#!/usr/bin/env python3

"""
A curses-based version of Conway's Game of Life.

An empty board will be displayed, and the following commands are available:
 E : Erase the board
 R : Fill the board randomly
 S : Step for a single generation
 C : Update continuously until a key is struck
 Q : Quit
 Cursor keys : Move the cursor around the board
 Space or Enter : Toggle the contents of the cursor's position

Contributed by Andrew Kuchling, Mouse support and color by Dafydd Crosby.
"""

import curses
import random


class LifeBoard:
 """Encapsulates a Life board

 Attributes:
 X,Y : horizontal and vertical size of the board
 state : dictionary mapping (x,y) to 0 or 1

 Methods:
 display(update_board) -- If update_board is true, compute the
 next generation. Then display the state
 of the board and refresh the screen.
 erase() -- clear the entire board
 make_random() -- fill the board randomly
 set(y,x) -- set the given cell to Live; doesn't refresh the screen
 toggle(y,x) -- change the given cell from live to dead, or vice
 versa, and refresh the screen display

 """
 def __init__(self, scr, char=ord('*')):
 """Create a new LifeBoard instance.

 scr -- curses screen object to use for display
 char -- character used to render live cells (default: '*')
 """
 self.state = {}
 self.scr = scr
 Y, X = self.scr.getmaxyx()
 self.X, self.Y = X - 2, Y - 2 - 1
 self.char = char
 self.scr.clear()

 # Draw a border around the board
 border_line = '+' + (self.X * '-') + '+'
 self.scr.addstr(0, 0, border_line)
 self.scr.addstr(self.Y + 1, 0, border_line)
 for y in range(0, self.Y):
 self.scr.addstr(1 + y, 0, '|')
 self.scr.addstr(1 + y, self.X + 1, '|')
 self.scr.refresh()

 def set(self, y, x):
 """Set a cell to the live state"""
 if x < 0 or self.X <= x or y < 0 or self.Y <= y:
 raise ValueError("Coordinates out of range %i,%i" % (y, x))
 self.state[x, y] = 1

 def toggle(self, y, x):
 """Toggle a cell's state between live and dead"""
 if x < 0 or self.X <= x or y < 0 or self.Y <= y:
 raise ValueError("Coordinates out of range %i,%i" % (y, x))
 if (x, y) in self.state:
 del self.state[x, y]
 self.scr.addch(y + 1, x + 1, ' ')
 else:
 self.state[x, y] = 1
 if curses.has_colors():
 # Let's pick a random color!
 self.scr.attrset(curses.color_pair(random.randrange(1, 7)))
 self.scr.addch(y + 1, x + 1, self.char)
 self.scr.attrset(0)
 self.scr.refresh()

 def erase(self):
 """Clear the entire board and update the board display"""
 self.state = {}
 self.display(update_board=False)

 def display(self, update_board=True):
 """Display the whole board, optionally computing one generation"""
 M, N = self.X, self.Y
 if not update_board:
 for i in range(0, M):
 for j in range(0, N):
 if (i, j) in self.state:
 self.scr.addch(j + 1, i + 1, self.char)
 else:
 self.scr.addch(j + 1, i + 1, ' ')
 self.scr.refresh()
 return

 d = {}
 self.boring = 1
 for i in range(0, M):
 L = range(max(0, i - 1), min(M, i + 2))
 for j in range(0, N):
 s = 0
 live = (i, j) in self.state
 for k in range(max(0, j - 1), min(N, j + 2)):
 for l in L:
 if (l, k) in self.state:
 s += 1
 s -= live
 if s == 3:
 # Birth
 d[i, j] = 1
 if curses.has_colors():
 # Let's pick a random color!
 self.scr.attrset(curses.color_pair(
 random.randrange(1, 7)))
 self.scr.addch(j + 1, i + 1, self.char)
 self.scr.attrset(0)
 if not live:
 self.boring = 0
 elif s == 2 and live:
 # Survival
 d[i, j] = 1
 elif live:
 # Death
 self.scr.addch(j + 1, i + 1, ' ')
 self.boring = 0
 self.state = d
 self.scr.refresh()

 def make_random(self):
 "Fill the board with a random pattern"
 self.state = {}
 for i in range(0, self.X):
 for j in range(0, self.Y):
 if random.random() > 0.5:
 self.set(j, i)


def erase_menu(stdscr, menu_y):
 "Clear the space where the menu resides"
 stdscr.move(menu_y, 0)
 stdscr.clrtoeol()
 stdscr.move(menu_y + 1, 0)
 stdscr.clrtoeol()


def display_menu(stdscr, menu_y):
 "Display the menu of possible keystroke commands"
 erase_menu(stdscr, menu_y)

