#!/bin/bash

_extractpubkey () {
 name=${2:-$(basename $1)}
 ssh-keygen -y -f $1 | sed "s/$/ ${name}/" 
}

getkeyname () {
  if [[ $(echo $1 | awk -F . '{print $NF}') == "pub" ]]; then
    basename "$1" | rev | cut -f 2- -d '.' | rev 
  else
   basename $1
  fi
}

extractpubkey () {
 [[ $1 ]] || return 1
 [[ -f $1 ]] && _extractpubkey $1 && return 0
#  echo try pubkeys dir
   [[ $SSH_PUB_KEYS_DIR ]] && [[ -f $SSH_PUB_KEYS_DIR/$1 ]] && _extractpubkey $SSH_PUB_KEYS_DIR/$1 && return 0
#  echo try home
 [[ -f $HOME/.ssh/$1 ]] && _extractpubkey $HOME/.ssh/$1 && return 0
 return 1
}

# need to use full filename including any .pub 
catpubkey () {
  [[ $1 ]] || return 1
  local key; local pub
  key=$1
  if [[ $(echo $1 | awk -F . '{print $NF}') == "pub" ]]; then
    key=$(basename "$1" | rev | cut -f 2- -d '.' | rev) 
    pub=$1
  else
    pub="${1}.pub"
    key=$(basename $1)
  fi
  # echo try agent $key
  key=$(ssh-add -L | sed -n /$key/p)
  [[ $key ]] && echo $key && return 0
  # echo try $pub
  [[ -f $pub ]] && cat $pub && return 0
  # echo try $SSH_PUB_KEYS_DIR/$pub
  [[ $SSH_PUB_KEYS_DIR ]] && [[ -f $SSH_PUB_KEYS_DIR/$pub ]] && cat $SSH_PUB_KEYS_DIR/$pub && return 0
  # echo $HOME/.ssh/$pub
  [[ -f $HOME/.ssh/$pub ]] &&  cat $HOME/.ssh/$pub && return 0
  # echo try extract key from private key
  extractpubkey $key
}


#example: 
# initial xfer of pubkey with a password
# sshpubkey <pubkey opts> host <ssh run options> -- <more ssh options>

# TODO way to get public key
# try agent first with sed ssh-add -L | sed -n /sysadmin.kebler.net/p
# then in current directory, in SSH_PUB_DIR directory, in .ssh directory (or within)
# try pub file, then extract from private key
    
export SSH_PUB_KEYS
module_load path
module_load net-utils
module_load remote

sshpubkey () {

    # echo default pub key dir: $SSH_PUB_KEYS

    local kname=id_rsa
    local user
    local opts;local dr="true";local rm; 
    local vkey; local kuser; local host; local upass; local remove
    local _sudo; local list; 



  help() {

  cat <<EOF  
usage: sshpubkey <pubkey opts> host <ssh script options> 
-a, <alternate user> put the key at another user on remote.  if you want to put it to root use 'root'  will require remote sudo
-u, <user> remote user if not available in host 
-k, <key> can be either the path to a public key file or the name of the key currently loaded in an ssh agent 
-l, list the keys for the remote user
-r, remove the key from the user, use the comment identifier of the public key
-o, <options> additional ssh options
-e, required to actually make the remote changes, otherwise it's a dry run.  This to avoid making a mistake and locking out of remote
-h, this help text  
EOF

  }
  local OPTION;local OPTARG;local OPTIND
  while getopts 'sp:hu:a:r:ek:o:s:l' OPTION; do
    # echo OPTION $OPTION ARG $OPTARG
    case "$OPTION" in
    a)
      # to put the key at another user on remote.  will require sudo on remote
      kuser="-u $OPTARG"
      ;;
    u)
      # user if not explicit from host
      user=$OPTARG
      ;;
    p)
      upass="-p $OPTARG"
    ;; 
    l)
      list=true  
    ;; 
    r)
      # remove key, must be "comment identifier in public key"
      rm=$OPTARG
      ;;  
    k)
      kpath=$OPTARG
      key=$(getkeyname $kpath)
      ;;
    o)
      opts=$OPTARG
      ;;  
    e)
      dr=""
      ;;
    h)
      help
    ;;    
    *)
      echo unknown option -$OPTARG
      help
      # opts="$opts ${@:$OPTIND:1}"
      # # ((OPTIND+=1))
      # #echo remaining ${@:$OPTIND}
      return 1
      ;;
    esac
  done

  shift $((OPTIND - 1))

