#!/usr/bin/env bash
# DESCRIPTION
# check if a given URL is returning a HTTP 200 or not.
#
# USAGE
#   1. We need to install (http://doc.ubuntu-fr.org/cron#autres_considerations) :
#     sudo apt-get install mailutils
#   2. Add the recipient to the crontab :
#     MAILTO="me@host.com"
#   3. Run :
#     ./monitor-app.sh me@host.com http://example.com/

# set -x
scriptDir="$(dirname "$0")" # emplacement du script
. "$scriptDir"/toolboxrc # charge quelques function utiles (today, etc.). Le
. "$scriptDir"/stylerc # include some style

# Email To ?
EMAIL_TO="${1:-me@host.com}"
LOGS_DIR="$scriptDir"/logs

# Remove the scheme (https?) and the trailing slash
# @param  string  application URL
function getSiteName() {
  local appUrl="$1"
  local site="${appUrl#*//}" # remove the protocole
  local site="${site%/*}" # remove trailing slash

  echo "$site"
}

# Get the HTTP status code
# @param  string  application URL
function getHttpCode() {
  local appUrl="$1"
  curl -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.104 Safari/537.36'  -s -o /dev/null -w "%{http_code}" "$appUrl"
}

# entry point
# @param  string  application URL
function doThings() {
  local appUrl="$1"
  local site="$(getSiteName "$appUrl")"
  local httpCode=$(getHttpCode "$appUrl")
  local notify=1 # assumption is that there is a problem
  currentDir=$(cd "$(dirname "$0")"; pwd)
  echo '-------------------------' >> ${currentDir}/logs/run.log
  date >> ${currentDir}/logs/run.log
  echo $appUrl >> ${currentDir}/logs/run.log
  echo $httpCode >> ${currentDir}/logs/run.log
  case "$httpCode" in
  200)
    msg="$(printf "[%s] Server is %s on: %%s%%s" \
            "$(_valid "$httpCode")" \
            "$(_valid "running")"
          )"
    notify=0  # don't send any notification when everything is ok
    unset httpCode # remove the code (less noise in the logs)
    ;;
  3??) # 301
    # msg="$(printf "[%s] Page %-40s on: %%s %s %s" \
    msg="$(printf "[%s] Page %s on: %%s %s %s" \
            "$(_warning "$httpCode")" \
            "$(_warning "redirection")" \
            "$(_valid "->\t")" \
            "$(_warning "Check the resulting page is valid")"
          )"
    notify=0  # don't send any notification when everything is ok
    ;;
  4??)
    msg="$(printf "[%s] Client %s on: %%s %s %s" \
            "$(_error "$httpCode")" \
            "$(_error "Error")" \
            "$(_valid "->\t")" \
            "$(_warning "Check your connectivity")"
          )"
    ;;
  500)
    msg="$(printf "[%s] Internal %s on: %%s %s %s" \
            "$(_error "$httpCode")" \
            "$(_error "Server Error")" \
            "$(_valid "->\t")" \
            "$(_error "Restart Tomcat")"
          )"
    ;;
  503)
    msg="$(printf "[%s] Service %s on: %%s %s %s" \
            "$(_error "$httpCode")" \
            "$(_error "Unavailable")" \
            "$(_valid "->\t")" \
            "$(_error "Restart Tomcat")"
          )"
    ;;
  5??)
    msg="$(printf "[%s] Server %s on: %%s %s %s" \
            "$(_error "$httpCode")" \
            "$(_error "error")" \
            "$(_valid "->\t")" \
            "$(_error "Check manually")"
          )"
    ;;
  *)
    msg="$(printf "[%s] Unknown %s on: %%s %s %s" \
            "$(_error "$httpCode")" \
            "$(_error "error")" \
            "$(_valid "->\t")" \
            "$(_error "Check manually")"
          )"
    ;;
  esac

  subject="$(printf "[Monitor] %s [error: %s] @ %s" "$site" "$httpCode" "$(now)")"
  message="$(printf "$msg\n" "${appUrl:0:40}")"
  logEvent "$appUrl" "$message"

  if (( $notify != 0 ))
  then
    warn="`date`, url: "$appUrl" is down !!!"
    printf "$message\n" #"$(getSiteName "$appUrl")"
    sendNotification "url服务检测报警" "$warn"
    currentDir=$(cd "$(dirname "$0")"; pwd)
    /home/work/xuemengwang/jdk1.7.0_67/bin/java -jar ${currentDir}/weixin-alert.jar "${warn}"
  #else
    printf "$message\n" #"$(getSiteName "$appUrl")"
  fi
}


# Write message into log files (app and aggregate)
# @param  string  application URL
# @param  string  message to log
function logEvent() {
  local appUrl="$1"
  local message=$(printf "[%s] %s\n" "$(now)" "$2")
  local site="$(getSiteName "$appUrl")"
  local site="${site/\//-}" # pour avoir un nom de fichier valide

  local appLog="$LOGS_DIR"/monitor-"$(today)"-"$site".log # one file per app
  local metaLog="$LOGS_DIR"/monitor-meta-"$(today)".log # aggregate one file per day

  #echo $message >> "$appLog" # add to app log
  #echo $message >> "$metaLog" # add to meta log
}


# Send mail notification
# @param  string  subject of the mail
# @param  string  message of the mail
function sendNotification() {
  local subject="$1"
  local message="$2"

  if type mail 2> /dev/null; then
    echo $message | mail -v -s "$subject" "$EMAIL_TO" # send Email
  fi
}

[[ ! -d "$LOGS_DIR" ]] && mkdir -p "$LOGS_DIR" # create log dir
doThings "$2" # || { echo "[!] Could not execute monitor-app.sh ($@)" >&2; exit 1; }