#!/bin/bash

#parameters
###
# <Interval in Sec> <BURN-IN> <ACCEPTDIFF> <ACCEPTSIZE> <GIVEUP> <chain1> <chain2> <...?>
#

#
#CONVTEST : copied to reduce the number of dependencies
#

#export a different CONVTESTDEBUGFILE to redirect debugging output
export CONVTESTDEBUGFILE=${CONVTESTDEBUGFILE-'/dev/null'}


function run_comparison(){
##
##Preconditions: <chain1> and <chain2> (at least) exist.
##Parameters : <BURNIN (required)> <chain1> <chain2> <...?>
##Postconditions: "bpcom.bpdiff" and "tracecom.contdiff" exist in the PWD
##
	local BURNIN=$1
	shift 1
	
	bpcomp -x $BURNIN $* 2>&1 >> ${CONVTESTDEBUGFILE}
	tracecomp -x $BURNIN $* 2>&1 >> ${CONVTESTDEBUGFILE}

	local tracefiles=""

	for one_chain_file in $*
	do
		tracefiles="${tracefiles} ${one_chain_file}.trace"
	done

	#Get the number of cycles finished by the chain that is furthest behind.
	tail -q -n1 ${tracefiles} | awk 'BEGIN { min = 1000000000;} ((/^[^#]/) && $0 != "") { if($1 < min) min = $1; } END{print min;}' > min.cycles 2>>${CONVTESTDEBUGFILE}
	
	#DEBUG
	tail -q -n1 ${tracefiles} > numcycles.debug 2>> ${CONVTESTDEBUGFILE}
}

function convtest(){
##
##Preconditions: "bpcom.bpdiff" and "tracecom.contdiff" exist in the PWD
##Parameters: $1 : maximum maxdiff to accept < 0.1 for good, < 0.3 for acceptable
##		$2 : minimum minimium effective size > 300 for good, > 50 for acceptable
##Returns : 1 if we accept the chain, 0 if not yet converged
##
	local ACCEPTDIFF=$1
	local ACCEPTSIZE=$2


	local mineff=$(awk 'BEGIN { min = 100000;} NR>1 && $0 != "" { if($2 < min) min = $2; } END{print min;}'  tracecomp.contdiff 2>> ${CONVTESTDEBUGFILE})
	local maxdiff=$(awk '$1 == "maxdiff" {print $3;}' bpcomp.bpdiff 2>>${CONVTESTDEBUGFILE})
	local accept=$(echo "($maxdiff < ${ACCEPTDIFF}) && ($mineff > ${ACCEPTSIZE})" | bc 2>> ${CONVTESTDEBUGFILE})

	#DEBUG
	echo ${mineff} ${maxdiff} ${accept} >> ${CONVTESTDEBUGFILE}

	return $accept
}

function chainstuck(){
##
##Preconditions: "bpcom.bpdiff" and "tracecom.contdiff" exist in the PWD
##Parameters : GIVEUP : the number of MCMC steps to take before deciding to giveup (if not making any progress) OPTIONAL
##Returns : 1 if stuck, 0 if progressing
##
	local GIVEUP=${1-'10000'}

	local maxdiff=$(awk '$1 == "maxdiff" {print $3;}' bpcomp.bpdiff 2>> ${CONVTESTDEBUGFILE})
	local numpoints=$(cat min.cycles 2>> ${CONVTESTDEBUGFILE})

	local stuck=$(echo "($maxdiff == 1) && ($numpoints >= ${GIVEUP})" | bc 2>> ${CONVTESTDEBUGFILE})

	return $stuck
}

function check_terminate(){
##
##Parameters : <BURN-IN> <ACCEPTDIFF> <ACCEPTSIZE> <GIVEUP> <chain1> <chain2> <...?>
##
	local burnin=$1
	local acceptdiff=$2
	local acceptsize=$3
	local giveup=$4
	shift 4

	run_comparison $burnin $*
	
	convtest $acceptdiff $acceptsize
	local accept=$?

	chainstuck $giveup
	local stuck=$?

	local terminate=$(( !(($accept==0) && ($stuck==0)) ))
	return $terminate
}

#
#END CONVTEST : Copied
#

#main / test
#check_terminate 500 0.3 50 10000 $*

#echo TERMINATE : $?

if [ -n "$DEBUG" ]
then
	export > __terminator_environ.txt 
	#not good. The terminator is assuming there is a directory called "HIDDEN"
fi

interval=$1
burnin=$2
acceptdiff=$3
acceptsize=$4
giveup=$5
shift 5

#Test that all the programs we need are available
set -e
which bpcomp
which tracecomp
set +e


echo "#Starting the Terminator, PID= ${$} with an interval of ${interval}, a burnin of ${burnin}, acceptdiff: ${acceptdiff}, acceptsize: ${acceptsize}, giveup: ${giveup}"
echo "#These are the chains: $*"


export RUNNING='1'
trap 'echo Terminator got a signal; RUNNING=0; pkill -9 -P $$; exit 0;' SIGTERM SIGINT EXIT

sleep ${interval}
while [ "${RUNNING}" == "1" ]
do
	
	check_terminate ${burnin} ${acceptdiff} ${acceptsize} ${giveup} $*
	if [ "$?" == 1 ]
	then
		echo "Converged!"
		for onechain in $*
		do
			echo 0 > ${onechain}.run
		done
		exit 0
	else
		#still running. Maybe give some output?
		echo "Failed convergence test, continuing..."
	fi

	if [ "${RUNNING}" == "1" ]
	then
		#Need this check so we don't leave extraneous sleep processes if the exit signal came during the above function calls.
		sleep ${interval}
	fi
done

pkill -9 -P $$
echo "#Terminator Terminating"