// Copyright (C) 2014-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/sdl/sdl_input.hh"

#include "nv/lib/sdl.hh"
#include "nv/core/logging.hh"

using namespace nv;

nv::sdl::input::input()
{
	if ( ! SDL_WasInit( SDL_INIT_JOYSTICK ) ) SDL_InitSubSystem( SDL_INIT_JOYSTICK );
	if ( ! SDL_WasInit( SDL_INIT_GAMECONTROLLER ) ) SDL_InitSubSystem( SDL_INIT_GAMECONTROLLER );
}

static bool sdl_key_event_to_io_event( const SDL_KeyboardEvent& ke, io_event& kevent )
{
	kevent.type        = EV_KEY;
	kevent.key.pressed = ( ke.state != SDL_RELEASED );
	kevent.key.ascii   = 0;
	kevent.key.code    = KEY_NONE;

	uint32 ucode = (uint32)ke.keysym.sym;

	// if result is a typable char place it into the structure
	if (ucode >= 32 && ucode < 128 )
	{
		kevent.key.ascii = static_cast<uchar8>( ucode );
		if (ucode >= 'a' && ucode <= 'z')
		{
			int shifted = !!(ke.keysym.mod & KMOD_SHIFT);
			int capslock = !!(ke.keysym.mod & KMOD_CAPS);
			if ((shifted ^ capslock) != 0) {
				kevent.key.ascii = (uchar8)SDL_toupper((int)ucode);
			}
		}
	}

	// Get the Key value from the SDL Keyboard event
	int result = ke.keysym.sym;

	// Check the control and shift states
	kevent.key.alt     = (ke.keysym.mod & KMOD_ALT ) != 0;
	kevent.key.control = (ke.keysym.mod & KMOD_CTRL ) != 0;
	kevent.key.shift   = (ke.keysym.mod & KMOD_SHIFT ) != 0;

	// if result is a typable char from the directly transformable ranges
	if ( ( result >= KEY_A && result <= KEY_Z ) || 
		( result >= KEY_0 && result <= KEY_9 ) ||
		result == ' ' )
	{
		kevent.key.code = static_cast<key_code>(result);
	}

	// if result is a typable char from the a..z range
	if ( result >= KEY_A + 32 && result <= KEY_Z + 32 )
	{
		kevent.key.code = static_cast<key_code>(result - 32);
	}

	if ( result >= SDLK_F1 && result <= SDLK_F12 )
	{
		kevent.key.code = static_cast<key_code>(result - SDLK_F1 + KEY_F1 );
	}

	// other recognized codes
	switch ( result ) 
	{
	case SDLK_BACKSPACE    : kevent.key.code = KEY_BACK; break;
	case SDLK_TAB          : kevent.key.code = KEY_TAB; break;
	case SDLK_RETURN       : kevent.key.code = KEY_ENTER; break;
	case SDLK_PAGEUP       : kevent.key.code = KEY_PGUP; break;
	case SDLK_PAGEDOWN     : kevent.key.code = KEY_PGDOWN; break;
	case SDLK_END          : kevent.key.code = KEY_END; break;
	case SDLK_HOME         : kevent.key.code = KEY_HOME; break;
	case SDLK_LEFT         : kevent.key.code = KEY_LEFT; break;
	case SDLK_UP           : kevent.key.code = KEY_UP; break;
	case SDLK_RIGHT        : kevent.key.code = KEY_RIGHT; break;
	case SDLK_DOWN         : kevent.key.code = KEY_DOWN; break;
	case SDLK_DELETE       : kevent.key.code = KEY_DELETE; break;
	case SDLK_INSERT       : kevent.key.code = KEY_INSERT; break;
	//case SDLK_KP5          : kevent.key.code = KEY_CENTER; break;
	case SDLK_ESCAPE       : kevent.key.code = KEY_ESCAPE; break;
	case SDLK_QUOTE        : kevent.key.code = KEY_QUOTE; break;
	case SDLK_COMMA        : kevent.key.code = KEY_COMMA; break;
	case SDLK_MINUS        : kevent.key.code = KEY_MINUS; break;
	case SDLK_PERIOD       : kevent.key.code = KEY_PERIOD; break;
	case SDLK_SLASH        : kevent.key.code = KEY_SLASH; break;
	case SDLK_SEMICOLON    : kevent.key.code = KEY_SCOLON; break;
	case SDLK_LEFTBRACKET  : kevent.key.code = KEY_LBRACKET; break;
	case SDLK_BACKSLASH    : kevent.key.code = KEY_BSLASH; break;
	case SDLK_RIGHTBRACKET : kevent.key.code = KEY_RBRACKET; break;
	case SDLK_BACKQUOTE    : kevent.key.code = KEY_BQUOTE; break;
	default : break;
	}

