# ==================================================================================================================== #
#            __     ___   _ ____  _     ____                                                                           #
#  _ __  _   \ \   / / | | |  _ \| |   |  _ \ __ _ _ __ ___  ___ _ __                                                  #
# | '_ \| | | \ \ / /| |_| | | | | |   | |_) / _` | '__/ __|/ _ \ '__|                                                 #
# | |_) | |_| |\ V / |  _  | |_| | |___|  __/ (_| | |  \__ \  __/ |                                                    #
# | .__/ \__, | \_/  |_| |_|____/|_____|_|   \__,_|_|  |___/\___|_|                                                    #
# |_|    |___/                                                                                                         #
# ==================================================================================================================== #
# Authors:                                                                                                             #
#   Patrick Lehmann                                                                                                    #
#                                                                                                                      #
# License:                                                                                                             #
# ==================================================================================================================== #
# Copyright 2017-2021 Patrick Lehmann - Boetzingen, Germany                                                            #
# Copyright 2016-2017 Patrick Lehmann - Dresden, Germany                                                               #
#                                                                                                                      #
# Licensed under the Apache License, Version 2.0 (the "License");                                                      #
# you may not use this file except in compliance with the License.                                                     #
# You may obtain a copy of the License at                                                                              #
#                                                                                                                      #
#   http://www.apache.org/licenses/LICENSE-2.0                                                                         #
#                                                                                                                      #
# Unless required by applicable law or agreed to in writing, software                                                  #
# distributed under the License is distributed on an "AS IS" BASIS,                                                    #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.                                             #
# See the License for the specific language governing permissions and                                                  #
# limitations under the License.                                                                                       #
# ==================================================================================================================== #
#
from pyTooling.Decorators           import export

from pyVHDLParser.Token             import SpaceToken, LinebreakToken, CommentToken, IndentationToken, SingleLineCommentToken, MultiLineCommentToken
from pyVHDLParser.Token             import CharacterToken
from pyVHDLParser.Token.Keywords    import BoundaryToken, EndToken
from pyVHDLParser.Blocks            import Block, ParserState, CommentBlock, BlockParserException
from pyVHDLParser.Blocks.Common     import LinebreakBlock, WhitespaceBlock
from pyVHDLParser.Blocks.Generic1   import EndOfStatementBlock


@export
class EndBlock(EndOfStatementBlock):
	pass


@export
class NullBlock(Block):
	@classmethod
	def stateNullKeyword(cls, parserState: ParserState):
		token = parserState.Token
		if (isinstance(token, CharacterToken) and (token == ";")):
			parserState.NewToken =    EndToken(token)
			parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=parserState.NewToken)
			parserState.Pop()
			return
		elif isinstance(token, SpaceToken):
			parserState.NextState =   cls.stateWhitespace1
			return
		elif isinstance(token, (LinebreakToken, CommentToken)):
			block =                   LinebreakBlock if isinstance(token, LinebreakToken) else CommentBlock
			parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
			_ =                       block(parserState.NewBlock, token)
			parserState.TokenMarker = None
			parserState.NextState =   cls.stateWhitespace1
			return

		raise BlockParserException("Expected ';' or whitespace after keyword NULL.", token)

	@classmethod
	def stateWhitespace1(cls, parserState: ParserState):
		token = parserState.Token
		if (isinstance(token, CharacterToken) and (token == ";")):
			parserState.NewToken =    EndToken(token)
			parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=parserState.NewToken)
			parserState.Pop()
			return
		elif isinstance(token, (LinebreakToken, CommentToken)):
			block =                   LinebreakBlock if isinstance(token, LinebreakToken) else CommentBlock
			parserState.NewBlock =    block(parserState.LastBlock, token)
			parserState.TokenMarker = None
			return
		elif (isinstance(token, IndentationToken) and isinstance(token.PreviousToken, (LinebreakToken, SingleLineCommentToken))):
			return
		elif (isinstance(token, SpaceToken) and (isinstance(parserState.LastBlock, CommentBlock) and isinstance(parserState.LastBlock.StartToken, MultiLineCommentToken))):
			parserState.NewToken =    BoundaryToken(token)
			parserState.NewBlock =    WhitespaceBlock(parserState.LastBlock, parserState.NewToken)
			parserState.TokenMarker = None
			return

		raise BlockParserException("Expected ';'.", token)
