# protobuf_parser.py

#

#  simple parser for parsing protobuf .proto files

#

#  Copyright 2010, Paul McGuire

#



from pyparsing import (Word, alphas, alphanums, Regex, Suppress, Forward,

    Group, oneOf, ZeroOrMore, Optional, delimitedList, Keyword,

    restOfLine, quotedString)



ident = Word(alphas+"_",alphanums+"_").setName("identifier")

integer = Regex(r"[+-]?\d+")



LBRACE,RBRACE,LBRACK,RBRACK,LPAR,RPAR,EQ,SEMI = map(Suppress,"{}[]()=;")



kwds = """message required optional repeated enum extensions extends extend 

          to package service rpc returns true false option import"""

for kw in kwds.split():

    exec("%s_ = Keyword('%s')" % (kw.upper(), kw))



messageBody = Forward()



messageDefn = MESSAGE_ - ident("messageId") + LBRACE + messageBody("body") + RBRACE



typespec = oneOf("""double float int32 int64 uint32 uint64 sint32 sint64 

                    fixed32 fixed64 sfixed32 sfixed64 bool string bytes""") | ident

rvalue = integer | TRUE_ | FALSE_ | ident

fieldDirective = LBRACK + Group(ident + EQ + rvalue) + RBRACK

fieldDefn = (( REQUIRED_ | OPTIONAL_ | REPEATED_ )("fieldQualifier") - 

              typespec("typespec") + ident("ident") + EQ + integer("fieldint") + ZeroOrMore(fieldDirective) + SEMI)



# enumDefn ::= 'enum' ident '{' { ident '=' integer ';' }* '}'

enumDefn = ENUM_ - ident + LBRACE + ZeroOrMore( Group(ident + EQ + integer + SEMI) ) + RBRACE



# extensionsDefn ::= 'extensions' integer 'to' integer ';'

extensionsDefn = EXTENSIONS_ - integer + TO_ + integer + SEMI



# messageExtension ::= 'extend' ident '{' messageBody '}'

messageExtension = EXTEND_ - ident + LBRACE + messageBody + RBRACE



# messageBody ::= { fieldDefn | enumDefn | messageDefn | extensionsDefn | messageExtension }*

messageBody << Group(ZeroOrMore( Group(fieldDefn | enumDefn | messageDefn | extensionsDefn | messageExtension) ))



# methodDefn ::= 'rpc' ident '(' [ ident ] ')' 'returns' '(' [ ident ] ')' ';'

methodDefn = (RPC_ - ident("methodName") + 

              LPAR + Optional(ident("methodParam")) + RPAR + 

              RETURNS_ + LPAR + Optional(ident("methodReturn")) + RPAR)



# serviceDefn ::= 'service' ident '{' methodDefn* '}'

serviceDefn = SERVICE_ - ident("serviceName") + LBRACE + ZeroOrMore(Group(methodDefn)) + RBRACE



# packageDirective ::= 'package' ident [ '.' ident]* ';'

packageDirective = Group(PACKAGE_ - delimitedList(ident, '.', combine=True) + SEMI)



comment = '//' + restOfLine



importDirective = IMPORT_ - quotedString("importFileSpec") + SEMI



optionDirective = OPTION_ - ident("optionName") + EQ + quotedString("optionValue") + SEMI



topLevelStatement = Group(messageDefn | messageExtension | enumDefn | serviceDefn | importDirective | optionDirective)



parser = Optional(packageDirective) + ZeroOrMore(topLevelStatement)



parser.ignore(comment)





test1 = """message Person { 

  required int32 id = 1; 

  required string name = 2; 

  optional string email = 3; 

}"""



test2 = """package tutorial;



message Person {

  required string name = 1;

  required int32 id = 2;

  optional string email = 3;



  enum PhoneType {

    MOBILE = 0;

    HOME = 1;

    WORK = 2;

  }



  message PhoneNumber {

    required string number = 1;

    optional PhoneType type = 2 [default = HOME];

  }



  repeated PhoneNumber phone = 4;

}



message AddressBook {

  repeated Person person = 1;

}"""



from pprint import pprint

#~ print parser.parseString(test2, parseAll=True).dump()

pprint( parser.parseString(test2, parseAll=True).asList())