import curses
import math
import threading
from utils import CHUNK_HEIGHT, CHUNK_WIDTH, chunkx, chunky, inchunkx, inchunky, Position

import sys

class Map():
	"""
	A map which displays chunks and a cursor on the screen.
	Allows for user to modify chunks in an intuitive way.
	"""
	
	def __init__(self, width, height, chunkpool, drawevent):
		self._lock = threading.RLock()
		
		self.worldx = 0
		self.worldy = 0
		self.cursorx = 0
		self.cursory = 0
		self.chunkpreload = 0
		self.cursorpadding = 2
		
		self.chunkpool = chunkpool
		self.drawevent = drawevent
		
		self._pad = curses.newpad(5, 5)
		self.resize(width, height)
	
	def __enter__(self):
		self._lock.acquire()
		return self
	
	def __exit__(self, type, value, tb):
		self._lock.release()
	
	def redraw(self):
		self._pad.redrawwin()
		
		self.drawevent.set()
	
	def draw(self):
		with self.chunkpool as pool:
			for x in range(chunkx(self.width) + 2):      # +2, not +1, or there will be empty gaps
				for y in range(chunky(self.height) + 2): # in the bottom and right borders
					chunk = pool.get(x+chunkx(self.worldx), y+chunky(self.worldy))
					if chunk:
						chunk.draw_to(x*CHUNK_WIDTH, y*CHUNK_HEIGHT, self._pad)
					else:
						self.draw_empty_to(x*CHUNK_WIDTH, y*CHUNK_HEIGHT)
		
		# set cursor position in world
		self._pad.move(
			self.cursory - chunky(self.worldy)*CHUNK_HEIGHT,
			self.cursorx - chunkx(self.worldx)*CHUNK_WIDTH
		)
		
		self._pad.noutrefresh(inchunky(self.worldy), inchunkx(self.worldx), 0, 0, self.height-1, self.width-1)
	
	def draw_empty_to(self, x, y):
		if curses.has_colors():
			curses.init_pair(1, curses.COLOR_BLACK, curses.COLOR_WHITE)
			for dy in range(CHUNK_HEIGHT):
				self._pad.addstr(y+dy, x, " "*CHUNK_WIDTH, curses.color_pair(1))
		else:
			for dy in range(CHUNK_HEIGHT):
				s = "."*CHUNK_WIDTH
				self._pad.addstr(y+dy, x, s)
	
	def resize(self, width, height):
		self.width = width
		self.height = height
		
		self._pad.resize(
			(chunky(height) + 2)*CHUNK_HEIGHT,
			(chunkx(width) + 2)*CHUNK_WIDTH + 1 # workaround for addwstr issue when drawing
		)
		
		with self.chunkpool as pool:
			pool.load_list(self.visible_chunk_coords())
		
		self.drawevent.set()
	
	def visible_chunk_coords(self):
		coords = []
		
		xstart = chunkx(self.worldx) - self.chunkpreload
		ystart = chunky(self.worldy) - self.chunkpreload
		xend = xstart + chunkx(self.width) + 1 + 2*self.chunkpreload
		yend = ystart + chunky(self.height) + 1 + 2*self.chunkpreload
		
		for x in range(xstart, xend):
			for y in range(ystart, yend):
				coords.append(Position(x, y))
		
		return coords
	
	def write(self, char):
		with self.chunkpool as pool:
			chunk = pool.get(chunkx(self.cursorx), chunky(self.cursory))
			if not chunk:
				chunk = pool.create(chunkx(self.cursorx), chunky(self.cursory))
			
			chunk.setch(inchunkx(self.cursorx), inchunky(self.cursory), char)
		
		self.move_cursor(1, 0)
	
	def move_cursor(self, dx, dy):
		self.cursorx += dx
		self.cursory += dy
		
		self.worldx = min(
			self.cursorx - self.cursorpadding,
			max(
				self.cursorx - self.width+1 + self.cursorpadding,
				self.worldx
			)
		)
		
		self.worldy = min(
			self.cursory - self.cursorpadding,
			max(
				self.cursory - self.height+1 + self.cursorpadding,
				self.worldy
			)
		)
		
		self.drawevent.set()
	
	def scroll(self, dx, dy):
		self.worldx += dx
		self.worldy += dy
		
		# new scrolling code: The cursor stays on the same screen position while scrolling
		self.cursorx += dx
		self.cursory += dy
		
		# old scrolling code: The cursor would stay on the same world coordinates while scrolling,
		# and only if it was at the edge of the screen, it would get carried with the window.
		#self.cursorx = min(
			#self.worldx + self.width-1 - self.cursorpadding,
			#max(
				#self.worldx + self.cursorpadding,
				#self.cursorx
			#)
		#)
		
		#self.cursory = min(
			#self.worldy + self.height-1 - self.cursorpadding,
			#max(
				#self.worldy + self.cursorpadding,
				#self.cursory
			#)
		#)
		
		self.drawevent.set()
	

class ChunkMap():
	"""
	A map that shows which chunks are currently loaded.
	Might show additional details too (i.e. if a chunk has been modified).
	"""
	
	def __init__(self, chunkpool):
		self.cpool = chunkpool
#	
#	def draw(self):
#		pass
#	
#	def resize(self, size):
#		pass
#	
	def move(self, x, y, corner):
		pass
	
	def toggle(self):
		pass