#!/usr/bin/python
# Copyright 2008-2012 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

from __future__ import print_function

import sys

from os import path as osp
pym_path = osp.join(osp.dirname(osp.dirname(osp.realpath(__file__))), "pym")
sys.path.insert(0, pym_path)
import portage
from portage import os
from portage.output import *

from optparse import OptionGroup, OptionParser

__program__ = "glsa-check"
__author__ = "Marius Mauch <genone@gentoo.org>"
__version__ = "1.0"

def cb_version(*args, **kwargs):
	"""Callback for --version"""
	sys.stderr.write("\n"+ __program__ + ", version " + __version__ + "\n")
	sys.stderr.write("Author: " + __author__ + "\n")
	sys.stderr.write("This program is licensed under the GPL, version 2\n\n")
	sys.exit(0)

# option parsing
parser = OptionParser(usage="%prog <option> [glsa-list]",
		version="%prog "+ __version__)
parser.epilog = "glsa-list can contain an arbitrary number of GLSA ids," \
		" filenames containing GLSAs or the special identifiers" \
		" 'all', 'new' and 'affected'"

modes = OptionGroup(parser, "Modes")
modes.add_option("-l", "--list", action="store_const",
		const="list", dest="mode",
		help="List all unapplied GLSA")
modes.add_option("-d", "--dump", action="store_const",
		const="dump", dest="mode",
		help="Show all information about the given GLSA")
modes.add_option("", "--print", action="store_const",
		const="dump", dest="mode",
		help="Alias for --dump")
modes.add_option("-t", "--test", action="store_const",
		const="test", dest="mode",
		help="Test if this system is affected by the given GLSA")
modes.add_option("-p", "--pretend", action="store_const",
		const="pretend", dest="mode",
		help="Show the necessary commands to apply this GLSA")
modes.add_option("-f", "--fix", action="store_const",
		const="fix", dest="mode",
		help="Try to auto-apply this GLSA (experimental)")
modes.add_option("-i", "--inject", action="store_const", dest="mode",
		help="Inject the given GLSA into the checkfile")
modes.add_option("-m", "--mail", action="store_const",
		const="mail", dest="mode",
		help="Send a mail with the given GLSAs to the administrator")
parser.add_option_group(modes)

parser.remove_option("--version")
parser.add_option("-V", "--version", action="callback",
		callback=cb_version, help="Some information about this tool")
parser.add_option("-v", "--verbose", action="store_true", dest="verbose",
		help="Print more information")
parser.add_option("-n", "--nocolor", action="callback",
		callback=lambda *args, **kwargs: nocolor(),
		help="Disable colors")
parser.add_option("-e", "--emergelike", action="store_false", dest="least_change",
		help="Do not use a least-change algorithm")
parser.add_option("-c", "--cve", action="store_true", dest="list_cve",
		help="Show CAN ids in listing mode")

options, params = parser.parse_args()

mode = options.mode
least_change = options.least_change
list_cve = options.list_cve
verbose = options.verbose

# Sanity checking
if mode is None:
	sys.stderr.write("No mode given: what should I do?\n")
	parser.print_help()
	sys.exit(1)
elif mode != "list" and not params:
	sys.stderr.write("\nno GLSA given, so we'll do nothing for now. \n")
	sys.stderr.write("If you want to run on all GLSA please tell me so \n")
	sys.stderr.write("(specify \"all\" as parameter)\n\n")
	parser.print_help()
	sys.exit(1)
elif mode in ["fix", "inject"] and os.geteuid() != 0:
	# we need root privileges for write access
	sys.stderr.write("\nThis tool needs root access to "+options.mode+" this GLSA\n\n")
	sys.exit(2)
elif mode == "list" and not params:
	params.append("new")

# delay this for speed increase
from portage.glsa import *

eroot = portage.settings['EROOT']
vardb = portage.db[eroot]["vartree"].dbapi
portdb = portage.db[eroot]["porttree"].dbapi

