/*
 * 86Box	A hypervisor and IBM PC system emulator that specializes in
 *		running old operating systems and software designed for IBM
 *		PC systems and compatibles from 1981 through fairly recent
 *		system designs based on the PCI bus.
 *
 *		This file is part of the 86Box distribution.
 *
 *		Windows raw keyboard input handler.
 *
 * Version:	@(#)win_keyboard.c	1.0.7	2018/01/20
 *
 * Author:	Miran Grca, <mgrca8@gmail.com>
 *
 *		Copyright 2016-2018 Miran Grca.
 */
#define UNICODE
#define  _WIN32_WINNT 0x0501
#define BITMAP WINDOWS_BITMAP
#include <windows.h>
#include <windowsx.h>
#undef BITMAP
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "../86box.h"
#include "../device.h"
#include "../keyboard.h"
#include "../plat.h"
#include "win.h"


static uint16_t	scancode_map[768];


/* This is so we can disambiguate scan codes that would otherwise conflict and get
   passed on incorrectly. */
static UINT16
convert_scan_code(UINT16 scan_code)
{
    if ((scan_code & 0xFF00) == 0xE000) {
	scan_code &= 0x00FF;
	scan_code |= 0x0100;
    } else if (scan_code == 0xE11D)
	scan_code = 0xE000;
    /* E0 00 is sent by some USB keyboards for their special keys, as it is an
       invalid scan code (it has no untranslated set 2 equivalent), we mark it
       appropriately so it does not get passed through. */
    else if ((scan_code > 0x00FF) || (scan_code == 0xE000)) {
	scan_code = 0xFFFF;
    }

    return scan_code;
}


void
keyboard_getkeymap(void)
{
    WCHAR *keyName = L"SYSTEM\\CurrentControlSet\\Control\\Keyboard Layout";
    WCHAR *valueName = L"Scancode Map";
    unsigned char buf[32768];
    DWORD bufSize;
    HKEY hKey;
    int j;
    UINT32 *bufEx2;
    int scMapCount;
    UINT16 *bufEx;
    int scancode_unmapped;
    int scancode_mapped;

    /* First, prepare the default scan code map list which is 1:1.
     * Remappings will be inserted directly into it.
     * 512 bytes so this takes less memory, bit 9 set means E0
     * prefix.
     */
    for (j = 0; j < 512; j++)
	scancode_map[j] = j;

    /* Get the scan code remappings from:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout */
    bufSize = 32768;
    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyName, 0, 1, &hKey) == ERROR_SUCCESS) {
	if (RegQueryValueEx(hKey, valueName, NULL, NULL, buf, &bufSize) == ERROR_SUCCESS) {
		bufEx2 = (UINT32 *) buf;
		scMapCount = bufEx2[2];
		if ((bufSize != 0) && (scMapCount != 0)) {
			bufEx = (UINT16 *) (buf + 12);
			for (j = 0; j < scMapCount*2; j += 2) {
 				/* Each scan code is 32-bit: 16 bits of remapped scan code,
 				   and 16 bits of original scan code. */
  				scancode_unmapped = bufEx[j + 1];
  				scancode_mapped = bufEx[j];

				scancode_unmapped = convert_scan_code(scancode_unmapped);
				scancode_mapped = convert_scan_code(scancode_mapped);
				/* pclog("Scan code map found: %04X -> %04X\n", scancode_unmapped, scancode_mapped); */

				/* Ignore source scan codes with prefixes other than E1
				   that are not E1 1D. */
				if (scancode_unmapped != 0xFFFF)
					scancode_map[scancode_unmapped] = scancode_mapped;
			}
		}
	}
	RegCloseKey(hKey);
    }
}


void
keyboard_handle(LPARAM lParam, int infocus)
{
    uint32_t ri_size = 0;
    UINT size;
    RAWINPUT *raw;
    USHORT scancode;

    if (! infocus) return;

    GetRawInputData((HRAWINPUT)lParam, RID_INPUT, NULL,
		    &size, sizeof(RAWINPUTHEADER));

    raw = malloc(size);
    if (raw == NULL) return;

    /* Here we read the raw input data for the keyboard */
    ri_size = GetRawInputData((HRAWINPUT)(lParam), RID_INPUT,
			      raw, &size, sizeof(RAWINPUTHEADER));
    if (ri_size != size) return;

    /* If the input is keyboard, we process it */
    if (raw->header.dwType == RIM_TYPEKEYBOARD) {
	RAWKEYBOARD rawKB = raw->data.keyboard;
	scancode = rawKB.MakeCode;

	/* If it's not a scan code that starts with 0xE1 */
	if (!(rawKB.Flags & RI_KEY_E1)) {
		if (rawKB.Flags & RI_KEY_E0)
			scancode |= (0xE0 << 8);

		/* Translate the scan code to 9-bit */
		scancode = convert_scan_code(scancode);

		/* Remap it according to the list from the Registry */
                /* pclog("Scan code: %04X (map: %04X)\n", scancode, scancode_map[scancode]); */
		scancode = scancode_map[scancode];

		/* If it's not 0xFFFF, send it to the emulated
		   keyboard.
		   We use scan code 0xFFFF to mean a mapping that
		   has a prefix other than E0 and that is not E1 1D,
		   which is, for our purposes, invalid. */
		if ((scancode == 0x00F) &&
		    !(rawKB.Flags & RI_KEY_BREAK) &&
		    (keyboard_recv(0x038) || keyboard_recv(0x138)) &&
		    !mouse_capture) {
			/* We received a TAB while ALT was pressed, while the mouse
			   is not captured, suppress the TAB and send an ALT key up. */
			if (keyboard_recv(0x038))
				keyboard_input(0, 0x038);
			if (keyboard_recv(0x138))
				keyboard_input(0, 0x138);
		} else if (((scancode == 0x038) || (scancode == 0x138)) &&
			   !(rawKB.Flags & RI_KEY_BREAK) &&
			   keyboard_recv(0x00F) &&
			   !mouse_capture) {
			/* We received an ALT while TAB was pressed, while the mouse
			   is not captured, suppress the ALT and send a TAB key up. */
			keyboard_input(0, 0x00F);
		} else {
			/* Normal scan code pass through, pass it through as is if
			   it's not an invalid scan code. */
			if (scancode != 0xFFFF)
				keyboard_input(!(rawKB.Flags & RI_KEY_BREAK), scancode);
		}
	} else {
		if (rawKB.MakeCode == 0x1D) {
			scancode = scancode_map[0x100];	/* Translate E1 1D to 0x100 (which would
							   otherwise be E0 00 but that is invalid
							   anyway).
							   Also, take a potential mapping into
							   account. */
		} else
			scancode = 0xFFFF;
		if (scancode != 0xFFFF)
			keyboard_input(!(rawKB.Flags & RI_KEY_BREAK), scancode);
	}
    }

    free(raw);
}