# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import os, sys
from ply import lex, yacc

from ipdl.ast import *

##-----------------------------------------------------------------------------

class ParseError(Exception):
    def __init__(self, loc, fmt, *args):
        self.loc = loc
        self.error = ('%s%s: error: %s'% (
            Parser.includeStackString(), loc, fmt)) % args
    def __str__(self):
        return self.error

def _safeLinenoValue(t):
    lineno, value = 0, '???'
    if hasattr(t, 'lineno'): lineno = t.lineno
    if hasattr(t, 'value'):  value = t.value
    return lineno, value

def _error(loc, fmt, *args):
    raise ParseError(loc, fmt, *args)

class Parser:
    # when we reach an |include [protocol] foo;| statement, we need to
    # save the current parser state and create a new one.  this "stack" is
    # where that state is saved
    #
    # there is one Parser per file
    current = None
    parseStack = [ ]
    parsed = { }

    def __init__(self, type, name, debug=0):
        assert type and name
        self.type = type
        self.debug = debug
        self.filename = None
        self.includedirs = None
        self.loc = None         # not always up to date
        self.lexer = None
        self.parser = None
        self.tu = TranslationUnit(type, name)
        self.direction = None

    def parse(self, input, filename, includedirs):
        assert os.path.isabs(filename)

        if filename in Parser.parsed:
            return Parser.parsed[filename].tu

        self.lexer = lex.lex(debug=self.debug,
                             optimize=not self.debug,
                             lextab="ipdl_lextab")
        self.parser = yacc.yacc(debug=self.debug,
                                optimize=not self.debug,
                                tabmodule="ipdl_yacctab")
        self.filename = filename
        self.includedirs = includedirs
        self.tu.filename = filename

        Parser.parsed[filename] = self
        Parser.parseStack.append(Parser.current)
        Parser.current = self

        try:
            ast = self.parser.parse(input=input, lexer=self.lexer,
                                    debug=self.debug)
        finally:
            Parser.current = Parser.parseStack.pop()

        return ast

    def resolveIncludePath(self, filepath):
        '''Return the absolute path from which the possibly partial
|filepath| should be read, or |None| if |filepath| cannot be located.'''
        for incdir in self.includedirs +[ '' ]:
            realpath = os.path.join(incdir, filepath)
            if os.path.isfile(realpath):
                return os.path.abspath(realpath)
        return None

    # returns a GCC-style string representation of the include stack.
    # e.g.,
    #   in file included from 'foo.ipdl', line 120:
    #   in file included from 'bar.ipd', line 12:
    # which can be printed above a proper error message or warning
    @staticmethod
    def includeStackString():
        s = ''
        for parse in Parser.parseStack[1:]:
            s += "  in file included from `%s', line %d:\n"% (
                parse.loc.filename, parse.loc.lineno)
        return s

def locFromTok(p, num):
    return Loc(Parser.current.filename, p.lineno(num))


##-----------------------------------------------------------------------------

reserved = set((
        'async',
        'both',
        'child',
        'class',
        'compress',
        'compressall',
        'from',
        'include',
        'intr',
        'manager',
        'manages',
        'namespace',
        'nested',
        'nullable',
        'or',
        'parent',
        'prio',
        'protocol',
        'returns',
        'struct',
        'sync',
        'union',
        'upto',
        'using',
        'verify'))
tokens = [
    'COLONCOLON', 'ID', 'STRING',
] + [ r.upper() for r in reserved ]

t_COLONCOLON = '::'

literals = '(){}[]<>;:,'
t_ignore = ' \f\t\v'

def t_linecomment(t):
    r'//[^\n]*'

def t_multilinecomment(t):
    r'/\*(\n|.)*?\*/'
    t.lexer.lineno += t.value.count('\n')

def t_NL(t):
    r'(?:\r\n|\n|\n)+'
    t.lexer.lineno += len(t.value)

def t_ID(t):
    r'[a-zA-Z_][a-zA-Z0-9_]*'
    if t.value in reserved:
        t.type = t.value.upper()
    return t

def t_STRING(t):
    r'"[^"\n]*"'
    t.value = t.value[1:-1]
    return t

def t_error(t):
    _error(Loc(Parser.current.filename, t.lineno),
           'lexically invalid characters `%s', t.value)