# build glsa lists
completelist = get_glsa_list(portage.settings)

checklist = get_applied_glsas(portage.settings)
todolist = [e for e in completelist if e not in checklist]

glsalist = []
if "new" in params:
	glsalist = todolist
	params.remove("new")

if "all" in params:
	glsalist = completelist
	params.remove("all")
if "affected" in params:
	# replaced completelist with todolist on request of wschlich
	for x in todolist:
		try:
			myglsa = Glsa(x, portage.settings, vardb, portdb)
		except (GlsaTypeException, GlsaFormatException) as e:
			if verbose:
				sys.stderr.write(("invalid GLSA: %s (error message was: %s)\n" % (x, e)))
			continue
		if myglsa.isVulnerable():
			glsalist.append(x)
	params.remove("affected")

# remove invalid parameters
for p in params[:]:
	if not (p in completelist or os.path.exists(p)):
		sys.stderr.write(("(removing %s from parameter list as it isn't a valid GLSA specification)\n" % p))
		params.remove(p)

glsalist.extend([g for g in params if g not in glsalist])

def summarylist(myglsalist, fd1=sys.stdout, fd2=sys.stderr):
	fd2.write(white("[A]")+" means this GLSA was already applied,\n")
	fd2.write(green("[U]")+" means the system is not affected and\n")
	fd2.write(red("[N]")+" indicates that the system might be affected.\n\n")

	myglsalist.sort()
	for myid in myglsalist:
		try:
			myglsa = Glsa(myid, portage.settings, vardb, portdb)
		except (GlsaTypeException, GlsaFormatException) as e:
			if verbose:
				fd2.write(("invalid GLSA: %s (error message was: %s)\n" % (myid, e)))
			continue
		if myglsa.isApplied():
			status = "[A]"
			color = white
		elif myglsa.isVulnerable():
			status = "[N]"
			color = red
		else:
			status = "[U]"
			color = green

		if verbose:
			access = ("[%-8s] " % myglsa.access)
		else:
			access=""

		fd1.write(color(myglsa.nr) + " " + color(status) + " " + color(access) + myglsa.title + " (")
		if not verbose:
			for pkg in list(myglsa.packages)[:3]:
				fd1.write(" " + pkg + " ")
			if len(myglsa.packages) > 3:
				fd1.write("... ")
		else:
			for pkg in myglsa.packages:
				mylist = vardb.match(pkg)
				if len(mylist) > 0:
					pkg = color(" ".join(mylist))
				fd1.write(" " + pkg + " ")

		fd1.write(")")
		if list_cve:
			fd1.write(" "+(",".join([r[:13] for r in myglsa.references if r[:4] in ["CAN-", "CVE-"]])))
		fd1.write("\n")
	return 0

if mode == "list":
	sys.exit(summarylist(glsalist))

