#!/bin/bash
#
# Copyright 2012-2014 Red Hat, Inc.
#
# This file is part of Thermostat.
#
# Thermostat is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation; either version 2, or (at your
# option) any later version.
#
# Thermostat is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Thermostat; see the file COPYING.  If not see
# <http://www.gnu.org/licenses/>.
#
# Linking this code with other modules is making a combined work
# based on this code.  Thus, the terms and conditions of the GNU
# General Public License cover the whole combination.
#
# As a special exception, the copyright holders of this code give
# you permission to link this code with independent modules to
# produce an executable, regardless of the license terms of these
# independent modules, and to copy and distribute the resulting
# executable under terms of your choice, provided that you also
# meet, for each linked independent module, the terms and conditions
# of the license of that module.  An independent module is a module
# which is not derived from or based on this code.  If you modify
# this code, you may extend this exception to your version of the
# library, but you are not obligated to do so.  If you do not wish
# to do so, delete this exception statement from your version.
#
#####################################################################
#
# Setup utility script in order to assist users in setting up
# mongodb credentials and set web.xml accordingly.
# 
# Upon a new install of thermostat it will not run any command
# until this setup utility has been run. Upon completion this
# script creates a STAMP file in $USER_THERMOSTAT_HOME, namely:
# $USER_THERMOSTAT_HOME/data/setup-complete.stamp
# If the file was created by this utility, it will have content
# similar to:
# "Created by thermostat-setup on YYYY-MM-DD-hh:mm:ss"
# 
# Since this script merely uses thermostat commands for setting
# up the mongodb user, this causes a chicken-and-egg problem.
# We work around this by temporily creating an empty
# setup-complete-file and replacing it by the real file upon
# successful completion.

# For debugging
#set -xv

tty_flags="$(stty -g)"

# Interruptions are failures
trap exitFail SIGINT

displayThermostatBlurb() {
  cat <<EOF

Thermostat Basics:

Thermostat is a database backed distributed monitoring
solution with support for monitoring multiple JVM instances.
The system is made up of three (3) components:

  1. Agents which collect data.
  2. Clients, which allow users to visualize collected data.
  3. Storage layer which connects the above componets.

The storage layer itself is two-tiered. The endpoint agents
and clients communicate with is a web application which uses
Mongodb as a backing database.

This script helps with a setup where all three components
run on a local system. In particular, it helps with the setup
of the storage layer. First, a user is set up in mongodb which
the web endpoint will use for database connections. Second,
the web endpoint's servlet config is updated so as to use the
credentials of this database user.

Please see the Thermostat User Guide for more information on
how to connect clients and agents to the pre-configured storage
layer:
http://icedtea.classpath.org/wiki/Thermostat/UserGuide

-------------------------------------------------------------

EOF
}

setThermostatEnvironment() {
  # Thermostat home
  if [ "x$THERMOSTAT_HOME" = "x" ] ; then
    THERMOSTAT_HOME="@thermostat.home@"
  fi
  export THERMOSTAT_HOME
  # Thermostat user home
  if [ "x$USER_THERMOSTAT_HOME" = "x" ]; then
    USER_THERMOSTAT_HOME="$HOME/.thermostat"
  fi
  export USER_THERMOSTAT_HOME
  THERMOSTAT="$THERMOSTAT_HOME/bin/thermostat"
}

setStampCompleteVars() {
  scriptName="$(basename $0)"
  timestamp="$(date '+%Y-%m-%d-%H:%M:%S %Z')"
  SETUP_TMP_UNLOCK_CONTENT="Temporarily unlocked thermostat via $scriptName on $timestamp"
  SETUP_UNLOCK_CONTENT_REGULAR="Created by $scriptName on $timestamp"
  SETUP_UNLOCK_CONTENT_READ_ONLY_WEBXML="Created by $scriptName on $timestamp (web.xml read-only)"
}

exitFail() {
  # Remove temp stamp file if we've created it
  # in this script already, but failed somewhere
  # down the line.
  removeTempStampFile
  echo 'Thermostat setup failed!' 1>&2
  stty "$tty_flags"
  exit 1
}

removeTempStampFile() {
  if [ ! -z "$SETUP_TMP_UNLOCK_CONTENT" ] && 
     [ ! -z "$SETUP_COMPLETE_FILE" ] && 
     [ -e $SETUP_COMPLETE_FILE ] &&
     grep -s "$SETUP_TMP_UNLOCK_CONTENT" "$SETUP_COMPLETE_FILE" > /dev/null; then
    rm "$SETUP_COMPLETE_FILE"
  fi
}

exitSuccess() {
  # Remove temporary unlock file and create the actual setup-complete
  # file.
  removeTempStampFile
  echo $SETUP_UNLOCK_CONTENT_REGULAR > "$SETUP_COMPLETE_FILE"
  echo -e "\nThermostat setup complete!\n"
  echo -e "Be sure to configure thermostat-users.properties and"
  echo -e "thermostat-roles.properties before you attempt connections"
  echo -e "with agent(s) and/or client(s)."
  exit 0
}

