/*
Copyright (C) 2018 Parallel Realities

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include "input.h"

static int mouseDownTimer;
static SDL_Point dragStart;

void initInput(void)
{
	mouseDownTimer = 0;
}

static void doKeyDown(SDL_KeyboardEvent *event)
{
	if (event->keysym.scancode >= 0 && event->keysym.scancode < MAX_KEYBOARD_KEYS && event->repeat == 0)
	{
		app.keyboard[event->keysym.scancode] = 1;
	}
}

static void doKeyUp(SDL_KeyboardEvent *event)
{
	if (event->keysym.scancode >= 0 && event->keysym.scancode < MAX_KEYBOARD_KEYS)
	{
		app.keyboard[event->keysym.scancode] = 0;
	}
}

static void doMouseDown(SDL_MouseButtonEvent *event)
{
	if (event->button >= 0 && event->button < MAX_MOUSE_BUTTONS)
	{
		app.mouse.button[event->button] = 1;
	}
}

static void doMouseUp(SDL_MouseButtonEvent *event)
{
	if (event->button >= 0 && event->button < MAX_MOUSE_BUTTONS)
	{
		app.mouse.button[event->button] = 0;
		
		if (event->button == SDL_BUTTON_LEFT)
		{
			app.mouse.dragging = 0;
			
			mouseDownTimer = 0;
		}
	}
}

/*
 * Note: the following assumes that SDL_BUTTON_X1 and SDL_BUTTON_X2 are 4 and 5, respectively. They usually are.
 */
static void doMouseWheel(SDL_MouseWheelEvent *event)
{
	if (event->y == -1)
	{
		app.mouse.button[SDL_BUTTON_X1] = 1;
	}

	if (event->y == 1)
	{
		app.mouse.button[SDL_BUTTON_X2] = 1;
	}
}

static void doMouseMotion(SDL_MouseMotionEvent *event)
{
	if (event->state & SDL_BUTTON_LMASK)
	{
		if (++mouseDownTimer >= 4 && (abs(dragStart.x - event->x) >= MOUSE_DRAG_THRESHOLD || abs(dragStart.y - event->y) >= MOUSE_DRAG_THRESHOLD))
		{
			app.mouse.dx = event->xrel;
			app.mouse.dy = event->yrel;
			app.mouse.dragging = 1;
			dragStart.x = event->x;
			dragStart.y = event->y;
		}
	}
	else
	{
		mouseDownTimer = 0;
	}
}

void clearInput(void)
{
	SDL_Event event;
	
	memset(app.keyboard, 0, sizeof(int) * MAX_KEYBOARD_KEYS);
	memset(&app.mouse, 0, sizeof(Mouse));
	memset(&app.joypadButton, 0, sizeof(int) * SDL_CONTROLLER_BUTTON_MAX);

	while (SDL_PollEvent(&event))
	{
	}
}

void handleInput(void)
{
	int i;
	SDL_Event event;
	
	app.mouse.dx = 0;
	app.mouse.dy = 0;
	
	while (SDL_PollEvent(&event))
	{
		switch (event.type)
		{
			case SDL_MOUSEMOTION:
				doMouseMotion(&event.motion);
				break;
				
			case SDL_MOUSEWHEEL:
				doMouseWheel(&event.wheel);
				break;
			
			case SDL_MOUSEBUTTONDOWN:
				doMouseDown(&event.button);
				break;

			case SDL_MOUSEBUTTONUP:
				doMouseUp(&event.button);
				break;
			
			case SDL_KEYDOWN:
				doKeyDown(&event.key);
				break;
				
			case SDL_KEYUP:
				doKeyUp(&event.key);
				break;
			
			case SDL_QUIT:
				exit(0);
				break;
		}
	}
	
	SDL_GetMouseState(&app.mouse.x, &app.mouse.y);

	for (i = 0 ; i < SDL_CONTROLLER_BUTTON_MAX ; i++)
	{
		app.joypadButton[i] = SDL_JoystickGetButton(app.joypad, i);
	}
}