#!/usr/bin/env python
#
# $Id$
#
# Copyright (C) 2015-2016  Parsons Government Services ("PARSONS")
# Portions copyright (C) 2014  Dragon Research Labs ("DRL")
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notices and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND PARSONS AND DRL DISCLAIM ALL
# WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL
# PARSONS OR DRL BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
# CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
# OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
# NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
# WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""
Searches authenticated result tree from an rcynic run for ROAs
matching specified prefixes.
"""

import os
import argparse
import rpki.POW
import rpki.oids
import rpki.config


def check_dir(s):
    if os.path.isdir(s):
        return os.path.abspath(s)
    else:
        raise argparse.ArgumentTypeError("%r is not a directory" % s)


def filename_to_uri(filename):
    if not filename.startswith(args.rcynic_dir):
        raise ValueError
    return "rsync://" + filename[len(args.rcynic_dir):].lstrip("/")

def uri_to_filename(uri):
    if not uri.startswith("rsync://"):
        raise ValueError
    return os.path.join(args.rcynic_dir, uri[len("rsync://"):])


class Prefix(object):
    """
    One prefix parsed from the command line.
    """

    def __init__(self, val):
        addr, length = val.split("/")
        length, sep, maxlength = length.partition("-") # pylint: disable=W0612
        self.prefix = rpki.POW.IPAddress(addr)
        self.length = int(length)
        self.maxlength = int(maxlength) if maxlength else self.length
        if self.maxlength < self.length or self.length < 0 or self.length > self.prefix.bits:
            raise ValueError
        if self.prefix & ((1 << (self.prefix.bits - self.length)) - 1) != 0:
            raise ValueError

    def matches(self, roa):             # pylint: disable=W0621
        return any(self.prefix == prefix and
                   self.length == length and
                   (not args.match_maxlength or
                    self.maxlength == maxlength or
                    (maxlength is None and
                     self.length == self.maxlength))
                   for prefix, length, maxlength in roa.prefixes)


class ROA(rpki.POW.ROA):                # pylint: disable=W0232
    """
    Aspects of a ROA that we care about.
    """

    @classmethod
    def parse(cls, fn):                 # pylint: disable=W0621
        assert fn.startswith(args.rcynic_dir)
        self = cls.derReadFile(fn)      # pylint: disable=E1101
        self.fn = fn
        self.extractWithoutVerifying()
        v4, v6 = self.getPrefixes()
        self.prefixes = (v4 or ()) + (v6 or ())
        return self

    @property
    def uri(self):
        return filename_to_uri(self.fn) # pylint: disable=E1101

    @property
    def formatted_prefixes(self):
        for prefix in self.prefixes:    # pylint: disable=E1101
            if prefix[2] is None or prefix[1] == prefix[2]:
                yield "%s/%d" % (prefix[0], prefix[1])
            else:
                yield "%s/%d-%d" % (prefix[0], prefix[1], prefix[2])

    def __str__(self):
        # pylint: disable=E1101
        prefixes = " ".join(self.formatted_prefixes)
        plural = "es" if " " in prefixes else ""
        if args.show_inception:
            return "signingTime %s ASN %s prefix%s %s" % (self.signingTime(), self.getASID(), plural, prefixes)
        else:
            return "ASN %s prefix%s %s" % (self.getASID(), plural, prefixes)

    def show(self):
        # pylint: disable=E1101
        print "%s %s" % (self, self.fn if args.show_filenames else self.uri)

    def show_expiration(self):
        print self
        x = self.certs()[0]             # pylint: disable=E1101
        fn = self.fn                    # pylint: disable=E1101,W0621
        uri = self.uri
        while uri is not None:
            name = fn if args.show_filenames else uri
            if args.show_inception:
                print "notBefore", x.getNotBefore(), "notAfter", x.getNotAfter(), name
            else:
                print x.getNotAfter(), name
            for uri in x.getAIA() or ():
                if uri.startswith("rsync://"):
                    break
            else:
                break
            fn = uri_to_filename(uri)
            if not os.path.exists(fn):
                print "***** MISSING ******", uri
                break
            x = rpki.POW.X509.derReadFile(fn)
        print


cfg = rpki.config.argparser(doc =  __doc__)
cfg.argparser.add_argument("-a", "--all", action = "store_true", help = "show all ROAs, do no prefix matching at all")
cfg.argparser.add_argument("-m", "--match-maxlength", action = "store_true", help = "pay attention to maxLength values")
cfg.argparser.add_argument("-e", "--show-expiration", action = "store_true", help = "show ROA chain expiration dates")
cfg.argparser.add_argument("-f", "--show-filenames", action = "store_true", help = "show filenames instead of URIs")
cfg.argparser.add_argument("-i", "--show-inception", action = "store_true", help = "show inception dates")
cfg.argparser.add_argument("rcynic_dir", type = check_dir, help = "rcynic authenticated output directory")
cfg.argparser.add_argument("prefixes", type = Prefix, nargs = "*", help = "ROA prefix(es) to match")
args = cfg.argparser.parse_args()

# If there's some way to automate this in the parser, I don't know what it is, so just catch it here.
if args.all != (not args.prefixes):
    parser.error("--all and prefix list are mutually exclusive")

for root, dirs, files in os.walk(args.rcynic_dir):
    for fn in files:
        if fn.endswith(".roa"):
            roa = ROA.parse(os.path.join(root, fn))
            if args.all or any(prefix.matches(roa) for prefix in args.prefixes):
                if args.show_expiration:
                    roa.show_expiration()
                else:
                    roa.show()