#!/usr/bin/python -t
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# 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 Library 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
# Copyright 2005 Duke University 
#
# Seth Vidal <skvidal@linux.duke.edu>
# Luke Macken <lmacken@redhat.com>

"""
Update metadata (updateinfo.xml) parsing.
"""

import sys
import gzip

from yum.i18n import utf8_text_wrap, to_utf8
from yum.yumRepo import YumRepository
from yum.packages import FakeRepository
from yum.misc import to_xml
import Errors

import rpmUtils.miscutils

try:
    from xml.etree import cElementTree
except ImportError:
    import cElementTree
iterparse = cElementTree.iterparse


class UpdateNoticeException(Exception):
    """ An exception thrown for bad UpdateNotice data. """
    pass


class UpdateNotice(object):

    """
    A single update notice (for instance, a security fix).
    """

    def __init__(self, elem=None):
        self._md = {
            'from'             : '',
            'type'             : '',
            'title'            : '',
            'release'          : '',
            'status'           : '',
            'version'          : '',
            'pushcount'        : '',
            'update_id'        : '',
            'issued'           : '',
            'updated'          : '',
            'description'      : '',
            'references'       : [],
            'pkglist'          : [],
            'reboot_suggested' : False
        }

        if elem:
            self._parse(elem)

    def __getitem__(self, item):
        """ Allows scriptable metadata access (ie: un['update_id']). """
        return self._md.has_key(item) and self._md[item] or None

    def __str__(self):
        head = """
===============================================================================
  %(title)s
===============================================================================
  Update ID : %(update_id)s
    Release : %(release)s
       Type : %(type)s
     Status : %(status)s
     Issued : %(issued)s
""" % self._md

        if self._md['updated'] and self._md['updated'] != self._md['issued']:
            head += "    Updated : %s" % self._md['updated']

        # Add our bugzilla references
        bzs = filter(lambda r: r['type'] == 'bugzilla', self._md['references'])
        if len(bzs):
            buglist = "       Bugs :"
            for bz in bzs:
                buglist += " %s%s\n\t    :" % (bz['id'], bz.has_key('title')
                                               and ' - %s' % bz['title'] or '')
            head += buglist[: - 1].rstrip() + '\n'

        # Add our CVE references
        cves = filter(lambda r: r['type'] == 'cve', self._md['references'])
        if len(cves):
            cvelist = "       CVEs :"
            for cve in cves:
                cvelist += " %s\n\t    :" % cve['id']
            head += cvelist[: - 1].rstrip() + '\n'

        if self._md['description'] is not None:
            desc = utf8_text_wrap(self._md['description'], width=64,
                                  subsequent_indent=' ' * 12 + ': ')
            head += "Description : %s\n" % '\n'.join(desc)

        #  Get a list of arches we care about:
        #XXX ARCH CHANGE - what happens here if we set the arch - we need to
        # pass this in, perhaps
        arches = set(rpmUtils.arch.getArchList())

        filelist = "      Files :"
        for pkg in self._md['pkglist']:
            for file in pkg['packages']:
                if file['arch'] not in arches:
                    continue
                filelist += " %s\n\t    :" % file['filename']
        head += filelist[: - 1].rstrip()

        return head

    def get_metadata(self):
        """ Return the metadata dict. """
        return self._md

    def _parse(self, elem):
        """
        Parse an update element::

            <!ELEMENT update (id, synopsis?, issued, updated,
                              references, description, pkglist)>
                <!ATTLIST update type (errata|security) "errata">
                <!ATTLIST update status (final|testing) "final">
                <!ATTLIST update version CDATA #REQUIRED>
                <!ATTLIST update from CDATA #REQUIRED>
        """
        if elem.tag == 'update':
            for attrib in ('from', 'type', 'status', 'version'):
                self._md[attrib] = elem.attrib.get(attrib)
            for child in elem:
                if child.tag == 'id':
                    if not child.text:
                        raise UpdateNoticeException("No id element found")
                    self._md['update_id'] = child.text
                elif child.tag == 'pushcount':
                    self._md['pushcount'] = child.text
                elif child.tag == 'issued':
                    self._md['issued'] = child.attrib.get('date')
                elif child.tag == 'updated':
                    self._md['updated'] = child.attrib.get('date')
                elif child.tag == 'references':
                    self._parse_references(child)
                elif child.tag == 'description':
                    self._md['description'] = child.text
                elif child.tag == 'pkglist':
                    self._parse_pkglist(child)
                elif child.tag == 'title':
                    self._md['title'] = child.text
                elif child.tag == 'release':
                    self._md['release'] = child.text
        else:
            raise UpdateNoticeException('No update element found')

    def _parse_references(self, elem):
        """
        Parse the update references::

