#!/usr/bin/env bash
#
# xaval - xiringuito connection manager
#
[[ "${DEBUG}" == "true" ]] && set -x

set -e
set -o pipefail

declare -r ROOT_DIR=${HOME}/.xiringuito
declare -r DIR=${ROOT_DIR}/profiles; mkdir -p ${DIR}
declare -r LOG_DIR=${ROOT_DIR}/logs; mkdir -p ${LOG_DIR}
declare -r RECONNECT_AFTER=5
declare -r WAIT_TIMEOUT=15

declare -r ATTACH_MARKER="${ROOT_DIR}/attach"
if [[ -f "${ATTACH_MARKER}" ]]; then
  declare -r ATTACH=true
else
  declare -r ATTACH=false
fi

function print_help(){
  cat <<EOF
[ xaval - xiringuito connection manager ]

Usage: ${0} connect|attach PROFILE
       ${0} toggle
       ${0} list [FILTER_EXPR]
       ${0} kill PROFILE
       ${0} logs PROFILE
       ${0} create PROFILE XIRINGUITO_PARAMS
       ${0} update PROFILE XIRINGUITO_PARAMS
       ${0} upsert PROFILE XIRINGUITO_PARAMS
       ${0} delete PROFILE
       ${0} rename OLD_PROFILE NEW_PROFILE

HINT: Run without any arguments to enter interactive mode!

Examples:
  ${0} create PROD -f 3 -X root@production.server.com 10.67.42.0/24 172.21.0.0/16
  ${0} connect PROD

EOF
}

function commit_suicide(){
  echo "[ ERROR ]"
  echo "${@}"
  exit 1
}

function print_help_and_commit_suicide(){
  print_help
  commit_suicide "${@}"
}

function validate_command(){
  for _CMD in 'connect' 'attach' 'toggle' 'list' 'kill' 'logs' 'create' 'update' 'upsert' 'delete' 'rename'; do
    if [[ "${_CMD}" == "${1}" ]]; then
      echo "${1}"
      return
    fi
  done
}

function suicide_on_absent_profile(){
  if [[ ! -f "${DIR}/${1}" ]]; then
    commit_suicide "Profile does not exist: ${1}"
  fi
}

function suicide_on_existing_profile(){
  if [[ -f "${DIR}/${1}" ]]; then
    commit_suicide "Profile already exists: ${1}"
  fi
}

function get_profile_pid() {
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  pgrep -U ${USER} -f -- "$(cat ${DIR}/${PROFILE} | sed 's/\+/\\\+/g')"
}

function get_profile_status() {
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  if [[ "$(get_profile_pid ${PROFILE})" != "" ]]; then
    echo "UP"
  else
    echo "DOWN"
  fi
}

function suicide_on_profile_up(){
  if [[ "$(get_profile_status ${1})" == "UP" ]]; then
    commit_suicide "Profile already up: ${1}"
  fi
}

function suicide_on_profile_down(){
  if [[ "$(get_profile_status ${1})" == "DOWN" ]]; then
    commit_suicide "Profile already down: ${1}"
  fi
}

function do_mfa_prewarm(){
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  local PROFILE_FILE=${DIR}/${PROFILE}

  ROUTES_PASSED=$(egrep "[0-9]/[0-9]+$" ${PROFILE_FILE} >/dev/null && echo "true" || echo "false")
  DISCOVERY_OFF=$(egrep "(^| )-X "      ${PROFILE_FILE} >/dev/null && echo "true" || echo "false")

  if [[ "${ROUTES_PASSED}" == "false" && "${DISCOVERY_OFF}" == "false" ]]; then
    echo "true"
  else
    echo "false"
  fi
}

function select_profile(){
  local START_NUMBER=1
  local PROFILE_COUNT=$(list_profiles | wc -l | sed 's/ //g')

  if [[ ${PROFILE_COUNT} -eq 0 ]]; then
    print_help
    echo "You have no profiles configured..."
    exit 0
  fi

  list_profiles | awk '{printf "%2d) %s\n", NR, $0}' 
  echo; read -p "PROFILE NUMBER (${START_NUMBER}-${PROFILE_COUNT})>" PROFILE_NUMBER

  if [[ ${PROFILE_NUMBER} =~ "^[0-9]+$" ]]; then
    commit_suicide "Should be a natural number!"
  fi

  if [[ ${PROFILE_NUMBER} -lt ${START_NUMBER} ]]; then
    commit_suicide "Should be >= ${START_NUMBER}"
  fi

  if [[ ${PROFILE_NUMBER} -gt ${PROFILE_COUNT} ]]; then
    commit_suicide "Should be <= ${PROFILE_COUNT}"
  fi

  local PROFILE=$(list_profiles | head -n${PROFILE_NUMBER} | tail -n1 | cut -d' ' -f1)

  if [[ "${ATTACH}" == "true" ]]; then
    attach_profile ${PROFILE}
  else
    connect_profile ${PROFILE}
  fi
}

function list_profiles(){
  local FILTER_EXPR="${@}"
  if [[ -z "${FILTER_EXPR}" ]]; then
    FILTER_EXPR=".*"
  fi
  for PROFILE in $(find ${DIR} -type f | awk -F"/" '{print $NF}' | egrep "${FILTER_EXPR}" | sort); do
    printf "%-20s %-4s = %s\n" ${PROFILE} $(get_profile_status ${PROFILE}) "$(cat ${DIR}/${PROFILE})"
  done
}

