#!/usr/local/bin/python2.6
# rdiffdir -- Extend rdiff functionality to directories
# Version 0.6.10 released September 19, 2010
#
# Copyright 2002 Ben Escoto <ben@emerose.org>
# Copyright 2007 Kenneth Loafman <kenneth@loafman.com>
#
# This file is part of duplicity.
#
# Duplicity 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.
#
# Duplicity 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 duplicity; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# See http://www.nongnu.org/duplicity for more information.
# Please send mail to me or the mailing list if you find bugs or have
# any suggestions.

import sys, getopt, gzip, os

import gettext
gettext.install('duplicity')

from duplicity import diffdir
from duplicity import patchdir
from duplicity import log
from duplicity import tarfile
from duplicity import globals
from duplicity import selection
from duplicity import path

# If set, compress diff and delta files using gzip
gzip_compress = None

# If set, when computing delta, also compute signature and write to
# specified file.
sig_fileobj = None

select_opts = [] # Add selection argument tuples to this
select_files = [] # Will hold file objects when filelist given

def parse_cmdline_options(arglist):
    """Parse argument list"""
    global gzip_compress, select_opts, select_files, sig_fileobj
    def sel_fl(filename):
        """Helper function for including/excluding filelists below"""
        try:
            return open(filename, "r")
        except IOError:
            log.FatalError("Error opening file %s" % filename)

    try:
        optlist, args = getopt.getopt(arglist, "v:Vz",
                                      ["gzip-compress", "exclude=", "exclude-device-files",
                                       "exclude-filelist=", "exclude-filelist-stdin",
                                       "exclude-globbing-filelist", "exclude-other-filesystems",
                                       "exclude-regexp=", "include=", "include-filelist=",
                                       "include-filelist-stdin", "include-globbing-filelist",
                                       "include-regexp=", "null-separator", "verbosity=",
                                       "write-sig-to="])
    except getopt.error, e:
        command_line_error("Bad command line option: %s" % (str(e),))

    for opt, arg in optlist:
        if opt == "--gzip_compress" or opt == "-z":
            gzip_compress = 1
        elif (opt == "--exclude" or opt == "--exclude-regexp" or
              opt == "--include" or opt == "--include-regexp"):
            select_opts.append((opt, arg))
        elif (opt == "--exclude-device-files" or
              opt == "--exclude-other-filesystems"):
            select_opts.append((opt, None))
        elif (opt == "--exclude-filelist" or opt == "--include-filelist" or
              opt == "--exclude-globbing-filelist" or
              opt == "--include-globbing-filelist"):
            select_opts.append((opt, arg))
            select_files.append(sel_fl(arg))
        elif opt == "--exclude-filelist-stdin":
            select_opts.append(("--exclude-filelist", "standard input"))
            select_files.append(sys.stdin)
        elif opt == "--include-filelist-stdin":
            select_opts.append(("--include-filelist", "standard input"))
            select_files.append(sys.stdin)
        elif opt == "--null-separator":
            globals.null_separator = 1
        elif opt == "-V":
            print "rdiffdir", str(globals.version)
            sys.exit(0)
        elif opt == "-v" or opt == "--verbosity":
            log.setverbosity(int(arg))
        elif opt == "--write-sig-to" or opt == "--write-signature-to":
            sig_fileobj = get_fileobj(arg, "wb")
        else:
            command_line_error("Unknown option %s" % opt)

    return args

def command_line_error(message):
    """Indicate a command line error and exit"""
    sys.stderr.write("Error: %s\n" % (message,))
    sys.stderr.write("See the rdiffdir manual page for instructions\n")
    sys.exit(1)

def check_does_not_exist(filename):
    """Exit with error message if filename already exists"""
    try:
        os.lstat(filename)
    except OSError:
        pass
    else:
        log.FatalError("File %s already exists, will not "
                       "overwrite." % filename)