            <!ELEMENT references (reference*)>
            <!ELEMENT reference>
                <!ATTLIST reference href CDATA #REQUIRED>
                <!ATTLIST reference type (self|cve|bugzilla) "self">
                <!ATTLIST reference id CDATA #IMPLIED>
                <!ATTLIST reference title CDATA #IMPLIED>
        """
        for reference in elem:
            if reference.tag == 'reference':
                data = {}
                for refattrib in ('id', 'href', 'type', 'title'):
                    data[refattrib] = reference.attrib.get(refattrib)
                self._md['references'].append(data)
            else:
                raise UpdateNoticeException('No reference element found')

    def _parse_pkglist(self, elem):
        """
        Parse the package list::

            <!ELEMENT pkglist (collection+)>
            <!ELEMENT collection (name?, package+)>
                <!ATTLIST collection short CDATA #IMPLIED>
                <!ATTLIST collection name CDATA #IMPLIED>
            <!ELEMENT name (#PCDATA)>
        """
        for collection in elem:
            data = { 'packages' : [] }
            if collection.attrib.has_key('short'):
                data['short'] = collection.attrib.get('short')
            for item in collection:
                if item.tag == 'name':
                    data['name'] = item.text
                elif item.tag == 'package':
                    data['packages'].append(self._parse_package(item))
            self._md['pkglist'].append(data)

    def _parse_package(self, elem):
        """
        Parse an individual package::

            <!ELEMENT package (filename, sum, reboot_suggested)>
                <!ATTLIST package name CDATA #REQUIRED>
                <!ATTLIST package version CDATA #REQUIRED>
                <!ATTLIST package release CDATA #REQUIRED>
                <!ATTLIST package arch CDATA #REQUIRED>
                <!ATTLIST package epoch CDATA #REQUIRED>
                <!ATTLIST package src CDATA #REQUIRED>
            <!ELEMENT reboot_suggested (#PCDATA)>
            <!ELEMENT filename (#PCDATA)>
            <!ELEMENT sum (#PCDATA)>
                <!ATTLIST sum type (md5|sha1) "sha1">
        """
        package = {}
        for pkgfield in ('arch', 'epoch', 'name', 'version', 'release', 'src'):
            package[pkgfield] = elem.attrib.get(pkgfield)
        for child in elem:
            if child.tag == 'filename':
                package['filename'] = child.text
            elif child.tag == 'sum':
                package['sum'] = (child.attrib.get('type'), child.text)
            elif child.tag == 'reboot_suggested':
                self._md['reboot_suggested'] = True
        return package

    def xml(self):
        """Generate the xml for this update notice object"""
        msg = """
<update from="%s" status="%s" type="%s" version="%s">
  <id>%s</id>
  <title>%s</title>
  <release>%s</release>
  <issued date="%s"/>
  <description>%s</description>\n""" % (to_xml(self._md['from']),
                to_xml(self._md['status']), to_xml(self._md['type']),
                to_xml(self._md['version']), to_xml(self._md['update_id']),
                to_xml(self._md['title']), to_xml(self._md['release']),
                to_xml(self._md['issued'], attrib=True),
                to_xml(self._md['description']))
        
        if self._md['references']:
            msg += """  <references>\n"""
            for ref in self._md['references']:
                if ref['title']:
                    msg += """    <reference href="%s" id="%s" title="%s" type="%s"/>\n""" % (
                    to_xml(ref['href'], attrib=True), to_xml(ref['id'], attrib=True),
                    to_xml(ref['title'], attrib=True), to_xml(ref['type'], attrib=True))
                else:
                    msg += """    <reference href="%s" id="%s"  type="%s"/>\n""" % (
                    to_xml(ref['href'], attrib=True), to_xml(ref['id'], attrib=True),
                    to_xml(ref['type'], attrib=True))

            msg += """  </references>\n"""
        
        if self._md['pkglist']:
            msg += """  <pkglist>\n"""
            for coll in self._md['pkglist']:
                msg += """    <collection short="%s">\n      <name>%s</name>\n""" % (
                      to_xml(coll['short'], attrib=True),
                      to_xml(coll['name']))
  
                for pkg in coll['packages']:
                    msg += """      <package arch="%s" name="%s" release="%s" src="%s" version="%s">
        <filename>%s</filename>
      </package>\n""" % (to_xml(pkg['arch'], attrib=True),
                                to_xml(pkg['name'], attrib=True),
                                to_xml(pkg['release'], attrib=True),
                                to_xml(pkg['src'], attrib=True),
                                to_xml(pkg['version'], attrib=True),
                                to_xml(pkg['filename']))
                msg += """    </collection>\n"""
                msg += """  </pkglist>\n"""
        msg += """</update>\n"""
        return msg

def _rpm_tup_vercmp(tup1, tup2):
    """ Compare two "std." tuples, (n, a, e, v, r). """
    return rpmUtils.miscutils.compareEVR((tup1[2], tup1[3], tup1[4]),
                                         (tup2[2], tup2[3], tup2[4]))

class UpdateMetadata(object):

