#! /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, string, 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 = string.split(e, '/')
	    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, 'rb')
    except IOError:
	sf = None
    try:
	mf = open(master, 'rb')
    except IOError:
	mf = None
    if not sf:
	if not mf:
	    print "Not updating missing master", master
	    return
	print "Creating missing slave", slave
	copy(master, slave, answer=create_files)
	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
    # 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 = string.lower(string.strip(answer))
    if not answer or answer[0] not in 'ny':
	answer = raw_input(prompt)
	answer = string.lower(string.strip(answer))
	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)

main()
