#!/usr/bin/python

#
# archive-conf -- save off a config file in the dispatch-conf rcs archive
#
#  Wayne Davison <gentoo@blorf.net> with code snagged from Jeremy Wohl's
#  dispatch-conf script and the portage chkcontents script.
#

import os, sys, string, shutil
import portage

FIND_EXTANT_CONTENTS  = "find %s -name CONTENTS"

RCS_BRANCH = '1.1.1'
RCS_LOCK = 'rcs -ko -M -l'
RCS_PUT = 'ci -t-"Archived config file." -m"archive-conf update."'
RCS_GET = 'co'

MANDATORY_OPTS  = [ 'archive-dir' ]

try:
    import fchksum
    def perform_checksum(filename): return fchksum.fmd5t(filename)
except ImportError:
    import md5
    def md5_to_hex(md5sum):
        hexform = ""
        for ix in xrange(len(md5sum)):
            hexform = hexform + "%02x" % ord(md5sum[ix])
        return string.lower(hexform)
    
    def perform_checksum(filename):
        f = open(filename, 'rb')
        blocksize=32768
        data = f.read(blocksize)
        size = 0L
        sum = md5.new()
        while data:
            sum.update(data)
            size = size + len(data)
            data = f.read(blocksize)
        return (md5_to_hex(sum.digest()),size)

class save_conf:
    options = {}

    def doit(self):
        args = sys.argv[1:]
        content_files = []
        md5_match_hash = {}

        self.read_my_config()

        todo_cnt = 0
        for conf in args:
            if not os.path.isabs(conf):
                conf = os.path.abspath(conf)
            args[todo_cnt] = conf
            md5_match_hash[conf] = 0
            todo_cnt += 1

        # Find all the CONTENT files in /var/db/pkg.
        content_files += os.popen(FIND_EXTANT_CONTENTS % ('/var/db/pkg')).readlines()

        # Search for the saved md5 checksum of all the specified config files
        # and see if the current file is unmodified or not.
        try:
            for file in content_files:
                file = file.rstrip()
                try:
                    contents = open(file, "r")
                except IOError, e:
                    print "Unable to open %s: %s" % (file, e)
                    sys.exit(1)
                lines = contents.readlines()
                for line in lines:
                    items = string.split(line)
                    if items[0] == 'obj':
                        for conf in args:
                            if items[1] == conf:
                                stored = string.lower(items[2])
                                real = string.lower(perform_checksum(conf)[0])
                                if stored == real:
                                    md5_match_hash[conf] = 1
                                todo_cnt -= 1
                                if todo_cnt == 0:
                                    raise "Break"
        except "Break":
            pass

        for conf in args:
            s.do_rcs(conf, md5_match_hash[conf])

    def do_rcs(self, curconf, md5_matches):
        """Archive existing config in rcs (on trunk). Then, if the file
        matches the MD5 checksum for the last package install, also check
        it in on the branch."""
        archive = os.path.join(self.options['archive-dir'], curconf.lstrip('/'))
        try:
            os.makedirs(os.path.dirname(archive))
        except:
            pass

        try:
            shutil.copy2(curconf, archive)
        except(IOError, os.error), why:
            print >> sys.stderr, 'archive-conf: Error copying %s to %s: %s; fatal' % \
                  (curconf, archive, str(why))

        if os.path.exists(archive + ',v'):
            os.system(RCS_LOCK + ' ' + archive)
        os.system(RCS_PUT + ' ' + archive)

        if md5_matches:
            # There is probably a better way of checking for the branch...
            os.system(RCS_GET + ' -r' + RCS_BRANCH + ' ' + archive)
            has_branch = os.path.exists(archive)

            try:
                shutil.copy2(curconf, archive)
            except(IOError, os.error), why:
                print >> sys.stderr, 'archive-conf: Error copying %s to %s: %s; fatal' % \
                      (curconf, archive, str(why))
            if has_branch:
                # Commit the config file onto the branch, just in case.
                os.system(RCS_LOCK + RCS_BRANCH + ' ' + archive)
                os.system(RCS_PUT + ' -r' + RCS_BRANCH + ' ' + archive)
            else:
                # Forcefully commit the config file onto the branch.
                os.system(RCS_PUT + ' -f -r' + RCS_BRANCH + ' ' + archive)

    def read_my_config(self):
        try:
            opts = portage.getconfig('/etc/dispatch-conf.conf')
        except:
            opts = None

        if not opts:
            print >> sys.stderr, 'archive-conf: Error reading /etc/dispatch-conf.conf; fatal'
            sys.exit(1)

        for key in MANDATORY_OPTS:
            if not opts.has_key(key):
                print >> sys.stderr, 'archive-conf: Missing option "%s" in /etc/dispatch-conf.conf; fatal' % (key,)

        if not (os.path.exists(opts['archive-dir']) and os.path.isdir(opts['archive-dir'])):
            print >> sys.stderr, 'archive-conf: Config archive dir [%s] must exist; fatal' % (opts['archive-dir'],)
            sys.exit(1)

        self.options = opts


# run
if len(sys.argv) > 1:
    s = save_conf()
    s.doit()
else:
    print 'Usage: archive-conf /CONFIG/FILE [/CONFIG/FILE...]'