#foreign_system_library "user32"
#foreign_system_library "gdi32"

HANDLE    :: type rawptr
HWND      :: type HANDLE
HDC       :: type HANDLE
HINSTANCE :: type HANDLE
HICON     :: type HANDLE
HCURSOR   :: type HANDLE
HMENU     :: type HANDLE
HBRUSH    :: type HANDLE
HGDIOBJ   :: type HANDLE
WPARAM    :: type uint
LPARAM    :: type int
LRESULT   :: type int
ATOM      :: type i16
BOOL      :: type i32
WNDPROC   :: type proc(hwnd: HWND, msg: u32, wparam: WPARAM, lparam: LPARAM) -> LRESULT

INVALID_HANDLE_VALUE :: (-1 as int) as HANDLE

CS_VREDRAW    :: 0x0001
CS_HREDRAW    :: 0x0002
CS_OWNDC      :: 0x0020
CW_USEDEFAULT :: 0x80000000

WS_OVERLAPPED       :: 0
WS_MAXIMIZEBOX      :: 0x00010000
WS_MINIMIZEBOX      :: 0x00020000
WS_THICKFRAME       :: 0x00040000
WS_SYSMENU          :: 0x00080000
WS_CAPTION          :: 0x00C00000
WS_VISIBLE          :: 0x10000000
WS_OVERLAPPEDWINDOW :: WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|WS_THICKFRAME|WS_MINIMIZEBOX|WS_MAXIMIZEBOX

WM_DESTROY :: 0x0002
WM_CLOSE   :: 0x0010
WM_QUIT    :: 0x0012
WM_KEYDOWN :: 0x0100
WM_KEYUP   :: 0x0101

PM_REMOVE :: 1

COLOR_BACKGROUND :: 1 as HBRUSH
BLACK_BRUSH :: 4

SM_CXSCREEN :: 0
SM_CYSCREEN :: 1

SW_SHOW :: 5

POINT :: struct #ordered {
	x, y: i32
}


WNDCLASSEXA :: struct #ordered {
	size, style:           u32
	wnd_proc:              WNDPROC
	cls_extra, wnd_extra:  i32
	instance:              HINSTANCE
	icon:                  HICON
	cursor:                HCURSOR
	background:            HBRUSH
	menu_name, class_name: ^u8
	sm:                    HICON
}

MSG :: struct #ordered {
	hwnd:    HWND
	message: u32
	wparam:  WPARAM
	lparam:  LPARAM
	time:    u32
	pt:      POINT
}

RECT :: struct #ordered {
	left:   i32
	top:    i32
	right:  i32
	bottom: i32
}


GetLastError     :: proc() -> i32                       #foreign #dll_import
ExitProcess      :: proc(exit_code: u32)                #foreign #dll_import
GetDesktopWindow :: proc() -> HWND                      #foreign #dll_import
GetCursorPos     :: proc(p: ^POINT) -> i32              #foreign #dll_import
ScreenToClient   :: proc(h: HWND, p: ^POINT) -> i32     #foreign #dll_import
GetModuleHandleA :: proc(module_name: ^u8) -> HINSTANCE #foreign #dll_import
GetStockObject   :: proc(fn_object: i32) -> HGDIOBJ     #foreign #dll_import
PostQuitMessage  :: proc(exit_code: i32)                #foreign #dll_import

QueryPerformanceFrequency :: proc(result: ^i64) -> i32 #foreign #dll_import
QueryPerformanceCounter   :: proc(result: ^i64) -> i32 #foreign #dll_import

Sleep :: proc(ms: i32) -> i32 #foreign

OutputDebugStringA :: proc(c_str: ^u8) #foreign #dll_import


RegisterClassExA :: proc(wc: ^WNDCLASSEXA) -> ATOM #foreign #dll_import
CreateWindowExA  :: proc(ex_style: u32,
                         class_name, title: ^u8,
                         style: u32,
                         x, y, w, h: i32,
                         parent: HWND, menu: HMENU, instance: HINSTANCE,
                         param: rawptr) -> HWND #foreign #dll_import