def get_action(args):
    """Figure out the main action from the arguments"""
    def require_args(num):
        if len(args)-1 < num:
            command_line_error("Too few arguments")
        elif len(args)-1 > num:
            command_line_error("Too many arguments")

    if not args:
        command_line_error("No arguments found")
    command = args[0]
    if command == "sig" or command == "signature":
        require_args(2)
        command = "sig"
    elif command == "tar":
        require_args(2)
    elif command == "delta":
        require_args(3)
    elif command == "patch":
        require_args(2)
    return command, args[1:]

def get_selection(filename):
    """Return selection iter starting at path with arguments applied"""
    global select_opts, select_files
    sel = selection.Select(path.Path(filename))
    sel.ParseArgs(select_opts, select_files)
    return sel.set_iter()

def get_fileobj(filename, mode):
    """Get file object or stdin/stdout from filename"""
    if mode == "r" or mode == "rb":
        if filename == "-":
            fp = sys.stdin
        else:
            fp = open(filename, mode)
    elif mode == "w" or mode == "wb":
        if filename == "-":
            fp = sys.stdout
        else:
            check_does_not_exist(filename)
            fp = open(filename, mode)
    else:
        assert 0, "Unknown mode " + str(mode)

    if gzip_compress:
        return gzip.GzipFile(None, fp.mode, 9, fp)
    else:
        return fp

def write_sig(dirname, outfp):
    """Write signature of dirname into file object outfp"""
    diffdir.write_block_iter(diffdir.DirSig(get_selection(dirname)), outfp)

def write_delta(dirname, sig_infp, outfp):
    """Write delta to fileobj outfp, reading from dirname and sig_infp"""
    delta_iter = diffdir.DirDelta(get_selection(dirname), sig_infp)
    diffdir.write_block_iter(delta_iter, outfp)
    assert not outfp.close()

def write_delta_and_sig(dirname, sig_infp, outfp, sig_outfp):
    """Write delta and also signature of dirname"""
    sel = get_selection(dirname)
    delta_iter = diffdir.DirDelta_WriteSig(sel, sig_infp, sig_outfp)
    diffdir.write_block_iter(delta_iter, outfp)
    assert not sig_outfp.close()

def patch(dirname, deltafp):
    """Patch dirname, reading delta tar from deltafp"""
    patchdir.Patch(path.Path(dirname), deltafp)

def write_tar(dirname, outfp):
    """Store dirname into a tarfile, write to outfp"""
    diffdir.write_block_iter(diffdir.DirFull(get_selection(dirname)), outfp)

def write_tar_and_sig(dirname, outfp, sig_outfp):
    """Write tar of dirname to outfp, signature of same to sig_outfp"""
    full_iter = diffdir.DirFull_WriteSig(get_selection(dirname), sig_outfp)
    diffdir.write_block_iter(full_iter, outfp)


def main():
    """Start here"""
    log.setup()
    args = parse_cmdline_options(sys.argv[1:])
    action, file_args = get_action(args)
    if action == "sig":
        write_sig(file_args[0], get_fileobj(file_args[1], "wb"))
    elif action == "delta":
        sig_infp = get_fileobj(file_args[0], "rb")
        delta_outfp = get_fileobj(file_args[2], "wb")
        if sig_fileobj:
            write_delta_and_sig(file_args[1], sig_infp,
                                delta_outfp, sig_fileobj)
        else:
            write_delta(file_args[1], sig_infp, delta_outfp)
    elif action == "patch":
        patch(file_args[0], get_fileobj(file_args[1], "rb"))
    elif action == "tar":
        if sig_fileobj:
            write_tar_and_sig(file_args[0],
                              get_fileobj(file_args[1], "wb"),
                              sig_fileobj)
        else:
            write_tar(file_args[0], get_fileobj(file_args[1], "wb"))
    else:
        command_line_error("Bad command " + action)


if __name__ == "__main__":
    main()
