# -*- coding: utf-8 -*-
#
# AWL data offset
#
# Copyright 2012-2014 Michael Buesch <m@bues.ch>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

from __future__ import division, absolute_import, print_function, unicode_literals
from awlsim.common.compat import *

from awlsim.common.datatypehelpers import *

#from awlsim.core.dynattrs cimport * #@cy

from awlsim.core.dynattrs import * #@nocy
from awlsim.core.util import *


class AwlOffset(DynAttrs): #+cdef
	"Memory area offset"

	dynAttrs = {
		# A DB-number for fully qualified access, or None.
		"dbNumber"	: None,

		# A symbolic DB-name for fully qualified access, or None.
		"dbName"	: None,

		# A DB-variable name for fully qualified access, or None.
		"varName"	: None,

		# A (S)FB-number for multi-instance calls, or None.
		"fbNumber"	: None,

		# List of Variable indices for fully qualified array access, or None.
		"indices"	: None,

		# Additional sub-offset that is added to this offset.
		# Defaults to 0.0
		# This is used for arrays and structs.
		"subOffset"	: lambda self, name: AwlOffset(),
	}

	def __init__(self, byteOffset=0, bitOffset=0):
		self.byteOffset, self.bitOffset =\
			byteOffset, bitOffset

	def dup(self):
		offset = AwlOffset(self.byteOffset,
				   self.bitOffset)
		offset.dbNumber = self.dbNumber
		return offset

	@classmethod
	def fromPointerValue(cls, value):
		return cls((value & 0x0007FFF8) >> 3,
			   (value & 0x7))

	def toPointerValue(self):
		return ((self.byteOffset << 3) & 0x0007FFF8) |\
		       (self.bitOffset & 0x7)

	@classmethod
	def fromBitOffset(cls, bitOffset):
		return cls(bitOffset // 8, bitOffset % 8)

	def toBitOffset(self):
		return self.byteOffset * 8 + self.bitOffset

	def __add__(self, other):
		bitOffset = (self.byteOffset + other.byteOffset) * 8 +\
			    self.bitOffset + other.bitOffset
		return AwlOffset(bitOffset // 8, bitOffset % 8)

	def __iadd__(self, other):
		bitOffset = (self.byteOffset + other.byteOffset) * 8 +\
			    self.bitOffset + other.bitOffset
		self.byteOffset = bitOffset // 8
		self.bitOffset = bitOffset % 8
		return self

	# Round the offset to a multiple of 'byteBase' bytes.
	# Returns an AwlOffset.
	def roundUp(self, byteBase):
		byteOffset = self.byteOffset
		if self.bitOffset:
			byteOffset += 1
		byteOffset = roundUp(byteOffset, byteBase)
		return AwlOffset(byteOffset)

	def __repr__(self):
		prefix = ""
		if self.dbNumber is not None:
			prefix = "DB%d" % self.dbNumber
		if self.dbName is not None:
			prefix = '"%s"' % self.dbName
		if self.varName is not None:
			indices = ""
			if self.indices is not None:
				indices = "[%s]" % ",".join(str(i) for i in self.indices)
			if prefix:
				return prefix + "." + self.varName + indices
			return "#%s%s" % (self.varName, indices)
		else:
			if prefix:
				prefix = prefix + ".DBX "
			return "%s%d.%d" % (prefix,
					    self.byteOffset,
					    self.bitOffset)