CallByMeta

class CallByMeta{
  static var used : Bool = false;
  macro static public function use(){
    var changed = false;
    if(!used){
              used  = true;
      var printer   = new haxe.macro.Printer();
      var here      = __.here();
      __.log().debug('"$here"');
      
      SyntaxHub.classLevel.add(
        {
          data  : function (cb:ClassBuilder){
            var metadata  = cb.target.meta.get();
            var stx_call  = metadata.ds().filter(
              (md) -> {
                //trace(md.name);
                return md.name.startsWith(":stx.");
              }
            );
            var shows = [];
            //__.log().debug(metadata.map((md)->md.name));
            if(stx_call.length>0){
              changed   = true;
              var exprs = [];
              for(call in stx_call){
                var arr             = call.name.split(".");
                    arr[0]          = arr[0].substr(1);
                var arg             = call.params;
                var show_args       = arg.ds().map(
                      (x:HExpr) -> {
                        return switch(x.expr){
                          case EConst(CIdent("__")) :
                            var a = cb.target.module.split(".");
                            var b = cb.target.pack;
                            var c = cb.target.name;
                            
                            var path = a;
                            if(c != a[a.length-1]){
                              path.push(c);
                            }
                            var expr = MacroStringTools.toFieldHExpr(path);

                            //trace(printer.printHExpr(expr));
                            expr;
                          default : x;
                        };
                      }
                    ).prj();
              




                shows.push(
                  {
                    name : call.name,
                    args : show_args.map(printer.printHExpr)
                  }
                );
                var expr    = { pos : Context.currentPos(), expr : ECall(macro $p{arr},$p{show_args}) };
                    exprs.push(expr);
              }
              var fn = switch(macro function(){
                $b{exprs};
              }){
                case { expr : EFunction(_,f) }  : f;
                case x                          : null;
              }
              
              var member = Member.method(
                "__init__",
                fn
              );
              member.isStatic = true;
              cb.addMember(member);
            }
            return changed;
          },  
          id    : null
        }
      );
    }
    return macro {};
  }
}