from aux import *	# to be removed
import portage, os, sys

sys.path.insert(0, "/usr/lib/portage/pym")

__transports__ = {}

def addTransport(protocol, handler):
	if not protocol in __transports__.keys():
		__transports__[protocol] = handler
	else:
		raise Exception("protocol %s already registered with %s" % (protocol, handler))

	
def getTransport(protocol):
	if protocol in __transports__.keys():
		return __transports__[protocol]
	else:
		return None


def removeTransport(protocol):
	try:
		__transports__.pop(protocol)
	except:
		pass


def getTransportList():
	return __transports__.keys()


class Connection:
	def create(self, src, dest, settings):
		src = src.strip()
		dest = os.path.normpath(dest)
		
		pos = src.find("://")
		if pos <= 0:
			raise Exception("invalid SYNC setting: %s" % src)
		elif src[:pos] not in getTransportList():
			raise Exception("unknown or unsupported transport type in SYNC: %s" % src[:pos])
		else:
			transtype = src[:pos]
			myconnection = getTransport(src[:pos])
	
			os.umask(0022)

			if not os.path.exists(dest):
				os.makedirs(dest, mode=0755)

			return myconnection(src, dest, settings)
			

	# check if a given command is available
	def toolcheck(self, cmd, pkg, quiet=True):
		if os.access(cmd, os.X_OK) and os.path.isfile(cmd):
			return True
		elif quiet:
			return False
		else:
			warn("%s does not exist or is not executable, so %s-sync support" % (cmd, self.transtype))
			warn("is disabled. Emerge \"%s\" to enable %s-sync support" % (pkg, self.transtype))
			return False

	create = classmethod(create)
	toolcheck = classmethod(toolcheck)


# dynamically loading all sync modules	
modulelist = portage.listdir("/usr/lib/portage/pym/sync", 
							filesonly=1, ignorecvs=1, 
							ignorelist=["aux.py", "__init__.py"])
modulelist = filter(isPythonSourceFile, modulelist)
for m in modulelist:
	__import__("sync."+m[:-3])