#! /bin/ksh

PROGRAM=$0

# System settings

set -eu
export PATH=/home/m/m300966/CDRSynTra-mpiesm-1.2.01p7/util/running/functions:$PATH

# Configured constants

EXP_ID=esm-ssp585-ocn-alk_EXP2
INTERVAL_MONTHS=12
CALENDAR=1

# Derived constants

inidate=20200101
findate=21001231

# Read command line options

function usage {
    cat >&2 << EOT
Usage: $(basename $PROGRAM) [OPTION]... JOB_ID...

Create job scripts for given date range and job identifiers.

Options:
    -f DATE
        set first date to DATE, formatted as YYYYMMD.
        Defaults to the latest experiment run if it was already started,
        else initial date of the experiment
    -l DATE
        set last date to DATE, formatted as YYYYMMDD.
        Defaults to end date corresponding to the first date
        (first date plus interval months minus one day)
    -i MONTHS
        override the experiment's starting interval.
        Do not use unless you know what you are doing
EOT
    exit
}
    

while getopts hi:f:l: OPTOPT
do
    case $OPTOPT in
        h) usage;;
        i) INTERVAL_MONTHS=$OPTARG;;
        f) firstdate=$OPTARG;;
        l) lastdate=$OPTARG;;
        *) exit 1;;
    esac
done
shift $((OPTIND - 1))

# Compute first start date and job number

startdate=$inidate
jobnum=1

if [[ -s $EXP_ID.date ]]
then
    read nextdate nextjob < $EXP_ID.date
    startdate=$(calc_date minus -c$CALENDAR -M$INTERVAL_MONTHS -- ${nextdate}_)
    jobnum=$((nextjob - 1))
fi

if [[ "${firstdate:-}" ]]
then
    startdate=$firstdate
    months=$(time_between -c$CALENDAR $inidate $startdate months)
    jobnum=$((months/INTERVAL_MONTHS + 1))
fi

# Compute last date

if [[ -z "${lastdate:-}" ]]
then
    lastdate=$(calc_date plus -c$CALENDAR -M$INTERVAL_MONTHS -- ${startdate}_)
    lastdate=$(calc_date minus -c$CALENDAR -D1 -- ${lastdate}_)
fi

# For all intervals

while [[ $(later_date -- $startdate $lastdate) == $lastdate ]]
do
    # Compute next and end date

    nextdate=$(calc_date plus -c$CALENDAR -M$INTERVAL_MONTHS -- ${startdate}_)
    enddate=$(calc_date minus -c$CALENDAR -D1 -- ${nextdate}_)

    # Create job scripts

    for job
    do
        template=${EXP_ID}.${job}
        script=${template}.${nextdate}
        temporary=$script.tmp
        sed "
            s/Jobnum/${jobnum}/
            s/Startdate/${startdate}/
            s/Nextdate/${nextdate}/
            s/Findate/${findate}/
            s/Inidate/${inidate}/
        " $template > $temporary
        chmod +x $temporary
        mv $temporary $script
        echo "created ${job} job for $startdate-$enddate ($script)"
    done

    # Re-compute start date and job number

    startdate=$nextdate
    jobnum=$((jobnum + 1))

done