#!/usr/bin/env bash
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
cd $DIR

##
## Make sure only root can run our script
##
check_root() {
  if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root. Please sudo or log in as root first." 1>&2
    exit 1
  fi
}

##
## Check whether a connection to HOSTNAME ($1) on PORT ($2) is possible
##
connect_to_port () {
  HOST="$1"
  PORT="$2"
  VERIFY=`date +%s | sha256sum | base64 | head -c 20`
  echo -e "HTTP/1.1 200 OK\n\n $VERIFY" | nc -w 4 -l -p $PORT >/dev/null 2>&1 &
  if curl --proto =http -s $HOST:$PORT --connect-timeout 3 | grep $VERIFY >/dev/null 2>&1
  then
      return 0
  else
    curl --proto =http -s localhost:$PORT >/dev/null 2>&1
    return 1
  fi
}

check_IP_match () {
  HOST="$1"
  echo
  echo Checking your domain name . . .
  if connect_to_port $HOST 443
  then
      echo
      echo "Connection to $HOST succeeded."
  else
    echo WARNING:: This server does not appear to be accessible at $HOST:443.
    echo
    if connect_to_port $HOST 80
    then
	echo A connection to port 80 succeeds, however.
	echo This suggests that your DNS settings are correct,
	echo but something is keeping traffic to port 443 from getting to your server.
	echo Check your networking configuration to see that connections to port 443 are allowed.
    else
      echo "A connection to http://$HOST (port 80) also fails."
      echo
      echo This suggests that $HOST resolves to the wrong IP address
      echo or that traffic is not being routed to your server.
    fi
    echo
    echo Google: \"open ports YOUR CLOUD SERVICE\" for information for resolving this problem.
    echo
    echo You should probably answer \"n\" at the next prompt and disable Let\'s Encrypt.
    echo
    echo This test might not work for all situations,
    echo so if you can access Discourse at http://$HOST, you might try anyway.
    sleep 3
  fi
}

##
## Do we have docker?
##
check_and_install_docker () {
  docker_path=`which docker.io || which docker`
  if [ -z $docker_path ]; then
    read  -p "Docker not installed. Enter to install from https://get.docker.com/ or Ctrl+C to exit"
    curl https://get.docker.com/ | sh
  fi
  docker_path=`which docker.io || which docker`
  if [ -z $docker_path ]; then
    echo Docker install failed. Quitting.
    exit
  fi
}

##
## What are we running on
##
check_OS() {
  echo `uname -s`
}

##
## OS X available memory
##
check_osx_memory() {
  echo `free -m | awk '/Mem:/ {print $2}'`
}

##
## Linux available memory
##
check_linux_memory() {
  echo `free -g --si | awk ' /Mem:/  {print $2} '`
}

##
## Do we have enough memory and disk space for Discourse?
##
check_disk_and_memory() {

  os_type=$(check_OS)
  avail_mem=0
  if [ "$os_type" == "Darwin" ]; then
    avail_mem=$(check_osx_memory)
  else
    avail_mem=$(check_linux_memory)
  fi

  if [ "$avail_mem" -lt 1 ]; then
    echo "WARNING: Discourse requires 1GB RAM to run. This system does not appear"
    echo "to have sufficient memory."
    echo
    echo "Your site may not work properly, or future upgrades of Discourse may not"
    echo "complete successfully."
    exit 1
  fi

  if [ "$avail_mem" -le 2 ]; then
    total_swap=`free -g --si | awk ' /Swap:/  {print $2} '`

    if [ "$total_swap" -lt 2 ]; then
      echo "WARNING: Discourse requires at least 2GB of swap when running with 2GB of RAM"
      echo "or less. This system does not appear to have sufficient swap space."
      echo
      echo "Without sufficient swap space, your site may not work properly, and future"
      echo "upgrades of Discourse may not complete successfully."
      echo
      echo "Ctrl+C to exit or wait 5 seconds to have a 2GB swapfile created."
      sleep 5

      ##
      ## derived from https://meta.discourse.org/t/13880
      ##
      install -o root -g root -m 0600 /dev/null /swapfile
      dd if=/dev/zero of=/swapfile bs=1k count=2048k
      mkswap /swapfile
      swapon /swapfile
      echo "/swapfile       swap    swap    auto      0       0" | tee -a /etc/fstab
      sysctl -w vm.swappiness=10
      echo 'vm.swappiness = 10' > /etc/sysctl.d/30-discourse-swap.conf

      total_swap=`free -g --si | awk ' /Swap:/ {print $2} '`
      if [ "$total_swap" -lt 2 ]; then
        echo "Failed to create swap: are you root? Are you running on real hardware, or a fully virtualized server?"
        exit 1
      fi

    fi
  fi


  free_disk="$(df /var | tail -n 1 | awk '{print $4}')"
  if [ "$free_disk" -lt 5000 ]; then
    echo "WARNING: Discourse requires at least 5GB free disk space. This system"
    echo "does not appear to have sufficient disk space."
    echo
    echo "Insufficient disk space may result in problems running your site, and"
    echo "may not even allow Discourse installation to complete successfully."
    echo
    echo "Please free up some space, or expand your disk, before continuing."
    echo
    echo "Run \`apt-get autoremove && apt-get autoclean\` to clean up unused"
    echo "packages and \`./launcher cleanup\` to remove stale Docker containers."
    exit 1
  fi

