures_count -= 1
        return figure

    def is_empty(self) -> bool:
        """
        Find out whether the drawing is empty or not.

        Empty means there are not any figures drawn on it.

        :return: True if empty, False otherwise.
        """
        if self.figures == []:
            return True
        else:
            return False

    def size(self) -> int:
        """Return the amount of figures on the drawing."""
        return len(self.figures)

    def __str__(self):
        """
        A string representation of the drawing.

        The returned string must follow this pattern:
        "The drawing painted by {author}. Contains {current amount of figures} figure(s)"

        :return: A correct string representing the drawing.
        """
        return "The drawing painted by " + self.author + ". " + "Contains " + str(self.figures_count) + " figure(s)"