/* (c) Magnus Auvinen. See licence.txt in the root of the distribution for more information. */
/* If you are missing that file, acquire a complete release at teeworlds.com.                */
#include "SDL.h"

#include <base/system.h>
#include <engine/graphics.h>
#include <engine/input.h>
#include <engine/keys.h>
#include <engine/shared/config.h>

#include "input.h"

//print >>f, "int inp_key_code(const char *key_name) { int i; if (!strcmp(key_name, \"-?-\")) return -1; else for (i = 0; i < 512; i++) if (!strcmp(key_strings[i], key_name)) return i; return -1; }"

// this header is protected so you don't include it from anywere
#define KEYS_INCLUDE
#include "keynames.h"
#undef KEYS_INCLUDE

void CInput::AddEvent(char *pText, int Key, int Flags)
{
	if(m_NumEvents != INPUT_BUFFER_SIZE)
	{
		m_aInputEvents[m_NumEvents].m_Key = Key;
		m_aInputEvents[m_NumEvents].m_Flags = Flags;
		if(!pText)
			m_aInputEvents[m_NumEvents].m_aText[0] = 0;
		else
			str_utf8_copy(m_aInputEvents[m_NumEvents].m_aText, pText, sizeof(m_aInputEvents[m_NumEvents].m_aText));
		m_aInputEvents[m_NumEvents].m_InputCount = m_InputCounter;
		m_NumEvents++;
	}
}

CInput::CInput()
{
	mem_zero(m_aInputCount, sizeof(m_aInputCount));
	mem_zero(m_aInputState, sizeof(m_aInputState));

	m_InputCounter = 1;
	m_InputGrabbed = 0;

	m_LastRelease = 0;
	m_ReleaseDelta = -1;

	m_NumEvents = 0;
	m_MouseFocus = true;

	m_VideoRestartNeeded = 0;
	m_pClipboardText = NULL;

	m_NumTextInputInstances = 0;
	m_EditingTextLen = -1;
	m_aEditingText[0] = 0;
}

void CInput::Init()
{
	m_pGraphics = Kernel()->RequestInterface<IEngineGraphics>();

	// increase ime instance counter for menu
	SetIMEState(true);
	MouseModeRelative();
}

void CInput::MouseRelative(float *x, float *y)
{
	if(!m_MouseFocus || !m_InputGrabbed)
		return;

	int nx = 0, ny = 0;
	float Sens = g_Config.m_InpMousesens / 100.0f;

	SDL_GetRelativeMouseState(&nx, &ny);

	*x = nx * Sens;
	*y = ny * Sens;
}

void CInput::MouseModeAbsolute()
{
	m_InputGrabbed = 0;
	SDL_SetRelativeMouseMode(SDL_FALSE);
	Graphics()->SetWindowGrab(false);
}

void CInput::MouseModeRelative()
{
	m_InputGrabbed = 1;
	SDL_SetRelativeMouseMode(SDL_TRUE);
	Graphics()->SetWindowGrab(true);
	// Clear pending relative mouse motion
	SDL_GetRelativeMouseState(0x0, 0x0);
}

int CInput::MouseDoubleClick()
{
	if(m_ReleaseDelta >= 0 && m_ReleaseDelta < (time_freq() / 3))
	{
		m_LastRelease = 0;
		m_ReleaseDelta = -1;
		return 1;
	}
	return 0;
}

const char *CInput::GetClipboardText()
{
	if(m_pClipboardText)
	{
		SDL_free(m_pClipboardText);
	}
	m_pClipboardText = SDL_GetClipboardText();
	return m_pClipboardText;
}

void CInput::SetClipboardText(const char *Text)
{
	SDL_SetClipboardText(Text);
}

void CInput::Clear()
{
	mem_zero(m_aInputState, sizeof(m_aInputState));
	mem_zero(m_aInputCount, sizeof(m_aInputCount));
	m_NumEvents = 0;
}

bool CInput::KeyState(int Key) const
{
	if(Key < 0 || Key >= KEY_LAST)
		return false;
	return m_aInputState[Key];
}

void CInput::NextFrame()
{
	int i;
	const Uint8 *pState = SDL_GetKeyboardState(&i);
	if(i >= KEY_LAST)
		i = KEY_LAST - 1;
	mem_copy(m_aInputState, pState, i);
	if(m_EditingTextLen == 0)
		m_EditingTextLen = -1;
}