exitSuccessNotWritable() {
  # Remove temporary unlock file. Note, we intentionally
  # do not clean up the sed files, since the user might
  # want to use them still.
  removeTempStampFile
  # Create successful stamp file with note that
  # web.xml might not have been properly set up.
  echo $SETUP_UNLOCK_CONTENT_READ_ONLY_WEBXML > "$SETUP_COMPLETE_FILE"
  echo "Thermostat setup complete!"
  echo -e "\nBe sure to configure $TH_WEB_AUTH as mentioned above."
  echo -e "\nThen, make sure to configure thermostat-users.properties and"
  echo -e "thermostat-roles.properties before you attempt connections"
  echo -e "with agent(s) and/or client(s)."
  exit 0
}

unlockThermostat() {
  setThermostatEnvironment
  setStampCompleteVars
  SETUP_COMPLETE_FILE="$USER_THERMOSTAT_HOME/data/setup-complete.stamp"
  if [ -e "$SETUP_COMPLETE_FILE" ]; then
    echo "File $SETUP_COMPLETE_FILE exists. Skipping setup!"
    exit 0
  fi
  # Be sure to create the "data" parent directory if it does not
  # yet exist.
  local datadir="$(dirname $SETUP_COMPLETE_FILE)"
  if [ ! -e "$datadir" ]; then
    mkdir -p "$datadir"
  fi
  echo "$SETUP_TMP_UNLOCK_CONTENT" > "$SETUP_COMPLETE_FILE"
}

runSetup() {
  unlockThermostat
  setupMongodbUser
  TH_WEB_AUTH="$THERMOSTAT_HOME/etc/web.auth"
  
  if [ ! -e $TH_WEB_AUTH ]; then
    echo "File not found: $TH_WEB_AUTH" 1>&2
    exitFail
  fi

  if [ ! -w $TH_WEB_AUTH ]; then
    echo -e "\n\n$(readlink -f $TH_WEB_AUTH) is NOT writable."
    mkdir -p "$USER_THERMOSTAT_HOME/etc/"
    TH_WEB_AUTH="$USER_THERMOSTAT_HOME/etc/web.auth"
    echo -e "Writing to $TH_WEB_AUTH\n"
  fi
  local success=0
  echo "storage.username = $USERNAME" > "$TH_WEB_AUTH"
  success=$(( $sedSuccess + $? ))
  echo "storage.password = $PASSWORD" >> "$TH_WEB_AUTH"
  success=$(( $sedSuccess + $? ))
  chmod 640 "$TH_WEB_AUTH"
  success=$(( $sedSuccess + $? ))
  if [ $success -eq 0 ]; then
    exitSuccess
  else
    echo "Automatic substitution of file $TH_WEB_AUTH failed!" 1>&2
    exitFail
  fi
}

readUsername() {
  dUsername="$1"
  prompt="Please enter the desired Mongodb username (press return in order to use '$dUsername'): "
  read -p "$prompt" USERNAME 
  if [ "x$USERNAME" = "x" ]; then
    USERNAME="$dUsername"
  fi
  echo "Chosen username is '$USERNAME'"
}

# Read in the desired password, not permitting
# empty passwords.
readFirstPassword() {
  prompt="Please enter the desired password for user '$USERNAME': "
  while true; do
    read -s -p "$prompt" PASSWORD 
    if [ "x$PASSWORD" = "x" ]; then
      echo -e "\nPassword must not be empty. Please try again."
    else
      echo # Formatting
      break
    fi
  done
}

# Read in the password confirmation
confirmReadPassword() {
  firstTry="$1"
  prompt="Please confirm password for user '$USERNAME': "
  read -s -p "$prompt" confirmedPwd 
  # Passwords cannot be empty
  if [ "$firstTry" != "$confirmedPwd" ]; then
    echo -e "\nPasswords did not match. Please try again."
    PASSWORDS_MATCH="no"
  else
    PASSWORDS_MATCH="yes"
  fi
}

readPassword() {
  while true; do
    readFirstPassword
    confirmReadPassword "$PASSWORD"
    if [ "x$PASSWORDS_MATCH" = "xyes" ]; then
      break;
    fi
  done
}

setupMongodbUser() {
  # Generate some form of a random default username
  defaultName="thermostat-user-$(date +%s)"
  echo -e "\nStarting Mongodb user setup ...\n"
  echo -e "Next, you are required to enter the username/password,"
  echo -e "which the web storage endpoint will use for mongodb"
  echo -e "connections.\n"
  readUsername "$defaultName"
  readPassword
  setupCmdName="add-mongodb-user -s"
  output="$(echo -e $USERNAME\\n$PASSWORD\\n | $THERMOSTAT $setupCmdName 2>&1)"
  # The above should have created the mongodb stamp file
  monogdbSetupStampFile="$USER_THERMOSTAT_HOME/data/mongodb-user-done.stamp"
  if [ ! -e "$monogdbSetupStampFile" ] ||
    ! echo $output | grep -s "setup complete" > /dev/null; then
    echo -e "\nMongodb user setup failed." 1>&2
    exitFail
  fi
}

doProceedLoop() {
  DO_SETUP=1
  while true; do
    read -p "Ready to proceed? Please type 'yes' or 'no': " RESPONSE
    if [ "x$RESPONSE" = "xyes" ]; then
      break
    elif [ "x$RESPONSE" = "xno" ]; then
      DO_SETUP=0
      break
    else
      echo "Unknown response. Please only type 'yes' or 'no'"
    fi
  done
}

displayThermostatBlurb 
doProceedLoop

if [ $DO_SETUP -eq 0 ]; then
  echo "Exiting on user request. Bye!"
  exit 0
else
  runSetup
fi