#!/bin/bash
# StringContain method comparison between `case` and `parameter expansion`
# (C) 2023 Felix Hauri - felix@f-hauri.ch
# Licensed under terms of GPL v3. www.gnu.org
# Run 42 hecti loops with `dash`, `busybox shell`, `bash` and `ksh`.
# Then compare method performances under each shell (not between shells)
# with short or long string and complex substring.

reqTestCnt=${1:-$(( 42 * 128 ))}
testCase() {
    cat <<-"eoCase"
	string="$1"; substr="$2"; doloop=$3
	while [ $doloop -gt 0 ]; do doloop=$((doloop-1))
	    case $string in
		*$substr*) ret=yes ;;
		*) ret=no ;;
	    esac
	done; echo $ret
	eoCase
}
testPExp() {
    cat <<-"eoPExp"
	string="$1"; substr="$2"; doloop=$3
	while [ $doloop -gt 0 ]; do doloop=$((doloop-1))
	    if [ -z "$substr" ] ||
		{ [ -z "${string##*$substr*}" ] && [ -n "$string" ];}
	    then ret=yes; else ret=no; fi
	done; echo $ret
	eoPExp
}

longStr='Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam non'
longStr+='ummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat volu'
longStr+='tpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamc'
longStr+='orper suscipit lobortis nisl ut aliquip ex comm'
longStr="$longStr $longStr"
longStr="$longStr $longStr."
results=() ; declare -A overall
for test in Case PExp; do
    testcnt=0
    for shell in 'busybox sh' dash ksh bash; do
	for string in 'echo "My string"' "Don't miss quotes" '' "$longStr"; do
	    for substr in "'t mis"   'o "My'   "s"   "Y"   ""  \
			"${longStr::12}"  "${longStr: -12}"  Long\"\ \'test.; do
		st=$EPOCHREALTIME
		res=$($shell <(test$test) "$string" "$substr" $reqTestCnt)
		end=$EPOCHREALTIME
		elap=00000$((${end/.}-${st/.}))
		if [[ -v results[testcnt] ]]; then
		    pres=${results[testcnt]% *}
		    pelap=${results[testcnt]#* }
		    prct=00$(( 10#$elap * 100000 / pelap ))
		    overall[${shell%% *}]+=$((10#$prct))+
		    if [[ $pres == $res ]]; then res=same; else res=DIFF; fi
		    printf '%-8s %s %-16s %-12s %4d %4d %4s %9.5fs %8.2f%%\n'\
			   ${shell% *} $test "${string::16}" "${substr}" \
			   ${#string} ${#substr} $res ${elap::-6}.${elap: -6} \
			   ${prct::-3}.${prct: -3}
		else
		    results[testcnt]="$res ${elap#00000}"
		    printf '%-8s %s %-16s %-12s %4d %4d %4s %9.5fs\n'\
			   ${shell% *} $test "${string::16}" "${substr}" \
			   ${#string} ${#substr} $res ${elap::-6}.${elap: -6}
		fi
		(( testcnt++ ))
	    done
	done
    done
done
valcnt=${overall[bash]//[0-9]}
for shell in ${!overall[@]}; do
    prct=000$(( ( ${overall[$shell]}0 ) / ${#valcnt} ))
    printf 'Comparing time PExp vs Case method under %-8s: %9.2f%%\n' $shell \
	   ${prct::-3}.${prct: -3}
done