# encoding: utf-8
"""
family.py

Created by Thomas Mangin on 2010-01-19.
Copyright (c) 2009-2017 Exa Networks. All rights reserved.
License: 3-clause BSD. (See the COPYRIGHT file)
"""

from struct import pack
from struct import unpack

from exabgp.util import character
from exabgp.util import ordinal
from exabgp.protocol.resource import Resource


# ======================================================================== AFI
# https://www.iana.org/assignments/address-family-numbers/

class _AFI (int):
	UNDEFINED = 0x00  # internal
	IPv4      = 0x01
	IPv6      = 0x02
	L2VPN     = 0x19
	BGPLS     = 0x4004

	_names = {
		UNDEFINED: 'undefined',
		IPv4:      'ipv4',
		IPv6:      'ipv6',
		L2VPN:     'l2vpn',
		BGPLS:     'bgp-ls',
	}

	_masks = {
		IPv4:  32,
		IPv6:  128,
	}

	def pack (self):
		return pack('!H',self)

	def name (self):
		return self._names.get(self,'unknown-afi-0x%s' % hex(self))

	def mask (self):
		return self._masks.get(self,'invalid request for this family')

	def __repr__ (self):
		return self.name()

	def __str__ (self):
		return self.name()


class AFI (Resource):
	undefined = _AFI(_AFI.UNDEFINED)
	ipv4      = _AFI(_AFI.IPv4)
	ipv6      = _AFI(_AFI.IPv6)
	l2vpn     = _AFI(_AFI.L2VPN)
	bgpls     = _AFI(_AFI.BGPLS)

	common = {
		undefined.pack(): undefined,
		ipv4.pack():      ipv4,
		ipv6.pack():      ipv6,
		l2vpn.pack():     l2vpn,
		bgpls.pack():     bgpls,
	}

	codes = dict ((k.lower().replace('_','-'),v) for (k,v) in {
		'ipv4':  ipv4,
		'ipv6':  ipv6,
		'l2vpn': l2vpn,
		'bgp-ls': bgpls,
	}.items())

	cache = dict([(r,r) for (l,r) in codes.items()])
	names = dict([(r,l) for (l,r) in codes.items()])

	inet_names = dict([(r,l.replace('ipv','inet')) for (l,r) in codes.items()])

	def name (self):
		return self.inet_names.get(self,"unknown afi")

	@staticmethod
	def unpack (data):
		return AFI.common.get(data,_AFI(unpack('!H',data)[0]))

	@classmethod
	def value (cls,name):
		return cls.codes.get(name,None)

	@staticmethod
	def implemented_safi (afi):
		if afi == 'ipv4':
			return ['unicast','multicast','nlri-mpls','mpls-vpn','flow','flow-vpn']
		if afi == 'ipv6':
			return ['unicast','mpls-vpn','flow','flow-vpn']
		if afi == 'l2vpn':
			return ['vpls','evpn']
		if afi == 'bgp-ls':
			return ['bgp-ls','bgp-ls-vpn']
		return []

	@classmethod
	def fromString (cls, string):
		return cls.codes.get(string,cls.undefined)

	@classmethod
	def create (cls, value):
		return cls.cache.get(value,_AFI(value))


# ======================================================================= SAFI
# https://www.iana.org/assignments/safi-namespace

class _SAFI (int):
	UNDEFINED  = 0              # internal
	UNICAST    = 1              # [RFC4760]
	MULTICAST  = 2              # [RFC4760]
	NLRI_MPLS  = 4              # [RFC3107]
	VPLS       = 65             # [RFC4761]
	EVPN       = 70             # [draft-ietf-l2vpn-evpn]
	BGPLS      = 71             # [RFC7752]
	BGPLS_VPN  = 72             # [RFC7752]
	MPLS_VPN   = 128            # [RFC4364]
	RTC        = 132            # [RFC4684]
	FLOW_IP    = 133            # [RFC5575]
	FLOW_VPN   = 134            # [RFC5575]
	# deprecated = 3            # [RFC4760]
	# mcast_vpn = 5             # [draft-ietf-l3vpn-2547bis-mcast-bgp] (TEMPORARY - Expires 2008-06-19)
	# pseudowire = 6            # [draft-ietf-pwe3-dynamic-ms-pw] (TEMPORARY - Expires 2008-08-23) Dynamic Placement of Multi-Segment Pseudowires
	# encapsulation = 7         # [RFC5512]
	# tunel = 64                # [Nalawade]
	# bgp_mdt = 66              # [Nalawade]
	# bgp_4over6 = 67           # [Cui]
	# bgp_6over4 = 67           # [Cui]
	# vpn_adi = 69              # [RFC-ietf-l1vpn-bgp-auto-discovery-05.txt]
	# mcast_bgp_mpls_vpn = 129  # [RFC2547]
	# rt = 132                  # [RFC4684]
	# vpn_ad = 140              # [draft-ietf-l3vpn-bgpvpn-auto]
	# private = [_ for _ in range(241,254)]   # [RFC4760]
	# unassigned = [_ for _ in range(8,64)] + [_ for _ in range(70,128)]
	# reverved = [0,3] + [130,131] + [_ for _ in range(135,140)] + [_ for _ in range(141,241)] + [255,]    # [RFC4760]

