// Move into src/Win32.cpp

struct OS_System_Info {
  s32 logical_processor_count;
  s32 physical_core_count;
  s32 primary_core_count;
  s32 secondary_core_count; // Any weaker or "Efficiency" cores.
  u64 page_size;
  u64 large_page_size;
  u64 allocation_granularity;
  string machine_name;
};

struct OS_Process_Info {
  u32 process_id;
  b32 large_pages_allowed;
  string binary_path;
  string working_path;
  string user_program_data_path;
  Array<string> module_load_paths;
  Array<string> environment_paths;
};

struct OS_State_Win32 {
  Arena* arena;
  
  OS_System_Info system_info;
  OS_Process_Info process_info;
};

global OS_State_Win32 os_state_w32;
internal b32 win32_g_is_quiet = 0; // No console output

internal LONG WINAPI Win32_Exception_Filter (EXCEPTION_POINTERS* exception_ptrs) {
  if (win32_g_is_quiet) { ExitProcess(1); }

  static volatile LONG first = 0;
  if(InterlockedCompareExchange(&first, 1, 0) != 0)
  { // prevent failures in other threads to popup same message box
    // this handler just shows first thread that crashes
    // we are terminating afterwards anyway
    for (;;) Sleep(1000);
  }
  
  // #TODO: Exception handling code.
  
  return 0;
}

internal void Win32_Entry_Point (int argc, WCHAR **argv) {
  // See: w32_entry_point_caller(); (raddebugger)
  SetUnhandledExceptionFilter(&Win32_Exception_Filter);
  
  SYSTEM_INFO sysinfo = {0};
  GetSystemInfo(&sysinfo);
  
  // Try to allow large pages if we can.
  // b32 large_pages_allowed = 0;
  // {
  //   HANDLE token;
  //   if(OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &token))
  //   {
  //     LUID luid;
  //     if(LookupPrivilegeValue(0, SE_LOCK_MEMORY_NAME, &luid))
  //     {
  //       TOKEN_PRIVILEGES priv;
  //       priv.PrivilegeCount           = 1;
  //       priv.Privileges[0].Luid       = luid;
  //       priv.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
  //       large_pages_allowed = !!AdjustTokenPrivileges(token, 0, &priv, sizeof(priv), 0, 0);
  //     }
  //     CloseHandle(token);
  //   }
  // }
  
  Bootstrap_Main_Thread_Context();
  
  push_arena(get_thread_context()->arena);
  
  // #TODO: Need to write Win32 abstraction layer first.
  { OS_System_Info* info = &os_state_w32.system_info;
    info->logical_processor_count = (s32)sysinfo.dwNumberOfProcessors;
    info->page_size               = sysinfo.dwPageSize;
    info->large_page_size         = GetLargePageMinimum();
    info->allocation_granularity  = sysinfo.dwAllocationGranularity;
  }
  { OS_Process_Info* info = &os_state_w32.process_info;
    info->large_pages_allowed = false;
    info->process_id = GetCurrentProcessId();
  }
  /*{ OS_System_Info* info = &os_state_w32.system_info;
    // [ ] Extract input args 
    u32 length;
    GetLogicalProcessorInformationEx(RelationProcessorCore, nullptr, (PDWORD)&length);
    u8* cpu_information_buffer = NewArray<u8>(length);
    GetLogicalProcessorInformationEx(RelationProcessorCore, // *sigh* 
      (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX)cpu_information_buffer, (PDWORD)&length);
    
    u32 offset = 0;
    
    u32 all_cpus_count = 0;
    u32 max_performance = 0;
    u32 performance_core_count = 0;
    // u32 efficient_core_count;
    
    while (offset < length) {
      SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX* cpu_information 
        = (SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX*)(cpu_information_buffer + offset);
      
      offset += cpu_information->Size;
      
      u32 count_per_group_physical = 1;
      u32 value = (u32)cpu_information->Processor.GroupMask->Mask;
      u32 count_per_group = __popcnt(value); // logical
      if (cpu_information->Relationship != RelationProcessorCore) continue;
      
      if (cpu_information->Processor.EfficiencyClass > max_performance) {
        max_performance = cpu_information->Processor.EfficiencyClass;
        performance_core_count = count_per_group_physical;
      } else if (cpu_information->Processor.EfficiencyClass == max_performance) {
        performance_core_count += count_per_group_physical;
      }
      
      all_cpus_count += count_per_group;  
    }
  
    info->physical_core_count = (s32)all_cpus_count;
    info->primary_core_count  = (s32)performance_core_count;
  } 
  // info->secondary_core_count = #TODO;
  */
  { OS_System_Info* info = &os_state_w32.system_info;
    u8 buffer[MAX_COMPUTERNAME_LENGTH + 1] = {0};
    DWORD size = MAX_COMPUTERNAME_LENGTH + 1;
    if(GetComputerNameA((char*)buffer, &size)) {
      string machine_name_temp = string(size, buffer);
      info->machine_name = copy_string(machine_name_temp);
    }
  }
  
  debug_break();
  
  { OS_Process_Info* info = &os_state_w32.process_info;
    DWORD length = GetCurrentDirectoryW(0, 0);
    // This can be freed later when we call temp_reset();
    u16* memory = NewArray<u16>(get_temp_allocator(), length + 1);
    length = GetCurrentDirectoryW(length + 1, (WCHAR*)memory);
    info->working_path = wide_to_utf8(memory, length);
    Assert(is_valid(info->working_path));
  }
  // [ ] Get Working directory (info->working_path)
  // [ ] GetEnvironmentStringsW
  
  printf("Hello there!\n\n");
  // See: main_thread_base_entry_point
  Main_Entry_Point(argc, argv);
}