    """
    The root update metadata object.
    """

    def __init__(self, repos=[]):
        self._notices = {}
        self._cache = {}    # a pkg nvr => notice cache for quick lookups
        self._no_cache = {}    # a pkg name only => notice list
        self._repos = []    # list of repo ids that we've parsed
        for repo in repos:
            try: # attempt to grab the updateinfo.xml.gz from the repodata
                self.add(repo)
            except Errors.RepoMDError:
                continue # No metadata found for this repo

    def get_notices(self, name=None):
        """ Return all notices. """
        if name is None:
            return self._notices.values()
        return name in self._no_cache and self._no_cache[name] or []

    notices = property(get_notices)

    def get_notice(self, nvr):
        """
        Retrieve an update notice for a given (name, version, release) string
        or tuple.
        """
        if type(nvr) in (type([]), type(())):
            nvr = '-'.join(nvr)
        return self._cache.has_key(nvr) and self._cache[nvr] or None

    #  The problem with the above "get_notice" is that not everyone updates
    # daily. So if you are at pkg-1, pkg-2 has a security notice, and pkg-3
    # has a BZ fix notice. All you can see is the BZ notice for the new "pkg-3"
    # with the above.
    #  So now instead you lookup based on the _installed_ pkg.pkgtup, and get
    # two notices, in order: [(pkg-3, notice), (pkg-2, notice)]
    # the reason for the sorting order is that the first match will give you
    # the minimum pkg you need to move to.
    def get_applicable_notices(self, pkgtup):
        """
        Retrieve any update notices which are newer than a
        given std. pkgtup (name, arch, epoch, version, release) tuple.
        """
        oldpkgtup = pkgtup
        name = oldpkgtup[0]
        arch = oldpkgtup[1]
        ret = []
        for notice in self.get_notices(name):
            for upkg in notice['pkglist']:
                for pkg in upkg['packages']:
                    if pkg['name'] != name or pkg['arch'] != arch:
                        continue
                    pkgtup = (pkg['name'], pkg['arch'], pkg['epoch'] or '0',
                              pkg['version'], pkg['release'])
                    if _rpm_tup_vercmp(pkgtup, oldpkgtup) <= 0:
                        continue
                    ret.append((pkgtup, notice))
        ret.sort(cmp=_rpm_tup_vercmp, key=lambda x: x[0], reverse=True)
        return ret

    def add(self, obj, mdtype='updateinfo'):
        """ Parse a metadata from a given YumRepository, file, or filename. """
        if not obj:
            raise UpdateNoticeException
        if type(obj) in (type(''), type(u'')):
            infile = obj.endswith('.gz') and gzip.open(obj) or open(obj, 'rt')
        elif isinstance(obj, YumRepository):
            if obj.id not in self._repos:
                self._repos.append(obj.id)
                md = obj.retrieveMD(mdtype)
                if not md:
                    raise UpdateNoticeException()
                infile = gzip.open(md)
        elif isinstance(obj, FakeRepository):
            raise Errors.RepoMDError, "No updateinfo for local pkg"
        else:   # obj is a file object
            infile = obj

        for event, elem in iterparse(infile):
            if elem.tag == 'update':
                try:
                    un = UpdateNotice(elem)
                except UpdateNoticeException, e:
                    print >> sys.stderr, "An update notice is broken, skipping."
                    # what else should we do?
                    continue
                if not self._notices.has_key(un['update_id']):
                    self._notices[un['update_id']] = un
                    for pkg in un['pkglist']:
                        for file in pkg['packages']:
                            self._cache['%s-%s-%s' % (file['name'],
                                                      file['version'],
                                                      file['release'])] = un
                            no = self._no_cache.setdefault(file['name'], set())
                            no.add(un)

    def __unicode__(self):
        ret = u''
        for notice in self.notices:
            ret += unicode(notice)
        return ret
    def __str__(self):
        return to_utf8(self.__unicode__())

    def xml(self, fileobj=None):
        msg = """<?xml version="1.0"?>\n<updates>"""
        if fileobj:
            fileobj.write(msg)

        for notice in self._notices.values():
            if fileobj:
                fileobj.write(notice.xml())
            else:
                msg += notice.xml()

        end = """</updates>\n"""
        if fileobj:
            fileobj.write(end)
        else:
            msg += end

        if fileobj:
            return

        return msg


def main():
    """ update_md test function. """
    import yum.misc

    yum.misc.setup_locale()
    def usage():
        print >> sys.stderr, "Usage: %s <update metadata> ..." % sys.argv[0]
        sys.exit(1)

    if len(sys.argv) < 2:
        usage()

    try:
        print sys.argv[1]
        um = UpdateMetadata()
        for srcfile in sys.argv[1:]:
            um.add(srcfile)
        print unicode(um)
    except IOError:
        print >> sys.stderr, "%s: No such file:\'%s\'" % (sys.argv[0],
                                                          sys.argv[1:])
        usage()

if __name__ == '__main__':
    main()
