// 
// setmbcp_internal from 0x18013a59c to 0x18013a75a (446 bytes)
// 
// 2 xrefs:
// > __acrt_initialize_multibyte @ 0x18013a861
// > <???> @ 0x180203860
// 
// This function is hookable on this platform!
// 
// Using BromaIDA 8.0.0 @ https://github.com/Stazzical/BromaIDA
// Using bindings at commit ba9f177b at Thu Jul 16 22:52:06 2026 from https://github.com/geode-sdk/bindings
// 

__int64 __fastcall setmbcp_internal(
        UINT a1,
        char a2,
        struct __acrt_ptd *const a3,
        struct __crt_multibyte_data **const a4)
{
  unsigned int SystemCP; // edi
  _DWORD *v8; // rax
  _DWORD *v9; // rbx
  __int64 v10; // rdx
  _OWORD *v11; // rcx
  _OWORD *v12; // rax
  __int128 v13; // xmm1
  unsigned int v14; // edi
  void *v15; // rcx
  _DWORD *v16; // rcx
  _BYTE v17[4]; // [rsp+20h] [rbp-20h] BYREF
  int v18; // [rsp+24h] [rbp-1Ch] BYREF
  int v19; // [rsp+28h] [rbp-18h] BYREF
  volatile signed __int32 ***v20[2]; // [rsp+30h] [rbp-10h] BYREF
  struct __acrt_ptd *v21; // [rsp+70h] [rbp+30h] BYREF
  void **v22; // [rsp+78h] [rbp+38h] BYREF

  v22 = (void **)a4;
  v21 = a3;
  update_thread_multibyte_data_internal(a3, a4);
  SystemCP = getSystemCP(a1);
  if ( SystemCP == *(_DWORD *)(*((_QWORD *)v21 + 17) + 4LL) )
    return 0;
  v8 = malloc_base(0x228u);
  v9 = v8;
  if ( v8 )
  {
    v10 = 4;
    v11 = v8;
    v12 = *((_OWORD **)v21 + 17);
    do
    {
      *v11 = *v12;
      v11[1] = v12[1];
      v11[2] = v12[2];
      v11[3] = v12[3];
      v11[4] = v12[4];
      v11[5] = v12[5];
      v11[6] = v12[6];
      v11 += 8;
      v13 = v12[7];
      v12 += 8;
      *(v11 - 1) = v13;
      --v10;
    }
    while ( v10 );
    *v11 = *v12;
    v11[1] = v12[1];
    *((_QWORD *)v11 + 4) = *((_QWORD *)v12 + 4);
    *v9 = 0;
    v14 = setmbcp_nolock(SystemCP, v9, 128);
    if ( v14 != -1 )
    {
      if ( !a2 )
        _acrt_set_locale_changed();
      if ( _InterlockedExchangeAdd(*((volatile signed __int32 **)v21 + 17), 0xFFFFFFFF) == 1 )
      {
        v15 = *((void **)v21 + 17);
        if ( v15 != &unk_1801B1A50 )
          free_base(v15);
      }
      *v9 = 1;
      v16 = v9;
      v9 = nullptr;
      *((_QWORD *)v21 + 17) = v16;
      if ( (*((_DWORD *)v21 + 234) & dword_1801B1F90) == 0 )
      {
        v20[0] = (volatile signed __int32 ***)&v21;
        v20[1] = (volatile signed __int32 ***)&v22;
        v18 = 5;
        v19 = 5;
        __crt_seh_guarded_call<void>::operator()<_lambda_efdfa57d1f175319df784efa44bb7b81_,_lambda_5f0a4c1567f8adc6734073e5d1e1b35c_ &,_lambda_2e8a7d3640ea6ccb4c2413664c2db6fd_>(
          (__int64)v17,
          &v19,
          v20,
          &v18);
        if ( a2 )
          off_1801B19E0 = *v22;
      }
      goto LABEL_9;
    }
    *errno() = 22;
  }
  v14 = -1;
LABEL_9:
  free_base(v9);
  return v14;
}