#! /usr/bin/env python

"""Script to synchronize two source trees.

Invoke with two arguments:

python treesync.py slave master

The assumption is that "master" contains CVS administration while

slave doesn't.  All files in the slave tree that have a CVS/Entries

entry in the master tree are synchronized.  This means:

    If the files differ:

        if the slave file is newer:

            normalize the slave file

            if the files still differ:

                copy the slave to the master

        else (the master is newer):

            copy the master to the slave

    normalizing the slave means replacing CRLF with LF when the master

    doesn't use CRLF

"""

import os, sys, stat, getopt

# Interactivity options

default_answer = "ask"

create_files = "yes"

create_directories = "no"

write_slave = "ask"

write_master = "ask"

def main():

    global always_no, always_yes

    global create_directories, write_master, write_slave

    opts, args = getopt.getopt(sys.argv[1:], "nym:s:d:f:a:")

    for o, a in opts:

        if o == '-y':

            default_answer = "yes"

        if o == '-n':

            default_answer = "no"

        if o == '-s':

            write_slave = a

        if o == '-m':

            write_master = a

        if o == '-d':

            create_directories = a

        if o == '-f':

            create_files = a

        if o == '-a':

            create_files = create_directories = write_slave = write_master = a

    try:

        [slave, master] = args

    except ValueError:

        print "usage: python", sys.argv[0] or "treesync.py",

        print "[-n] [-y] [-m y|n|a] [-s y|n|a] [-d y|n|a] [-f n|y|a]",

        print "slavedir masterdir"

        return

    process(slave, master)

def process(slave, master):

    cvsdir = os.path.join(master, "CVS")

    if not os.path.isdir(cvsdir):

        print "skipping master subdirectory", master

        print "-- not under CVS"

        return

    print "-"*40

    print "slave ", slave

    print "master", master

    if not os.path.isdir(slave):

        if not okay("create slave directory %s?" % slave,

                    answer=create_directories):

            print "skipping master subdirectory", master

            print "-- no corresponding slave", slave

            return

        print "creating slave directory", slave

        try:

            os.mkdir(slave)

        except os.error, msg:

            print "can't make slave directory", slave, ":", msg

            return

        else:

            print "made slave directory", slave

    cvsdir = None

    subdirs = []

    names = os.listdir(master)

    for name in names:

        mastername = os.path.join(master, name)

        slavename = os.path.join(slave, name)

        if name == "CVS":

            cvsdir = mastername

        else:

            if os.path.isdir(mastername) and not os.path.islink(mastername):

                subdirs.append((slavename, mastername))

    if cvsdir:

        entries = os.path.join(cvsdir, "Entries")

        for e in open(entries).readlines():

            words = e.split('/')

            if words[0] == '' and words[1:]:

                name = words[1]

                s = os.path.join(slave, name)

                m = os.path.join(master, name)

                compare(s, m)

    for (s, m) in subdirs:

        process(s, m)

def compare(slave, master):

    try:

        sf = open(slave, 'r')

    except IOError:

        sf = None

    try:

        mf = open(master, 'rb')

    except IOError:

        mf = None

    if not sf:

        if not mf:

            print "Neither master nor slave exists", master

            return

        print "Creating missing slave", slave

        copy(master, slave, answer=create_files)

        return

    if not mf:

        print "Not updating missing master", master

        return

    if sf and mf:

        if identical(sf, mf):

            return

    sft = mtime(sf)

    mft = mtime(mf)

    if mft > sft:

        # Master is newer -- copy master to slave

        sf.close()

        mf.close()

        print "Master             ", master

        print "is newer than slave", slave

        copy(master, slave, answer=write_slave)

        return

    # Slave is newer -- copy slave to master

    print "Slave is", sft-mft, "seconds newer than master"

    # But first check what to do about CRLF

    mf.seek(0)

    fun = funnychars(mf)

    mf.close()

    sf.close()

    if fun:

        print "***UPDATING MASTER (BINARY COPY)***"

        copy(slave, master, "rb", answer=write_master)

    else:

        print "***UPDATING MASTER***"

        copy(slave, master, "r", answer=write_master)

BUFSIZE = 16*1024

def identical(sf, mf):

    while 1:

        sd = sf.read(BUFSIZE)

        md = mf.read(BUFSIZE)

        if sd != md: return 0

        if not sd: break

    return 1

def mtime(f):

    st = os.fstat(f.fileno())

    return st[stat.ST_MTIME]

def funnychars(f):

    while 1:

        buf = f.read(BUFSIZE)

        if not buf: break

        if '\r' in buf or '\0' in buf: return 1

    return 0

def copy(src, dst, rmode="rb", wmode="wb", answer='ask'):

    print "copying", src

    print "     to", dst

    if not okay("okay to copy? ", answer):

        return

    f = open(src, rmode)

    g = open(dst, wmode)

    while 1:

        buf = f.read(BUFSIZE)

        if not buf: break

        g.write(buf)

    f.close()

    g.close()

def okay(prompt, answer='ask'):

    answer = answer.strip().lower()

    if not answer or answer[0] not in 'ny':

        answer = raw_input(prompt)

        answer = answer.strip().lower()

        if not answer:

            answer = default_answer

    if answer[:1] == 'y':

        return 1

    if answer[:1] == 'n':

        return 0

    print "Yes or No please -- try again:"

    return okay(prompt)

if __name__ == '__main__':

    main()