svtm-ctl

#!/bin/sh

die() {
	echo "$0: $*" 1>&2
	exit 1
}

numbers() {
	grep '^[0-9]\+$' "$@"
}

# lowest available number from stdin starting from 1
# similar behavior to open(3) - opens lowest file descriptor
lowest() {
	sort -n | awk 'NR != $1 { i = NR; exit } END { print i ? i : NR+1 }'
}


next() {
	# lowest number after focus OR very first
	awk '!first && NR==1 { first=$1 }
		$1 > '${focus:-1}' && ($1 < new || !new) { new=$1 }
		END { print new ? new : first }'
}

prev() {
	# highest number below focus OR very last
	awk '$1 < '${focus:-1}' && $1 > new { new=$1 }
		$1 > tail { tail = $1 }
		END { print new ? new : tail }'
}

create() {
	lowest | if read i; then
		if [ -f "$SVTM_DIR/$focus/pid" ] && read pid < "$SVTM_DIR/$focus/pid"; then
			cd "$(realpath /proc/$pid/cwd)"
		fi
		abduco -fn "$SVTM_SESSION-$i" svtm-vt "$SVTM_DIR/$i" "$@"
		echo "$i"
	fi
}

# kill the currently focused process
close() {
	prev
	if read pid < "$SVTM_DIR/$focus/pid"; then
		kill "$pid"
		# abduco doesn't finish session unless it sends content
		# to abduco server
		abduco -a "$SVTM_SESSION-$focus" < /dev/tty
		# TODO: https://github.com/martanne/abduco/issues/44
	fi
}

edit() {
	create sh -c "exec '$EDITOR' - < '$SVTM_DIR/$focus/dump'"
	echo dump > "$SVTM_DIR/$focus/cmd"
}

if [ -z "$SVTM_SESSION" ]; then
	die 'no SVTM session'
fi

if [ $# -lt 1 ]; then
	die 'give arg'
fi

read focus < "$SVTM_MASTER_DIR/focus"

case "$1" in
	# these functions read clients from stdin, and spit out the new client to focus on
	edit|close|create|prev|next) ls "$SVTM_DIR/" | numbers | "$@" > "$SVTM_MASTER_DIR/focus"
		if
			[ -f "$SVTM_MASTER_DIR/focus" ] && \
			read new < "$SVTM_MASTER_DIR/focus" && \
			[ -n "$new" ] && [ "$focus" != "$new" ]
		then
			:
		else
			die "cannot change focus from '$focus' to '$new'"
		fi;;
	scroll) echo "$@" > "$SVTM_DIR/$focus/cmd";;
	quit) xargs -r kill -s INT < "$SVTM_MASTER_DIR/pid";;
	*) die "unknown command";;

esac 

if [ -f "$SVTM_MASTER_DIR/view" ]; then
	numbers "$SVTM_MASTER_DIR/view" | while read pid; do
		kill "$pid"
	done
fi