ShowWindow       :: proc(hwnd: HWND, cmd_show: i32) -> BOOL #foreign #dll_import
TranslateMessage :: proc(msg: ^MSG) -> BOOL                 #foreign #dll_import
DispatchMessageA :: proc(msg: ^MSG) -> LRESULT              #foreign #dll_import
UpdateWindow     :: proc(hwnd: HWND) -> BOOL                #foreign #dll_import
PeekMessageA     :: proc(msg: ^MSG, hwnd: HWND,
                         msg_filter_min, msg_filter_max, remove_msg: u32) -> BOOL #foreign #dll_import

DefWindowProcA   :: proc(hwnd: HWND, msg: u32, wparam: WPARAM, lparam: LPARAM) -> LRESULT #foreign #dll_import

AdjustWindowRect :: proc(rect: ^RECT, style: u32, menu: BOOL) -> BOOL #foreign #dll_import


GetQueryPerformanceFrequency :: proc() -> i64 {
	r: i64
	_ = QueryPerformanceFrequency(^r)
	return r
}

GetCommandLineA :: proc() -> ^u8 #foreign #dll_import
GetSystemMetrics :: proc(index: i32) -> i32 #foreign #dll_import
GetCurrentThreadId :: proc() -> u32 #foreign #dll_import

// File Stuff

CloseHandle  :: proc(h: HANDLE) -> i32 #foreign #dll_import
GetStdHandle :: proc(h: i32) -> HANDLE #foreign #dll_import
CreateFileA  :: proc(filename: ^u8, desired_access, share_mode: u32,
                     security: rawptr,
                     creation, flags_and_attribs: u32, template_file: HANDLE) -> HANDLE #foreign #dll_import
ReadFile     :: proc(h: HANDLE, buf: rawptr, to_read: u32, bytes_read: ^i32, overlapped: rawptr) -> BOOL #foreign #dll_import
WriteFile    :: proc(h: HANDLE, buf: rawptr, len: i32, written_result: ^i32, overlapped: rawptr) -> i32 #foreign #dll_import

GetFileSizeEx :: proc(file_handle: HANDLE, file_size: ^i64) -> BOOL #foreign #dll_import

FILE_SHARE_READ      :: 0x00000001
FILE_SHARE_WRITE     :: 0x00000002
FILE_SHARE_DELETE    :: 0x00000004
FILE_GENERIC_ALL     :: 0x10000000
FILE_GENERIC_EXECUTE :: 0x20000000
FILE_GENERIC_WRITE   :: 0x40000000
FILE_GENERIC_READ    :: 0x80000000

STD_INPUT_HANDLE  :: -10
STD_OUTPUT_HANDLE :: -11
STD_ERROR_HANDLE  :: -12

CREATE_NEW        :: 1
CREATE_ALWAYS     :: 2
OPEN_EXISTING     :: 3
OPEN_ALWAYS       :: 4
TRUNCATE_EXISTING :: 5


HeapAlloc :: proc(h: HANDLE, flags: u32, bytes: int) -> rawptr #foreign #dll_import
HeapFree  :: proc(h: HANDLE, flags: u32, memory: rawptr) -> BOOL #foreign #dll_import
GetProcessHeap :: proc() -> HANDLE #foreign #dll_import


HEAP_ZERO_MEMORY :: 0x00000008



// GDI

BITMAPINFO :: struct #ordered {
	HEADER :: struct #ordered {
		size:              u32
		width, height:     i32
		planes, bit_count: i16
		compression:       u32
		size_image:        u32
		x_pels_per_meter:  i32
		y_pels_per_meter:  i32
		clr_used:          u32
		clr_important:     u32
	}
	using header: HEADER
	colors:       [1]RGBQUAD
}


RGBQUAD :: struct #ordered {
	blue, green, red, reserved: byte
}

BI_RGB         :: 0
DIB_RGB_COLORS :: 0x00
SRCCOPY        : u32 : 0x00cc0020

StretchDIBits :: proc(hdc: HDC,
                      x_dst, y_dst, width_dst, height_dst: i32,
                      x_src, y_src, width_src, header_src: i32,
                      bits: rawptr, bits_info: ^BITMAPINFO,
                      usage: u32,
                      rop: u32) -> i32 #foreign #dll_import