##-----------------------------------------------------------------------------

def p_TranslationUnit(p):
    """TranslationUnit : Preamble NamespacedStuff"""
    tu = Parser.current.tu
    tu.loc = Loc(tu.filename)
    for stmt in p[1]:
        if isinstance(stmt, CxxInclude):
            tu.addCxxInclude(stmt)
        elif isinstance(stmt, Include):
            tu.addInclude(stmt)
        elif isinstance(stmt, UsingStmt):
            tu.addUsingStmt(stmt)
        else:
            assert 0

    for thing in p[2]:
        if isinstance(thing, StructDecl):
            tu.addStructDecl(thing)
        elif isinstance(thing, UnionDecl):
            tu.addUnionDecl(thing)
        elif isinstance(thing, Protocol):
            if tu.protocol is not None:
                _error(thing.loc, "only one protocol definition per file")
            tu.protocol = thing
        else:
            assert(0)

    # The "canonical" namespace of the tu, what it's considered to be
    # in for the purposes of C++: |#include "foo/bar/TU.h"|
    if tu.protocol:
        assert tu.filetype == 'protocol'
        tu.namespaces = tu.protocol.namespaces
        tu.name = tu.protocol.name
    else:
        assert tu.filetype == 'header'
        # There's not really a canonical "thing" in headers.  So
        # somewhat arbitrarily use the namespace of the last
        # interesting thing that was declared.
        for thing in reversed(tu.structsAndUnions):
            tu.namespaces = thing.namespaces
            break

    p[0] = tu

##--------------------
## Preamble
def p_Preamble(p):
    """Preamble : Preamble PreambleStmt ';'
                |"""
    if 1 == len(p):
        p[0] = [ ]
    else:
        p[1].append(p[2])
        p[0] = p[1]

def p_PreambleStmt(p):
    """PreambleStmt : CxxIncludeStmt
                    | IncludeStmt
                    | UsingStmt"""
    p[0] = p[1]

def p_CxxIncludeStmt(p):
    """CxxIncludeStmt : INCLUDE STRING"""
    p[0] = CxxInclude(locFromTok(p, 1), p[2])

def p_IncludeStmt(p):
    """IncludeStmt : INCLUDE PROTOCOL ID
                   | INCLUDE ID"""
    loc = locFromTok(p, 1)

    Parser.current.loc = loc
    if 4 == len(p):
        id = p[3]
        type = 'protocol'
    else:
        id = p[2]
        type = 'header'
    inc = Include(loc, type, id)

    path = Parser.current.resolveIncludePath(inc.file)
    if path is None:
        raise ParseError(loc, "can't locate include file `%s'"% (
                inc.file))

    inc.tu = Parser(type, id).parse(open(path).read(), path, Parser.current.includedirs)
    p[0] = inc

def p_UsingStmt(p):
    """UsingStmt : USING CxxType FROM STRING
                 | USING CLASS CxxType FROM STRING
                 | USING STRUCT CxxType FROM STRING"""
    if 6 == len(p):
        header = p[5]
    elif 5 == len(p):
        header = p[4]
    else:
        header = None
    if 6 == len(p):
        kind = p[2]
    else:
        kind = None
    if 6 == len(p):
        cxxtype = p[3]
    else:
        cxxtype = p[2]
    p[0] = UsingStmt(locFromTok(p, 1), cxxtype, header, kind)

