/*
 * Video On Demand Samples
 *
 * Copyright (C) 2015 Microchip Technology Germany II GmbH & Co. KG
 *
 * 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 3 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * You may also obtain this software under a propriety license from Microchip.
 * Please contact Microchip for further information.
 *
 */

#include "Console.h"
#include "MostMsg.h"
#include <stdlib.h>

static uint32_t crc32_tab[] =
{
    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
    0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
    0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
    0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
    0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
    0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
    0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
    0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
    0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
    0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
    0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
    0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
    0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
    0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
    0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
    0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
    0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
    0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
    0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
    0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
    0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
    0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
    0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
    0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
    0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
    0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
    0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
    0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
    0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
    0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
    0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
    0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
    0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

static uint32_t CalcCRC32( const uint8_t *p, uint32_t size )
{
    uint32_t crc = ~0U;

    while( size-- )
        crc = crc32_tab[( crc ^ *p++ ) & 0xFF] ^ ( crc >> 8 );

    return crc ^ ~0U;
}


CMostMsg::CMostMsg() : m_nIsValid( false ), m_nRefCount( 1 ), m_nFBlock( 0 ), m_nFunc( 0 ), m_nInst( 0 ),
    m_nOpType( 0 ), m_nPayloadLen( 0 ), m_Payload( NULL ), m_nParsePos( 0 ),
    m_nHeaderCrc( 0 ), m_nPayloadCrc( 0 )
{
}

CMostMsg::CMostMsg( uint32_t nFBlock, uint32_t nInst, uint32_t nFunc, uint8_t nOpType, uint32_t nPayloadLen,
    const uint8_t *Payload ) : m_nIsValid( true ), m_nRefCount( 1 ), m_Payload( NULL ),
    m_nParsePos( 0xFFFFFFFF ), m_nHeaderCrc( 0 ), m_nPayloadCrc( 0 )
{
    m_nFBlock = nFBlock;
    m_nInst = nInst;
    m_nFunc = nFunc;
    m_nOpType = nOpType;
    m_nPayloadLen = nPayloadLen;
    if( nPayloadLen > 0 )
    {
        m_Payload = ( uint8_t * )malloc( m_nPayloadLen );
        if( NULL == m_Payload )
        {
            ConsolePrintf(
                PRIO_ERROR, RED"CMostMsg Constructor failed to allocated %d bytes of memory"RESETCOLOR"\n", m_nPayloadLen );
            m_nIsValid = false;
            m_nPayloadLen = 0;
            return;
        }
        memcpy( m_Payload, Payload, nPayloadLen );
    }
}

CMostMsg::~CMostMsg()
{
    m_nIsValid = false;
    m_nPayloadLen = 0;
    if( NULL != m_Payload )
    {
        free( m_Payload );
        m_Payload = NULL;
    }
}

void CMostMsg::AddReference()
{
    ++m_nRefCount;
}

void CMostMsg::RemoveReference()
{
    if( 0 == --m_nRefCount )
        delete this;
}