// Windows OpenGL

PFD_TYPE_RGBA             :: 0
PFD_TYPE_COLORINDEX       :: 1
PFD_MAIN_PLANE            :: 0
PFD_OVERLAY_PLANE         :: 1
PFD_UNDERLAY_PLANE        :: -1
PFD_DOUBLEBUFFER          :: 1
PFD_STEREO                :: 2
PFD_DRAW_TO_WINDOW        :: 4
PFD_DRAW_TO_BITMAP        :: 8
PFD_SUPPORT_GDI           :: 16
PFD_SUPPORT_OPENGL        :: 32
PFD_GENERIC_FORMAT        :: 64
PFD_NEED_PALETTE          :: 128
PFD_NEED_SYSTEM_PALETTE   :: 0x00000100
PFD_SWAP_EXCHANGE         :: 0x00000200
PFD_SWAP_COPY             :: 0x00000400
PFD_SWAP_LAYER_BUFFERS    :: 0x00000800
PFD_GENERIC_ACCELERATED   :: 0x00001000
PFD_DEPTH_DONTCARE        :: 0x20000000
PFD_DOUBLEBUFFER_DONTCARE :: 0x40000000
PFD_STEREO_DONTCARE       :: 0x80000000

HGLRC :: type HANDLE
PROC  :: type proc()
wglCreateContextAttribsARBType :: type proc(hdc: HDC, hshareContext: rawptr, attribList: ^i32) -> HGLRC


PIXELFORMATDESCRIPTOR :: struct #ordered {
	size,
	version,
	flags: u32

	pixel_type,
	color_bits,
	red_bits,
	red_shift,
	green_bits,
	green_shift,
	blue_bits,
	blue_shift,
	alpha_bits,
	alpha_shift,
	accum_bits,
	accum_red_bits,
	accum_green_bits,
	accum_blue_bits,
	accum_alpha_bits,
	depth_bits,
	stencil_bits,
	aux_buffers,
	layer_type,
	reserved: byte

	layer_mask,
	visible_mask,
	damage_mask: u32
}

GetDC             :: proc(h: HANDLE) -> HDC #foreign
SetPixelFormat    :: proc(hdc: HDC, pixel_format: i32, pfd: ^PIXELFORMATDESCRIPTOR ) -> BOOL #foreign #dll_import
ChoosePixelFormat :: proc(hdc: HDC, pfd: ^PIXELFORMATDESCRIPTOR) -> i32 #foreign #dll_import
SwapBuffers       :: proc(hdc: HDC) -> BOOL #foreign #dll_import
ReleaseDC         :: proc(wnd: HWND, hdc: HDC) -> i32 #foreign #dll_import

WGL_CONTEXT_MAJOR_VERSION_ARB             :: 0x2091
WGL_CONTEXT_MINOR_VERSION_ARB             :: 0x2092
WGL_CONTEXT_PROFILE_MASK_ARB              :: 0x9126
WGL_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB :: 0x0002

wglCreateContext  :: proc(hdc: HDC) -> HGLRC #foreign #dll_import
wglMakeCurrent    :: proc(hdc: HDC, hglrc: HGLRC) -> BOOL #foreign #dll_import
wglGetProcAddress :: proc(c_str: ^u8) -> PROC #foreign #dll_import
wglDeleteContext  :: proc(hglrc: HGLRC) -> BOOL #foreign #dll_import



GetAsyncKeyState :: proc(v_key: i32) -> i16 #foreign #dll_import

is_key_down :: proc(key: Key_Code) -> bool {
	return GetAsyncKeyState(key as i32) < 0
}

Key_Code :: enum i32 {
	LBUTTON    = 0x01,
	RBUTTON    = 0x02,
	CANCEL     = 0x03,
	MBUTTON    = 0x04,

	BACK       = 0x08,
	TAB        = 0x09,

	CLEAR      = 0x0C,
	RETURN     = 0x0D,

	SHIFT      = 0x10,
	CONTROL    = 0x11,
	MENU       = 0x12,
	PAUSE      = 0x13,
	CAPITAL    = 0x14,

	KANA       = 0x15,
	HANGEUL    = 0x15,
	HANGUL     = 0x15,
	JUNJA      = 0x17,
	FINAL      = 0x18,
	HANJA      = 0x19,
	KANJI      = 0x19,

