# Copyright 2005-2018 ECMWF.
#
# This software is licensed under the terms of the Apache Licence Version 2.0
# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
# 
# In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
# virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
#

section_length[3] section4Length ;

unsigned[1] reserved1=0 : hidden;

if (reserved1 == 0) {

flags[1] missingDataFlag 'grib1/1.table';

unsigned[1] numberOfBytesPerInteger ;

unsigned[2] reserved=0 : hidden ;

unsigned[3] numberOfChars ;

unsigned[3] numberOfFloats ;

unsigned[3] numberOfIntegers ;
alias numberOfInts=numberOfIntegers ;

unsigned[3] numberOfLogicals ;

unsigned[3] numberOfReservedBytes ;

unsigned[4] reserved=0 : hidden;
unsigned[4] reserved=0 : hidden;
unsigned[1] reserved=0 : hidden;

ibmfloat floatValues[numberOfFloats];
alias floatVal=floatValues;

if(numberOfBytesPerInteger == 1) { signed[1] integerValues[numberOfIntegers]; }
if(numberOfBytesPerInteger == 2) { signed[2] integerValues[numberOfIntegers]; }
if(numberOfBytesPerInteger == 3) { signed[3] integerValues[numberOfIntegers]; }
if(numberOfBytesPerInteger == 4) { signed[4] integerValues[numberOfIntegers]; }

if(numberOfChars >= 12)
{
	ascii[2] marsClass;
	ascii[2] dummy1;
	ascii[2] marsType;
	ascii[2] dummy2;
	ascii[4] experimentVersionNumber;

	alias expver=experimentVersionNumber;
    alias marsExpver=experimentVersionNumber;
    
	constant numberOfRemaininChars  = numberOfChars - 12;

	charValues list(numberOfRemaininChars) {
		ascii[1] char;
	}


	constant zero = 0;
	concept isEps(zero)  { 1 = { marsType = "pf"; } }
	concept isSens(zero) { 1 = { marsType = "sf"; } }

	constant oper = "oper";

	concept marsStream(oper) {
		"enfo" = { marsType = "pf"; }
		"enfo" = { marsType = "cf"; }
		"sens" = { marsType = "sf"; }
	}

	if(isEps)
	{
		constant perturbationNumber = 0;
		alias mars.number = perturbationNumber;
	}

	if(isSens)
	{
		constant iterationNumber  = 0;
		constant diagnosticNumber = 0;
		alias mars.iteration  = iterationNumber;
		alias mars.diagnostic = diagnosticNumber;
	}

	# This is commented out because some of the BUDG have the wrong info there
	alias mars.stream = marsStream;
	alias mars.class   = marsClass;
	alias mars.type    = marsType;
	alias mars.expver  = marsExpver;

}
else
{

	  charValues list(numberOfChars) {
		ascii[1] char;
	}

}
} else {
#TODO: decode properly these old data
  section_padding padding;
  
}