uint32_t CMostMsg::ToByteArray( uint8_t **ppBuffer )
{
    if( NULL == ppBuffer )
    {
        ConsolePrintf(
            PRIO_ERROR, RED"CMostMsg::ToByteArray ppBuffer is NULL < %d"RESETCOLOR"\n" );
        return 0;
    }
    uint32_t serializedLen = 20;
    if( 0 != m_nPayloadLen )
        serializedLen += m_nPayloadLen + 4; //If there is payload, it will be CRC checked
    uint8_t *b = ( uint8_t * )malloc( serializedLen );
    if( NULL == b )
    {
        ConsolePrintf(
            PRIO_ERROR, RED"CMostMsg::ToByteArray failed to allocate %d bytes"RESETCOLOR"\n", ( m_nPayloadLen + 24 ) );
        *ppBuffer = NULL;
        return 0;
    }
    *ppBuffer = b;
    b[0] = ( uint8_t )0x49;
    b[1] = ( uint8_t )0x72;
    b[2] = ( uint8_t )0x16;
    b[3] = ( uint8_t )0x25;
    b[4] = ( uint8_t )( m_nFBlock & 0xFF );
    b[5] = ( uint8_t )( m_nInst & 0xFF );
    b[6] = ( uint8_t )( ( m_nFunc >> 8 ) & 0xFF );
    b[7] = ( uint8_t )( ( m_nFunc )&0xFF );
    b[8] = ( uint8_t )( m_nOpType );
    b[9] = ( uint8_t )0x0;
    b[10] = ( uint8_t )0x0;
    b[11] = ( uint8_t )0x0;
    b[12] = ( uint8_t )( ( m_nPayloadLen >> 24 ) & 0xFF );
    b[13] = ( uint8_t )( ( m_nPayloadLen >> 16 ) & 0xFF );
    b[14] = ( uint8_t )( ( m_nPayloadLen >> 8 ) & 0xFF );
    b[15] = ( uint8_t )( m_nPayloadLen & 0xFF );

    uint32_t headerCrc = CalcCRC32( b, 16 );

    b[16] = ( uint8_t )( ( headerCrc >> 24 ) & 0xFF );
    b[17] = ( uint8_t )( ( headerCrc >> 16 ) & 0xFF );
    b[18] = ( uint8_t )( ( headerCrc >> 8 ) & 0xFF );
    b[19] = ( uint8_t )( headerCrc & 0xFF );

    if( 0 != m_nPayloadLen )
    {
        for( uint32_t i = 0; i < m_nPayloadLen; i++ )
            b[20 + i] = m_Payload[i];

        uint32_t payloadCrc = CalcCRC32( &b[20], m_nPayloadLen );

        b[20 + m_nPayloadLen] = ( uint8_t )( ( payloadCrc >> 24 ) & 0xFF );
        b[21 + m_nPayloadLen] = ( uint8_t )( ( payloadCrc >> 16 ) & 0xFF );
        b[22 + m_nPayloadLen] = ( uint8_t )( ( payloadCrc >> 8 ) & 0xFF );
        b[23 + m_nPayloadLen] = ( uint8_t )( payloadCrc & 0xFF );
    }
    return serializedLen;
}

bool CMostMsg::Parse( uint8_t receivedByte )
{
    if( 0xFFFFFFFF == m_nParsePos )
    {
        ConsolePrintf(
            PRIO_ERROR, RED"CMostMsg::Parse was called, but the parse state is invalid"RESETCOLOR"\n" );
        return false;
    }
    bool valid = true;
    if( m_nParsePos <= 19 )
    {
        if( m_nParsePos <= 15 )
            m_zHeader[m_nParsePos] = receivedByte;

