#include "ruby.h"
#include "rubyspec.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef FL_SHAREABLE
static const VALUE VISIBLE_BITS = FL_TAINT | FL_FREEZE;
static const VALUE DATA_VISIBLE_BITS = FL_TAINT | FL_FREEZE | ~(FL_USER0 - 1);
#else
static const VALUE VISIBLE_BITS = FL_FREEZE;
static const VALUE DATA_VISIBLE_BITS = FL_FREEZE | ~(FL_USER0 - 1);
#endif

#if SIZEOF_VALUE == SIZEOF_LONG
#define VALUE2NUM(v) ULONG2NUM(v)
#define NUM2VALUE(n) NUM2ULONG(n)
#elif SIZEOF_VALUE == SIZEOF_LONG_LONG
#define VALUE2NUM(v) ULL2NUM(v)
#define NUM2VALUE(n) NUM2ULL(n)
#else
#error "unsupported"
#endif


#ifndef RUBY_VERSION_IS_3_1
VALUE rbasic_spec_taint_flag(VALUE self) {
  return VALUE2NUM(RUBY_FL_TAINT);
}
#endif

VALUE rbasic_spec_freeze_flag(VALUE self) {
  return VALUE2NUM(RUBY_FL_FREEZE);
}

    static VALUE spec_get_flags(const struct RBasic *b, VALUE visible_bits) {
  VALUE flags = b->flags & visible_bits;
  return VALUE2NUM(flags);
}

static VALUE spec_set_flags(struct RBasic *b, VALUE flags, VALUE visible_bits) {
  flags &= visible_bits;
  b->flags = (b->flags & ~visible_bits) | flags;
  return VALUE2NUM(flags);
}

VALUE rbasic_spec_get_flags(VALUE self, VALUE val) {
  return spec_get_flags(RBASIC(val), VISIBLE_BITS);
}

VALUE rbasic_spec_set_flags(VALUE self, VALUE val, VALUE flags) {
  return spec_set_flags(RBASIC(val), NUM2VALUE(flags), VISIBLE_BITS);
}

VALUE rbasic_spec_copy_flags(VALUE self, VALUE to, VALUE from) {
  return spec_set_flags(RBASIC(to), RBASIC(from)->flags, VISIBLE_BITS);
}

VALUE rbasic_spec_get_klass(VALUE self, VALUE val) {
  return RBASIC(val)->klass;
}

VALUE rbasic_rdata_spec_get_flags(VALUE self, VALUE structure) {
  return spec_get_flags(&RDATA(structure)->basic, DATA_VISIBLE_BITS);
}

VALUE rbasic_rdata_spec_set_flags(VALUE self, VALUE structure, VALUE flags) {
  return spec_set_flags(&RDATA(structure)->basic, NUM2VALUE(flags), DATA_VISIBLE_BITS);
}

VALUE rbasic_rdata_spec_copy_flags(VALUE self, VALUE to, VALUE from) {
  return spec_set_flags(&RDATA(to)->basic, RDATA(from)->basic.flags, DATA_VISIBLE_BITS);
}

VALUE rbasic_rdata_spec_get_klass(VALUE self, VALUE structure) {
  return RDATA(structure)->basic.klass;
}

void Init_rbasic_spec(void) {
  VALUE cls = rb_define_class("CApiRBasicSpecs", rb_cObject);
#ifndef RUBY_VERSION_IS_3_1
  rb_define_method(cls, "taint_flag", rbasic_spec_taint_flag, 0);
#endif
  rb_define_method(cls, "freeze_flag", rbasic_spec_freeze_flag, 0);
  rb_define_method(cls, "get_flags", rbasic_spec_get_flags, 1);
  rb_define_method(cls, "set_flags", rbasic_spec_set_flags, 2);
  rb_define_method(cls, "copy_flags", rbasic_spec_copy_flags, 2);
  rb_define_method(cls, "get_klass", rbasic_spec_get_klass, 1);

  cls = rb_define_class("CApiRBasicRDataSpecs", rb_cObject);
  rb_define_method(cls, "get_flags", rbasic_rdata_spec_get_flags, 1);
  rb_define_method(cls, "set_flags", rbasic_rdata_spec_set_flags, 2);
  rb_define_method(cls, "copy_flags", rbasic_rdata_spec_copy_flags, 2);
  rb_define_method(cls, "get_klass", rbasic_rdata_spec_get_klass, 1);
}

#ifdef __cplusplus
}
#endif