	_names = {
		UNICAST:   'unicast',
		MULTICAST: 'multicast',
		NLRI_MPLS: 'nlri-mpls',
		VPLS:      'vpls',
		EVPN:      'evpn',
		BGPLS:     'bgp-ls',
		BGPLS_VPN: 'bgp-ls-vpn',
		MPLS_VPN:  'mpls-vpn',
		RTC:       'rtc',
		FLOW_IP:   'flow',
		FLOW_VPN:  'flow-vpn',
	}

	def pack (self):
		return character(self)

	def name (self):
		return self._names.get(self,'unknown safi %d' % int(self))

	def has_label (self):
		return self in (SAFI.nlri_mpls,SAFI.mpls_vpn)

	def has_rd (self):
		return self in (SAFI.nlri_mpls,SAFI.mpls_vpn,SAFI.flow_vpn)
		# technically self.flow_vpn and self.vpls has an RD but it is not an NLRI

	def has_path (self):
		return self in (SAFI.unicast,SAFI.nlri_mpls)
		# technically self.flow_vpn and self.vpls has an RD but it is not an NLRI

	def __str__ (self):
		return self.name()

	def __repr__ (self):
		return str(self)


class SAFI (Resource):
	undefined  = _SAFI(_SAFI.UNDEFINED)
	unicast    = _SAFI(_SAFI.UNICAST)
	multicast  = _SAFI(_SAFI.MULTICAST)
	nlri_mpls  = _SAFI(_SAFI.NLRI_MPLS)
	vpls       = _SAFI(_SAFI.VPLS)
	evpn       = _SAFI(_SAFI.EVPN)
	bgp_ls     = _SAFI(_SAFI.BGPLS)
	bgp_ls_vpn = _SAFI(_SAFI.BGPLS_VPN)
	mpls_vpn   = _SAFI(_SAFI.MPLS_VPN)
	rtc        = _SAFI(_SAFI.RTC)
	flow_ip    = _SAFI(_SAFI.FLOW_IP)
	flow_vpn   = _SAFI(_SAFI.FLOW_VPN)

	common = {
		undefined.pack():  undefined,
		unicast.pack():    unicast,
		multicast.pack():  multicast,
		nlri_mpls.pack():  nlri_mpls,
		vpls.pack():       vpls,
		evpn.pack():       evpn,
		bgp_ls.pack():     bgp_ls,
		bgp_ls_vpn.pack(): bgp_ls_vpn,
		mpls_vpn.pack():   mpls_vpn,
		rtc.pack():        rtc,
		flow_ip.pack():    flow_ip,
		flow_vpn.pack():   flow_vpn,
	}

	codes = dict ((k.lower().replace('_','-'),v) for (k,v) in {
		'unicast':   unicast,
		'multicast': multicast,
		'nlri-mpls': nlri_mpls,
		'vpls':      vpls,
		'evpn':      evpn,
		'bgp-ls':    bgp_ls,
		'bgp-ls-vpn':bgp_ls_vpn,
		'mpls-vpn':  mpls_vpn,
		'rtc':       rtc,
		'flow':      flow_ip,
		'flow-vpn':  flow_vpn,
	}.items())

	cache = dict([(r,r) for (l,r) in codes.items()])

	@staticmethod
	def unpack (data):
		return SAFI.common.get(data,_SAFI(ordinal(data)))

	@classmethod
	def value (cls,name):
		return cls.codes.get(name,None)

	@classmethod
	def fromString (cls, string):
		return cls.codes.get(string,cls.undefined)

	@classmethod
	def create (cls, value):
		return cls.cache.get(value,_SAFI(value))


# ===================================================================== FAMILY


class Family (object):
	size = {
		# family                   next-hop   RD
		(AFI.ipv4,SAFI.unicast):   ((4,),      0),
		(AFI.ipv4,SAFI.multicast): ((4,),      0),
		(AFI.ipv4,SAFI.nlri_mpls): ((4,),      0),
		(AFI.ipv4,SAFI.mpls_vpn):  ((12,),     8),
		(AFI.ipv4,SAFI.flow_ip):   ((0,4),     0),
		(AFI.ipv4,SAFI.flow_vpn):  ((0,4),     0),
		(AFI.ipv4,SAFI.rtc):       ((4,16),    0),
		(AFI.ipv6,SAFI.unicast):   ((16,32),   0),
		(AFI.ipv6,SAFI.nlri_mpls): ((16,32),   0),
		(AFI.ipv6,SAFI.mpls_vpn):  ((24,40),   8),
		(AFI.ipv6,SAFI.flow_ip):   ((0,16,32), 0),
		(AFI.ipv6,SAFI.flow_vpn):  ((0,16,32), 0),
		(AFI.l2vpn,SAFI.vpls):     ((4,),      0),
		(AFI.l2vpn,SAFI.evpn):     ((4,),      0),
		(AFI.bgpls,SAFI.bgp_ls):   ((4,),      0),
	}

	__slots__ = ['afi','safi']

	def __init__ (self, afi, safi):
		self.afi = AFI.create(afi)
		self.safi = SAFI.create(safi)

	def has_label (self):
		return self.safi.has_label()

	def has_rd (self):
		return self.safi.has_rd()

	def has_path (self):
		return self.safi.has_path()

	def __eq__ (self, other):
		return \
			self.afi == other.afi and \
			self.safi == other.safi

	def __neq__ (self, other):
		return \
			self.afi != other.afi or \
			self.safi != other.safi

	def __lt__ (self, other):
		raise RuntimeError('comparing Family for ordering does not make sense')

	def __le__ (self, other):
		raise RuntimeError('comparing Family for ordering does not make sense')

	def __gt__ (self, other):
		raise RuntimeError('comparing Family for ordering does not make sense')

	def __ge__ (self, other):
		raise RuntimeError('comparing Family for ordering does not make sense')

	def family (self):
		return (self.afi,self.safi)

	def extensive (self):
		return 'afi %s safi %s' % (self.afi,self.safi)

	def __repr__ (self):
		return "%s %s" % (str(self.afi),str(self.safi))
