#!/usr/bin/python

# opendiff2.py, by Steve Nygard

import getopt, os, shutil, string, sys
import posixpath

# When this is called from the shell script that makes sure FileMerge is running, it would pass in -s $PPID

class Usage(Exception):
    def __init__(self, msg):
        self.msg = msg

def usage():
    print "opendiff2.py 1.1 (2006-12-19)"
    print "Usage: opendiff2 [-u] [-L label] [-s session_id] <path1> <path2>"
    print

def main(argv=None):
    if (argv == None):
        argv = sys.argv

    session_id = "%d" % os.getppid()
    labels = []
    filenames = []

    try:
        opts, args = getopt.getopt(argv[1:], 'uL:s:');
    except getopt.error, msg:
        raise Usage(msg)

    for opt, arg in opts:
        if opt == '-u':
            pass
        if opt == '-L':
            (filename, desc) = string.split(arg, '\t', 1)
            filename = os.path.basename(filename)
            filenames.append(filename)
            labels.append(" ".join([filename, desc]))
        if opt == '-s':
            session_id = arg

    try:
        os.mkdir('/tmp/opendiff2')
    except OSError:
        pass

    try:
        os.mkdir('/tmp/opendiff2/%s' % session_id)
    except OSError:
        pass

    source1 = posixpath.join(posixpath.abspath(os.curdir), args[0])
    source2 = posixpath.join(posixpath.abspath(os.curdir), args[1])
    target1 = "/tmp/opendiff2/%s/%s" % (session_id, labels[0])
    target2 = "/tmp/opendiff2/%s/%s" % (session_id, labels[1])

    # Subversion 1.4.2 is giving the same label on file additions: i.e. "Foo.h\t(revision 0)"
    if target1 == target2:
        target2 = target2 + "-b"

    # Create hard links to foil FileMerge.
    #print "linking", source1, "to", target1
    #os.link(source1, target1)
    #print "linking", source2, "to", target2
    #os.link(source2, target2)

    # Alas, this is foiled because FileMerge resolves the symbolic links and shows you the orignal, ugly, useless name.  Bastards.
    #os.symlink(source1, target1)
    #os.symlink(source2, target2)

    #print "copying", source1, "to", target1
    #print "copying", source2, "to", target2
    shutil.copy(source1, target1)
    shutil.copy(source2, target2)
    os.system("Launcher")
    os.execv('/usr/bin/opendiff', ['opendiff', target1, target2])

if __name__ == '__main__':
    sys.exit(main())