#
# FFHO netfilter helper functions
#

import ipaddress

def generate_service_rules (services, acls, af):
	rules = []

	for srv in services:
		rule = ""
		comment = srv['descr']
		acl_comment = ""
		src_prefixes = []

		# If there are no DST IPs set at all or DST IPs for this AF set, we have a rule to build,
		# if this is NOT the case, there is no rule for this AF to generate, carry on.
		if not ((not srv['ips']['4'] and not srv['ips']['6']) or srv['ips'][str(af)]):
			continue

		# Is/are IP(s) set for this service?
		if srv['ips'][str(af)]:
			rule += "ip" if af == 4 else "ip6"

			dst_ips = srv['ips'][str(af)]
			if len (dst_ips) == 1:
				rule += " daddr %s " % dst_ips[0]
			else:
				rule += " daddr { %s } " % ", ".join (dst_ips)

		# ACLs defined for this service?
		if srv['acl']:
			srv_acl = sorted (srv['acl'])
			for ace in srv_acl:
				ace_pfx = (acls[ace][af])

				# Many entries
				if type (ace_pfx) == list:
					src_prefixes.extend (ace_pfx)
				else:
					src_prefixes.append (ace_pfx)

			acl_comment = "acl: %s" % ", ".join (srv_acl)

		# Additional prefixes defined for this service?
		if srv['additional_prefixes']:
			add_pfx = []
			# Additional prefixes are given as a space separated list
			for entry in srv['additional_prefixes'].split ():
				# Strip commas and spaces, just in case
				pfx_str = entry.strip (" ,")
				pfx_obj = ipaddress.ip_network (pfx_str)

				# We only care for additional pfx for this AF
				if pfx_obj.version != af:
					continue

				add_pfx.append (pfx_str)

			if add_pfx:
				src_prefixes.extend (add_pfx)

				if acl_comment:
					acl_comment += ", "
				acl_comment += "additional pfx"

		# Combine ACL + additional prefixes (if any)
		if src_prefixes:
			rule += "ip" if af == 4 else "ip6"
			if len (src_prefixes) > 1:
				rule += " saddr { %s } " % ", ".join (src_prefixes)
			else:
				rule += " saddr %s " % src_prefixes[0]

		if acl_comment:
			comment += " (%s)" % acl_comment

		# Multiple ports?
		if len (srv['ports']) > 1:
			ports = "{ %s }" % ", ".join (map (str, sorted (srv['ports'])))
		else:
			ports = srv['ports'][0]

		rule += "%s dport %s counter accept comment \"%s\"" % (srv['proto'], ports, comment)
		rules.append (rule)

	return rules