#if !defined(DN_OS_W32_H)
#define DN_OS_W32_H

#if defined(_CLANGD)
  #define DN_H_WITH_OS 1
  #include "../dn.h"
  #include "dn_os_windows.h"
#endif

typedef enum DN_OSW32DllLoadFunctionsResult
{
  DN_OSW32DllLoadFunctionsResult_Ok,
  DN_OSW32DllLoadFunctionsResult_LoadLibraryFailed,
  DN_OSW32DllLoadFunctionsResult_FunctionMissing,
}
DN_OSW32DllLoadFunctionsResult;

typedef struct DN_OSW32DllFunction DN_OSW32DllLoadFunction;
struct DN_OSW32DllFunction
{
  DN_Str8 name;
  void   *func_ptr;
};

typedef struct DN_OSW32DllCore DN_OSW32DllCore;
struct DN_OSW32DllCore
{
  void*                handle;
  DN_OSW32DllFunction* functions;
  DN_USize             functions_count;
};

typedef struct DN_OSW32Error DN_OSW32Error;
struct DN_OSW32Error
{
  unsigned long code;
  DN_Str8       msg;
};

typedef struct DN_OSW32FolderIteratorW DN_OSW32FolderIteratorW;
struct DN_OSW32FolderIteratorW
{
  void    *handle;
  DN_Str16 file_name;
  wchar_t  file_name_buf[512];
};

typedef struct DN_OSW32Window DN_OSW32Window;
struct DN_OSW32Window
{
  HWND            hwnd;
  // NOTE: For windows with custom title bars, this should be the rect in framebuffer units that
  // when the mouse is down will move the window, or if the mouse is double-clicked then toggle the
  // maximisation of the window. This rect should not include any custom drawn menu buttons so that
  // those buttons can be handled by your application.
  DN_Rect         custom_title_bar_rect_that_is_draggable;
  bool            custom_title_bar;
  DN_OSW32Window *next;
};

typedef enum DN_OSW32SyncPrimitiveType
{
  DN_OSW32SyncPrimitiveType_Semaphore,
  DN_OSW32SyncPrimitiveType_Mutex,
  DN_OSW32SyncPrimitiveType_ConditionVariable,
  DN_OSW32SyncPrimitiveType_Barrier,
}
DN_OSW32SyncPrimitiveType;

typedef struct DN_OSW32SyncPrimitive DN_OSW32SyncPrimitive;
struct DN_OSW32SyncPrimitive
{
  union
  {
    void                   *sem;
    CRITICAL_SECTION        mutex;
    CONDITION_VARIABLE      cv;
    SYNCHRONIZATION_BARRIER barrier;
  };

  DN_OSW32SyncPrimitive *next;
};

typedef HRESULT DN_OSW32SetThreadDescriptionFunc         (HANDLE hThread, PWSTR const lpThreadDescription);
typedef BOOL    DN_OSW32SetProcessDpiAwarenessContextFunc(void* value);
typedef UINT    DN_OSW32GetDpiForWindowFunc              (HWND hwnd);
typedef HRESULT DN_OSW32GetDpiForMonitorFunc             (HMONITOR hmonitor, MONITOR_DPI_TYPE dpiType, UINT *dpiX, UINT *dpiY);
typedef int     DN_OSW32GetSystemMetricsForDpiFunc       (int nIndex, UINT dpi);

#define DN_OSW32DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((void*)-4)
typedef struct DN_OSW32Core DN_OSW32Core;
struct DN_OSW32Core
{
  // NOTE: These functions are dynamically loaded because they might not be present on the user's
  // machine. For example the GetDpiForWindow is Windows 10+ only.
  DN_OSW32SetThreadDescriptionFunc   *set_thread_description;
  DN_OSW32GetDpiForWindowFunc        *get_dpi_for_window;
  DN_OSW32GetDpiForMonitorFunc       *get_dpi_for_monitor;
  DN_OSW32GetSystemMetricsForDpiFunc *get_system_metrics_for_dpi;

  LARGE_INTEGER                       qpc_frequency;
  void*                               bcrypt_rng_handle;
  bool                                bcrypt_init_success;
  bool                                sym_initialised;
  CRITICAL_SECTION                    sync_primitive_free_list_mutex;
  DN_OSW32SyncPrimitive*              sync_primitive_free_list;

  DN_OSW32Window*                     windows;
  WNDPROC                             fallback_wnd_proc;
};

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: DN Win32 book-keeping
DN_API void                           DN_OS_W32Init                    (DN_OSW32Core *w32);
DN_API DN_OSW32Core*                  DN_OS_W32GetCore                 ();
DN_API DN_OSW32Window*                DN_OS_W32WindowFromHwndMaybeAlloc(DN_OSW32Core *w32, HWND hwnd, DN_Arena *arena);

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: Process management
DN_API void                           DN_OS_W32ThreadSetName           (DN_Str8 name);
DN_API LRESULT __stdcall              DN_OS_W32WindowProcCustomTitlebar(HWND hwnd, UINT msg, WPARAM w_param, LPARAM l_param);
DN_API void                           DN_OS_W32MakeProcessDPIAware     ();

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: DLL
DN_API void                           DN_OS_W32DllUnload               (DN_OSW32DllCore *dll);
DN_API DN_OSW32DllLoadFunctionsResult DN_OS_W32DllLoadFunctions        (DN_OSW32DllCore *dll, DN_Str8 dll_path);

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: Errors
DN_API DN_Str16                       DN_OS_W32ErrorCodeToMsg16Alloc   (DN_U32 error_code);
DN_API DN_OSW32Error                  DN_OS_W32ErrorCodeToMsg          (DN_Arena *arena, DN_U32 error_code);
DN_API DN_OSW32Error                  DN_OS_W32ErrorCodeToMsgAlloc     (DN_U32 error_code);
DN_API DN_OSW32Error                  DN_OS_W32LastError               (DN_Arena *arena);
DN_API DN_OSW32Error                  DN_OS_W32LastErrorAlloc          ();

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: Windows Str8 <-> Str16
DN_API DN_Str16                       DN_OS_W32Str8ToStr16             (DN_Arena *arena, DN_Str8 src);
DN_API int                            DN_OS_W32Str8ToStr16Buffer       (DN_Str16 src, char *dest, int dest_size);
DN_API DN_Str8                        DN_OS_W32Str16ToStr8             (DN_Arena *arena, DN_Str16 src);
DN_API int                            DN_OS_W32Str16ToStr8Buffer       (DN_Str16 src, char *dest, int dest_size);
DN_API DN_Str8                        DN_OS_W32Str16ToStr8FromHeap     (DN_Str16 src);

////////////////////////////////////////////////////////////////////////////////////////////////////
// NOTE: Path navigation
DN_API DN_Str16                       DN_OS_W32ExePathW                (DN_Arena *arena);
DN_API DN_Str16                       DN_OS_W32ExeDirW                 (DN_Arena *arena);
DN_API DN_Str8                        DN_OS_W32WorkingDir              (DN_Arena *arena, DN_Str8 suffix);
DN_API DN_Str16                       DN_OS_W32WorkingDirW             (DN_Arena *arena, DN_Str16 suffix);
DN_API bool                           DN_OS_W32DirWIterate             (DN_Str16 path, DN_OSW32FolderIteratorW *it);
#endif // !defined(DN_OS_W32_H)