#!/bin/sh
##### -*- mode:shell-script; indent-tabs-mode:nil; sh-basic-offset:2 -*-
##### Author: Travis Cross <tc@traviscross.com>

log1 () { printf '%s' "$1">&2; }
log () { printf '%s\n' "$1">&2; }
err () { log "$1"; exit 1; }

usage () {
  log "usage: $0"
}

while getopts "h" o; do
  case "$o" in
    h) usage; exit 0; ;;
  esac
done
shift $(($OPTIND-1))

runscript=$(mktemp /tmp/bisectrunXXXXXXXX)
touch $runscript
chmod +x $runscript
cat > $runscript <<'EOF'
#!/bin/sh
##### -*- mode:shell-script; indent-tabs-mode:nil; sh-basic-offset:2 -*-
##### Author: Travis Cross <tc@traviscross.com>

build_fs () (
  set -e
  unset CC CXX CPPFLAGS CFLAGS CXXFLAGS LDFLAGS CCACHE_DIR V VERBOSE
  export V=1 VERBOSE=1
  git clean -fdx
  git reset --hard HEAD
  { git describe HEAD \
    && ./bootstrap.sh -j \
    && ./configure -C --enable-fhs \
    && make; } 2>&1 | tee build.log
)

good () { exit 0; }
bad () { exit 1; }
skip () { exit 125; }

printf "Building FS...\n"
if ! build_fs; then
  printf "FS didn't build correctly, skipping this revision...\n"
  skip
fi
printf "OK, now 'make install' if needed and test for the issue...\n"
printf "When done, type 'exit'\n"
bash
tested=""
while test -z "$tested"; do
  printf "Were you able to test the issue at this revision? [y/n]: "
  read tested
done
if test "$tested" != "y"; then
  printf "OK, we're skipping this revision then...\n"
  skip
fi
reproduced=""
while test -z "$reproduced"; do
  printf "Did the issue reproduce at this revision? [y/n]: "
  read reproduced
done
if test "$reproduced" = "y"; then
  printf "OK, marking this as a bad revision...\n"
  bad
else
  printf "OK, marking this as a good revision...\n"
  good
fi
EOF

run_bisect () {
  goods=""
  bad=""
  paths=""
  while test -z "$bad"; do
    printf "Enter git hash of earliest known bad revision: "
    read bad_
    [ -z "$bad_" ] || bad="$bad_"
  done
  good_=""
  while test -z "$goods" || ! test -z "$good_"; do
    printf "Enter git hash of latest known good revisions ('.' to end): "
    read good_
    [ "$good_" = "." ] && good_=""
    [ -z "$good_" ] || goods="$good_ "
  done
  path_="_"
  while ! test -z "$path_"; do
    printf "(optional) Enter source path related to issue ('.' to end): "
    read path_
    [ "$path_" = "." ] && path_=""
    [ -z "$path_" ] || paths="$path_ "
  done
  printf "Starting git bisect...\n"
  git bisect start $bad $goods -- $paths
  git bisect run $runscript
  rm -f $runscript
  git bisect reset
}

bisectlog=/tmp/$(date -u +%Y%m%dT%H%M%SZ)-bisect_log.txt
run_bisect | tee $bisectlog
printf "\n\nNow please upload $bisectlog to JIRA.\n"