#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <time.h>
#include "altera_dma_regs.h"

const int CRC16_XMODEM_TABLE[] = {
  0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
  0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
  0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
  0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
  0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
  0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
  0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
  0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
  0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
  0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
  0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
  0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
  0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
  0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
  0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
  0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
  0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
  0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
  0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
  0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
  0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
  0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
  0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
  0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
  0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
  0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
  0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
  0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
  0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
  0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
  0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
  0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
} ;



int crc_calc( int crc, unsigned int data ){ 
  int byte1, byte2, byte3, byte4, crc_temp ;
  byte1 = data & 0xFF;
  byte2 = ( data & 0xFF00 ) >> 8;
  byte3 = ( data & 0xFF0000 ) >> 16;
  byte4 = ( data & 0xFF000000 ) >> 24;
  crc_temp = (((crc)<<8)&0xff00) ^ CRC16_XMODEM_TABLE[(((crc)>>8)&0xff)^byte4] ;
  crc_temp = (((crc_temp)<<8)&0xff00) ^ CRC16_XMODEM_TABLE[(((crc_temp)>>8)&0xff)^byte3] ;
  crc_temp = (((crc_temp)<<8)&0xff00) ^ CRC16_XMODEM_TABLE[(((crc_temp)>>8)&0xff)^byte2] ;
  crc_temp = (((crc_temp)<<8)&0xff00) ^ CRC16_XMODEM_TABLE[(((crc_temp)>>8)&0xff)^byte1] ;
  return crc_temp;
}

int decode_data_wUL( unsigned int * data , unsigned int * ce , int * crc , int * run ) { 

  int magic; 
  int size, size_link;
  int ix ;

  int offset; 
  unsigned int exp_run, evenum, ctime, utime; 

  *crc = 0 ;
  size = data[ ( *ce ) % DMASIZE ] ;
  magic = data[ ( *ce + 1 ) % DMASIZE ] ;

  // Check a new event is available in the memory
  if( ( magic & 0xffff0000 ) != 0x7f7f0000 ){
    //    printf("Invalid magic number %.8x\n", magic );
    return 0;
  }

  ix = *ce + 4;
  ctime = data[ ix % DMASIZE ];
  ix = *ce + 3;
  evenum = data[ ix % DMASIZE ];
  ix = *ce + 5;
  utime = data[ ix % DMASIZE ];
  ix = *ce + 2;
  exp_run = data[ ix % DMASIZE ] >> 8 ;

  printf("exprun %.8x eve %d\n", exp_run, evenum );

  if ( exp_run != *run ) { // it may be that the old data is still in memory
    printf( "RUN = %d\n", *run  ) ;
    return 0 ; 
  }

  offset = 8; // size of ROB header [words]


  while( offset + 4 != size ){ // 4 = ROB trailer size
    *crc = 0xffff ;

    ix = *ce + offset;
    size_link = data[ ix ] & 0x00ffffff ;

    // Calculation of CRC
    *crc = crc_calc( *crc, ctime );
    *crc = crc_calc( *crc, evenum );
    *crc = crc_calc( *crc, utime );
    *crc = crc_calc( *crc, exp_run );

    for ( ix = *ce + offset + 2 ; ix < *ce + offset + size_link -2; ix++ ) {
      *crc = crc_calc( *crc, data[ ix % DMASIZE ] );
    }
  
    ix = *ce + 8 + size_link -2;
    if( ( *crc & 0xffff ) != ( data[ ix % DMASIZE ] & 0xffff ) ){
      printf( "Error in CRC comparison calc %.8x : data %.8x\n" , *crc , data[ ix % DMASIZE ] );
      return -1;
    }else{    
    }
    offset += size_link;
    if( offset + 4 > size ){
      printf( "Invalid data size sum of link size %d size = %d\n" , 
	      offset + 4, size );
      return -1 ; 
    }
  }
  return size ;
}


int main (int argc ,char** argv) {
  // Stop trigger
  system( "ssh vme \"resetft -80\"" ) ;
  sleep( 2 ) ; 
  int res = ecs_open( 0 , 0 ) ;
  if ( -1 == res ) printf("ERROR: Could not open device (BAR 0)\n") ;
  else printf("SUCCESS: Device opened for DMA\n");
  res = ecs_open( 0 , 2 ) ;
  pcie40_b2dmabufferreset( 0 ) ; 
  // Start trigger
  int run  = 0 ; 
  FILE* fp; 
  char * ptr ;
  char * tmp ;
  fp = popen( "ssh vme \"trigft -80 pulse 1 10\"" , "r" ) ;
  char buf[1000] ;
  char exp[] = "exp" ; 
  sleep( 2 ) ;
  while( fgets( buf , sizeof(buf) , fp ) != NULL ) { 
    // printf( "A= %d\n" , strncmp( exp , buf , 3 ) ) ;
    //    printf( strncmp( &buf[0] , 'exp' , 1 ) ) ;
    tmp = strdup( buf ) ;
    if ( strncmp( exp , buf , 3 ) == 0 ) {
      //printf( '%s\n' , buf )  ;
      // printf( "ICI\n" ) ;
      ptr = strtok( tmp , " " ) ;
      ptr = strtok( NULL , " " ) ;
      ptr = strtok( NULL , " " ) ;
      ptr = strtok( NULL , " " ) ;
      // while ( ptr != NULL ) {
      run = atoi( ptr ) ; 
      //	ptr = strtok( NULL , " " ) ; 
    }
      //}
  }
  pclose( fp ) ;

  //sleep( 2 ) ; 

  // Read DMA
  unsigned int * data ; 
  double time_spent ;
  int retry ;
  retry = 0 ;

  int i ;
  int size, size_256, currentEventIndex, crc, nErr, nEvt, nRetry ;
  currentEventIndex = 0 ;
  nErr = 0 ;
  nEvt = 0 ;
  nRetry = 0 ;
  clock_t begin = clock();
  for ( i = 0 ; i < 100 ; ++i ) { 
    if ( nEvt % 10000 == 1 ) printf( "Event number %d\n", nEvt ) ;

    res = pcie40_b2dmapointerread( 0 , &data ) ;

    size = decode_data_wUL( data , &currentEventIndex , &crc , &run ) ;
    if ( 0 == size ) continue ;
    if ( size == -1 ) { 
      nErr++ ;
      continue ; 
    }

    if( size % 8 != 0 ){
      size_256 = ( size/8 + 1 )*8;
    }

    currentEventIndex = ( currentEventIndex + size_256 ) % DMASIZE ; 
    nEvt++ ;  

  }
  clock_t end = clock();
  time_spent += (double)(end - begin) / CLOCKS_PER_SEC;

  res = ecs_close( 0 , 0 ) ;
  if ( -1 == res ) printf("ERROR: Could not close device (BAR 0)\n");
  else printf("SUCCESS: Device closed for DMA\n");

  printf( "Timing = %f s\n" , time_spent ) ;
  printf( "Number of events = %d \n", nEvt ) ;  
  printf( "Number of errors = %d \n", nErr ) ; 
  printf( "Number of retries = %d \n", nRetry ) ;
  return 0 ;
}