#pragma comment(lib, "user32")

f64 GetUnixTimestamp ();
s64 GetUnixTimestampNanoseconds ();

enum class Wait_For_Result : s32 {
  SUCCESS = 0,
  TIMEOUT = 1,
  ERROR = 2 // can't use ERROR because of Windows.h *sigh*
};

internal void semaphore_init (Semaphore* sem, s32 initial_value = 0);
internal void semaphore_destroy (Semaphore* sem);
internal void signal (Semaphore* sem);
internal Wait_For_Result wait_for (Semaphore* sem, s32 milliseconds = -1);

internal void condition_variable_init (Condition_Variable* cv);
internal void condition_variable_destroy (Condition_Variable* cv);
internal void wait (Condition_Variable* cv, Mutex* mutex, s32 wait_time_ms = -1);
internal void wake (Condition_Variable* cv);
internal void wake_all (Condition_Variable* cv);

typedef u32 OS_Error_Code;
internal string get_error_string (OS_Error_Code error_code);

internal bool file_is_valid (File file);
internal File file_open (string file_path, bool for_writing=false, bool keep_existing_content=false, bool log_errors=false);
internal void file_close (File* file);
internal bool file_read (File file, void* data, s64 bytes_to_read_count, s64* bytes_read_count=nullptr);
internal bool file_length (File file, s64* length);
internal bool file_length (string file_path, s64* length);
internal s64 file_current_position (File file);
internal bool file_set_position (File file, s64 position);
internal ArrayView<u8> read_entire_file (File file);
internal ArrayView<u8> read_entire_file (string file_path, bool log_errors=false);

// use to_byte_view to convert ArrayView<non-u8> to ArrayView<u8>
internal bool file_write (File* file, void* data, s64 length);
internal bool write_entire_file (string file_path, void* file_data, s64 count);
internal bool write_entire_file (string file_path, ArrayView<u8> file_data);

// file_write
// write_entire_file...

// #TODO #fs File System Operations
// file_move, file_delete

// #window_creation
typedef HWND Window_Type;

struct Window_Dimensions {
  s32 window_x;
  s32 window_y;
  s32 window_width;
  s32 window_height;
};

struct Window_Info {
  Window_Type window;
  Window_Dimensions initial_dimensions; // for resetting.
  
  
  b32 is_main_window;
  b32 backend_initialized;
  // Platform-Specific (Win32)
  HDC hdc;
};

// #move: Monitor - platform-independent hardware monitor information: 
struct Monitor {
  s64 left;
  s64 top;
  s64 right;
  s64 bottom;
  bool primary;
  bool present;
#if OS_WINDOWS
  MONITORINFO monitor_info;
#endif
};


bool os_create_window (string new_window_name, Window_Type parent=nullptr, bool center_window=true, bool open_on_largest_monitor=true, bool display_window=true, void* wnd_proc_override=nullptr);

Window_Info get_main_window ();
Window_Info* get_main_window_pointer ();

// struct File_Contents {
//   File file = {};
//   ArrayView<u8> file_data = {};
//   bool read_success = false;
// };