#!/bin/sh

USAGE='[help|start|bad|good|skip|next|reset|visualize|replay|log|run]'
LONG_USAGE='git bisect help
        print this long help message.
git bisect start [<bad> [<good>...]] [--] [<pathspec>...]
        reset bisect state and start bisection.
git bisect bad [<rev>]
        mark <rev> a known-bad revision.
git bisect good [<rev>...]
        mark <rev>... known-good revisions.
git bisect skip [(<rev>|<range>)...]
        mark <rev>... untestable revisions.
git bisect next
        find next bisection to test and check it out.
git bisect reset [<commit>]
        finish bisection search and go back to commit.
git bisect visualize
        show bisect status in gitk.
git bisect replay <logfile>
        replay bisection log.
git bisect log
        show bisect log.
git bisect run <cmd>...
        use <cmd>... to automatically bisect.

Please use "git help bisect" to get the full man page.'

OPTIONS_SPEC=
. git-sh-setup
. git-sh-i18n
require_work_tree

_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"

bisect_autostart() {
	test -s "$GIT_DIR/BISECT_START" || {
		(
			gettext "You need to start by \"git bisect start\"" &&
			echo
		) >&2
		if test -t 0
		then
			# TRANSLATORS: Make sure to include [Y] and [n] in your
			# translation. The program will only accept English input
			# at this point.
	    gettext "Do you want me to do it for you [Y/n]? " >&2
			read yesno
			case "$yesno" in
			[Nn]*)
				exit ;;
			esac
			bisect_start
		else
			exit 1
		fi
	}
}

bisect_start() {
	#
	# Check for one bad and then some good revisions.
	#
	has_double_dash=0
	for arg; do
	    case "$arg" in --) has_double_dash=1; break ;; esac
	done
	orig_args=$(git rev-parse --sq-quote "$@")
	bad_seen=0
	eval=''
	while [ $# -gt 0 ]; do
	    arg="$1"
	    case "$arg" in
	    --)
		shift
		break
		;;
	    *)
		rev=$(git rev-parse -q --verify "$arg^{commit}") || {
		    test $has_double_dash -eq 1 &&
			die "$(eval_gettext "'\$arg' does not appear to be a valid revision")"
		    break
		}
		case $bad_seen in
		0) state='bad' ; bad_seen=1 ;;
		*) state='good' ;;
		esac
		eval="$eval bisect_write '$state' '$rev' 'nolog'; "
		shift
		;;
	    esac
	done

	#
	# Verify HEAD.
	#
	head=$(GIT_DIR="$GIT_DIR" git symbolic-ref -q HEAD) ||
	head=$(GIT_DIR="$GIT_DIR" git rev-parse --verify HEAD) ||
	die "$(gettext "Bad HEAD - I need a HEAD")"

	#
	# Check if we are bisecting.
	#
	start_head=''
	if test -s "$GIT_DIR/BISECT_START"
	then
		# Reset to the rev from where we started.
		start_head=$(cat "$GIT_DIR/BISECT_START")
		git checkout "$start_head" -- || exit
	else
		# Get rev from where we start.
		case "$head" in
		refs/heads/*|$_x40)
			# This error message should only be triggered by
			# cogito usage, and cogito users should understand
			# it relates to cg-seek.
			[ -s "$GIT_DIR/head-name" ] &&
				die "$(gettext "won't bisect on seeked tree")"
			start_head="${head#refs/heads/}"
			;;
		*)
			die "$(gettext "Bad HEAD - strange symbolic ref")"
			;;
		esac
	fi

	#
	# Get rid of any old bisect state.
	#
	bisect_clean_state || exit

	#
	# Change state.
	# In case of mistaken revs or checkout error, or signals received,
	# "bisect_auto_next" below may exit or misbehave.
	# We have to trap this to be able to clean up using
	# "bisect_clean_state".
	#
	trap 'bisect_clean_state' 0
	trap 'exit 255' 1 2 3 15