##--------------------
## Namespaced stuff
def p_NamespacedStuff(p):
    """NamespacedStuff : NamespacedStuff NamespaceThing
                       | NamespaceThing"""
    if 2 == len(p):
        p[0] = p[1]
    else:
        p[1].extend(p[2])
        p[0] = p[1]

def p_NamespaceThing(p):
    """NamespaceThing : NAMESPACE ID '{' NamespacedStuff '}'
                      | StructDecl
                      | UnionDecl
                      | ProtocolDefn"""
    if 2 == len(p):
        p[0] = [ p[1] ]
    else:
        for thing in p[4]:
            thing.addOuterNamespace(Namespace(locFromTok(p, 1), p[2]))
        p[0] = p[4]

def p_StructDecl(p):
    """StructDecl : STRUCT ID '{' StructFields '}' ';'
                  | STRUCT ID '{' '}' ';'"""
    if 7 == len(p):
        p[0] = StructDecl(locFromTok(p, 1), p[2], p[4])
    else:
        p[0] = StructDecl(locFromTok(p, 1), p[2], [ ])

def p_StructFields(p):
    """StructFields : StructFields StructField ';'
                    | StructField ';'"""
    if 3 == len(p):
        p[0] = [ p[1] ]
    else:
        p[1].append(p[2])
        p[0] = p[1]

def p_StructField(p):
    """StructField : Type ID"""
    p[0] = StructField(locFromTok(p, 1), p[1], p[2])

def p_UnionDecl(p):
    """UnionDecl : UNION ID '{' ComponentTypes  '}' ';'"""
    p[0] = UnionDecl(locFromTok(p, 1), p[2], p[4])

def p_ComponentTypes(p):
    """ComponentTypes : ComponentTypes Type ';'
                      | Type ';'"""
    if 3 == len(p):
        p[0] = [ p[1] ]
    else:
        p[1].append(p[2])
        p[0] = p[1]

def p_ProtocolDefn(p):
    """ProtocolDefn : OptionalProtocolSendSemanticsQual PROTOCOL ID '{' ProtocolBody '}' ';'"""
    protocol = p[5]
    protocol.loc = locFromTok(p, 2)
    protocol.name = p[3]
    protocol.nested = p[1][0]
    protocol.sendSemantics = p[1][1]
    p[0] = protocol

    if Parser.current.type == 'header':
        _error(protocol.loc, 'can\'t define a protocol in a header.  Do it in a protocol spec instead.')


def p_ProtocolBody(p):
    """ProtocolBody : ManagersStmtOpt"""
    p[0] = p[1]


##--------------------
## manager/manages stmts

def p_ManagersStmtOpt(p):
    """ManagersStmtOpt : ManagersStmt ManagesStmtsOpt
                       | ManagesStmtsOpt"""
    if 2 == len(p):
        p[0] = p[1]
    else:
        p[2].managers = p[1]
        p[0] = p[2]

def p_ManagersStmt(p):
    """ManagersStmt : MANAGER ManagerList ';'"""
    if 1 == len(p):
        p[0] = [ ]
    else:
        p[0] = p[2]

def p_ManagerList(p):
    """ManagerList : ID
                   | ManagerList OR ID"""
    if 2 == len(p):
        p[0] = [ Manager(locFromTok(p, 1), p[1]) ]
    else:
        p[1].append(Manager(locFromTok(p, 3), p[3]))
        p[0] = p[1]

def p_ManagesStmtsOpt(p):
    """ManagesStmtsOpt : ManagesStmt ManagesStmtsOpt
                       | MessageDeclsOpt"""
    if 2 == len(p):
        p[0] = p[1]
    else:
        p[2].managesStmts.insert(0, p[1])
        p[0] = p[2]

def p_ManagesStmt(p):
    """ManagesStmt : MANAGES ID ';'"""
    p[0] = ManagesStmt(locFromTok(p, 1), p[2])


