//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:  Basic Keyboard Driver                                              //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K 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 3 of the License, or         //
//  any later version.                                                        //
//                                                                            //
//  OS/K 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 OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#include <lib/buf.h>
#include <io/keyb.h>
#include <ke/idt.h>

#include "scan.c"

static bool capsLockActive = 0;
static bool leftAltPressed = 0;
static bool leftShiftPressed = 0;
static bool leftControlPressed = 0;

void KeybPrint(uchar _code)
{    
    uint code = (uint)_code;

    const uint *table =
        (leftAltPressed ? LeftAltScanCodes
        : (leftShiftPressed ? LeftShiftScanCodes
        : (leftControlPressed ? LeftControlScanCodes
        : RegularScanCodes)));

    if (capsLockActive && !leftShiftPressed &&
            !!(table[2 * code + 1] & CAPSLOCK) && !leftAltPressed)
        table = LeftShiftScanCodes;

    uchar ch = table[2 * code];
    
    if (!ch) {
        switch (code) {
        case 0x38: leftAltPressed = 1; break;
        case 0xB8: leftAltPressed = 0; break;

        case 0x36: case 0x2A: leftShiftPressed = 1; break;
        case 0xB6: case 0xAA: leftShiftPressed = 0; break;

        case 0x1D: leftControlPressed = 1; break;
        case 0x9D: leftControlPressed = 0; break;
        
        case 0x3A: capsLockActive = !capsLockActive; break;
        }
        return;
    }
    
    bputc(BStdIn, ch);
    if (code && (table[2 * code + 1] & INVISIBLE) == 0) {
        bputc(BStdOut, table[2 * code]);
        BStdOut->flusher(BStdOut);
    }
}

static void KeybHandler(ISRFrame_t *regs)
{
    char status;
    uchar code = 0;

    // write EOI
    IoWriteByteOnPort(0x20, 0x20);

    status = IoReadByteFromPort(0x64);

    if (status & 0x01) {
        code = IoReadByteFromPort(0x60);
    }
    KeybPrint(code);
    KeSendEOItoPIC(0x21);
}

void IoCreateInputBuffer(void)
{
    error_t rc;

    rc = BOpenPureBuf(&BStdIn, BS_RDWR, 4 * KB);

    if (rc) KeStartPanic("[Keyb] Couldn't create BStdIn");

    //BEnableLineBuffering(BStdIn);
    BStdIn->flusher = bemptybuf;
}

void IoEnableKeyb(void)
{
    ulong flags = KePauseIRQs();
 
    KeRegisterISR(KeybHandler, 0x21);
    char readedInterruptConfig = IoReadByteFromPort(0x21);
    IoWriteByteOnPort(0x21, 0xFD & readedInterruptConfig);
 
    KeRestoreIRQs(flags);

    KeEnableNMI();
    
    IoCreateInputBuffer();
}