#!/usr/bin/env ruby
#
# c++2rb : partial conversion from C and C++ to Ruby
#
# Copyright (c) 2001 Issac Trotts <itrotts at idolminds dot com>
#
# Under the Ruby license 
#
# TODO
# - template functions
# - template classes
# - build a database of all the functions for a given class and 
#   put them all in a single file as a post-processing step


$type_re = '(void|char|short|int|long|float|double)'
$map_re = '\bmap\s*<.*>'
$list_re = '\blist\s*<.*>'
$vector_re = '\bvector\s*<.*>'
$token_re = '[a-zA-Z_][a-zA-Z0-9_]*'

def do_generic_line(line, outfile)
    line.gsub!(/;/, '')
    line.gsub!(/#include\s+\<([^>.]+)(.h)?>/, 'require \'\1\'')
    line.gsub!(/\<const\>/, '')
    line.gsub!(/\<unsigned\>\s*/, '')
    line.gsub!(/\<virtual\>\s*/, '')
    line.gsub!(/\<inline\>\s*/, '')
    eval('line.gsub!(/#{$list_re}\s*(#{$token_re})/, \'\1 = []\')')
    eval('line.gsub!(/#{$vector_re}\s*(#{$token_re})/, \'\1 = []\')')
    eval('line.gsub!(/#{$map_re}\s*(#{$token_re})/, \'\1 = {}\')')
    line.gsub!(/push_back/, 'push')
    line.gsub!(/\<std::/, '')
    line.gsub!(/\<cout\s*\<\</, 'puts ')
    line.gsub!(/\<\</, '+')
    line.gsub!(/\<this\>/, 'self')
    line.gsub!(/\<endl\>/, '"\n"')
    line.gsub!(/\<(public|protected|private)\>\s*\:/, '\1')
    # comments
    line.gsub!(/\/\//, '#')                             
    line.gsub!(/\{/, '')
    line.gsub!(/^(\s*)}/, '\1end')
    line.sub!(/(\S+)(\s*)}/, '\1\2; end')
    line.gsub!(/\<case\>/, 'when')
    line.gsub!(/\<switch\>/, 'case')
    line.gsub!(/\<default\>/, 'else')
    line.gsub!(/\<struct\>/, 'class')
    line.gsub!(/if\s*\(([^)]+)\)/, 'if \1')
    # inheritance
    line.gsub!(/:\s+(public|private|protected)/, '<')    
    line.gsub!(/\-\>/, '.')
    # global functions with no args
    eval("line.sub!(/#{$type_re}\\s+(#{$token_re})\\s*\\(\\s*\\)/, "+
        '\'def \2\')')
    # global functions with args
    eval("line.sub!(/#{$type_re}\\s+(#{$token_re})\\s*(\\(.*\\))\s*{?/, "+
        '\'def \2\3\')')
    # constructors 
    #if eval("line.gsub!(/(#{$token_re})::\\1(.*)/, 'class \\1; def initialize\\2')")
        #return
    #end
    #eval("gsub!(/#{token_re)::#{(token_re)}, 'class \\1; def initialize\\2')")
    # member functions with no args
    eval("line.sub!(/#{$type_re}\\s+(#{$token_re})::(#{$token_re})\\s*\\(\\s*\\)/, "+
        '\'class \2; def \3 # FIXME: put another end at the end\')') 
    # member functions with args
    eval("line.sub!(/#{$type_re}\\s+(#{$token_re})::(#{$token_re})\\s*\\((.*)\\)/, "+
        '\'class \2; def \3 (\4) # FIXME: put another end at the end\')') 
    # member function invocations with no args

    # member function invocations with args

    # for-loops...

    # using std::cout;  -->  cout = std::cout

    # using namespace X

    # namespaces
    line.gsub!(/namespace/, 'module')
    #eval("gsub!(/#{type_re}\s+#{token_re}/, 'TYPE VAR')")
    #eval("gsub!(/#{type_re}\\s*#{token_re}\\s*\\(\\s*\\)\\*;/, 'TYPE FUNC')")
    # functions

    # OpenGL calls (using the Ruby OpenGL extension)
    line.gsub!(/\bgl([a-zA-Z0-9]+)/, 'GL.\1')

    outfile.write(line)
end

def parse(filename)
    newname = filename+'.rb'
    $stdout.sync = true
    puts 'Creating '+newname
    infile = File.new(filename, 'r')
    outfile = File.new(newname, 'w')
    lines = infile.readlines()
    infile.close()
    mode = 'default'
    lines.each_with_index { |line, i|
        do_generic_line(line, outfile)
        #case mode
            #when 'class_decl' 
                 
            #when  
            #else
                #mode = do_generic_line(line, outfile, mode)
        #end
    }
end

ARGV.each { |filename| parse(filename) }

# TODO: THE NEW WAY:

# step 1: gather namespace/class/struct/function/variable declarations/definitions 
#         making a note of the file basename for each one

# step 2: for each basename, create a ruby file containing the appropriate 
#         contents