# dump, fix, inject and fix are nearly the same code, only the glsa method call differs
if mode in ["dump", "fix", "inject", "pretend"]:
	for myid in glsalist:
		try:
			myglsa = Glsa(myid, portage.settings, vardb, portdb)
		except (GlsaTypeException, GlsaFormatException) as e:
			if verbose:
				sys.stderr.write(("invalid GLSA: %s (error message was: %s)\n" % (myid, e)))
			continue
		if mode == "dump":
			myglsa.dump()
		elif mode == "fix":
			sys.stdout.write("fixing "+myid+"\n")
			mergelist = myglsa.getMergeList(least_change=least_change)
			for pkg in mergelist:
				sys.stdout.write(">>> merging "+pkg+"\n")
				# using emerge for the actual merging as it contains the dependency
				# code and we want to be consistent in behaviour. Also this functionality
				# will be integrated in emerge later, so it shouldn't hurt much.
				emergecmd = "emerge --oneshot " + portage.settings["EMERGE_OPTS"] + " =" + pkg
				if verbose:
					sys.stderr.write(emergecmd+"\n")
				exitcode = os.system(emergecmd)
				# system() returns the exitcode in the high byte of a 16bit integer
				if exitcode >= 1<<8:
					exitcode >>= 8
				if exitcode:
					sys.exit(exitcode)
			myglsa.inject()
		elif mode == "pretend":
			sys.stdout.write("Checking GLSA "+myid+"\n")
			mergelist = myglsa.getMergeList(least_change=least_change)
			if mergelist:
				sys.stdout.write("The following updates will be performed for this GLSA:\n")
				for pkg in mergelist:
					oldver = None
					for x in vardb.match(portage.cpv_getkey(pkg)):
						if vardb._pkg_str(x, None).slot == portdb._pkg_str(pkg, None).slot:
							oldver = x
					if oldver == None:
						raise ValueError("could not find old version for package %s" % pkg)
					oldver = oldver[len(portage.cpv_getkey(oldver))+1:]
					sys.stdout.write("     " + pkg + " (" + oldver + ")\n")
			else:
				sys.stdout.write("Nothing to do for this GLSA\n")
		elif mode == "inject":
			sys.stdout.write("injecting " + myid + "\n")
			myglsa.inject()
		sys.stdout.write("\n")
	sys.exit(0)

# test is a bit different as Glsa.test() produces no output
if mode == "test":
	outputlist = []
	for myid in glsalist:
		try:
			myglsa = Glsa(myid, portage.settings, vardb, portdb)
		except (GlsaTypeException, GlsaFormatException) as e:
			if verbose:
				sys.stderr.write(("invalid GLSA: %s (error message was: %s)\n" % (myid, e)))
			continue
		if myglsa.isVulnerable():
			outputlist.append(str(myglsa.nr))
	if len(outputlist) > 0:
		sys.stderr.write("This system is affected by the following GLSAs:\n")
		if verbose:
			summarylist(outputlist)
		else:
			sys.stdout.write("\n".join(outputlist)+"\n")
	else:
		sys.stderr.write("This system is not affected by any of the listed GLSAs\n")
	sys.exit(0)

# mail mode as requested by solar
if mode == "mail":
	import portage.mail, socket
	from io import StringIO
	from email.mime.text import MIMEText

	# color doesn't make any sense for mail
	nocolor()

	if "PORTAGE_ELOG_MAILURI" in portage.settings:
		myrecipient = portage.settings["PORTAGE_ELOG_MAILURI"].split()[0]
	else:
		myrecipient = "root@localhost"

	if "PORTAGE_ELOG_MAILFROM" in portage.settings:
		myfrom = portage.settings["PORTAGE_ELOG_MAILFROM"]
	else:
		myfrom = "glsa-check"

	mysubject = "[glsa-check] Summary for %s" % socket.getfqdn()

	# need a file object for summarylist()
	myfd = StringIO()
	myfd.write("GLSA Summary report for host %s\n" % socket.getfqdn())
	myfd.write("(Command was: %s)\n\n" % " ".join(sys.argv))
	summarylist(glsalist, fd1=myfd, fd2=myfd)
	summary = str(myfd.getvalue())
	myfd.close()

	myattachments = []
	for myid in glsalist:
		try:
			myglsa = Glsa(myid, portage.settings, vardb, portdb)
		except (GlsaTypeException, GlsaFormatException) as e:
			if verbose:
				sys.stderr.write(("invalid GLSA: %s (error message was: %s)\n" % (myid, e)))
			continue
		myfd = StringIO()
		myglsa.dump(outstream=myfd)
		myattachments.append(MIMEText(str(myfd.getvalue()), _charset="utf8"))
		myfd.close()

	mymessage = portage.mail.create_message(myfrom, myrecipient, mysubject, summary, myattachments)
	portage.mail.send_mail(portage.settings, mymessage)

	sys.exit(0)

# something wrong here, all valid paths are covered with sys.exit()
sys.stderr.write("nothing more to do\n")
sys.exit(2)