#!/usr/bin/env -S bash

name='main' addr='d' myapp='backsshbash2' 
bye() { printf "${@:2}"
exit "$1"

}
start() { [[ -p $i ]] || { kill -9 $( <"$p" ) $( <"$pp" ) ; rm -f "${a[@]}" ; }
mkfifo "$i" "$i1" "$i2" "$o"

while read -r -N 2 r ; do
if [[ $r == c* ]] ; then printf %s "${r:1:1}"
else printf %s "${r:1:1}" >&2 ; fi
done <"$i1" >"$i" 2> >( while read -r -N 1 r ; do
if [[ $r == e ]] ; then kill -0 $( <"$p" )
else kill -9 $( <"$p" ) $( <"$pp" ) ; rm -f "${a[@]}" ; fi
done ) & printf $! >"$pp"

bash -i >"$o" 2>&1 <"$i" & printf $! >"$p"

<"$o" >"$i1" ssh "$addr" bash --init-file <( printf %s "$( declare -p z )"$'
[[ -d $z ]] || mkdir -p "$z"
cd "$z" || exit 1
[[ -p in || -p out ]] && rm -f {in,out}
mkfifo -p {in,out}
while cat in ; do sleep .15 ; done &
while cat >out ; do sleep .15 ; done' )

}
connect() { ssh "$addr" bash --init-file <( printf %s "$( declare -p z )"$'
cd "$z" || exit 1
[[ -p in && -p out ]] && exit 1
while cat out ; do sleep .15 ; done &
while cat >in ; do sleep .15 ; done' ) < <( while read -r -N 1 r ; do printf c%s "$r" ; done )


}
help() { printf %s\\n $'simple args help
possible args are
name <name>     | session name
addr <sshaddr>  | ssh addr str
start           | start bash and ssh to transit
connect         | connect to session in transit'
exit 0

}
[[ $BASH_SOURCE == */* ]] && name=${name%/*} name=${name##*/} || name=${PWD##*/}
myd=~/."$myapp" z=$myd/$name \
i=$z/i i1=$z/1 i2=$z/2 o=$z/o p=$z/p pp=$p. \
a=( "$i" "$i1" "$i2" "$o" "$p" "$pp" )

[[ -d $z ]] || mkdir -p "$z"

cd "$z" || bye 1 'cant cd to safety dir %s\n' "$z"

declare -A \
supported0=( help '' start '' stop '' connect '' )
supported1=( name '' addr '' )

(( $# )) || set -- help

fill=( '' "$@" ) i=

while [[ -v fill[++i] ]] && arg=${fill[i]} ; do
if [[ -v supported0[\$arg] ]] ; then "$arg"
elif [[ -v supported1[\$arg] ]] ; then declare "$arg=${fill[++i]}"
else printf $'unsupported arg %s, please consult running with \'help\' arg\n' "$arg" ; fi
done