#!/usr/bin/python
# -*- coding: utf-8 -*-
# vim: ts=4
###
#
# Copyright (c) 2012 Mehdi Abaakouk
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3 as
# published by the Free Software Foundation
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
#
###

import subprocess
import re
from urllib2 import urlopen
from urllib import quote, unquote
import json

from toolbox import mask_is_valid, ipv6_is_valid, ipv4_is_valid, resolve

import pydot
from flask import Flask, render_template, jsonify, redirect, session, request, abort, Response

app = Flask(__name__)
app.config.from_pyfile('lg.cfg')

def add_links(text):
	"""Browser a string and replace ipv4, ipv6, as number, with a whois link """

	if type(text) in [ str, unicode ]:
		text = text.split("\n")

	ret_text = []
	for line in text:
		# Some heuristic to create link
		if line.strip().startswith("BGP.as_path:") or \
			line.strip().startswith("Neighbor AS:") :
			ret_text.append(re.sub(r'(\d+)',r'<a href="/whois/\1" class="whois">\1</a>',line))
		else:
			line = re.sub(r'([a-zA-Z0-9\-]*\.([a-zA-Z]{2,3}){1,2})(\s|$)', r'<a href="/whois/\1" class="whois">\1</a>\3',line)
			line = re.sub(r'AS(\d+)', r'<a href="/whois/\1" class="whois">AS\1</a>',line)
			line = re.sub(r'(\d+\.\d+\.\d+\.\d+)', r'<a href="/whois/\1" class="whois">\1</a>',line)
			hosts = "/".join(request.path.split("/")[2:])
			line = re.sub(r'\[(\w+)\s+((|\d\d\d\d-\d\d-\d\d\s)(|\d\d:)\d\d:\d\d|\w\w\w\d\d)', r'[<a href="/detail/%s?q=\1">\1</a> \2' % hosts, line)
			line = re.sub(r'(^|\s+)(([a-f\d]{0,4}:){3,10}[a-f\d]{0,4})', r'\1<a href="/whois/\2" class="whois">\2</a>',line , re.I)
			ret_text.append(line)
	return "\n".join(ret_text)

def extract_paths(text):
	paths = []
	for line in text:
		line = line.strip()
		if line.startswith("BGP.as_path:"):
			paths.append(line.replace("BGP.as_path:", "").strip().split(" "))

	return paths

def set_session(request_type, hosts, proto, request_args):
	""" Store all data from user in the user session """
	session.permanent = True
	session.update( {
		"request_type": request_type,
		"hosts": hosts,
		"proto": proto,
		"request_args": request_args,
	})
	history = session.get("history", [])

	# erase old format history
	if type(history) != type(list()): history = []

	t = (hosts, proto, request_type, request_args)
	if t in history:
		del history[history.index(t)]
	history.insert(0, t)
	session["history"] = history[:20]

def whois_command(query):
	return subprocess.Popen( [ 'whois', query], stdout=subprocess.PIPE).communicate()[0].decode('utf-8', 'ignore')

def bird_command(host, proto, query):
	"""Alias to bird_proxy for bird service"""
	return bird_proxy(host, proto, "bird", query)

def bird_proxy(host, proto, service, query):
	"""Retreive data of a service from a running lg-proxy on a remote node
	
	First and second arguments are the node and the port of the running lg-proxy
	Third argument is the service, can be "traceroute" or "bird"
	Last argument, the query to pass to the service

	return tuple with the success of the command and the returned data
	"""

	path = ""
	if proto == "ipv6": path = service + "6"
	elif proto == "ipv4": path = service
	port = app.config["PROXY"].get(host,"")
	if not port or not path:
		return False, "Host/Proto not allowed"
	else:
		url = "http://%s.%s:%d/%s?q=%s" % (host, app.config["DOMAIN"], port, path, quote(query))
		try:
			f = urlopen(url)
			resultat = f.read()
			status = True # retreive remote status
		except IOError:
			resultat = "Failed retreive url: %s" % url
			status = False
		return status, resultat
		
@app.context_processor
def inject_commands():
	commands = [
			("traceroute","traceroute ..."),
			("summary","show protocols"),
			("detail","show protocols ... all"),
			("prefix","show route for ..."),
			("prefix_detail","show route for ... all"),
			("where","show route where net ~ [ ... ]"),
			("where_detail","show route where net ~ [ ... ] all"),
			("adv","show route ..."),
		]
	commands_dict = {}
	for id, text in commands:
		commands_dict[id] = text
	return dict(commands=commands, commands_dict=commands_dict)

