/***************************************************************************
* Additional implementation of "BIKE: Bit Flipping Key Encapsulation". 
* Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Written by Nir Drucker and Shay Gueron
* AWS Cryptographic Algorithms Group
* (ndrucker@amazon.com, gueron@amazon.com)
*
* The license is detailed in the file LICENSE.md, and applies to this file.
* ***************************************************************************/

#include "utilities.h"
#include <inttypes.h>

#define BITS_IN_QW 64ULL
#define BITS_IN_BYTE 8ULL

// Print a new line only if we prints in qw blocks
_INLINE_ void print_newline(IN const uint64_t qw_pos)
{
#ifndef NO_NEWLINE
    if((qw_pos % 4) == 3)
    {
        printf("\n    ");
    }
#endif
}

// Prints a QW in LE/BE in win/linux format
_INLINE_ void print_uint64(IN const uint64_t val)
{
    // If printing in BE is requried swap the order of bytes
#ifdef PRINT_IN_BE
    uint64_t tmp = bswap_64(val);
#else
    uint64_t tmp = val;
#endif

printf("%.16"PRIx64,  tmp);

#ifndef NO_SPACE
    printf(" ");
#endif
}

// Last block requires a special handling as we should zero mask all the bits above the desired number
// endien - 0 - BE, 1 - LE
// Return 1 if last block was printed else 0
_INLINE_ uint8_t print_last_block(IN const uint8_t* last_bytes,
                                  IN const uint32_t bits_num,
                                  IN const uint32_t endien)
{
    // Floor of bits/64 the reminder is in the next QW
    const uint32_t qw_num = bits_num/BITS_IN_QW;

    // How many bits to pad with zero
    const uint32_t rem_bits = bits_num - (BITS_IN_QW * qw_num);

    // We read byte byte and not the whole QW to avoid reading bad memory address
    const uint32_t bytes_num = ((rem_bits % 8) == 0) ? rem_bits / BITS_IN_BYTE : 1 + rem_bits / BITS_IN_BYTE;

    // Must be signed for the LE loop
    int i;

    if(0 == rem_bits)
    {
        return 0;
    }
    
    // Mask unneeded bits
    const uint8_t last_byte = (rem_bits % 8 == 0) ? last_bytes[bytes_num - 1] :
                                    last_bytes[bytes_num - 1] & MASK(rem_bits % 8);
    // BE
    if(0 == endien)
    {
        for(i = 0; (uint32_t)i < (bytes_num - 1); i++)
        {
            printf("%.2x", last_bytes[i]);
        }
        
        printf("%.2x", last_byte);
        
        for(i++; (uint32_t)i < sizeof(uint64_t); i++)
        {
            printf("__");
        }
    }
    else
    {
        for(i = sizeof(uint64_t) - 1; (uint32_t)i >= bytes_num ; i--)
        {
            printf("__");
        }
        
        printf("%.2x", last_byte);
        
        for(i--; i >= 0; i--)
        {
            printf("%.2x", last_bytes[i]);
        }
    }

#ifndef NO_SPACE
    printf(" ");
#endif
    
    return 1;
}

void print_LE(IN const uint64_t *in, IN const uint32_t bits_num)
{
    const uint32_t qw_num = bits_num/BITS_IN_QW;

    // Print the MSB QW
    uint32_t qw_pos = print_last_block((const uint8_t*)&in[qw_num], bits_num, 1);

    // Print each 8 bytes separated by space (if required)
    for (int i = ((int)qw_num)-1; i >= 0; i--, qw_pos++)
    {
        print_uint64(in[i]);
        print_newline(qw_pos);
    }

    printf("\n");
}

void print_BE(IN const uint64_t *in, IN const uint32_t bits_num)
{
    const uint32_t qw_num = bits_num/BITS_IN_QW;

    // Print each 16 numbers separatly
    for (uint32_t i = 0; i < qw_num ; ++i)
    {
        print_uint64(in[i]);
        print_newline(i);
    }

    // Print the MSB QW
    print_last_block((const uint8_t *)&in[qw_num], bits_num, 0);

    printf("\n");
}