##--------------------
## Message decls

def p_MessageDeclsOpt(p):
    """MessageDeclsOpt : MessageDeclThing MessageDeclsOpt
                       | """
    if 1 == len(p):
        # we fill in |loc| in the Protocol rule
        p[0] = Protocol(None)
    else:
        p[2].messageDecls.insert(0, p[1])
        p[0] = p[2]

def p_MessageDeclThing(p):
    """MessageDeclThing : MessageDirectionLabel ':' MessageDecl ';'
                        | MessageDecl ';'"""
    if 3 == len(p):
        p[0] = p[1]
    else:
        p[0] = p[3]

def p_MessageDirectionLabel(p):
    """MessageDirectionLabel : PARENT
                             | CHILD
                             | BOTH"""
    if p[1] == 'parent':
        Parser.current.direction = IN
    elif p[1] == 'child':
        Parser.current.direction = OUT
    elif p[1] == 'both':
        Parser.current.direction = INOUT
    else:
        assert 0

def p_MessageDecl(p):
    """MessageDecl : SendSemanticsQual MessageBody"""
    msg = p[2]
    msg.nested = p[1][0]
    msg.prio = p[1][1]
    msg.sendSemantics = p[1][2]

    if Parser.current.direction is None:
        _error(msg.loc, 'missing message direction')
    msg.direction = Parser.current.direction

    p[0] = msg

def p_MessageBody(p):
    """MessageBody : ID MessageInParams MessageOutParams OptionalMessageModifiers"""
    # FIXME/cjones: need better loc info: use one of the quals
    name = p[1]
    msg = MessageDecl(locFromTok(p, 1))
    msg.name = name
    msg.addInParams(p[2])
    msg.addOutParams(p[3])
    msg.addModifiers(p[4])

    p[0] = msg

def p_MessageInParams(p):
    """MessageInParams : '(' ParamList ')'"""
    p[0] = p[2]

def p_MessageOutParams(p):
    """MessageOutParams : RETURNS '(' ParamList ')'
                        | """
    if 1 == len(p):
        p[0] = [ ]
    else:
        p[0] = p[3]

def p_OptionalMessageModifiers(p):
    """OptionalMessageModifiers : OptionalMessageModifiers MessageModifier
                                | MessageModifier
                                | """
    if 1 == len(p):
        p[0] = [ ]
    elif 2 == len(p):
        p[0] = [ p[1] ]
    else:
        p[1].append(p[2])
        p[0] = p[1]

def p_MessageModifier(p):
    """ MessageModifier : MessageVerify
                        | MessageCompress """
    p[0] = p[1]

def p_MessageVerify(p):
    """MessageVerify : VERIFY"""
    p[0] = p[1]

def p_MessageCompress(p):
    """MessageCompress : COMPRESS
                       | COMPRESSALL"""
    p[0] = p[1]


##--------------------
## Minor stuff
def p_Nested(p):
    """Nested : ID"""
    kinds = {'not': 1,
             'inside_sync': 2,
             'inside_cpow': 3}
    if p[1] not in kinds:
        _error(locFromTok(p, 1), "Expected not, inside_sync, or inside_cpow for nested()")

    p[0] = { 'nested': kinds[p[1]] }

def p_Priority(p):
    """Priority : ID"""
    kinds = {'normal': 1,
             'input': 2,
             'high': 3}
    if p[1] not in kinds:
        _error(locFromTok(p, 1), "Expected normal or high for prio()")

    p[0] = { 'prio': kinds[p[1]] }

def p_SendQualifier(p):
    """SendQualifier : NESTED '(' Nested ')'
                     | PRIO '(' Priority ')'"""
    p[0] = p[3]

def p_SendQualifierList(p):
    """SendQualifierList : SendQualifier SendQualifierList
                         | """
    if len(p) > 1:
        p[0] = p[1]
        p[0].update(p[2])
    else:
        p[0] = {}

def p_SendSemanticsQual(p):
    """SendSemanticsQual : SendQualifierList ASYNC
                         | SendQualifierList SYNC
                         | INTR"""
    quals = {}
    if len(p) == 3:
        quals = p[1]
        mtype = p[2]
    else:
        mtype = 'intr'