@app.context_processor
def inject_all_host():
	return dict(all_hosts="+".join(app.config["PROXY"].keys()))

@app.route("/")
def hello():
	return redirect("/summary/%s/ipv4" % "+".join(app.config["PROXY"].keys()) )

def error_page(text):
	return render_template('error.html', error = text ), 500

@app.errorhandler(400)
def incorrect_request(e):
	    return render_template('error.html', warning="The server could not understand the request"), 400

@app.errorhandler(404)
def page_not_found(e):
	    return render_template('error.html', warning="The requested URL was not found on the server."), 404

@app.route("/whois/<query>")
def whois(query):
	if not query.strip(): abort(400)
	try:
		asnum = int(query)
		query = "as%d"%asnum
	except:
		m = re.match(r"[\w\d-]*\.(?P<domain>[\d\w-]+\.[\d\w-]+)$", query)
		if m: query = query.groupdict()["domain"]
	output = whois_command(query).replace("\n","<br>")
	return jsonify(output=output, title=query)

SUMMARY_UNWANTED_PROTOS = ["Kernel", "Static", "Device"]
SUMMARY_RE_MATCH = r"(?P<name>[\w_]+)\s+(?P<proto>\w+)\s+(?P<table>\w+)\s+(?P<state>\w+)\s+(?P<since>((|\d\d\d\d-\d\d-\d\d\s)(|\d\d:)\d\d:\d\d|\w\w\w\d\d))($|\s+(?P<info>.*))"

@app.route("/summary/<hosts>")
@app.route("/summary/<hosts>/<proto>")
def summary(hosts, proto="ipv4"):
	set_session("summary", hosts, proto, "")
	command = "show protocols"
	
	summary = {}
	error = []
	for host in hosts.split("+"):
		ret, res = bird_command(host, proto, command)
		res = res.split("\n")
		if len(res) > 1: #if ret:
			data = []
			for line in res[1:]:
				line = line.strip()
				if line and ( line.split() + [""] )[1] not in SUMMARY_UNWANTED_PROTOS:
					m = re.match(SUMMARY_RE_MATCH ,line)
					if m:
						data.append(m.groupdict())
					else:
						app.logger.warning("couldn't parse: %s" , line)

			summary[host] = data 
		else:
			error.append("%s: bird command failed with error, %s" % (host,"\n".join(res)))

	return render_template('summary.html', summary=summary, command=command, error="<br>".join(error))

@app.route("/detail/<hosts>/<proto>")
def detail(hosts, proto):
	name = request.args.get('q', '')
	if not name.strip(): abort(400)

	set_session("detail", hosts, proto, name)
	command = "show protocols all %s" % name

	detail = {}
	error = []
	for host in hosts.split("+"):
		ret, res = bird_command(host, proto, command)
		res = res.split("\n")
		if len(res) > 1 : #if ret:
			detail[host] = { "status": res[1], "description": add_links(res[2:]) }
		else:
			error.append("%s: bird command failed with error, %s" % (host,"\n".join(res)))
	
	return render_template('detail.html', detail=detail, command=command, error="<br>".join(error))

@app.route("/traceroute/<hosts>/<proto>")
def traceroute(hosts, proto):
	q = request.args.get('q', '')
	if not q.strip(): abort(400)
	set_session("traceroute", hosts, proto, q)

	if proto == "ipv6" and not ipv6_is_valid(q):
		try: q = resolve(q, "AAAA")
		except:	return error_page("%s is unresolvable or invalid for %s" % (q, proto))
	if proto == "ipv4" and not ipv4_is_valid(q):
		try: q = resolve(q, "A")
		except:	return error_page("%s is unresolvable or invalid for %s" % (q, proto))

	infos = {}
	for host in hosts.split("+"):
		status, resultat = bird_proxy(host, proto, "traceroute", q)
		infos[host] = add_links(resultat)
	return render_template('traceroute.html', infos=infos)

@app.route("/adv/<hosts>/<proto>")
def show_route_filter(hosts, proto):
	return show_route("adv", hosts, proto)