	kevent.key.native = ke.keysym.scancode;

	// If key was understood by nv, then it's valid, otherwise ignored
	return kevent.key.ascii != 0 || kevent.key.code != 0;
}

static bool sdl_mouse_button_to_io_event( const SDL_MouseButtonEvent& mb, io_event& mevent )
{
	mevent.type            = EV_MOUSE_BUTTON;
	mevent.mbutton.button  = MOUSE_NONE;
	mevent.mbutton.pressed = (mb.state != SDL_RELEASED);
	mevent.mbutton.x       = static_cast< uint16 >( mb.x );
	mevent.mbutton.y       = static_cast< uint16 >( mb.y );

	switch ( mb.button )
	{
	case SDL_BUTTON_LEFT      : mevent.mbutton.button = MOUSE_LEFT; break;
	case SDL_BUTTON_MIDDLE    : mevent.mbutton.button = MOUSE_MIDDLE; break;
	case SDL_BUTTON_RIGHT     : mevent.mbutton.button = MOUSE_RIGHT; break;
	default : break;
	}

	return mevent.mbutton.button != MOUSE_NONE;
}

static bool sdl_mouse_wheel_to_io_event( const SDL_MouseWheelEvent& mm, io_event& mevent )
{
	mevent.type          = EV_MOUSE_WHEEL;
	mevent.mwheel.x      = static_cast< sint32 >( mm.x );
	mevent.mwheel.y      = static_cast< sint32 >( mm.y );
	return true;
}

static bool sdl_mouse_motion_to_io_event( const SDL_MouseMotionEvent& mm, io_event& mevent )
{
	mevent.type          = EV_MOUSE_MOVE;
	mevent.mmove.pressed = (mm.state != SDL_RELEASED);
	mevent.mmove.x       = static_cast< uint16 >( mm.x );
	mevent.mmove.y       = static_cast< uint16 >( mm.y );
	mevent.mmove.rx      = static_cast< sint16 >( mm.xrel );
	mevent.mmove.ry      = static_cast< sint16 >( mm.yrel );
	return true;
}

static bool sdl_pad_button_event_to_io_event( const SDL_ControllerButtonEvent& cb, io_event& cevent )
{
	cevent.type            = EV_PAD_BUTTON;
	cevent.pbutton.id      = cb.which;
	cevent.pbutton.button  = cb.button;
	cevent.pbutton.pressed = (cb.type == SDL_PRESSED);
	return true;
}

static bool sdl_pad_axis_event_to_io_event( const SDL_ControllerAxisEvent& ca, io_event& cevent )
{
	cevent.type          = EV_PAD_AXIS;
	cevent.paxis.id      = ca.which;
	cevent.paxis.axis    = ca.axis;
	cevent.paxis.value   = ca.value;
	return true;
}


static bool sdl_joy_button_event_to_io_event( const SDL_JoyButtonEvent& jb, io_event& jevent )
{
	jevent.type            = EV_JOY_BUTTON;
	jevent.jbutton.id      = jb.which;
	jevent.jbutton.button  = jb.button;
	jevent.jbutton.pressed = (jb.type == SDL_PRESSED);
	return true;
}