bool CInput::GetIMEState()
{
	return m_NumTextInputInstances > 0;
}

void CInput::SetIMEState(bool Activate)
{
	if(Activate)
	{
		if(m_NumTextInputInstances == 0)
			SDL_StartTextInput();
		m_NumTextInputInstances++;
	}
	else
	{
		if(m_NumTextInputInstances == 0)
			return;
		m_NumTextInputInstances--;
		if(m_NumTextInputInstances == 0)
			SDL_StopTextInput();
	}
}

const char *CInput::GetIMEEditingText()
{
	if(m_EditingTextLen > 0)
		return m_aEditingText;
	else
		return "";
}

int CInput::GetEditingCursor()
{
	return m_EditingCursor;
}

void CInput::SetEditingPosition(float X, float Y)
{
	float ScreenX0, ScreenY0, ScreenX1, ScreenY1;
	int ScreenWidth = Graphics()->ScreenWidth();
	int ScreenHeight = Graphics()->ScreenHeight();
	Graphics()->GetScreen(&ScreenX0, &ScreenY0, &ScreenX1, &ScreenY1);

	vec2 ScreenScale = vec2(ScreenWidth / (ScreenX1 - ScreenX0), ScreenHeight / (ScreenY1 - ScreenY0));

	SDL_Rect ImeWindowRect;
	ImeWindowRect.x = X * ScreenScale.x;
	ImeWindowRect.y = Y * ScreenScale.y;
	ImeWindowRect.h = 60;
	ImeWindowRect.w = 1000;

	SDL_SetTextInputRect(&ImeWindowRect);
}

int CInput::Update()
{
	// keep the counter between 1..0xFFFF, 0 means not pressed
	m_InputCounter = (m_InputCounter % 0xFFFF) + 1;

	// these states must always be updated manually because they are not in the GetKeyState from SDL
	int i = SDL_GetMouseState(NULL, NULL);
	if(i & SDL_BUTTON(1))
		m_aInputState[KEY_MOUSE_1] = 1; // 1 is left
	if(i & SDL_BUTTON(3))
		m_aInputState[KEY_MOUSE_2] = 1; // 3 is right
	if(i & SDL_BUTTON(2))
		m_aInputState[KEY_MOUSE_3] = 1; // 2 is middle
	if(i & SDL_BUTTON(4))
		m_aInputState[KEY_MOUSE_4] = 1;
	if(i & SDL_BUTTON(5))
		m_aInputState[KEY_MOUSE_5] = 1;
	if(i & SDL_BUTTON(6))
		m_aInputState[KEY_MOUSE_6] = 1;
	if(i & SDL_BUTTON(7))
		m_aInputState[KEY_MOUSE_7] = 1;
	if(i & SDL_BUTTON(8))
		m_aInputState[KEY_MOUSE_8] = 1;
	if(i & SDL_BUTTON(9))
		m_aInputState[KEY_MOUSE_9] = 1;

	{
		SDL_Event Event;
		bool IgnoreKeys = false;
		while(SDL_PollEvent(&Event))
		{
			int Scancode = 0;
			int Action = IInput::FLAG_PRESS;
			switch(Event.type)
			{
			case SDL_TEXTEDITING:
			{
				m_EditingTextLen = str_length(Event.edit.text);
				if(m_EditingTextLen)
				{
					str_copy(m_aEditingText, Event.edit.text, sizeof(m_aEditingText));
					m_EditingCursor = 0;
					for(int i = 0; i < Event.edit.start; i++)
						m_EditingCursor = str_utf8_forward(m_aEditingText, m_EditingCursor);
				}
				else
				{
					m_aEditingText[0] = 0;
				}
				break;
			}
			case SDL_TEXTINPUT:
				m_EditingTextLen = -1;
				AddEvent(Event.text.text, 0, IInput::FLAG_TEXT);
				break;
			// handle keys
			case SDL_KEYDOWN:
				// See SDL_Keymod for possible modifiers:
				// NONE   =     0
				// LSHIFT =     1
				// RSHIFT =     2
				// LCTRL  =    64
				// RCTRL  =   128
				// LALT   =   256
				// RALT   =   512
				// LGUI   =  1024
				// RGUI   =  2048
				// NUM    =  4096
				// CAPS   =  8192
				// MODE   = 16384
				// Sum if you want to ignore multiple modifiers.
				if(!(Event.key.keysym.mod & g_Config.m_InpIgnoredModifiers))
				{
					Scancode = Event.key.keysym.scancode;
				}
				break;
			case SDL_KEYUP:
				Action = IInput::FLAG_RELEASE;
				Scancode = Event.key.keysym.scancode;
				break;

