# ==================================================================================================================== #
#            __     ___   _ ____  _     ____                                                                           #
#  _ __  _   \ \   / / | | |  _ \| |   |  _ \ __ _ _ __ ___  ___ _ __                                                  #
# | '_ \| | | \ \ / /| |_| | | | | |   | |_) / _` | '__/ __|/ _ \ '__|                                                 #
# | |_) | |_| |\ 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 LinebreakToken, CommentToken, MultiLineCommentToken, IndentationToken, SingleLineCommentToken, ExtendedIdentifier, CharacterToken, SpaceToken
from pyVHDLParser.Token.Keywords      import InKeyword, ForKeyword, LoopKeyword, BoundaryToken, IdentifierToken, WordToken
from pyVHDLParser.Blocks              import BlockParserException, Block, CommentBlock, ParserState
from pyVHDLParser.Blocks.Common       import LinebreakBlock, WhitespaceBlock
from pyVHDLParser.Blocks.Generic      import SequentialBeginBlock
from pyVHDLParser.Blocks.Generic1     import EndBlock as EndBlockBase
from pyVHDLParser.Blocks.Expression   import ExpressionBlockEndedByKeywordORClosingRoundBracket, ExpressionBlockEndedByKeywordOrToOrDownto


@export
class IteratorBlock(Block):
	@classmethod
	def stateForKeyword(cls, parserState: ParserState):
		token = parserState.Token
		if isinstance(token, SpaceToken):
			parserState.NewToken =    BoundaryToken(token)
			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 whitespace after keyword FOR.", token)

	@classmethod
	def stateWhitespace1(cls, parserState: ParserState):
		token = parserState.Token
		if isinstance(token, WordToken):
			parserState.NewToken =      IdentifierToken(token)
			parserState.NextState =     cls.stateIteratorName
			return
		elif isinstance(token, ExtendedIdentifier):
			parserState.NextState =     cls.stateIteratorName
			return
		elif isinstance(token, LinebreakToken):
			if (not (isinstance(parserState.LastBlock, CommentBlock) and isinstance(parserState.LastBlock.StartToken, MultiLineCommentToken))):
				parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
				_ =                       LinebreakBlock(parserState.NewBlock, token)
			else:
				parserState.NewBlock =    LinebreakBlock(parserState.LastBlock, token)
			parserState.TokenMarker =   None
			return
		elif isinstance(token, CommentToken):
			parserState.NewBlock =      cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
			_ =                         CommentBlock(parserState.NewBlock, 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 iterator name (identifier).", token)

	@classmethod
	def stateIteratorName(cls, parserState: ParserState):
		token = parserState.Token
		if isinstance(token, SpaceToken):
			parserState.NewToken =    BoundaryToken(token)
			parserState.NextState =   cls.stateWhitespace2
			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.stateWhitespace2
			return

		raise BlockParserException("Expected whitespace after iterator name.", token)

	@classmethod
	def stateWhitespace2(cls, parserState: ParserState):
		token = parserState.Token
		if (isinstance(token, WordToken) and (token <= "in")):
			parserState.NewToken =      InKeyword(token)
			# parserState.NewBlock =      cls(parserState.LastBlock, parserState.TokenMarker, endToken=parserState.NewToken)
			# parserState.TokenMarker =   None
			parserState.NextState =     cls.stateInKeyword
			return
		elif isinstance(token, LinebreakToken):
			if (not (isinstance(parserState.LastBlock, CommentBlock) and isinstance(parserState.LastBlock.StartToken, MultiLineCommentToken))):
				parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
				_ =                       LinebreakBlock(parserState.NewBlock, token)
			else:
				parserState.NewBlock =    LinebreakBlock(parserState.LastBlock, token)
			parserState.TokenMarker =   None
			return
		elif isinstance(token, CommentToken):
			parserState.NewBlock =      cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
			_ =                         CommentBlock(parserState.NewBlock, 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 keyword IN after iterator name.", token)

	@classmethod
	def stateInKeyword(cls, parserState: ParserState):
		token = parserState.Token
		if (isinstance(token, CharacterToken) and (token == "(")):
			parserState.NewToken =    BoundaryToken(token)
			parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=parserState.NewToken.PreviousToken)
			parserState.TokenMarker = parserState.NewToken
			parserState.NextState =   LoopBlock.stateSequentialRegion
			parserState.PushState =   ExpressionBlockEndedByLoopORToORDownto.stateExpression
			return
		elif isinstance(token, SpaceToken):
			parserState.NewToken =    BoundaryToken(token)
			parserState.NextState =   cls.stateWhitespace3
			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.stateWhitespace3
			return

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

	@classmethod
	def stateWhitespace3(cls, parserState: ParserState):
		token = parserState.Token
		if isinstance(token, LinebreakToken):
			if (not (isinstance(parserState.LastBlock, CommentBlock) and isinstance(parserState.LastBlock.StartToken, MultiLineCommentToken))):
				parserState.NewBlock =    cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
				_ =                       LinebreakBlock(parserState.NewBlock, token)
			else:
				parserState.NewBlock =    LinebreakBlock(parserState.LastBlock, token)
			parserState.TokenMarker =   None
			return
		elif isinstance(token, CommentToken):
			parserState.NewBlock =      cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken, multiPart=True)
			_ =                         CommentBlock(parserState.NewBlock, 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
		else:
			parserState.NewBlock =      cls(parserState.LastBlock, parserState.TokenMarker, endToken=token.PreviousToken)
			parserState.NextState =     LoopBlock.stateLoopKeyword
			parserState.PushState =     ExpressionBlockEndedByLoop.stateExpression
			parserState.PushState =     ExpressionBlockEndedByLoopORToORDownto.stateExpression
			parserState.TokenMarker =   parserState.Token
			parserState.NextState(parserState)
			return


@export
class EndBlock(EndBlockBase):
	KEYWORD =             ForKeyword
	KEYWORD_IS_OPTIONAL = False
	EXPECTED_NAME =       KEYWORD.__KEYWORD__


@export
class LoopBlock(SequentialBeginBlock):
	END_BLOCK = EndBlock

	@classmethod
	def stateLoopKeyword(cls, parserState: ParserState):
		parserState.NextState = cls.stateSequentialRegion
		parserState.NextState(parserState)


@export
class ExpressionBlockEndedByLoopORToORDownto(ExpressionBlockEndedByKeywordOrToOrDownto):
	EXIT_KEYWORD =  LoopKeyword
	EXIT_BLOCK =    LoopBlock


@export
class ExpressionBlockEndedByLoop(ExpressionBlockEndedByKeywordORClosingRoundBracket):
	EXIT_KEYWORD = LoopKeyword
	EXIT_BLOCK =   LoopBlock


@export
class LoopIterationDirectionBlock(Block):
	pass
