/*
* Copyright (C) 2010-2011 Mamadou Diop.
*
* Contact: Mamadou Diop <diopmamadou(at)doubango[dot]org>
*
* This file is part of Open Source Doubango Framework.
*
* DOUBANGO 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
* (at your option) any later version.
*
* DOUBANGO 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 DOUBANGO.
*
*/

/**@file tcomp_udvm.nack.c
 * @brief  SigComp UDVM machine (byte copying).
 *
 * @author Mamadou Diop <diopmamadou(at)yahoo.fr>
 *

 */
#include "tcomp_udvm.h"

#include "tsk_debug.h"


#define TCOMP_UDVM_MEMORY_REGISTERS_PTR TCOMP_UDVM_GET_BUFFER_AT(UDVM_REGISTERS_START)


/**RFC3320-Setction_8.4.  Byte copying
From UDVM to UDVM
*/
tsk_bool_t tcomp_udvm_bytecopy_self(tcomp_udvm_t *udvm, uint32_t *destination, uint32_t source, uint32_t tsk_size_tocopy)
{
    uint32_t byte_copy_left, byte_copy_right;
    uint8_t* destination_ptr;

    //if (*destination == TCOMP_UDVM_GET_SIZE() || source == TCOMP_UDVM_GET_SIZE())
    if (*destination >= TCOMP_UDVM_GET_SIZE() || source >= TCOMP_UDVM_GET_SIZE()) {
        /* SEGFAULT */
        tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
        return tsk_false;
    }

    /*
    * The string of bytes is copied in ascending order of memory address,
    * respecting the bounds set by byte_copy_left and byte_copy_right.
    */
    byte_copy_left = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_LEFT_INDEX);
    byte_copy_right = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_RIGHT_INDEX);

    // string of bytes is copied one byte at a time
    while((tsk_size_tocopy--)) {
        if(!(destination_ptr = TCOMP_UDVM_GET_BUFFER_AT((*destination)++))) {
            tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
            return tsk_false;
        }
        *destination_ptr = *TCOMP_UDVM_GET_BUFFER_AT(source++);
        *destination = (*destination == byte_copy_right)? byte_copy_left : *destination;
        source = (source == byte_copy_right)? byte_copy_left : source;
    }

    return tsk_true;
}

/**RFC3320-Setction_8.4.  Byte copying
From EXTERNAL to UDVM
*/
tsk_bool_t tcomp_udvm_bytecopy_to(tcomp_udvm_t *udvm, uint32_t destination, const uint8_t* source, uint32_t tsk_size_tocopy)
{
    uint32_t byte_copy_left, byte_copy_right;
    uint8_t* destination_ptr;

    if(destination == TCOMP_UDVM_GET_SIZE()) {
        /* SEGFAULT */
        tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
        return tsk_false;
    }

    /*
    * The string of bytes is copied in ascending order of memory address,
    * respecting the bounds set by byte_copy_left and byte_copy_right.
    */
    byte_copy_left = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_LEFT_INDEX);
    byte_copy_right = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_RIGHT_INDEX);

    // string of bytes is copied one byte at a time
    while((tsk_size_tocopy--)) {
        if(!(destination_ptr = TCOMP_UDVM_GET_BUFFER_AT(destination++))) {
            tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
            return tsk_false;
        }
        *destination_ptr = *(source++);
        destination = (destination == byte_copy_right)? byte_copy_left : destination;
    }

    return tsk_true;
}

/**RFC3320-Setction_8.4.  Byte copying
From UDVM to EXTERNAL
*/
tsk_bool_t tcomp_udvm_bytecopy_from(tcomp_udvm_t *udvm, uint8_t* destination, uint32_t source, uint32_t tsk_size_tocopy)
{
    uint32_t byte_copy_left, byte_copy_right;
    uint8_t* source_ptr;

    if(source >= TCOMP_UDVM_GET_SIZE()) {
        TSK_DEBUG_ERROR("SEGFAULT");
        tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
        return tsk_false;
    }

    /*
    * The string of bytes is copied in ascending order of memory address,
    * respecting the bounds set by byte_copy_left and byte_copy_right.
    */
    byte_copy_left = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_LEFT_INDEX);
    byte_copy_right = TCOMP_UDVM_GET_2BYTES_VAL(TCOMP_UDVM_HEADER_BYTE_COPY_RIGHT_INDEX);


    // string of bytes is copied one byte at a time
    while((tsk_size_tocopy--)) {
        if(!(source_ptr = TCOMP_UDVM_GET_BUFFER_AT(source++))) {
            tcomp_udvm_createNackInfo2(udvm, NACK_SEGFAULT);
            return tsk_false;
        }
        *(destination++) = *source_ptr;
        source = (source == byte_copy_right)? byte_copy_left : source;
    }

    return tsk_true;
}