-- tolua: operator class
-- Written by Waldemar Celes
-- TeCGraf/PUC-Rio
-- Jul 1998
-- $Id: $

-- This code is free software; you can redistribute it and/or modify it.
-- The software provided hereunder is on an "as is" basis, and
-- the author has no obligation to provide maintenance, support, updates,
-- enhancements, or modifications.


-- Operator class
-- Represents an operator function or a class operator method.
-- It stores the same fields as functions do plus:
--  kind = set of character representing the operator (as it appers in C++ code)
classOperator = {
    kind = '',
}
classOperator.__index = classOperator
setmetatable(classOperator,classFunction)

-- table to transform operator kind into the appropriate tag method name
_TM = {
    ['+'] = 'add',
    ['-'] = 'sub',
    ['*'] = 'mul',
    ['/'] = 'div',
    ['<'] = 'lt',
    ['<='] = 'le',
    ['=='] = 'eq',
    ['[]'] = 'geti',
    ['&[]'] = 'seti',
    --['->'] = 'flechita',
}


-- Print method
function classOperator:print (ident,close)
    print(ident.."Operator{")
    print(ident.." kind  = '"..self.kind.."',")
    print(ident.." mod  = '"..self.mod.."',")
    print(ident.." type = '"..self.type.."',")
    print(ident.." ptr  = '"..self.ptr.."',")
    print(ident.." name = '"..self.name.."',")
    print(ident.." const = '"..self.const.."',")
    print(ident.." cname = '"..self.cname.."',")
    print(ident.." lname = '"..self.lname.."',")
    print(ident.." args = {")
    local i=1
    while self.args[i] do
        self.args[i]:print(ident.."  ",",")
        i = i+1
    end
    print(ident.." }")
    print(ident.."}"..close)
end

function classOperator:supcode_tmp()

    if not _TM[self.kind] then
        return classFunction.supcode(self)
    end

    -- no overload, no parameters, always inclass
    output("/* method:",self.name," of class ",self:inclass()," */")

    output("#ifndef TOLUA_DISABLE_"..self.cname)
    output("\nstatic int",self.cname,"(lua_State* tolua_S)")

    if overload < 0 then
        output('#ifndef TOLUA_RELEASE\n')
    end
    output(' tolua_Error tolua_err;')
    output(' if (\n')
    -- check self
    output('     !'..'tolua_isusertype(tolua_S,1,"'..self.parent.type..'",0,&tolua_err) ||\n')
    output('     !tolua_isnoobj(tolua_S,2,&tolua_err)\n )')
    output('  goto tolua_lerror;')

    output(' else\n')
    output('#endif\n') -- tolua_release
    output(' {')

    -- declare self
    output(' ',self.const,self.parent.type,'*','self = ')
    output('(',self.const,self.parent.type,'*) ')
    output('tolua_tousertype(tolua_S,1,0);')

    -- check self
    output('#ifndef TOLUA_RELEASE\n')
    output('  if (!self) tolua_error(tolua_S,"invalid \'self\' in function \''..self.name..'\'",NULL);');
    output('#endif\n')

    -- cast self
    output('  ',self.mod,self.type,self.ptr,'tolua_ret = ')
    output('(',self.mod,self.type,self.ptr,')(*self);')

    -- return value
    local t,ct = isbasic(self.type)
    if t then
        output('   tolua_push'..t..'(tolua_S,(',ct,')tolua_ret);')
    else
        t = self.type
        new_t = string.gsub(t, "const%s+", "")
        if self.ptr == '' then
            output('   {')
            output('#ifdef __cplusplus\n')
            output('    void* tolua_obj = new',new_t,'(tolua_ret);')
            output('    tolua_pushusertype_and_takeownership(tolua_S,tolua_obj,"',t,'");')
            output('#else\n')
            output('    void* tolua_obj = tolua_copy(tolua_S,(void*)&tolua_ret,sizeof(',t,'));')
            output('    tolua_pushusertype_and_takeownership(tolua_S,tolua_obj,"',t,'");')
            output('#endif\n')
            output('   }')
        elseif self.ptr == '&' then
            output('   tolua_pushusertype(tolua_S,(void*)&tolua_ret,"',t,'");')
        else
            if local_constructor then
                output('   tolua_pushusertype_and_takeownership(tolua_S,(void *)tolua_ret,"',t,'");')
            else
                output('   tolua_pushusertype(tolua_S,(void*)tolua_ret,"',t,'");')
            end
        end
    end

    output('  }')
    output(' return 1;')

    output('#ifndef TOLUA_RELEASE\n')
    output('tolua_lerror:\n')
    output(' tolua_error(tolua_S,"#ferror in function \''..self.lname..'\'.",&tolua_err);')
    output(' return 0;')
    output('#endif\n')


    output('}')
    output('#endif //#ifndef TOLUA_DISABLE\n')
    output('\n')
end

-- Internal constructor
function _Operator (t)
    setmetatable(t,classOperator)

    if t.const ~= 'const' and t.const ~= '' then
        error("#invalid 'const' specification")
    end

    append(t)
    if not t:inclass() then
        error("#operator can only be defined as class member")
    end

    --t.name = t.name .. "_" .. (_TM[t.kind] or t.kind)
    t.cname = t:cfuncname("tolua")..t:overload(t)
    t.name = "operator" .. t.kind  -- set appropriate calling name
    return t
end

-- Constructor
function Operator (d,k,a,c)

    local op_k = string.gsub(k, "^%s*", "")
    op_k = string.gsub(k, "%s*$", "")
    --if string.find(k, "^[%w_:%d<>%*%&]+$") then
    if d == "operator" and k ~= '' then

        d = k.." operator"
    elseif not _TM[op_k] then

        if flags['W'] then
            error("tolua: no support for operator" .. f.kind)
        else
            warning("No support for operator "..op_k..", ignoring")
            return nil
        end
    end

    local ref = ''
    local t = split_c_tokens(strsub(a,2,strlen(a)-1),',') -- eliminate braces
    local i=1
    local l = {n=0}
    while t[i] do
        l.n = l.n+1
        l[l.n] = Declaration(t[i],'var')
        i = i+1
    end
    if k == '[]' then
        local _
        _, _, ref = strfind(d,'(&)')
        d = gsub(d,'&','')
    elseif k=='&[]' then
        l.n = l.n+1
        l[l.n] = Declaration(d,'var')
        l[l.n].name = 'tolua_value'
    end
    local f = Declaration(d,'func')
    if k == '[]' and (l[1]==nil or isbasic(l[1].type)~='number') then
        error('operator[] can only be defined for numeric index.')
    end
    f.args = l
    f.const = c
    f.kind = op_k
    f.lname = "."..(_TM[f.kind] or f.kind)
    if not _TM[f.kind] then
        f.cast_operator = true
    end
    if f.kind == '[]' and ref=='&' and f.const~='const' then
        Operator(d,'&'..k,a,c)     -- create correspoding set operator
    end
    return _Operator(f)
end