 # If color, then light the menu up :-)
 if curses.has_colors():
 stdscr.attrset(curses.color_pair(1))
 stdscr.addstr(menu_y, 4,
 'Use the cursor keys to move, and space or Enter to toggle a cell.')
 stdscr.addstr(menu_y + 1, 4,
 'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit')
 stdscr.attrset(0)


def keyloop(stdscr):
 # Clear the screen and display the menu of keys
 stdscr.clear()
 stdscr_y, stdscr_x = stdscr.getmaxyx()
 menu_y = (stdscr_y - 3) - 1
 display_menu(stdscr, menu_y)

 # If color, then initialize the color pairs
 if curses.has_colors():
 curses.init_pair(1, curses.COLOR_BLUE, 0)
 curses.init_pair(2, curses.COLOR_CYAN, 0)
 curses.init_pair(3, curses.COLOR_GREEN, 0)
 curses.init_pair(4, curses.COLOR_MAGENTA, 0)
 curses.init_pair(5, curses.COLOR_RED, 0)
 curses.init_pair(6, curses.COLOR_YELLOW, 0)
 curses.init_pair(7, curses.COLOR_WHITE, 0)

 # Set up the mask to listen for mouse events
 curses.mousemask(curses.BUTTON1_CLICKED)

 # Allocate a subwindow for the Life board and create the board object
 subwin = stdscr.subwin(stdscr_y - 3, stdscr_x, 0, 0)
 board = LifeBoard(subwin, char=ord('*'))
 board.display(update_board=False)

 # xpos, ypos are the cursor's position
 xpos, ypos = board.X // 2, board.Y // 2

 # Main loop:
 while True:
 stdscr.move(1 + ypos, 1 + xpos) # Move the cursor
 c = stdscr.getch() # Get a keystroke
 if 0 < c < 256:
 c = chr(c)
 if c in ' \n':
 board.toggle(ypos, xpos)
 elif c in 'Cc':
 erase_menu(stdscr, menu_y)
 stdscr.addstr(menu_y, 6, ' Hit any key to stop continuously '
 'updating the screen.')
 stdscr.refresh()
 # Activate nodelay mode; getch() will return -1
 # if no keystroke is available, instead of waiting.
 stdscr.nodelay(1)
 while True:
 c = stdscr.getch()
 if c != -1:
 break
 stdscr.addstr(0, 0, '/')
 stdscr.refresh()
 board.display()
 stdscr.addstr(0, 0, '+')
 stdscr.refresh()

 stdscr.nodelay(0) # Disable nodelay mode
 display_menu(stdscr, menu_y)

 elif c in 'Ee':
 board.erase()
 elif c in 'Qq':
 break
 elif c in 'Rr':
 board.make_random()
 board.display(update_board=False)
 elif c in 'Ss':
 board.display()
 else:
 # Ignore incorrect keys
 pass
 elif c == curses.KEY_UP and ypos > 0:
 ypos -= 1
 elif c == curses.KEY_DOWN and ypos + 1 < board.Y:
 ypos += 1
 elif c == curses.KEY_LEFT and xpos > 0:
 xpos -= 1
 elif c == curses.KEY_RIGHT and xpos + 1 < board.X:
 xpos += 1
 elif c == curses.KEY_MOUSE:
 mouse_id, mouse_x, mouse_y, mouse_z, button_state = curses.getmouse()
 if (mouse_x > 0 and mouse_x < board.X + 1 and
 mouse_y > 0 and mouse_y < board.Y + 1):
 xpos = mouse_x - 1
 ypos = mouse_y - 1
 board.toggle(ypos, xpos)
 else:
 # They've clicked outside the board
 curses.flash()
 else:
 # Ignore incorrect keys
 pass


def main(stdscr):
 keyloop(stdscr) # Enter the main loop

if __name__ == '__main__':
 curses.wrapper(main)