from tkinter import Tk, Text, END
from tkinter.font import Font


class Game:

    def __init__(self,
                 width=80,
                 height=24,
                 title="Untitled",
                 active_keys=None):

        self._root = Tk()
        self._root.resizable(False, False)
        self._root.title(title)
        if active_keys is None:
            active_keys = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
                           'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
                           'u', 'v', 'w', 'x', 'y', 'z',
                           '<Left>', '<Right>', '<Down>', '<Up>']
        for key in active_keys:
            self._root.bind(key, self._render)
        self.width = width
        self.height = height
        self._text = Text(
            self._root,
            width=self.width,
            height=self.height,
            bg='black',
            fg='white',
        )
        self._text.insert('1.0', ' ' * (self.width * self.height))
        self._text.pack()
        self._text['state'] = 'disabled'

    def _render(self, event):
        self._text['state'] = 'normal'
        self._text.delete('1.0', END)
        content = self.loop(event)
        if len(content) == self.width * self.height:
            self._text.insert('1.0', content)
        else:
            raise ValueError("Game.loop(event) must return a string of "
                             "length {}x{}".format(self.width, self.height))
        self._text.pack()
        self._text['state'] = 'disabled'

    def loop(self, event):
        raise NotImplementedError("Subclass must implement Game.loop(event).")

    def run(self):
        self._root.mainloop()


# # Usage example:
# import random
# import string
# from functools import reduce
#
# class Rogue(Game):
#     def loop(self, event):
#         if event.keysym == 'Left':
#             return 24 * 80 * '<'
#         return ''.join([random.choice(string.ascii_letters)
#                         for _ in range(24 * 80)])
#
# Rogue().run()