	#
	# Write new start state.
	#
	echo "$start_head" >"$GIT_DIR/BISECT_START" &&
	git rev-parse --sq-quote "$@" >"$GIT_DIR/BISECT_NAMES" &&
	eval "$eval" &&
	echo "git bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG" || exit
	#
	# Check if we can proceed to the next bisect state.
	#
	bisect_auto_next

	trap '-' 0
}

bisect_write() {
	state="$1"
	rev="$2"
	nolog="$3"
	case "$state" in
		bad)		tag="$state" ;;
		good|skip)	tag="$state"-"$rev" ;;
		*)		die "$(eval_gettext "Bad bisect_write argument: \$state")" ;;
	esac
	git update-ref "refs/bisect/$tag" "$rev" || exit
	echo "# $state: $(git show-branch $rev)" >>"$GIT_DIR/BISECT_LOG"
	test -n "$nolog" || echo "git bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
}

is_expected_rev() {
	test -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
	test "$1" = $(cat "$GIT_DIR/BISECT_EXPECTED_REV")
}

check_expected_revs() {
	for _rev in "$@"; do
		if ! is_expected_rev "$_rev"; then
			rm -f "$GIT_DIR/BISECT_ANCESTORS_OK"
			rm -f "$GIT_DIR/BISECT_EXPECTED_REV"
			return
		fi
	done
}

bisect_skip() {
        all=''
	for arg in "$@"
	do
	    case "$arg" in
            *..*)
		revs=$(git rev-list "$arg") || die "$(eval_gettext "Bad rev input: \$arg")" ;;
            *)
                revs=$(git rev-parse --sq-quote "$arg") ;;
	    esac
            all="$all $revs"
        done
        eval bisect_state 'skip' $all
}

bisect_state() {
	bisect_autostart
	state=$1
	case "$#,$state" in
	0,*)
		die "$(gettext "Please call 'bisect_state' with at least one argument.")" ;;
	1,bad|1,good|1,skip)
		rev=$(git rev-parse --verify HEAD) ||
			die "$(gettext "Bad rev input: HEAD")"
		bisect_write "$state" "$rev"
		check_expected_revs "$rev" ;;
	2,bad|*,good|*,skip)
		shift
		eval=''
		for rev in "$@"
		do
			sha=$(git rev-parse --verify "$rev^{commit}") ||
				die "$(eval_gettext "Bad rev input: \$rev")"
			eval="$eval bisect_write '$state' '$sha'; "
		done
		eval "$eval"
		check_expected_revs "$@" ;;
	*,bad)
		die "$(gettext "'git bisect bad' can take only one argument.")" ;;
	*)
		usage ;;
	esac
	bisect_auto_next
}

bisect_next_check() {
	missing_good= missing_bad=
	git show-ref -q --verify refs/bisect/bad || missing_bad=t
	test -n "$(git for-each-ref "refs/bisect/good-*")" || missing_good=t

	case "$missing_good,$missing_bad,$1" in
	,,*)
		: have both good and bad - ok
		;;
	*,)
		# do not have both but not asked to fail - just report.
		false
		;;
	t,,good)
		# have bad but not good.  we could bisect although
		# this is less optimum.
		(
			gettext "Warning: bisecting only with a bad commit." &&
			echo
		) >&2
		if test -t 0
		then
			# TRANSLATORS: Make sure to include [Y] and [n] in your
			# translation. The program will only accept English input
			# at this point.
			gettext "Are you sure [Y/n]? " >&2
			read yesno
			case "$yesno" in [Nn]*) exit 1 ;; esac
		fi
		: bisect without good...
		;;
	*)

		if test -s "$GIT_DIR/BISECT_START"
		then
			(
				gettext "You need to give me at least one good and one bad revisions.
(You can use \"git bisect bad\" and \"git bisect good\" for that.)" &&
				echo
			) >&2
		else
			(
				gettext "You need to start by \"git bisect start\".
You then need to give me at least one good and one bad revisions.
(You can use \"git bisect bad\" and \"git bisect good\" for that.)" &&
				echo
			) >&2
		fi
		exit 1 ;;
	esac
}

bisect_auto_next() {
	bisect_next_check && bisect_next || :
}

bisect_next() {
	case "$#" in 0) ;; *) usage ;; esac
	bisect_autostart
	bisect_next_check good

	# Perform all bisection computation, display and checkout
	git bisect--helper --next-all
	res=$?

        # Check if we should exit because bisection is finished
	test $res -eq 10 && exit 0

	# Check for an error in the bisection process
	test $res -ne 0 && exit $res

	return 0
}

bisect_visualize() {
	bisect_next_check fail

	if test $# = 0
	then
		if test -n "${DISPLAY+set}${SESSIONNAME+set}${MSYSTEM+set}${SECURITYSESSIONID+set}" &&
		   type gitk >/dev/null 2>&1; then
			set gitk
		else
			set git log
		fi
	else
		case "$1" in
		git*|tig) ;;
		-*)	set git log "$@" ;;
		*)	set git "$@" ;;
		esac
	fi

