# This script modifies the namelist and finds the best
set -ue

# Avoid issues with handling floating point numbers
export LC_NUMERIC="en_US.UTF-8"


SCRIPTPATH=$(readlink -f "`dirname \"$0\"`")

# Function to check if the script is executed in a NEMO RUNDIR
# The elements checked are the bathymetry, the presence of the namelist_cfg 
# and the nemo binary that can be called opa or nemo.exe.
function in_rundir () {
    [[ -f bathy_meter.nc ]] && [[ -f opa  || -f nemo.exe ]]
}


# Function to modify namelist parameter
function modify_parameter () {

 [ $# -ne 3 ] &&  echo "Needed arguments are :" &&  echo "namelist variable new_value" &&  return 1

 namelist=$1

 [ ! -f $namelist ] &&  echo "ERROR: Namelist $namelist not present" && return 1

 var=$2 && value=$3

 cond=$( grep -c " $var " $namelist )
 [ $cond -eq 0 ] && echo "ERROR: Variable $var not present in namelist $namelist" &&  return 1

 REG="^\( *$var *= *\).*"

 sed -i "s|$REG|\1$value ! Parameter modified |g " $namelist

}

# Parameters are:
# bathymetry
# Max number of processors
# Check that file exists
binary=$SCRIPTPATH/bin/mpp_domain_decomposition.exe
[ ! -f $binary ] && printf "Tool is not configured. Configure it!\n" && exit 1


ldd $binary | grep "not found" -q && echo "ERROR: Must load proper version of NETCDF" && exit 1
# Check the parameters
if in_rundir ; then 
    [ $# -ne 1 ] && printf "ELPiN v2\nYou are in a NEMO rundir.\nNeeded parameter is:\nmax_number_of_processes\n" && exit 1
    num=$1 && max_num=$( echo "1.05 * $num" | bc -l ) && max_num=$( printf "%.0f\n" "$max_num" )
    
     
    min_num=$( echo "0.9 * $num" | bc -l ) && min_num=$( printf "%.0f\n" "$min_num" )
    
    # Take parameter and check that file exists
    bathymetry="bathy_meter.nc"

else
    [ $# -ne 2 ] && printf "ELPiN v2\nNeeded parameters are:\n/path/to/bathymetry\nmax_number_of_processes\n" && exit 1
    
    num=$2 && max_num=$( echo "1.05 * $num" | bc -l ) && max_num=$( printf "%.0f\n" "$max_num" )
    
    
    min_num=$( echo "0.9 * $num" | bc -l ) && min_num=$( printf "%.0f\n" "$min_num" )
    
    # Take parameter and check that file exists
    bathymetry=$1

fi

[ ! -f $bathymetry ] && echo "Error file does not exist" && exit 1

bathy_checksum=$(md5sum $bathymetry | cut -d" " -f1)

# If bathymetry has been already processed
if [  -f $SCRIPTPATH/database/$bathy_checksum ]; then
   # Check that our number of processes falls inside the saved range
   layout=$SCRIPTPATH/database/$bathy_checksum
   existing_min=$( grep '%' $layout | awk '{print $5}' | sort -n | head -n 1)
   existing_max=$( grep '%' $layout | awk '{print $5}' | sort -n | tail -n 1)

   if [ $num -ge $existing_min ] && [ $num -le $existing_max ]; then
      CASE_EXIST=TRUE
   else
      CASE_EXIST=FALSE
   fi
else
   CASE_EXIST=FALSE
fi


# If ELPiN has been already executed for this bathymetry for this number of cores
# we simply load the previously generated list
if [ "$CASE_EXIST" == "FALSE" ]; then
   # Read dimensions
   X=$(ncdump -h $bathymetry | grep "\sx = [0-9]*" -o | grep -e "[0-9]*" -o)
   Y=$(ncdump -h $bathymetry | grep "\sy = [0-9]*" -o | grep -e "[0-9]*" -o)
   
   
   # Modify the namelist
   
    cp $SCRIPTPATH/src/namelist_mpp .
    
    # Put bathymetry name in namelist
    modify_parameter namelist_mpp cbathy "\'$bathymetry\'"
   
    # Put grid dimensions
    modify_parameter namelist_mpp jpiglo $X
    modify_parameter namelist_mpp jpjglo $Y
   
   
    # Put min and max number of processes
   
    modify_parameter namelist_mpp jprocmin $min_num
    modify_parameter namelist_mpp jprocmax $max_num
   
   
   
   
   # Execute Binary. It will generate a file with name expgrid_PEs_decomposition.layout
   $binary &> /dev/null 
   
   # Check that the execution completed correctly
   ERRORCODE=$?
   if [[ $ERRORCODE -ne 0 ]] ;then 
       echo "Not possible to run dd.x for error $ERRORCODE"
       exit 1
   fi
   
else
   cp $SCRIPTPATH/database/$bathy_checksum expgrid_PEs_decomposition.layout
fi


# Process the generated file to find the best decomposition.
# Get the best decomposition and split the output into jpnij, jpni and jpnj variables to put it inside the namelist

# Get rid of decompositions that need more processes than num

DECOMPOSITION_VARS=$( grep "%" expgrid_PEs_decomposition.layout | awk -v maxnum=$num '{ if( $5 <= maxnum ) print $5/($6/100)**2" " $2 " " $3" " $5 }' | sort -n | tail -n 1 | awk '{print $4" "$2" "$3}')
jpnij=$(echo $DECOMPOSITION_VARS | cut -d " " -f 1 )
jpni=$(echo $DECOMPOSITION_VARS | cut -d " " -f 2 )
jpnj=$(echo $DECOMPOSITION_VARS | cut -d " " -f 3 )


# If the script is executed in the rundir, it automatically modifies the namelist making first a backup for safety.

# Check that the tool is configured properly


# This feature is useless right now but can be useful in the future,
# by now we will comment this and leave it here.
# if in_rundir ; then
#    cp namelist_cfg namelist_cfg.$(date +%d%m%Y-%H:%M)_backup
#    modify_parameter namelist_cfg jpnij $jpnij &&  modify_parameter namelist_cfg jpni $jpni && modify_parameter namelist_cfg jpnj $jpnj || exit 1
#    echo "The namelist_cfg has been modified, you must run with $jpnij NEMO processes"
# else
#    echo $jpnij $jpni $jpnj
# fi

    # Output the jpnij jpni and jpnj values
    echo $jpnij $jpni $jpnj


# Copying the list of decompositions to the database named as the checksum.
if [ "$CASE_EXIST" == "FALSE" ]; then
   # In case database folder does not exist, create it
   [ ! -d $SCRIPTPATH/database ] && mkdir -p $SCRIPTPATH/database 
   cp expgrid_PEs_decomposition.layout $SCRIPTPATH/database/$bathy_checksum
fi

# Remove the tmp file containing the possible decompositions
rm -f expgrid_PEs_decomposition.layout
rm -f namelist_mpp

set +xuve