import py, os, stat


class RSync(object):

    def __init__(self, **options):
        for name in options:
            assert name in ('delete',)
        self.options = options
        self.channels = []

    def filter(self, path):
        return True

    def add_target(self, gateway, destdir):
        channel = gateway.remote_exec(REMOTE_SOURCE)
        channel.send((str(destdir), self.options))
        self.channels.append(channel)

    def send(self, sourcedir):
        sourcedir = str(sourcedir)
        # send directory structure and file timestamps/sizes
        self._send_directory_structure(sourcedir)
        # send modified file in a round-robin fashion to clients
        # XXX good enough for now :-(
        while self.channels:
            for channel in self.channels:
                try:
                    modified_rel_path = channel.receive()
                except EOFError:
                    self.channels.remove(channel)
                    continue
                modifiedpath = os.path.join(sourcedir, *modified_rel_path)
                f = open(modifiedpath, 'rb')
                data = f.read()
                f.close()
                channel.send(data)
                del data

    def _broadcast(self, msg):
        for channel in self.channels:
            channel.send(msg)

    def _send_directory_structure(self, path):
        st = os.lstat(path)
        if stat.S_ISREG(st.st_mode):
            # regular file: send a timestamp/size pair
            self._broadcast((st.st_mtime, st.st_size))
        elif stat.S_ISDIR(st.st_mode):
            # dir: send a list of entries
            names = []
            subpaths = []
            for name in os.listdir(path):
                p = os.path.join(path, name)
                if self.filter(p):
                    names.append(name)
                    subpaths.append(p)
            self._broadcast(names)
            for p in subpaths:
                self._send_directory_structure(p)
        elif stat.S_ISLNK(st.st_mode):
            pass     # ignore symlinks for now
        else:
            raise ValueError, "cannot sync %r" % (path,)


REMOTE_SOURCE = """
    import os, stat, shutil
    destdir, options = channel.receive() 
    modifiedfiles = []

    def remove(path):
        assert path.startswith(destdir)
        try:
            os.unlink(path)
        except OSError:
            # assume it's a dir
            shutil.rmtree(path)

    def receive_directory_structure(path, relcomponents):
        try:
            st = os.lstat(path)
        except OSError:
            st = None
        msg = channel.receive()
        if isinstance(msg, list):
            if st and not stat.S_ISDIR(st.st_mode):
                os.unlink(path)
                st = None
            if not st:
                os.mkdir(path)
            entrynames = {}
            for entryname in msg:
                receive_directory_structure(os.path.join(path, entryname),
                    relcomponents + [entryname])
                entrynames[entryname] = True
            if options.get('delete'): 
                for othername in os.listdir(path):
                    if othername not in entrynames:
                        otherpath = os.path.join(path, othername)
                        remove(otherpath)
        else:
            if st and stat.S_ISREG(st.st_mode):
                mystamp = (st.st_mtime, st.st_size)
            else:
                if st:
                    remove(path)
                mystamp = None
            if mystamp != msg:
                channel.send(relcomponents)
                modifiedfiles.append(path)
    receive_directory_structure(destdir, [])
    for path in modifiedfiles:
        data = channel.receive()
        f = open(path, 'wb')
        f.write(data)
        f.close()
        del data
"""

# ____________________________________________________________


def setup_module(mod):
    mod.gw = py.execnet.PopenGateway()
    mod.gw2 = py.execnet.PopenGateway()

def teardown_module(mod):
    mod.gw.exit()
    mod.gw2.exit()


def test_dirsync():
    base = py.test.ensuretemp('dirsync')
    dest = base.join('dest') 
    dest2 = base.join('dest2') 
    source = base.mkdir('source') 

    for s in ('content1', 'content2-a-bit-longer'): 
        source.ensure('subdir', 'file1').write(s) 
        rsync = RSync()
        rsync.add_target(gw, dest)
        rsync.add_target(gw2, dest2)
        rsync.send(source)
        assert dest.join('subdir').check(dir=1)
        assert dest.join('subdir', 'file1').check(file=1)
        assert dest.join('subdir', 'file1').read() == s 
        assert dest2.join('subdir').check(dir=1)
        assert dest2.join('subdir', 'file1').check(file=1)
        assert dest2.join('subdir', 'file1').read() == s 
    
    source.join('subdir').remove('file1')
    rsync = RSync()
    rsync.add_target(gw2, dest2)
    rsync.add_target(gw, dest)
    rsync.send(source)
    assert dest.join('subdir', 'file1').check(file=1)
    assert dest2.join('subdir', 'file1').check(file=1)
    rsync = RSync(delete=True)
    rsync.add_target(gw2, dest2)
    rsync.add_target(gw, dest)
    rsync.send(source)
    assert not dest.join('subdir', 'file1').check() 
    assert not dest2.join('subdir', 'file1').check()