function create_profile(){
  local PROFILE=${1}; shift

  suicide_on_existing_profile ${PROFILE}

  echo "${@}" >${DIR}/${PROFILE}
}

function update_profile(){
  local PROFILE=${1}; shift

  suicide_on_absent_profile ${PROFILE}

  echo "${@}" >${DIR}/${PROFILE}
}

function upsert_profile(){
  local PROFILE=${1}; shift

  echo "${@}" >${DIR}/${PROFILE}
}

function delete_profile(){
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  rm ${DIR}/${PROFILE}
}

function toggle_attach {
  if [[ "${ATTACH}" == "true" ]]; then
    rm "${ATTACH_MARKER}"
    echo "ATTACH: ON->OFF"
  else
    touch "${ATTACH_MARKER}"
    echo "ATTACH: OFF->ON"
  fi
}

function loop_connection() {
  trap "echo 'HUP is trapped'" HUP

  local PROFILE=${1}

  local TRY=true
  local OPTS=""

  set +e

  while [[ ${TRY} == true ]]; do
    $(dirname ${0})/xiringuito ${OPTS} $(cat ${DIR}/${PROFILE})
    if [[ ${?} -eq 0 || ${?} -eq 143 ]]; then
      echo "=> Will sleep ${RECONNECT_AFTER} seconds before reconnection..."
      OPTS="-c"
      sleep ${RECONNECT_AFTER}
    else
      TRY=false
    fi
  done
}

function attach_profile(){
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}
  suicide_on_profile_up ${PROFILE}

  loop_connection ${PROFILE}
}

function connect_profile(){
  echo -n "[ sudo check ] "; sudo true; echo

  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}
  suicide_on_profile_up ${PROFILE}

  local LOG_FILE=${LOG_DIR}/${PROFILE}

  if [[ "$(do_mfa_prewarm ${PROFILE})" == "true" ]]; then
    ./discover-routes $(awk '{print $NF}' ${DIR}/${PROFILE}) >/dev/null
  fi

  echo
  echo "Connecting (in background): ${PROFILE}"
  echo
  echo "Use \"xaval logs ${PROFILE}\" to see connection logs"
  loop_connection ${PROFILE} &>${LOG_FILE} &

  wait_connection ${PROFILE}
}

function wait_connection(){
  local PROFILE=${1}

  sleep 2

  local WAIT_TIME=0
  while [[ "$(get_profile_status ${PROFILE})" != "UP" ]]; do
    if [[ ${WAIT_TIME} -ge ${WAIT_TIMEOUT} ]]; then
      dump_profile_log ${PROFILE}

      commit_suicide "Unable to bring up \"${PROFILE}\" after ${WAIT_TIMEOUT} seconds"
    fi

    echo "* Waiting for connection to come up..."
    sleep 1

    ((++WAIT_TIME))
  done
}

function kill_profile() {
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}
  suicide_on_profile_down ${PROFILE}

  kill -HUP $(get_profile_pid ${PROFILE})
}

function logs_profile() {
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  local LOG_FILE=${LOG_DIR}/${PROFILE}

  cat ${LOG_FILE}

  echo
  echo "STATUS: $(get_profile_status ${PROFILE})"
}

function dump_profile_log() {
  local PROFILE=${1}

  suicide_on_absent_profile ${PROFILE}

  local LOG_FILE=${LOG_DIR}/${PROFILE}

  echo "--- LOG ---" >>/dev/stderr
  cat ${LOG_FILE} >>/dev/stderr
  echo "--- LOG ---" >>/dev/stderr
}

function rename_profile(){
  local OLD_PROFILE=${1}
  local NEW_PROFILE=${2}

  suicide_on_absent_profile ${OLD_PROFILE}
  suicide_on_existing_profile ${NEW_PROFILE}

  mv ${DIR}/${OLD_PROFILE} ${DIR}/${NEW_PROFILE}
}

if [[ $(echo "${@}" | egrep "((^|(^| )-{1,2})help|^-h)($| )") ]]; then
  print_help
  exit 0
fi

if [[ ${#} -eq 0 ]]; then
  select_profile
fi

declare -r CMD=${1}; shift

if [[ "${CMD}" == "" ]]; then
  echo "- Bye bye!"
  exit 0
fi

if [[ ! $(validate_command ${CMD}) ]]; then
  print_help_and_commit_suicide "Illegal command: ${CMD}"
fi

if [[ "${CMD}" == "list" ]]; then
  list_profiles "${@}"
  exit 0
fi

# ... this happens when you do not like case..esac ...
if [[ "${CMD}" == "connect" || "${CMD}" == "attach" || "${CMD}" == "delete"  || "${CMD}" == "kill" || "${CMD}" == "logs" ]]; then
  if [[ ${#} -ne 1 ]]; then
    print_help_and_commit_suicide "Command requires exactly 1 parameter: ${CMD}"
  fi
elif [[ ${CMD} == "rename" ]]; then
  if [[ ${#} -ne 2 ]]; then
    print_help_and_commit_suicide "Command requires exactly 2 parameters: ${CMD}"
  fi
elif [[ ${CMD} == "toggle" ]]; then
  if [[ ${#} -ne 0 ]]; then
    print_help_and_commit_suicide "Command does not require any parameters: ${CMD}"
  fi
  toggle_attach
  exit 0
else
  if [[ ${#} -lt 2 ]]; then
    print_help_and_commit_suicide "Not enough parameters for the command: ${CMD}"
  fi
fi

eval ${CMD}_profile ${@}