def read_mapfile(fn):
	comments = []
	status = None
	blockstrings = []
	with open(fn, 'r') as f:
		for line in f:
			if line.startswith("#"):
				comments.append(line)
			elif status is None:
				status = line
			else:
				blockstrings.append(line)
	
	# Post-processing
	status = status.split()
	status[0] = int(status[0], base=0)
	status[2] = int(status[2], base=0)
	status = tuple(status)

	blocks = []
	for blockstring in blockstrings:
		spl = blockstring.split()
		start = int(spl[0], base=0)
		length = int(spl[1], base=0)
		char = spl[2]
		blocks.append((start, length, char))
	
	return (status, blocks, comments)


class MapFile:
	def __init__(self, filename, start=None, end=None):
		self.mapfilename = filename
		self.start = start if start is not None else 0
		self.end = end
	
	def load(self):
		self.status, self.blocks, self.comments = read_mapfile(self.mapfilename)
		# Virtual self-position block
		self.blocks.append((self.status[0], 1, '@'))
		if self.end is not None: # FIXME: what about only start being set?
			self.filter_data()
		self.size = max(map(lambda blk: blk[0]+blk[1], self.blocks))
	
	def filter_data(self):
		self.blocks = self.filter_blocks(self.blocks, self.start, self.end)
		self.blocks = self.trim_blocks(self.blocks, self.start, self.end)
		
		# Move blocks:
		self.status = tuple([self.status[0] - self.start, *self.status[1:]])
		nblocks = []
		for blk in self.blocks:
			nblk = tuple([blk[0] - self.start, *blk[1:]])
			nblocks.append(nblk)
		self.blocks = nblocks

	
	def get_state(self, pos):
		# TODO: this is lame
		for blk in self.blocks:
			if pos >= blk[0] and pos < blk[0] + blk[1]:
				return blk[2]
	
	@staticmethod
	def filter_blocks(blocks, start, end):
		relevant_blocks = []
		for blk in blocks:
			if start < blk[0] + blk[1] and end >= blk[0]:
				relevant_blocks.append(blk)
		return relevant_blocks

	@staticmethod
	def trim_blocks(blocks, start, end):
		trmblks = []
		for blk in blocks:
			bg, lt, symb = blk
			if bg < start:
				lt -= start - bg
				bg = start
			if bg + lt > end:
				lt -= bg+lt - end
			trmblks.append((bg, lt, symb))
		return trmblks

	def get_hist(self, start, end):
		relevant_blocks = self.filter_blocks(self.blocks, start, end)

		trmblks = self.trim_blocks(relevant_blocks, start, end)

		# Grouping by symbols:
		grp = {}
		for blk in trmblks:
			if blk[2] not in grp:
				grp[blk[2]] = 0
			grp[blk[2]] += blk[1]

		return grp