#!/usr/bin/env sh

# Usage:
# pgrep <command> | xargs find_tmux_pane
# Or if you already have the pids:
# find_tmux_pane <pid1> <pid2> ...

server_pid="$(tmux ls -F '#{pid}' | head -n 1)"
pane_list="$(tmux lsp -aF '#{session_name}:#{window_index}.#{pane_index}	#{pane_pid}')"

get_pane_pid() {
	current_pid="$pid"
	if ! parent_pid="$(printf %d "$(ps -p "$current_pid" -o ppid=)")"
	then return $?
	fi
	while [ "$parent_pid" != "$server_pid" ]
	do
		current_pid="$parent_pid"
		parent_pid="$(printf %d "$(ps -p "$current_pid" -o ppid=)")"
		if [ "$parent_pid" = 0 ]
		then printf "%s is not a tmux process\n" "$pid" >&2; return 1
		fi
	done
	printf %d "$current_pid"
	return 0
}

get_pane_name() {
	while IFS= read -r line
	do
		if [ "${line#*	}" = "$1" ]
		then printf %s "${line%	*}"
		fi
	done <<-PANE_PID
	$pane_list
	PANE_PID
}

for pid in "$@"
do
	if pane_pid="$(get_pane_pid "$pid")"
	then printf "%d\t%s\n" "$pid" "$(get_pane_name "$pane_pid")"
	fi
done