static bool sdl_joy_axis_event_to_io_event( const SDL_JoyAxisEvent& ja, io_event& jevent )
{
	jevent.type          = EV_JOY_AXIS;
	jevent.jaxis.id      = ja.which;
	jevent.jaxis.axis    = ja.axis;
	jevent.jaxis.value   = ja.value;
	return true;
}

static bool sdl_joy_hat_event_to_io_event( const SDL_JoyHatEvent& jh, io_event& jevent )
{
	jevent.type          = EV_JOY_HAT;
	jevent.jhat.id       = jh.which;
	jevent.jhat.hat      = jh.hat;
	jevent.jhat.value    = jh.value;
	return true;
}

static bool sdl_joy_ball_event_to_io_event( const SDL_JoyBallEvent& jb, io_event& jevent )
{
	jevent.type          = EV_JOY_HAT;
	jevent.jball.id      = jb.which;
	jevent.jball.ball    = jb.ball;
	jevent.jball.rx      = jb.xrel;
	jevent.jball.ry      = jb.yrel;
	return true;
}

static bool sdl_event_to_io_event( const SDL_Event& e, io_event& ioevent )
{
	switch ( e.type )
	{
	case SDL_KEYDOWN         : return sdl_key_event_to_io_event( e.key, ioevent );
	case SDL_KEYUP           : return sdl_key_event_to_io_event( e.key, ioevent );
	case SDL_MOUSEMOTION     : return sdl_mouse_motion_to_io_event( e.motion, ioevent );
	case SDL_MOUSEBUTTONDOWN : return sdl_mouse_button_to_io_event( e.button, ioevent );
	case SDL_MOUSEBUTTONUP   : return sdl_mouse_button_to_io_event( e.button, ioevent );
	case SDL_MOUSEWHEEL      : return sdl_mouse_wheel_to_io_event( e.wheel, ioevent );
/* // SDL 2.0 incompatible 
	case SDL_ACTIVEEVENT     : 
		ioevent.type = EV_ACTIVE; 
		ioevent.active.gain = (e.active.gain != 0); 
		return e.active.state == SDL_APPINPUTFOCUS;
	case SDL_VIDEORESIZE     : 
		ioevent.type     = EV_RESIZE; 
		ioevent.resize.x = e.resize.w;
		ioevent.resize.y = e.resize.h;
		return true;
	case SDL_NOEVENT         : return false;
	case SDL_VIDEOEXPOSE     : return false;
*/
	case SDL_SYSWMEVENT      : ioevent.type = EV_SYSTEM; return true;
	case SDL_QUIT            : ioevent.type = EV_QUIT;   return true;
	case SDL_CONTROLLERAXISMOTION : return sdl_pad_axis_event_to_io_event( e.caxis, ioevent ); 
	case SDL_CONTROLLERBUTTONDOWN : return sdl_pad_button_event_to_io_event( e.cbutton, ioevent ); 
	case SDL_CONTROLLERBUTTONUP   :
	case SDL_JOYAXISMOTION   : return sdl_joy_axis_event_to_io_event( e.jaxis, ioevent ); 
	case SDL_JOYBALLMOTION   : return sdl_joy_ball_event_to_io_event( e.jball, ioevent ); 
	case SDL_JOYHATMOTION    : return sdl_joy_hat_event_to_io_event( e.jhat, ioevent ); 
	case SDL_JOYBUTTONDOWN   : return sdl_joy_button_event_to_io_event( e.jbutton, ioevent );
	case SDL_JOYBUTTONUP     : return sdl_joy_button_event_to_io_event( e.jbutton, ioevent );
	default : return false;
	}
}

bool sdl::input::is_event_pending()
{
	return SDL_PollEvent( nullptr ) != 0;
}

bool sdl::input::poll_event( io_event& event )
{
	SDL_Event sdl_event;
	if ( SDL_PollEvent( &sdl_event ) == 0 ) return false;
	return sdl_event_to_io_event( sdl_event, event );
}