//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
//	DOOM graphics stuff for SDL.
//


#include "SDL/SDL.h"
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <string.h>

#include "config.h"
#include "deh_str.h"
#include "doomtype.h"
#include "doomkeys.h"
#include "i_joystick.h"
#include "i_system.h"
#include "i_swap.h"
#include "i_timer.h"
#include "i_video.h"
#include "i_scale.h"
#include "m_argv.h"
#include "m_config.h"
#include "m_misc.h"
#include "tables.h"
#include "v_video.h"
#include "w_wad.h"
#include "z_zone.h"

// SDL surface for the screen.

static SDL_Surface *screen;

// If true, keyboard mapping is ignored, like in Vanilla Doom.
// The sensible thing to do is to disable this if you have a non-US
// keyboard.

int vanilla_keyboard_mapping = true;

// Is the shift key currently down?

static int shiftdown = 0;
// Lookup table for mapping ASCII characters to their equivalent when
// shift is pressed on an American layout keyboard:

static const char shiftxform[] =
{
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
    11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
    21, 22, 23, 24, 25, 26, 27, 28, 29, 30,
    31, ' ', '!', '"', '#', '$', '%', '&',
    '"', // shift-'
    '(', ')', '*', '+',
    '<', // shift-,
    '_', // shift--
    '>', // shift-.
    '?', // shift-/
    ')', // shift-0
    '!', // shift-1
    '@', // shift-2
    '#', // shift-3
    '$', // shift-4
    '%', // shift-5
    '^', // shift-6
    '&', // shift-7
    '*', // shift-8
    '(', // shift-9
    ':',
    ':', // shift-;
    '<',
    '+', // shift-=
    '>', '?', '@',
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    '[', // shift-[
    '!', // shift-backslash - OH MY GOD DOES WATCOM SUCK
    ']', // shift-]
    '"', '_',
    '\'', // shift-`
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    '{', '|', '}', '~', 127
};


//
// Translates the SDL key
//

static int TranslateKey(SDL_keysym *sym)
{
    switch(sym->sym)
    {
      case SDLK_LEFT:	return KEY_LEFTARROW;
      case SDLK_RIGHT:	return KEY_RIGHTARROW;
      case SDLK_DOWN:	return KEY_DOWNARROW;
      case SDLK_UP:	return KEY_UPARROW;
      case SDLK_ESCAPE:	return KEY_ESCAPE;
      case SDLK_RETURN:	return KEY_ENTER;
      case SDLK_TAB:	return KEY_TAB;
      case SDLK_F1:	return KEY_F1;
      case SDLK_F2:	return KEY_F2;
      case SDLK_F3:	return KEY_F3;
      case SDLK_F4:	return KEY_F4;
      case SDLK_F5:	return KEY_F5;
      case SDLK_F6:	return KEY_F6;
      case SDLK_F7:	return KEY_F7;
      case SDLK_F8:	return KEY_F8;
      case SDLK_F9:	return KEY_F9;
      case SDLK_F10:	return KEY_F10;
      case SDLK_F11:	return KEY_F11;
      case SDLK_F12:	return KEY_F12;
      case SDLK_PRINT:  return KEY_PRTSCR;

      case SDLK_BACKSPACE: return KEY_BACKSPACE;
      case SDLK_DELETE:	return KEY_DEL;

      case SDLK_PAUSE:	return KEY_PAUSE;

#if !SDL_VERSION_ATLEAST(1, 3, 0)
      case SDLK_EQUALS: return KEY_EQUALS;
#endif

      case SDLK_MINUS:          return KEY_MINUS;

      case SDLK_LSHIFT:
      case SDLK_RSHIFT:
	return KEY_RSHIFT;
	
      case SDLK_LCTRL:
      case SDLK_RCTRL:
	return KEY_RCTRL;
	
      case SDLK_LALT:
      case SDLK_RALT:
#if !SDL_VERSION_ATLEAST(1, 3, 0)
      case SDLK_LMETA:
      case SDLK_RMETA:
#endif
        return KEY_RALT;

      case SDLK_CAPSLOCK: return KEY_CAPSLOCK;
      case SDLK_SCROLLOCK: return KEY_SCRLCK;
      case SDLK_NUMLOCK: return KEY_NUMLOCK;

      case SDLK_KP0: return KEYP_0;
      case SDLK_KP1: return KEYP_1;
      case SDLK_KP2: return KEYP_2;
      case SDLK_KP3: return KEYP_3;
      case SDLK_KP4: return KEYP_4;
      case SDLK_KP5: return KEYP_5;
      case SDLK_KP6: return KEYP_6;
      case SDLK_KP7: return KEYP_7;
      case SDLK_KP8: return KEYP_8;
      case SDLK_KP9: return KEYP_9;

      case SDLK_KP_PERIOD:   return KEYP_PERIOD;
      case SDLK_KP_MULTIPLY: return KEYP_MULTIPLY;
      case SDLK_KP_PLUS:     return KEYP_PLUS;
      case SDLK_KP_MINUS:    return KEYP_MINUS;
      case SDLK_KP_DIVIDE:   return KEYP_DIVIDE;
      case SDLK_KP_EQUALS:   return KEYP_EQUALS;
      case SDLK_KP_ENTER:    return KEYP_ENTER;

      case SDLK_HOME: return KEY_HOME;
      case SDLK_INSERT: return KEY_INS;
      case SDLK_END: return KEY_END;
      case SDLK_PAGEUP: return KEY_PGUP;
      case SDLK_PAGEDOWN: return KEY_PGDN;