    if mtype == 'async': mtype = ASYNC
    elif mtype == 'sync': mtype = SYNC
    elif mtype == 'intr': mtype = INTR
    else: assert 0

    p[0] = [ quals.get('nested', NOT_NESTED), quals.get('prio', NORMAL_PRIORITY), mtype ]

def p_OptionalProtocolSendSemanticsQual(p):
    """OptionalProtocolSendSemanticsQual : ProtocolSendSemanticsQual
                                         | """
    if 2 == len(p): p[0] = p[1]
    else:           p[0] = [ NOT_NESTED, ASYNC ]

def p_ProtocolSendSemanticsQual(p):
    """ProtocolSendSemanticsQual : ASYNC
                                 | SYNC
                                 | NESTED '(' UPTO Nested ')' ASYNC
                                 | NESTED '(' UPTO Nested ')' SYNC
                                 | INTR"""
    if p[1] == 'nested':
        mtype = p[6]
        nested = p[4]
    else:
        mtype = p[1]
        nested = NOT_NESTED

    if mtype == 'async': mtype = ASYNC
    elif mtype == 'sync': mtype = SYNC
    elif mtype == 'intr': mtype = INTR
    else: assert 0

    p[0] = [ nested, mtype ]

def p_ParamList(p):
    """ParamList : ParamList ',' Param
                 | Param
                 | """
    if 1 == len(p):
        p[0] = [ ]
    elif 2 == len(p):
        p[0] = [ p[1] ]
    else:
        p[1].append(p[3])
        p[0] = p[1]

def p_Param(p):
    """Param : Type ID"""
    p[0] = Param(locFromTok(p, 1), p[1], p[2])

def p_Type(p):
    """Type : MaybeNullable BasicType"""
    # only actor types are nullable; we check this in the type checker
    p[2].nullable = p[1]
    p[0] = p[2]

def p_BasicType(p):
    """BasicType : CxxID
                 | CxxID '[' ']'"""
    # ID == CxxType; we forbid qnames here,
    # in favor of the |using| declaration
    if not isinstance(p[1], TypeSpec):
        loc, id = p[1]
        p[1] = TypeSpec(loc, QualifiedId(loc, id))
    if 4 == len(p):
        p[1].array = 1
    p[0] = p[1]

def p_MaybeNullable(p):
    """MaybeNullable : NULLABLE
                     | """
    p[0] = (2 == len(p))

##--------------------
## C++ stuff
def p_CxxType(p):
    """CxxType : QualifiedID
               | CxxID"""
    if isinstance(p[1], QualifiedId):
        p[0] = TypeSpec(p[1].loc, p[1])
    else:
        loc, id = p[1]
        p[0] = TypeSpec(loc, QualifiedId(loc, id))

def p_QualifiedID(p):
    """QualifiedID : QualifiedID COLONCOLON CxxID
                   | CxxID COLONCOLON CxxID"""
    if isinstance(p[1], QualifiedId):
        loc, id = p[3]
        p[1].qualify(id)
        p[0] = p[1]
    else:
        loc1, id1 = p[1]
        _, id2 = p[3]
        p[0] = QualifiedId(loc1, id2, [ id1 ])

def p_CxxID(p):
    """CxxID : ID
             | CxxTemplateInst"""
    if isinstance(p[1], tuple):
        p[0] = p[1]
    else:
        p[0] = (locFromTok(p, 1), str(p[1]))

def p_CxxTemplateInst(p):
    """CxxTemplateInst : ID '<' ID '>'"""
    p[0] = (locFromTok(p, 1), str(p[1]) +'<'+ str(p[3]) +'>')

def p_error(t):
    lineno, value = _safeLinenoValue(t)
    _error(Loc(Parser.current.filename, lineno),
           "bad syntax near `%s'", value)