	ESCAPE     = 0x1B,

	CONVERT    = 0x1C,
	NONCONVERT = 0x1D,
	ACCEPT     = 0x1E,
	MODECHANGE = 0x1F,

	SPACE      = 0x20,
	PRIOR      = 0x21,
	NEXT       = 0x22,
	END        = 0x23,
	HOME       = 0x24,
	LEFT       = 0x25,
	UP         = 0x26,
	RIGHT      = 0x27,
	DOWN       = 0x28,
	SELECT     = 0x29,
	PRINT      = 0x2A,
	EXECUTE    = 0x2B,
	SNAPSHOT   = 0x2C,
	INSERT     = 0x2D,
	DELETE     = 0x2E,
	HELP       = 0x2F,

	NUM0 = #rune "0",
	NUM1 = #rune "1",
	NUM2 = #rune "2",
	NUM3 = #rune "3",
	NUM4 = #rune "4",
	NUM5 = #rune "5",
	NUM6 = #rune "6",
	NUM7 = #rune "7",
	NUM8 = #rune "8",
	NUM9 = #rune "9",

	A = #rune "A",
	B = #rune "B",
	C = #rune "C",
	D = #rune "D",
	E = #rune "E",
	F = #rune "F",
	G = #rune "G",
	H = #rune "H",
	I = #rune "I",
	J = #rune "J",
	K = #rune "K",
	L = #rune "L",
	M = #rune "M",
	N = #rune "N",
	O = #rune "O",
	P = #rune "P",
	Q = #rune "Q",
	R = #rune "R",
	S = #rune "S",
	T = #rune "T",
	U = #rune "U",
	V = #rune "V",
	W = #rune "W",
	X = #rune "X",
	Y = #rune "Y",
	Z = #rune "Z",

	LWIN       = 0x5B,
	RWIN       = 0x5C,
	APPS       = 0x5D,

	NUMPAD0    = 0x60,
	NUMPAD1    = 0x61,
	NUMPAD2    = 0x62,
	NUMPAD3    = 0x63,
	NUMPAD4    = 0x64,
	NUMPAD5    = 0x65,
	NUMPAD6    = 0x66,
	NUMPAD7    = 0x67,
	NUMPAD8    = 0x68,
	NUMPAD9    = 0x69,
	MULTIPLY   = 0x6A,
	ADD        = 0x6B,
	SEPARATOR  = 0x6C,
	SUBTRACT   = 0x6D,
	DECIMAL    = 0x6E,
	DIVIDE     = 0x6F,
	F1         = 0x70,
	F2         = 0x71,
	F3         = 0x72,
	F4         = 0x73,
	F5         = 0x74,
	F6         = 0x75,
	F7         = 0x76,
	F8         = 0x77,
	F9         = 0x78,
	F10        = 0x79,
	F11        = 0x7A,
	F12        = 0x7B,
	F13        = 0x7C,
	F14        = 0x7D,
	F15        = 0x7E,
	F16        = 0x7F,
	F17        = 0x80,
	F18        = 0x81,
	F19        = 0x82,
	F20        = 0x83,
	F21        = 0x84,
	F22        = 0x85,
	F23        = 0x86,
	F24        = 0x87,

	NUMLOCK    = 0x90,
	SCROLL     = 0x91,

	LSHIFT     = 0xA0,
	RSHIFT     = 0xA1,
	LCONTROL   = 0xA2,
	RCONTROL   = 0xA3,
	LMENU      = 0xA4,
	RMENU      = 0xA5,
	PROCESSKEY = 0xE5,
	ATTN       = 0xF6,
	CRSEL      = 0xF7,
	EXSEL      = 0xF8,
	EREOF      = 0xF9,
	PLAY       = 0xFA,
	ZOOM       = 0xFB,
	NONAME     = 0xFC,
	PA1        = 0xFD,
	OEM_CLEAR  = 0xFE,
}