			// handle mouse buttons
			case SDL_MOUSEBUTTONUP:
				Action = IInput::FLAG_RELEASE;

				if(Event.button.button == 1) // ignore_convention
				{
					m_ReleaseDelta = time_get() - m_LastRelease;
					m_LastRelease = time_get();
				}

				// fall through
			case SDL_MOUSEBUTTONDOWN:
				if(Event.button.button == SDL_BUTTON_LEFT)
					Scancode = KEY_MOUSE_1; // ignore_convention
				if(Event.button.button == SDL_BUTTON_RIGHT)
					Scancode = KEY_MOUSE_2; // ignore_convention
				if(Event.button.button == SDL_BUTTON_MIDDLE)
					Scancode = KEY_MOUSE_3; // ignore_convention
				if(Event.button.button == SDL_BUTTON_X1)
					Scancode = KEY_MOUSE_4; // ignore_convention
				if(Event.button.button == SDL_BUTTON_X2)
					Scancode = KEY_MOUSE_5; // ignore_convention
				if(Event.button.button == 6)
					Scancode = KEY_MOUSE_6; // ignore_convention
				if(Event.button.button == 7)
					Scancode = KEY_MOUSE_7; // ignore_convention
				if(Event.button.button == 8)
					Scancode = KEY_MOUSE_8; // ignore_convention
				if(Event.button.button == 9)
					Scancode = KEY_MOUSE_9; // ignore_convention
				break;

			case SDL_MOUSEWHEEL:
				if(Event.wheel.y > 0)
					Scancode = KEY_MOUSE_WHEEL_UP; // ignore_convention
				if(Event.wheel.y < 0)
					Scancode = KEY_MOUSE_WHEEL_DOWN; // ignore_convention
				if(Event.wheel.x > 0)
					Scancode = KEY_MOUSE_WHEEL_LEFT; // ignore_convention
				if(Event.wheel.x < 0)
					Scancode = KEY_MOUSE_WHEEL_RIGHT; // ignore_convention
				Action |= IInput::FLAG_RELEASE;
				break;

			case SDL_WINDOWEVENT:
				// Ignore keys following a focus gain as they may be part of global
				// shortcuts
				switch(Event.window.event)
				{
				case SDL_WINDOWEVENT_RESIZED:
					Graphics()->Resize(Event.window.data1, Event.window.data2, -1);
					break;
				case SDL_WINDOWEVENT_FOCUS_GAINED:
					if(m_InputGrabbed)
						MouseModeRelative();
					m_MouseFocus = true;
					IgnoreKeys = true;
					break;
				case SDL_WINDOWEVENT_FOCUS_LOST:
					m_MouseFocus = false;
					IgnoreKeys = true;
					if(m_InputGrabbed)
					{
						MouseModeAbsolute();
						// Remember that we had relative mouse
						m_InputGrabbed = true;
					}
					break;
#if defined(CONF_PLATFORM_MACOS) // Todo: remove this when fixed in SDL
				case SDL_WINDOWEVENT_MAXIMIZED:
					MouseModeAbsolute();
					MouseModeRelative();
					break;
#endif
				}
				break;

			// other messages
			case SDL_QUIT:
				return 1;
			}

			if(Scancode > KEY_FIRST && Scancode < g_MaxKeys && !IgnoreKeys && (!SDL_IsTextInputActive() || m_EditingTextLen == -1))
			{
				if(Action & IInput::FLAG_PRESS)
				{
					m_aInputState[Scancode] = 1;
					m_aInputCount[Scancode] = m_InputCounter;
				}
				AddEvent(0, Scancode, Action);
			}
		}
	}

	return 0;
}

int CInput::VideoRestartNeeded()
{
	if(m_VideoRestartNeeded)
	{
		m_VideoRestartNeeded = 0;
		return 1;
	}
	return 0;
}

IEngineInput *CreateEngineInput()
{
	return new CInput;
}