import py 
import vsync 

rsync = py.path.local.sysfind('rsync') 

def debug(msg):
    """ report debug output. """
    pass # print "DEBUG:", msg 

def warn(msg):
    """ report warnings. """ 
    print "WARN:", msg 

def info(msg):
    """ report warnings. """ 
    print "INFO:", msg 

def error(msg):
    """ report errors. """ 
    print "ERROR:", msg 

def getdatepaths(backupdir, name): 
    l = []
    for x in backupdir.listdir(): 
        if x.basename.startswith(name): 
            try:
                date = vsync.parsedate(x.basename[len(name)+1:]) 
            except ValueError: 
                warn("parse-error (ignore) %s" % str(x)) 
                continue
            l.append(vsync.DatedPath(x, date)) 
    return l 

def cleanupbyconf(cfg, date): 
    datepaths = getdatepaths(py.path.local(cfg.backupdir), cfg.name) 
    l = []
    for x in ('years', 'months', 'weeks', 'days'): 
        value = int(getattr(cfg, x, 2)) 
        l.append((x, value))
    kw = dict(l) 
    remaining, removable = vsync.sortout(date, datepaths, **kw) 
    for x in removable: 
        info("renaming and then removing %s" % x.path.basename)
        y = x.path + '_temp' 
        x.path.rename(y) 
        y.remove() 

def make_new_datepath(backupdir, name, date):
    datestring = vsync.unparsedate(date)
    p = backupdir.join("%s-%s" %(name, datestring)) 
    dp = vsync.DatedPath(p, date) 
    assert not dp.path.check()
    return dp 

def getyoungest(backupdir, name):
    l = getdatepaths(backupdir, name)
    l.sort()
    if l:
        return l[-1]

def syncbyconf(cfg, date):
    """ rsync according to the given specification. """
    backupdir = py.path.local(cfg.backupdir)
    assert backupdir.dirpath().check()
    backupdir.ensure(dir=1) 
    name = cfg.name 
    youngestpath = getyoungest(backupdir, name)
    dp = make_new_datepath(backupdir, name, date) 
    if youngestpath: 
        assert youngestpath.date < dp.date, "date confusion!"

    source = cfg.source
    tempdest = dp.path + '_temp' 
    if '@' in str(source) or ':' in str(source): 
        compress = 'z'
    else:
        compress = ''
    options = ['--delete', '--numeric-ids', '-ax' + compress, ]
    exclude = getattr(cfg, 'exclude', None) 
    if exclude: 
        l = [("--exclude=%s" % x) for x in exclude.split()]
        options.extend(l) 
    ssh = getattr(cfg, 'ssh', None) 
    if ssh: 
        l = ["-e", str(ssh)] 
        options.extend(l) 
    if youngestpath:
        options.append("--link-dest=%s" % str(youngestpath.path)) 
    
    options.extend([str(source), str(tempdest)]) 
    debug("executing: rsync " + " ".join(options)) 
    try:
        info("starting sync to %s from %s" %(tempdest.basename, source)) 
        rsync.sysexec(*options) 
    except py.process.cmdexec.Error, ex:
        s = str(ex)
        if ex.status == 24 or ex.status == 23: 
            warn("flakey: rsync %s\n%s" % (" ".join(options), s))
        else:
            error("FAILED rsync %s \n%s" % (" ".join(options), s))
            if tempdest.check():
                warn("removing temp directory %s" % tempdest) 
                tempdest.remove() 
            raise
    tempdest.rename(dp.path) 
    info("sucessfully synced %s from %s" % (dp.path.basename, source))