#!/bin/sh
PORT=9090
PROCFILE=/tmp/.xrsh

usage(){ echo "Usage: xrsh [--keyboard] [--kill]"; exit; }

assert_cmds(){
  for cmd in $1; do 
    command -v $cmd &>/dev/null || { echo "error: please install $cmd (not found)"; exit 1; }
  done
}

showip(){
  { # naive way of getting network ip
    command -v ip       &>/dev/null && ip addr show
    command -v ifconfig &>/dev/null && ifconfig    
  } | grep 'inet ' | grep -v ' 127' | awk '! /addr:/ { gsub(/\/.*/,"",$2); if( !SEEN[$2] ) print $2; SEEN[$2]=1 }'

}

setupcerts(){
  test -f ~/.websocat/cert.pem && return 0
  mkdir ~/.websocat 2>/dev/null || true
  echo "--- generating temporary SSL certs (press enter to all questions) ---"
  #openssl req -x509 -newkey rsa:4096 -keyout ~/.websocat/key.pem -out ~/.websocat/cert.pem -days 365
  openssl req -x509 -newkey rsa:2048 -new -nodes -keyout ~/.websocat/key.pem -out ~/.websocat/cert.pem -days 3650
  openssl pkcs12 -export -out ~/.websocat/q.pkcs12 -inkey ~/.websocat/key.pem -in ~/.websocat/cert.pem
  wget "https://curl.haxx.se/ca/cacert.pem" -O ~/.websocat/cacert.pem
}

keyboard(){
  assert_cmds websocat pkill
  trap "stty sane; trap - SIGTERM && kill -- -$$" SIGINT SIGTERM EXIT # cleanup processes when exit
  echo $$ > $PROCFILE
  echo ""
  echo "    1. type 'k' (remote keyboard) in xrsh"
  echo "    2. enter ipaddress: $(showip)"
  echo ""
  echo "warn: CTRL-C is forwarded too"
  echo "warn: to exit this app run: $0 --kill"
  echo "warn: this terminal is now in raw sendmode, expect weird characters!"
  stty raw
  if test -n "$SSL"; then
	  setupcerts
	  websocat -E -b -s --pkcs12-der ~/.websocat/q.pkcs12 0.0.0.0:$PORT 2>&1 
  else
	  websocat -E -b -s 0.0.0.0:$PORT 2>&1 # http-only
  fi
}

# launch!
test -n "$1" || { echo "usage: xrsh [--ssl] [--keyboard] [--kill]"; exit; }
for arg in $*; do
	case $arg in
		--kill)     pkill -P $(cat $PROCFILE); exit ;;
		--ssl)      export SSL=1; ;;
		--keyboard) keyboard "$@"; ;; 
	esac
done