#!/bin/bash
#
# This script checks each commit in a given interval by:
# - checking out the commit in a clean manner
# - compiling completely (with debug)
# - running the testsuite
# and rounding all up in a suitable log to tell what if went wrong.

# check sufficiently given arguments
if [ -z $4 ]; then
	echo "Usage: $0 <source repo> <Path where to check> <first commit> <second commit> [...parameters for configure...]"
	echo "This will check each of the commits in the inclusive interval [first, second]."
	exit 255
fi
# check source
SOURCEDIR=`realpath $1`
shift
if [ ! $? -eq 0 ]; then
	echo "Please install realpath package!"
	exit 128
fi
DIR=$1
shift
base=$1
shift
limit=$1
shift

# some variables
LOG="`pwd`/commitcheck-${base}-${limit}"
checkdir="commitchecking"
cores=12

# check whether base dir contains valid repo
if [ ! -e $SOURCEDIR ]; then
	echo "$SOURCEDIR does not exist!"
	exit 255
fi
if [ ! -e $SOURCEDIR/HEAD ]; then
	if [ ! -e $SOURCEDIR/.git ]; then
		echo "$SOURCEDIR does not contain a git repository!" | tee -a ${LOG}.log
		exit 255
	else
		SOURCEDIR="$SOURCEDIR/.git"
	fi
fi

# check whether target is empty and create clone of git repo
if [ -e $DIR ]; then
	echo "Target directory $DIR must not be present!"
	exit 255
fi
echo -e "#Begin of Logfile" >${LOG}.log
git clone $SOURCEDIR $DIR | tee -a ${LOG}.log
DIR=`realpath $DIR`

# we are set go to target dir
OLDDIR=`pwd`
cd $DIR

# check whether both given commit names are valid
test=`git rev-list ${base}..${limit} &>/dev/null`
if [ $? -eq 128 ]; then
	# try with remote on either side
	test=`git rev-list remotes/origin/${base}..${limit} &>/dev/null`
	if [ $? -eq 128 ]; then
		test=`git rev-list ${base}..remotes/origin/${limit} &>/dev/null`
		if [ $? -eq 128 ]; then
			test=`git rev-list remotes/origin/${base}..remotes/origin/${limit} &>/dev/null`
			if [ $? -eq 128 ]; then
				echo "At least one of the given commits ${base} or ${limit} does not exist!" | tee -a ${LOG}.log
				exit 255
			else
				echo "Using remotes/origin/${base} instead of ${base} and remotes/origin/${limit} instead of ${limit}"
				base="remotes/origin/${base}"
				limit="remotes/origin/${limit}"
			fi
		else
			echo "Using remotes/origin/${limit} instead of ${limit}."
			limit="remotes/origin/${limit}"
		fi
	else
		echo "Using remotes/origin/${base} instead of ${base}."
		base="remotes/origin/${base}"
	fi
fi

# calculate the number of commits
commitscount=`git rev-list --no-merges ${base}..${limit} | wc -l`
if [ $commitscount -eq 0 ]; then
	echo "There are no commits to check!" | tee -a ${LOG}.log
	echo "Maybe you have given first and second wrong way round?" | tee -a ${LOG}.log
	echo "Remember: First has to be older than second." | tee -a ${LOG}.log
	exit 1
fi
# DON't set limit for HEAD~: git starts counting at 0, wc however at 1, but git does not include last commit ${base} in the list!
let commitlimit=$commitscount
# and check whether it conincides with ${base}
basecommitdescribe=`git describe ${base}`
topcommitdescribe=`git describe ${limit}`
basecommitdescribefromtop=`git describe ${limit}~${commitlimit}`
if [ "$basecommitdescribe" != "$basecommitdescribefromtop" ]; then
	echo "Something went wrong internally!" | tee -a ${LOG}.log
	echo "Compared $basecommitdescribe with $basecommitdescribefromtop ..."
	echo "The number of commits calculated in between does not lead to the base commit." | tee -a ${LOG}.log
	exit 128
fi

# ============== PERFORMING CHECKS ==========================
echo "We are checking all commits from ${base} to ${limit}." | tee -a ${LOG}.log
echo "Base: ${basecommitdescribe}" | tee -a ${LOG}.log
echo -e "Top: ${topcommitdescribe}\n" | tee -a ${LOG}.log
# first fast overview without debug, then thorough with debug
for debug_option in "--disable-debug" "--enable-debug"; do
	i=${commitlimit}
	while [ $i -ge 0 ]; do
		let nr=${commitlimit}-$i
		git checkout -f ${limit}~${i}
		./bootstrap
		rm -rf $checkdir
		mkdir -p $checkdir
		cd $checkdir
		echo "Now testing version `git describe --dirty --always` with $debug_option" &>${LOG}-${nr}.log
		../configure --prefix=${DIR}/$checkdir ${debug_option} "$@" &>>${LOG}-${nr}.log
		make -k -j${cores} check &>>${LOG}-${nr}.log
		if [ $? -gt 0 ]; then
			echo -e "${nr}: `git describe --dirty --always`, ${debug_option}: FAILED." >>${LOG}.log
		else
			echo -e "${nr}: `git describe --dirty --always`, ${debug_option}: ok." >>${LOG}.log
		fi
		cd ..
		((i-=1));
	done
done
# =================== DONE =================================

echo -e "#End of Logfile" >>${LOG}.log
cd $OLDDIR
exit 0