#!/usr/bin/env python
# life.py
'''
Conway's Game of Life '''

import random
import itertools
import pygame

# Set Up
pygame.init()
colors = pygame.color.THECOLORS
ON, OFF = 1, 0

# The Plan:
# Put the cells in a dict from {relative location : cell}
# That way neighbors can be looked-up easily in a flat list.
#
#
# Helper Functions ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!
def randcolor (lower=40, upper=230):
	cvals = range(lower, upper)
	r, g, b = [random.choice(cvals) for i in range(3)]
	return pygame.Color(r, g, b)


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!
class Cell (object):
	
	
	def __init__ (self, **kwargs):
		
		# defaults
		self.size = (25, 25)		
		self.oncolor = colors['green']
		self.offcolor = colors['black']
		self.state = OFF
		
		# absolute topleft pixel position. 
		self.position = None   
		
		# unpack kwargs
		for k in kwargs:
			setattr(self, k, kwargs[k])
		
		self._init_default_config()
	
	
	@property
	def width (self):
		return self.size[0]

	@property
	def height (self):
		return self.size[1]
	
	def _init_default_config (self):
		self.image = pygame.Surface(self.size)
		self.image.set_alpha(0)
		self.rect = self.image.get_rect()
	
		if self.state:
			self.image.fill(self.oncolor)
		else:
			self.image.fill(self.offcolor)

		if hasattr(self, 'position'):
			self.rect.topleft = self.position
	
	def update (self):
		if self.state:
			self.image.fill(self.oncolor)
			self.image.set_alpha(70)
		else:
			self.image.fill(self.offcolor)
	
	def __repr__ (self):
		return "<cell>"


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!	
class Grid (object):


	def __init__ (self, gridsize, cellsize):
		self.cell_w, self.cell_h = cellsize   # cell w, h 
		self.w, self.h = gridsize             # grid w, h 
		self.n = self.w * self.h              # n cells
		self.cells = []               
		
		# Initial Configuration
		self._do_init_config()
	
	
	def _do_init_config (self):
		absx = absy = 0
		for i in xrange(self.h):
			row = []
			for j in xrange(self.w):
				initstate = random.choice([ON,OFF])
				nhood = self.get_neighbors(i, j)
				cell = Cell( nhood = [n for n in nhood],
						     size=(self.cell_w, self.cell_h),
						     position=(absx, absy), 
						     state=initstate,
						     history=initstate )
				
				row.append(cell)
				absx += cell.width 

			self.cells.append(row)
			absy += cell.height
			absx = 0
					
	def update (self):
		newcolor = randcolor()
		for row in self.cells:
			
			for cell in row:
			
				cell.history = cell.state    # stores previous state
				cell.update()                # sets cell state color
				
				states = [ON for (i,j) in cell.nhood if self.cells[i][j].history]
				score = sum( states )						
				
				# set new cell state		
				if score < 4 and score > 1 and cell.history:
					cell.state = ON
				elif score == 3 and not cell.history:
					cell.state = ON
					cell.oncolor = newcolor
				else:
					cell.state = OFF
				
				# draw to screen
				screen.blit(cell.image, cell.position)
	
	def get_neighbors (self, x, y):
		for point in itertools.product(range(-1,2), range(-1,2)):
			_x, _y = point[0]+x, point[1]+y
			if (x, y) == (_x, _y): 
				continue
			_x %= self.w
			_y %= self.h
			yield (_x, _y)
	
	def __getitem__ (self, i):
		i, j = divmod(i, self.w)
		return self.cells[i][j]





# ///////////////////////!
if __name__ == '__main__':
	grid = Grid((120, 120), (2,2))
	screen = pygame.display.set_mode((grid.w*grid.cell_w, grid.h*grid.cell_h))
	clock = pygame.time.Clock()
	running = True
	
	while running:
		clock.tick(36)
		for e in pygame.event.get():
			if not hasattr(e, 'key'): 
				continue
			if e.key == pygame.K_q or e.key == pygame.K_ESCAPE: 
				running = False
		
		grid.update()		

		#pygame.display.update([cell.rect for cell in grid if cell.state])
		pygame.display.flip()