        //Check Header
        switch( m_nParsePos )
        {
        case 0:
            if( 0x49 != receivedByte )
                valid = false;
            break;
        case 1:
            if( 0x72 != receivedByte )
                valid = false;
            break;
        case 2:
            if( 0x16 != receivedByte )
                valid = false;
            break;
        case 3:
            if( 0x25 != receivedByte )
                valid = false;
            break;
        case 4:
            m_nFBlock = receivedByte;
            break;
        case 5:
            m_nInst = receivedByte;
            break;
        case 6:
            m_nFunc = receivedByte << 8;
            break;
        case 7:
            m_nFunc += receivedByte;
            break;
        case 8:
            m_nOpType = receivedByte;
            break;
        case 9:
        case 10:
        case 11:
            //Reserved for future use cases
            break;
        case 12:
            m_nPayloadLen = receivedByte << 24;
            break;
        case 13:
            m_nPayloadLen += receivedByte << 16;
            break;
        case 14:
            m_nPayloadLen += receivedByte << 8;
            break;
        case 15:
            m_nPayloadLen += receivedByte;
            break;
        case 16:
            m_nHeaderCrc = receivedByte << 24;
            break;
        case 17:
            m_nHeaderCrc += receivedByte << 16;
            break;
        case 18:
            m_nHeaderCrc += receivedByte << 8;
            break;
        case 19:
            m_nHeaderCrc += receivedByte;
            if( m_nHeaderCrc == CalcCRC32( m_zHeader, 16 ) )
            {
                if( 0 != m_nPayloadLen )
                {
                    //Continue to parse the payload
                    m_Payload = ( uint8_t * )malloc( m_nPayloadLen );
                    if( NULL == m_Payload )
                    {
                        ConsolePrintf(
                            PRIO_ERROR, RED"MostMsg::Protocol deserializing error, could not allocate %d bytes of memory"RESETCOLOR
                            "\n", m_nPayloadLen );
                        valid = false;
                        m_nPayloadLen = 0;
                    }
                }
                else
                {
                    //No payload, we are finished
                    m_nIsValid = true;
                    m_nParsePos = 0xFFFFFFFF - 1;
                }
            }
            else
            {
                ConsolePrintf(
                    PRIO_ERROR, RED"MostMsg::Protocol error, header CRC does not match"RESETCOLOR"\n" );
                valid = false;
            }
            break;
        }
    }
    else
    {
        if( m_nParsePos < ( m_nPayloadLen + 20 ) )
        {
            //Check Payload and store it
            if( NULL != m_Payload )
            {
                m_Payload[m_nParsePos - 20] = receivedByte;
            }
            else
            {
                ConsolePrintf(
                    PRIO_ERROR, RED"MostMsg::Protocol deserializing error, payload buffer is NULL"RESETCOLOR"\n" );
                valid = false;
                m_nPayloadLen = 0;
            }
        }
        else
        {
            //Finally check CRC of payload
            uint32_t crcState = m_nParsePos - m_nPayloadLen - 20;
            switch( crcState )
            {
            case 0:
                m_nPayloadCrc = receivedByte << 24;
                break;
            case 1:
                m_nPayloadCrc += receivedByte << 16;
                break;
            case 2:
                m_nPayloadCrc += receivedByte << 8;
                break;
            case 3:
                m_nPayloadCrc += receivedByte;
                if( m_nPayloadCrc == CalcCRC32( m_Payload, m_nPayloadLen ) )
                {
                    //Payload is successfully received
                    m_nIsValid = true;
                    m_nParsePos = 0xFFFFFFFF - 1;
                }
                else
                {
                    ConsolePrintf(
                        PRIO_ERROR, RED"MostMsg::Protocol deserializing error, Payload CRC mismatch"RESETCOLOR"\n" );
                    valid = false;
                }
                break;
            default:
                ConsolePrintf(
                    PRIO_ERROR, RED"MostMsg::Protocol deserializing error, Payload CRC state is out of range"RESETCOLOR"\n" );
                valid = false;
            }
        }
    }

    if( valid )
    {
        ++m_nParsePos;
    }
    else
    {
        ConsolePrintf(
            PRIO_ERROR, RED"CMostMsg::Parse failed at parse position %d"RESETCOLOR"\n", m_nParsePos );
        m_nParsePos = 0xFFFFFFFF;
    }
    return valid;
}

bool CMostMsg::IsValid()
{
    return m_nIsValid;
}

uint32_t CMostMsg::GetFBlock()
{
    return m_nFBlock;
}

uint32_t CMostMsg::GetFunc()
{
    return m_nFunc;
}

uint32_t CMostMsg::GetInst()
{
    return m_nInst;
}

uint8_t CMostMsg::GetOpType()
{
    return m_nOpType;
}

uint8_t *CMostMsg::GetPayload()
{
    return m_Payload;
}

uint32_t CMostMsg::GetPayloadLen()
{
    return m_nPayloadLen;
}