#!/bin/bash

GITEXEC=`which git`
GITPID=0
TMPSRVDIR=""

# Trap SIGINT / SIGTERM
# errex is used as the general error exit
trap errex SIGINT SIGTERM
function errex {
  echo -e "\nERROR: Abnormal termination of gubllt script!"
  if [ $GITPID -ne 0 ]; then
    echo "... killing git daemon (ppid $GITPID)"
    kill -n 9 -- $(ps -o pid= --ppid $GITPID)
  fi
  if [ "x$TMPSRVDIR" != "x" ]; then
    if [ -d "$TMPSRVDIR" ]; then
      echo "... removing $TMPSRVDIR"
      rm -rf $TMPSRVDIR
    fi
  fi
  exit 255
}

# procFN function
# This function canonicalizes / simplifies path names given as argument 1
# - replace './' at the beginning of $1 with '$PWD/'
# - replace '../' at the beginning of $1 with '$PWD/../'
# - if there is no '/' at the beginning of $1, put '$PWD' in front of $1
# - replace each occurrence of '/something/../' with '/'
# - replace each occurrence of '/./' with '/'
procFN () {
  echo $1 | \
  sed -e "s|^./|$PWD/|" \
      -e  "s|^../|$PWD/../|" \
      -e  "s|\(^[^/]\)|$PWD/\1|" \
      -e ':loopA s|/[^/]*/../|/|; t loopA' \
      -e ':loopB s|/./|/|; t loopB'
}

echo "gubllt --- GUB Local Lilypond Tester"

# abort if not exactly 4 arguments are provided
if [ $# -ne 4 ]; then
  echo "ERROR: invalid number of command line arguments!"
  echo "USAGE: gubllt gub_directory lilypond_repository_directory testbase test"
  echo "       'testbase' and 'test' must be valid braches or commit names"
  echo "       in 'lilypond_repository_directory'"
  errex
fi

GUBDIR=`procFN $1`
LILYREPODIR=`procFN $2`
LILYTESTBASE=$3
LILYTESTVER=$4

echo "Trying to"
echo "  - build regression testbase for '$LILYTESTBASE' of local lilypond repository '$LILYREPODIR'"
echo "  - do a full build of lilypond version '$LILYTESTVER'"
echo "with GUB located in '$GUBDIR'"

# abort if a git-daemon is active
ps ax | grep git-daemon | grep -v grep | grep git-daemon
if [ $? -eq 0 ]; then
  echo "ERROR: A git-daemon is already running on this system!"
  errex
fi

# abort if GUBDIR parameter is invalid
if [ ! -f "$GUBDIR/bin/gub" ]; then
  echo "ERROR: gub_directory parameter '$GUBDIR' invalid!"
  errex
fi
mkdir -p $GUBDIR/regtests $GUBDIR/target $GUBDIR/uploads

# abort if LILYREPODIR parameter is invalid
if [ ! -f "$LILYREPODIR/lily/lilypond-version.cc" ]; then
  echo "ERROR: lilypond_repository_directory '$LILYREPODIR' invalid!"
  errex
fi

# create temporary branches
cd $LILYREPODIR
git branch -f tmp-gubllt-test $LILYTESTBASE
if [ $? -ne 0 ]; then
  echo "ERROR: could not create branch 'tmp-gubllt-test', maybe there is no branch/commit $LILYTESTBASE!"
  errex
fi

# create a temporary git server directory in GUBDIR, abort if this fails
TMPSRVDIR=$(mktemp -d -t -p $GUBDIR/ gubllt-XXXXXXXXXX)
if [ ! -d "$TMPSRVDIR" ]; then
  echo "ERROR: We failed to created the directory $TMPSRVDIR!"
  TMPSRVDIR=""
  errex
else
  echo "INFO:  Temporary git daemon directory is $TMPSRVDIR"
fi

# create the lilypong.git link in TMPSRVDIR
ln -s $LILYREPODIR $TMPSRVDIR/lilypond.git

# start git-daemon in the background
$GITEXEC daemon --log-destination=none --export-all --reuseaddr --base-path=$TMPSRVDIR/ $TMPSRVDIR &> /dev/null &
GITPID=$!
echo "INFO:  Started git daemon with PID $GITPID"

# wait until git-daemon starts to provide its service ... abort if this does not occur within a reasonable time
# it is assumed that every lilypond git repository has a valid branch master, so test for that.
i=0
while [ $i -le 10 ]
do
  ((i++))
  echo Waiting for git daemon ...
  TESTOUT=`git ls-remote git://localhost/lilypond.git master 2>&1 | grep -o refs/heads/master`
  if [ "$TESTOUT" == "refs/heads/master" ]; then
    break;
  fi
  if [ $i -eq 10 ]; then
    echo "ERROR: Git daemon timed out!"
    errex
  fi
  sleep 1
done

# try to build LILYTESTBASE regtest archive
cd  $GUBDIR
rm -rf regtests/* uploads/* target/*/*/*lilypond* ./downloads/lilypond/git/refs/heads/localhost/lilypond.git/tmp-gubllt-test
bin/gub --platform=linux-64 git://localhost/lilypond-test.git?branch=tmp-gubllt-test
TESTOUT=`ls uploads/lilypond*.*.*-*.test-output.tar.bz2`
if [ "x$TESTOUT" == "x" ]; then
  echo "ERROR: creating testbase regression test archive failed!"
  errex
fi

# now try a full gub build of LILYTESTVER
cd $LILYREPODIR
git branch -f tmp-gubllt-test $LILYTESTVER
if [ $? -ne 0 ]; then
  echo "ERROR: could not create branch 'tmp-gubllt-test', maybe there is no branch/commit $LILYTESTVER!"
  errex
fi
cd $GUBDIR
cp $TESTOUT regtests/lilypond-0.00.0-1.test-output.tar.bz2
touch regtests/ignore
rm -rf uploads/* target/*/*/*lilypond*
make LILYPOND_REPO_URL=git://localhost/lilypond.git LILYPOND_BRANCH=tmp-gubllt-test lilypond

# kill our git daemon and remove our temporary git server directory
kill -n 9 -- $(ps -o pid= --ppid $GITPID)
rm -rf $TMPSRVDIR
exit 0