#ifdef SDL_HAVE_APP_KEYS
        case SDLK_APP1:        return KEY_F1;
        case SDLK_APP2:        return KEY_F2;
        case SDLK_APP3:        return KEY_F3;
        case SDLK_APP4:        return KEY_F4;
        case SDLK_APP5:        return KEY_F5;
        case SDLK_APP6:        return KEY_F6;
#endif

      default:
        return tolower(sym->sym);
    }
}

// Get the equivalent ASCII (Unicode?) character for a keypress.

static int GetTypedChar(SDL_Event *event)
{
    int key;

    // If Vanilla keyboard mapping enabled, the keyboard
    // scan code is used to give the character typed.
    // This does not change depending on keyboard layout.
    // If you have a German keyboard, pressing 'z' will
    // give 'y', for example.  It is desirable to be able
    // to fix this so that people with non-standard 
    // keyboard mappings can type properly.  If vanilla
    // mode is disabled, use the properly translated 
    // version.

    if (vanilla_keyboard_mapping)
    {
        key = TranslateKey(&event->key.keysym);

        // Is shift held down?  If so, perform a translation.

        if (shiftdown > 0)
        {
            if (key >= 0 && key < arrlen(shiftxform))
            {
                key = shiftxform[key];
            }
            else
            {
                key = 0;
            }
        }

        return key;
    }
    else
    {
        // Unicode value, from key layout.

        return tolower(event->key.keysym.unicode);
    }
}

static void UpdateShiftStatus(SDL_Event *event)
{
    int change;

    if (event->type == SDL_KEYDOWN)
    {
        change = 1;
    }
    else if (event->type == SDL_KEYUP)
    {
        change = -1;
    }
    else
    {
        return;
    }

    if (event->key.keysym.sym == SDLK_LSHIFT 
     || event->key.keysym.sym == SDLK_RSHIFT)
    {
        shiftdown += change;
    }
}


void I_GetEvent(void)
{
    SDL_Event sdlevent;
    event_t event;

    // possibly not needed
    
    SDL_PumpEvents();

    // put event-grabbing stuff in here
    
    while (SDL_PollEvent(&sdlevent))
    {
        if (sdlevent.type == SDL_QUIT)
        {
            I_Quit();
        }

        UpdateShiftStatus(&sdlevent);

        // process event
        
        switch (sdlevent.type)
        {
            case SDL_KEYDOWN:
                // data1 has the key pressed, data2 has the character
                // (shift-translated, etc)
                event.type = ev_keydown;
                event.data1 = TranslateKey(&sdlevent.key.keysym);
                event.data2 = GetTypedChar(&sdlevent);

                if (event.data1 != 0)
                {
                    D_PostEvent(&event);
                }
                break;

            case SDL_KEYUP:
                event.type = ev_keyup;
                event.data1 = TranslateKey(&sdlevent.key.keysym);

                // data2 is just initialized to zero for ev_keyup.
                // For ev_keydown it's the shifted Unicode character
                // that was typed, but if something wants to detect
                // key releases it should do so based on data1
                // (key ID), not the printable char.

                event.data2 = 0;

                if (event.data1 != 0)
                {
                    D_PostEvent(&event);
                }
                break;

                /*
            case SDL_MOUSEMOTION:
                event.type = ev_mouse;
                event.data1 = mouse_button_state;
                event.data2 = AccelerateMouse(sdlevent.motion.xrel);
                event.data3 = -AccelerateMouse(sdlevent.motion.yrel);
                D_PostEvent(&event);
                break;
                */

            case SDL_QUIT:
                event.type = ev_quit;
                D_PostEvent(&event);
                break;

            case SDL_ACTIVEEVENT:
                // need to update our focus state
                //UpdateFocus();
                break;

            default:
                break;
        }
    }
}


//void I_ShutdownGraphics(void)
//{
//    //SDL_QuitSubSystem(SDL_INIT_VIDEO);
//}

//
// I_StartTic
//
void I_StartTic (void)
{
    I_GetEvent();
}

void I_InitInput(void)
{
    SDL_Event dummy;
    byte *doompal;
    char *env;

    // Pass through the XSCREENSAVER_WINDOW environment variable to 
    // SDL_WINDOWID, to embed the SDL window into the Xscreensaver
    // window.

    env = getenv("XSCREENSAVER_WINDOW");

    if (env != NULL)
    {
        char winenv[30];
        int winid;

        sscanf(env, "0x%x", &winid);
        M_snprintf(winenv, sizeof(winenv), "SDL_WINDOWID=%i", winid);

        putenv(winenv);
    }

    if (SDL_Init(SDL_INIT_VIDEO) < 0) 
    {
        I_Error("Failed to initialize video: %s", SDL_GetError());
    }

    //UpdateFocus();

    // We need SDL to give us translated versions of keys as well

    SDL_EnableUNICODE(1);

    // Repeat key presses - this is what Vanilla Doom does
    // Not sure about repeat rate - probably dependent on which DOS
    // driver is used.  This is good enough though.

    SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);

    // clear out any events waiting at the start and center the mouse
  
    while (SDL_PollEvent(&dummy));
}