#!/usr/bin/env python
"""Run diff3 and an interactive tool if this fails.
"""

__copyright__ = """
Copyright (C) 2006, Catalin Marinas <catalin.marinas@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

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 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
"""

import sys, os

if len(sys.argv) != 5:
    print >> sys.stderr, 'Usage: %s ancestor branch1 branch2 output' \
          % sys.argv[0]
    sys.exit(1)

ancestor = sys.argv[1]
branch1  = sys.argv[2]
branch2  = sys.argv[3]
output   = sys.argv[4]

# default merger
if os.system('diff3 -L current -L ancestor -L patched -m -E '
             '"%s" "%s" "%s" > "%s"'
             % (branch1, ancestor, branch2, output)):
    # interactive merge
    if os.path.exists(output):
        mtime = os.path.getmtime(output)
    else:
        mtime = 0

    ret = os.system('emacs --eval \'(ediff-merge-files-with-ancestor '
                    '"%s" "%s" "%s" nil "%s")\''
                    % (branch1, branch2, ancestor, output))

    #ret = os.system(
    #    'xxdiff --title1 current --title2 ancestor --title3 patched '
    #    '--show-merged-pane -m -E -O -X -M "%s" "%s" "%s" "%s"'
    #    % (output, branch1, ancestor, branch2))

    # error in the interactive merger, just exit
    if ret:
        sys.exit(2)

    # check for file modification
    if not os.path.exists(output) or mtime == os.path.getmtime(output):
        sys.exit(3)

# everything's fine
sys.exit(0)