#!/usr/bin/env python3

# Simple as of now.

import re

def _dumbload(f) -> list[tuple[int, str]]:
	"""Loads file into list of lines with their indentations"""
	tabs = re.compile(r'^\t*')
	return [(tabs.match(line).end(), line[tabs.match(line).end():]) for line in f]

def _load(f):
	"""Loads state file into tuples of the sections"""
	dumb = _dumbload(f)
	maxdepth = max(x[0] for x in dumb)
	state = [None] * (maxdepth+1)
	result = []
	for depth, line in dumb:
		line = line.strip()
		if line == '': continue
		state[depth] = line
		for x in range(depth+1, maxdepth+1):
			state[x] = None
		result.append(state.copy()) # It's all strings, so OK.
	return result

def load(f) -> dict[tuple[str, str], list[str]]:
	"""Loads state file into dictionaries area+router/network -> list of parameters"""
	# FIXME: Shouldn't we just create a ton of ordered dictionaries?
	#   i.e. area -> router -> param -> None; all string.
	params = _load(f)
	result = {}
	for x in params:
		if x[-1] is None: continue # FIXME: Not working for general output.
		k = (x[0], x[1])
		if k not in result:
			result[k] = []
		result[k].append(' '.join(x[2:]))
	return result

def create_graph(d):
	"""takes the dict from load() and returns list of edges.

	The graph is bipartite, one part is the routers, other is the networks"""
	edges = []
	names = {}
	for k, v in d.items():
		v1 = k[1]
		for l in v:
			# UGLY!
			if v1.startswith('router') and l.startswith(('network', 'stubnet', 'external')):
				m = re.match(r'^([^ ]+ [^ ]+) metric ([0-9]+)$', l)
				v2 = m.group(1)
				metric = int(m.group(2))
				edges.append((v1, v2, metric))
			if v1.startswith('network') and l.startswith('address'):
				names[v1] = l
				# NOTE: Not all networks have reasonable address (external, stubnets), so they will not be listed.
	return edges, names

if __name__ == '__main__':
	#from pprint import pprint
	#pprint(create_graph(load(open('state'))))
	edges, names = create_graph(load(open('state')))
	
	# Prologue:
	print(r'graph "Visualisation" {')
	
	for edge in edges:
		print(f'"{edge[0]}" -- "{edge[1]}" [label={edge[2]}];')

	for ident,name in names.items():
		print(f'"{ident}" [label="{name}"]')
		# Dot falls back to vertex name, so this solves the missing keys in names.
	
	# Epi:
	print('}')