import sys

from pyparsing import *
ParserElement.enablePackrat()

filename = sys.argv[1]

code = file(filename).read()

hlslFile = Forward()
hlslStructDefinition = Forward()
hlslExpression = Forward()
hlslNoArithmeticExpr = Forward()
hlslNoComparisonExpr = Forward()
hlslStatement = Forward()
hlslFunctionBody = Forward()
hlslFunctionLine = Forward()

hlslLine = hlslStatement + Suppress(';')

hlslComment = cppStyleComment 

hlslIdentifier = Regex(r'[a-zA-Z_][a-zA-Z0-9_]*')
hlslHexNumber = Regex(r'0x[0-9a-fA-F]+')
hlslNumber = hlslHexNumber ^ Regex(r'-?[0-9]+(\.[0-9]*f?)?')
hlslSubscript = Suppress('[') + hlslExpression + Suppress(']')
hlslOperand = hlslIdentifier + ZeroOrMore((Suppress('.') + hlslIdentifier) ^ hlslSubscript)

hlslVariableDecl = Group(hlslIdentifier + hlslIdentifier + Optional(hlslSubscript))
hlslAssignmentOp = Group(Optional(Regex(r'[\-+/*%\^&^]')) + Suppress('='))
hlslAssignment = (hlslVariableDecl ^ hlslOperand ^ hlslIdentifier) + hlslAssignmentOp + hlslExpression

hlslStructMember = Group(hlslIdentifier + hlslIdentifier + Suppress(':') + hlslIdentifier + Suppress(';'))

hlslStructDefinition << (Keyword('struct') + hlslIdentifier + Suppress('{') + ZeroOrMore(hlslStructMember) + Suppress('}') + Suppress(';'))

hlslFunctionArgs = \
Group(
    OneOrMore(hlslIdentifier) + 
    Optional(hlslSubscript) + 
    Optional(Suppress('<') + hlslIdentifier + Suppress('>')) + 
    Optional(hlslIdentifier) + 
    Optional(Suppress(':') + hlslIdentifier)
)

hlslMaxVertex = Group(Suppress('[') + Keyword('maxvertexcount') + Suppress('(') + hlslNumber + Suppress(')') + Suppress(']'))
hlslFunctionDefinition = \
(
    Optional(hlslMaxVertex) + 
    OneOrMore(hlslIdentifier) + 
    Suppress('(') + Optional(delimitedList(hlslFunctionArgs)) + Suppress(')') + 
    Optional(Suppress(':') + hlslIdentifier)
)

hlslStateDecl = \
Group(
    hlslIdentifier + Optional(hlslSubscript) + Suppress('=') + 
    (hlslIdentifier ^ hlslNumber) + 
    Suppress(';')
)
hlslSamplerState = \
Group(
    Keyword('SamplerState') + hlslIdentifier + 
    Suppress('{') + 
    ZeroOrMore(hlslStateDecl) + 
    Suppress('}') + Suppress(';')
)
hlslBlendState = \
Group(
    Keyword('BlendState') + hlslIdentifier + 
    Suppress('{') + 
    ZeroOrMore(hlslStateDecl) + 
    Suppress('}') + Suppress(';')
)
hlslDepthStencilState = \
Group(
    Keyword('DepthStencilState') + hlslIdentifier + 
    Suppress('{') + 
    ZeroOrMore(hlslStateDecl) + 
    Suppress('}') + Suppress(';')
)

hlslCBuffer = \
Group(
    Keyword('cbuffer') + hlslIdentifier +
    Suppress('{') + 
    ZeroOrMore((hlslAssignment ^ hlslVariableDecl) + Suppress(';')) + 
    Suppress('}') + Suppress(';')
)

hlslForLoop = \
Group(
    Keyword('for') + Suppress('(') +
    hlslExpression + Suppress(';') + 
    hlslExpression + Suppress(';') + 
    hlslExpression + Suppress(')') + 
    Suppress('{') + 
    hlslFunctionBody + 
    Suppress('}')
)

hlslIfStatement = \
Group(
    Optional(Keyword('branch') ^ Keyword('flatten')) + 
    Keyword('if') + Suppress('(') + hlslExpression + Suppress(')') +
    ((Suppress('{') + hlslFunctionBody + Suppress('}')) ^ hlslFunctionLine) +
    Optional(
        Suppress('else') + 
        ((Suppress('{') + hlslFunctionBody + Suppress('}')) ^ hlslFunctionLine)
    )
)

hlslPass = Keyword('pass') + hlslIdentifier + Suppress('{') + Group(ZeroOrMore(hlslLine)) + Suppress('}')

hlslTechnique = Group(Keyword('technique10') + hlslIdentifier + Suppress('{') + Group(ZeroOrMore(hlslPass)) + Suppress('}'))

hlslFunctionCall = hlslOperand + Suppress('(') + Group(Optional(delimitedList(hlslExpression))) + Suppress(')')

hlslReturnStatement = Keyword('return') + hlslExpression

hlslArithmetic = hlslNoArithmeticExpr + Regex(r'[\-+/*%\^&^]') + hlslExpression

hlslIncDec = (hlslOperand ^ hlslIdentifier) + (Literal('--') ^ Literal('++'))
hlslNegative = Literal('-') + hlslExpression
hlslUnary = hlslIncDec ^ hlslNegative

hlslComparison = hlslNoComparisonExpr + Regex(r'(<=^<^>=^>^==^!=)') + hlslExpression

hlslCast = Suppress('(') + hlslIdentifier + Suppress(')')

hlslGroup = Suppress('(') + hlslExpression + Suppress(')')

hlslNoArithmeticExpr << \
Group(
    Optional(hlslCast) + 
    (
        hlslGroup ^ 
        hlslAssignment ^ 
        hlslFunctionCall ^ 
        hlslOperand ^ 
        hlslIdentifier ^ 
        hlslNumber ^
        hlslUnary
    )
)

hlslNoComparisonExpr << \
Group(
    Optional(hlslCast) + 
    (
        hlslGroup ^ 
        hlslAssignment ^ 
        hlslFunctionCall ^ 
        hlslOperand ^ 
        hlslIdentifier ^ 
        hlslNumber ^ 
        hlslArithmetic ^
        hlslUnary
    )
)

hlslExpression << \
Group(
    Optional(hlslCast) + 
    (
        hlslGroup ^ 
        hlslAssignment ^ 
        hlslFunctionCall ^ 
        hlslOperand ^ 
        hlslIdentifier ^ 
        hlslNumber ^ 
        hlslArithmetic ^ 
        hlslUnary ^ 
        hlslComparison
    )
)

hlslStatement << Group(hlslReturnStatement | hlslVariableDecl | hlslExpression)

hlslFunctionLine << hlslLine ^ hlslIfStatement ^ hlslForLoop
hlslFunctionBody << Group(ZeroOrMore(hlslFunctionLine))

hlslFunction = Group(hlslFunctionDefinition + Suppress('{') + hlslFunctionBody +
        Suppress('}'))

hlslAssignStmt = Group(hlslAssignment + Suppress(';'))

hlslBlock = \
(
    hlslFunction ^ 
    hlslTechnique ^ 
    hlslAssignStmt ^ 
    hlslStructDefinition ^ 
    hlslSamplerState ^ 
    hlslDepthStencilState ^
    hlslBlendState ^ 
    hlslCBuffer
)

hlslFile << (ZeroOrMore(hlslBlock) + StringEnd())

hlslFile.ignore(hlslComment)

hlslFile.validate()

try:
    print hlslFile.parseString(code)
except ParseException, pe:
    print "Parsing failed"
    print pe.markInputline()
    print pe.msg