  host=$1
  shift 1
  if [[ ! $host ]]; then
   >&2 echo "no host supplied, aborting"
   help
   return 2
  fi 

  sshsopts=("${@}")

  user=${user:-$(get_user_host $host)}
  [[ ! $user ]] && >&2 echo "unable to determine remote user, aborting" && return 2

  run () (
    local func; local _sudo
    func=$1; shift
  if [[ "${kuser}" =~ "root" ]]; then
   kuser=""
   _sudo=-s
  fi 
  # echo run opts: $@
  [[ $upass || "${sshsopts[*]}" ]] && opts="-- " 
  echo remote_script $_sudo $kuser -x $func $host "$@" $opts $upass "${sshsopts[@]}"
  remote_script $_sudo $kuser -x $func $host "$@" $opts $upass "${sshsopts[@]}"
  )

  if [[ $list ]]; then
    run list_keys
    return $?
  fi 

  if [[ $rm ]]; then
   ############# REMOVE PUBLIC KEY #################
   # todo allow removeall without access to public key
    echo ">>>>> removing public key: \"$rm\" from ${kuser:-$user}"
    [[ ! $dr ]] && remove="_remove_"
    run rm_key "$remove" "$rm"
    return $?
  fi 

  vkey=$(catpubkey $kpath) # get actaul content of public key
   [[ $? -gt 0 ]] && echo no valid public key for $key at $kpath found && return 4
  
  # ## Alternate remote user?
  # if [[ $kuser ]]; then 
  #   [[ ! $supass ]] && { echo remote user, $user, password must be supplied for sudo. use -s;return 7; }
  # fi

  if [[ $key ]] ; then
    ############## ADD PUBLIC KEY ########################
    echo ">>>>>> sending key $key to remote user ${kuser:-$user}"
    run cpy_key $vkey
    return $?
  fi

}  
  

function cpy_key () {

  vkey=$*
  if [[ $(cat $HOME/.ssh/authorized_keys | grep "$vkey") ]]; then
    echo key $key already in authorized_keys for remote user $USER
    else  
      echo -e "\nInstalling key for $USER"
      echo -e "\n############ appending key to -s$HOME/.ssh/authorized_keys ############"
      cat $HOME/.ssh/authorized_keys 
      echo "###########################"
      # echo "#################### adding ####################"
      # echo $vkey
      # echo "#################################################"

      if [[ ! -f $HOME/.ssh/authorized_keys ]]; then
      mkdir $HOME/.ssh >/dev/null 2>&1
      touch $HOME/.ssh/authorized_keys >/dev/null 2>&1 
      chmod 600 $HOME/.ssh/authorized_keys >/dev/null 2>&1
      ls -la $HOME/.ssh/authorized_keys
      fi

      echo "$vkey"  >> $HOME/.ssh/authorized_keys
      ls -la $HOME/.ssh/authorized_keys
      echo "******** updated authorized_keys for $USER *******************" 
      cat $HOME/.ssh/authorized_keys
      echo "******************************************************"

  fi

}

function rm_key () {
  local kname; local remove; local found
  echo "$@"
  [[ $1 = "_remove_" ]] && remove="-i" && shift 1
  kname="$*"
  if [[ ! -f $HOME/.ssh/authorized_keys ]]; then
    echo no $HOME/authorized_keys file nothing to remove
   else
      # found=$(sed "\,$kname$,p" $HOME/.ssh/authorized_keys)
      found=$(cat $HOME/.ssh/authorized_keys | grep "${kname}$")
      if [[ $found ]]; then
        echo key found in authorized_keys, removing...
        echo "$found"
        if [[ $remove ]]; then
          echo "********updated authorized_keys file for $USER *******************" 
          sed $remove "\,$kname$,d" $HOME/.ssh/authorized_keys
          cat $HOME/.ssh/authorized_keys
          echo "******************************************************"
        else 
         echo "--- this is a dry run by default ---"  
         echo "--- if  you are SURE this is the key you want removed"
         echo "--- run again with -e to actaully remove this key ---"
         echo "!!! REMOVING THE WRONG KEY MAY RESULT IN LOOSING ACCESS TO THE MACHINE !!!"
        fi
        else
          echo no key $kname found in the authorized_keys, nothing to remove
      fi
  fi

}

function list_keys () {
 echo "********authorized_keys file for user: $USER at host: $HOSTNAME *******************" 
 cat $HOME/.ssh/authorized_keys
 echo "******************************************************"
}