#!/usr/bin/env bash
#set -x

CURL_ACTION=''
CURL_IP='127.0.0.1'
CURL_URL=''
CURL_PROTO=''
CURL_DOMAIN=''

function handle_args() {
  if [[ "$#" -eq 0 ]]; then
    show_help
    exit 1
  fi

  while [[ "$1" != '' ]]; do
    case $1 in
      -r )  CURL_ACTION='REFRESH' ;;
      -p )  CURL_ACTION='PURGE' ;;
      -ip ) shift; CURL_IP="$1" ;;
      -h )  show_help; exit 1 ;;
      * )   CURL_URL="$1" ;;
    esac
    shift
  done

  if [[ "${CURL_ACTION}" == '' ]] || [[ "${CURL_URL}" == '' ]]; then
    show_help
    exit 1
  fi

  if [[ "${CURL_IP}" == '' ]]; then
    echo 'IP parameter passed but no value set!'
    exit 1
  fi

  if ! [[ "${CURL_URL}" =~ https?:// ]]; then
    echo 'Please use full URL include http/https!'
    exit 1
  fi

  if [[ "${CURL_IP}" != '' ]] && [[ "${CURL_IP}" != '127.0.0.1' ]]; then
    if [[ "${CURL_URL}" =~ 'https://' ]]; then
      CURL_PROTO='443'
    else
      CURL_PROTO='80'
    fi
    CURL_DOMAIN=$(echo ${CURL_URL} | awk -F[/:] '{print $4}')
  fi
}

function show_help() {
  cat <<EOF
Usage: purge_cache_byurl -(r|p) [-ip <ip>] <URL>

Purge/Refresh cache for specific URL.

Required Arguments:
 -r|-p,    Refreshes/Purges the cache for specific page.
 *,        Full URL of the specific page to refresh/purge.

Optional Arguments:
 -ip,      IP to resolve the hostname of the request to (Only
           if it differs from what the DNS A record is set to.)

Notes:
  If running on a server other than the one the site is located on,
  make sure to add this machines IP to the trusted list inside of
  LiteSpeed Web Server or else the Purge/Refresh requests will not
  work.
EOF
}

function send_cmd() {
  if [[ "${CURL_PROTO}" != '' ]] && [[ "${CURL_DOMAIN}" != '' ]]; then
    CURL_OUTPUT=$(curl --resolve ${CURL_DOMAIN}:${CURL_PROTO}:${CURL_IP} -Iks -X ${CURL_ACTION} "${CURL_URL}" | grep 'HTTP/' | awk '{print $2}')
  else
    CURL_OUTPUT=$(curl -Iks -X ${CURL_ACTION} "${CURL_URL}" | grep 'HTTP/' | awk '{print $2}')
  fi
  if [[ "${CURL_OUTPUT}" != '200' ]]; then
    if [[ "${CURL_OUTPUT}" == '301' ]]; then
      if [[ "${CURL_NEW_URL}" == '' ]]; then
        if [[ "${CURL_PROTO}" != '' ]] && [[ "${CURL_DOMAIN}" != '' ]]; then
          CURL_NEW_URL=$(curl --resolve ${CURL_DOMAIN}:${CURL_PROTO}:${CURL_IP} -Iks -X ${CURL_ACTION} "${CURL_URL}" | grep 'Location:' | awk '{print $2}')
          if [[ "${CURL_NEW_URL}" =~ 'https://' ]]; then
            CURL_PROTO='443'
          else
            CURL_PROTO='80'
          fi
          CURL_DOMAIN=$(echo ${CURL_NEW_URL} | awk -F[/:] '{print $4}')
        else
          CURL_NEW_URL=$(curl -Iks -X ${CURL_ACTION} "${CURL_URL}" | grep 'Location:' | awk '{print $2}')
        fi
        CURL_URL="${CURL_NEW_URL}"
        send_cmd
      else
        echo 'URL keeps redirecting! Please make sure URL is final URL after any https or other redirects!'
        exit 1
      fi
    elif [[ "${CURL_OUTPUT}" == '405' ]]; then
      echo 'This IP is not valid to PURGE or REFRESH cache! Please add this IP as a trusted IP inside of LiteSpeed Web Server!'
      exit 1
    else
      echo 'HTTP return code is not 200! Please make sure this is a valid page!'
      exit 1
    fi
  else
    echo "Page ${CURL_ACTION} Successfully!"
  fi
}

function main() {
  handle_args "$@"
  send_cmd
  exit 0
}

main "$@"