	eval '"$@"' --bisect -- $(cat "$GIT_DIR/BISECT_NAMES")
}

bisect_reset() {
	test -s "$GIT_DIR/BISECT_START" || {
		gettext "We are not bisecting."; echo
		return
	}
	case "$#" in
	0) branch=$(cat "$GIT_DIR/BISECT_START") ;;
	1) git rev-parse --quiet --verify "$1^{commit}" > /dev/null || {
	       invalid="$1"
	       die "$(eval_gettext "'\$invalid' is not a valid commit")"
	   }
	   branch="$1" ;;
	*)
	    usage ;;
	esac
	if git checkout "$branch" -- ; then
		bisect_clean_state
	else
		die "$(eval_gettext "Could not check out original HEAD '\$branch'.
Try 'git bisect reset <commit>'.")"
	fi
}

bisect_clean_state() {
	# There may be some refs packed during bisection.
	git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
	while read ref hash
	do
		git update-ref -d $ref $hash || exit
	done
	rm -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
	rm -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
	rm -f "$GIT_DIR/BISECT_LOG" &&
	rm -f "$GIT_DIR/BISECT_NAMES" &&
	rm -f "$GIT_DIR/BISECT_RUN" &&
	# Cleanup head-name if it got left by an old version of git-bisect
	rm -f "$GIT_DIR/head-name" &&

	rm -f "$GIT_DIR/BISECT_START"
}

bisect_replay () {
	file="$1"
	test "$#" -eq 1 || die "$(gettext "No logfile given")"
	test -r "$file" || die "$(eval_gettext "cannot read \$file for replaying")"
	bisect_reset
	while read git bisect command rev
	do
		test "$git $bisect" = "git bisect" -o "$git" = "git-bisect" || continue
		if test "$git" = "git-bisect"; then
			rev="$command"
			command="$bisect"
		fi
		case "$command" in
		start)
			cmd="bisect_start $rev"
			eval "$cmd" ;;
		good|bad|skip)
			bisect_write "$command" "$rev" ;;
		*)
			die "$(gettext "?? what are you talking about?")" ;;
		esac
	done <"$file"
	bisect_auto_next
}

bisect_run () {
    bisect_next_check fail

    while true
    do
      command="$@"
      eval_gettext "running \$command"; echo
      "$@"
      res=$?

      # Check for really bad run error.
      if [ $res -lt 0 -o $res -ge 128 ]; then
	  (
	    eval_gettext "bisect run failed:
exit code \$res from '\$command' is < 0 or >= 128" &&
	    echo
	  ) >&2
	  exit $res
      fi

      # Find current state depending on run success or failure.
      # A special exit code of 125 means cannot test.
      if [ $res -eq 125 ]; then
	  state='skip'
      elif [ $res -gt 0 ]; then
	  state='bad'
      else
	  state='good'
      fi

      # We have to use a subshell because "bisect_state" can exit.
      ( bisect_state $state > "$GIT_DIR/BISECT_RUN" )
      res=$?

      cat "$GIT_DIR/BISECT_RUN"

      if sane_grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
		> /dev/null; then
	  (
	      gettext "bisect run cannot continue any more" &&
	      echo
	  ) >&2
	  exit $res
      fi

      if [ $res -ne 0 ]; then
	  (
	      eval_gettext "bisect run failed:
'bisect_state \$state' exited with error code \$res" &&
	      echo
	  ) >&2
	  exit $res
      fi

      if sane_grep "is the first bad commit" "$GIT_DIR/BISECT_RUN" > /dev/null; then
	  gettext "bisect run success"; echo
	  exit 0;
      fi

    done
}

bisect_log () {
	test -s "$GIT_DIR/BISECT_LOG" || die "$(gettext "We are not bisecting.")"
	cat "$GIT_DIR/BISECT_LOG"
}

case "$#" in
0)
    usage ;;
*)
    cmd="$1"
    shift
    case "$cmd" in
    help)
        git bisect -h ;;
    start)
        bisect_start "$@" ;;
    bad|good)
        bisect_state "$cmd" "$@" ;;
    skip)
        bisect_skip "$@" ;;
    next)
        # Not sure we want "next" at the UI level anymore.
        bisect_next "$@" ;;
    visualize|view)
	bisect_visualize "$@" ;;
    reset)
        bisect_reset "$@" ;;
    replay)
	bisect_replay "$@" ;;
    log)
	bisect_log ;;
    run)
        bisect_run "$@" ;;
    *)
        usage ;;
    esac
esac