@app.route("/where/<hosts>/<proto>")
def show_route_where(hosts, proto):
	return show_route("where", hosts, proto)

@app.route("/where_detail/<hosts>/<proto>")
def show_route_where_detail(hosts, proto):
	return show_route("where_detail", hosts, proto)

@app.route("/prefix/<hosts>/<proto>")
def show_route_for(hosts, proto):
	return show_route("prefix", hosts, proto)

@app.route("/prefix_detail/<hosts>/<proto>")
def show_route_for_detail(hosts, proto):
	return show_route("prefix_detail", hosts, proto)

ASNAME_CACHE = {}
def get_as_name(_as):
	return "AS%s" % _as
	if not ASNAME_CACHE.has_key(_as):
		whois_answer = whois_command("as%s" % _as)
		as_name = re.search('as-name: (.*)', whois_answer)
		if as_name:
			ASNAME_CACHE[_as] = as_name.group(1).strip()
		else:
			ASNAME_CACHE[_as] = _as
	if ASNAME_CACHE[_as] == _as:
		return "AS%s" % _as
	else:
		return "AS%s\r%s" % (_as, ASNAME_CACHE[_as])

@app.route("/bgpmap/<data>")
def show_bgpmap(data):
	data = json.loads(unquote(data))
	graph = pydot.Dot('BGPMAP', graph_type='digraph')
	nodes = {}
	edges = {}
	for host, asmaps in data.iteritems():
		nodes[host] = pydot.Node(host, shape="box", style="filled", fillcolor="#F5A9A9")
		graph.add_node(nodes[host])
	for host, asmaps in data.iteritems():
		first = True
		for asmap in asmaps:
			previous_as = host
			for _as in asmap:
				_as = get_as_name(_as)
				if _as == previous_as: 
					continue
				if not nodes.has_key(_as):
					nodes[_as] = pydot.Node(_as, label=_as, style="filled", fillcolor=(first and "#F5A9A9" or "white"))
					graph.add_node(nodes[_as])
				
				edge_tuple = (nodes[previous_as], nodes[_as])
				if not edges.has_key(edge_tuple):
					edge = pydot.Edge(*edge_tuple)
					graph.add_edge(edge)
					edges[edge_tuple] = edge

				if edge.get_color() != "red" and first:
					edge.set_color("red")
					
				previous_as = _as
			first = False

	#return Response("<pre>" + graph.create_dot() + "</pre>")
	return Response(graph.create_png(), mimetype='image/png')

def show_route(request_type, hosts, proto):
	expression = unquote(request.args.get('q', ''))
	if not expression.strip(): abort(400)
	set_session(request_type, hosts, proto, expression)

	all = (request_type.endswith("detail") and " all" or "" )

	if request_type.startswith("adv"):
		command = "show route " + expression
	elif request_type.startswith("where"):
		command = "show route where net ~ [ " + expression + " ]" + all
	else:
		mask = ""
		if len(expression.split("/")) > 1:
			expression, mask = (expression.split("/"))

		if not mask and proto == "ipv4" : mask = "32"
		if not mask and proto == "ipv6" : mask = "128"
		if not mask_is_valid(mask):
			return error_page("mask %s is invalid" % mask)
		if proto == "ipv6" and not ipv6_is_valid(expression):
			try: expression = resolve(expression, "AAAA")
			except:	return error_page("%s is unresolvable or invalid for %s" % (expression, proto))
		if proto == "ipv4" and not ipv4_is_valid(expression):
			try: expression = resolve(expression, "A")
			except:	return error_page("%s is unresolvable or invalid for %s" % (expression, proto))

		if mask: expression += "/" + mask
		command = "show route for " + expression + all

	detail = {}
	error = []
	bgpmap = {}
	for host in hosts.split("+"):
		ret, res = bird_command(host, proto, command)

		res = res.split("\n")
		if len(res) > 1 : #if ret:
			detail[host] = add_links(res)
			bgpmap[host] = extract_paths(res)
		else:
			error.append("%s: bird command failed with error, %s" % (host,"\n".join(res)))
	
	return render_template('route.html', detail=detail, command=command, expression=expression, bgpmap=json.dumps(bgpmap), error="<br>".join(error) )

app.secret_key = app.config["SESSION_KEY"]
app.debug = True
if __name__ == "__main__":
	app.run("0.0.0.0")