}


##
## If we have lots of RAM or lots of CPUs, bump up the defaults to scale better
##
scale_ram_and_cpu() {

  local changelog=/tmp/changelog.$PPID
  # grab info about total system ram and physical (NOT LOGICAL!) CPU cores
  avail_gb=0
  avail_cores=0
  os_type=$(check_OS)
  if [ "$os_type" == "Darwin" ]; then
    avail_gb=$(check_osx_memory)
    avail_cores=`sysctl hw.ncpu | awk '/hw.ncpu:/ {print $2}'`
  else
    avail_gb=$(check_linux_memory)
    avail_cores=$((`awk '/cpu cores/ {print $4;exit}' /proc/cpuinfo`*`sort /proc/cpuinfo | uniq | grep -c "physical id"`))
  fi
  echo "Found ${avail_gb}GB of memory and $avail_cores physical CPU cores"

  # db_shared_buffers: 128MB for 1GB, 256MB for 2GB, or 256MB * GB, max 4096MB
  if [ "$avail_gb" -eq "1" ]
  then
    db_shared_buffers=128
  else
    if [ "$avail_gb" -eq "2" ]
    then
      db_shared_buffers=256
    else
      db_shared_buffers=$(( 256 * $avail_gb ))
    fi
  fi
  db_shared_buffers=$(( db_shared_buffers < 4096 ? db_shared_buffers : 4096 ))

  sed -i -e "s/^  #\?db_shared_buffers:.*/  db_shared_buffers: \"${db_shared_buffers}MB\"/w $changelog" $data_file
  if [ -s $changelog ]
  then
    echo "setting db_shared_buffers = ${db_shared_buffers}MB"
    rm $changelog
  fi

  # UNICORN_WORKERS: 2 * GB for 2GB or less, or 2 * CPU, max 8
  if [ "$avail_gb" -le "2" ]
  then
    unicorn_workers=$(( 2 * $avail_gb ))
  else
    unicorn_workers=$(( 2 * $avail_cores ))
  fi
  unicorn_workers=$(( unicorn_workers < 8 ? unicorn_workers : 8 ))

  sed -i -e "s/^  #\?UNICORN_WORKERS:.*/  UNICORN_WORKERS: ${unicorn_workers}/w $changelog" $web_file
  if [ -s $changelog ]
  then
      echo "setting UNICORN_WORKERS = ${unicorn_workers}"
      rm $changelog
  fi

  echo $data_file memory parameters updated.
}


##
## standard http / https ports must not be occupied
##
check_ports() {
    check_port "80"
    check_port "443"
    echo "Ports 80 and 443 are free for use"
}


##
## check a port to see if it is already in use
##
check_port() {

  local valid=$(netstat -tln | awk '{print $4}' | grep ":${1}\$")

  if [ -n "$valid" ]; then
    echo "Port ${1} appears to already be in use."
    echo
    echo "This will show you what command is using port ${1}"
    lsof -i tcp:${1} -s tcp:listen
    echo
    echo "If you are trying to run Discourse simultaneously with another web"
    echo "server like Apache or nginx, you will need to bind to a different port"
    echo
    echo "See https://meta.discourse.org/t/17247"
    echo
    echo "If you are reconfiguring an already-configured Discourse, use "
    echo
    echo "./launcher stop app"
    echo
    echo "to stop Discourse before you reconfigure it and try again."
    exit 1
  fi
}

##
## read a variable from the config file
##
read_config() {
  config_line=`egrep "^  #?$1:" $web_file`
  read_config_result=`echo $config_line | awk  -F":" '{print $2}'`
  read_config_result=`echo $read_config_result | sed "s/^\([\"']\)\(.*\)\1\$/\2/g"`
}

read_default() {
  config_line=`egrep "^  #?$1:" samples/standalone.yml`
  read_default_result=`echo $config_line | awk  -F":" '{print $2}'`
  read_default_result=`echo $read_config_result | sed "s/^\([\"']\)\(.*\)\1\$/\2/g"`
}

##
## prompt user for typical Discourse config file values
##
ask_user_for_config() {

  # NOTE: Defaults now come from standalone.yml

  local changelog=/tmp/changelog.$PPID
  read_config "DISCOURSE_SMTP_ADDRESS"
  local smtp_address=$read_config_result
  # NOTE: if there are spaces between emails, this breaks, but a human should be paying attention
  read_config "DISCOURSE_DEVELOPER_EMAILS"
  local developer_emails=$read_config_result
  read_config "DISCOURSE_SMTP_PASSWORD"
  local smtp_password=$read_config_result
  read_config "DISCOURSE_SMTP_PORT"
  local smtp_port=$read_config_result
  read_config "DISCOURSE_SMTP_USER_NAME"
  local smtp_user_name=$read_config_result
  if [ "$smtp_password" = "pa$$word" ]
  then
      smtp_password = ""
  fi
  read_config "LETSENCRYPT_ACCOUNT_EMAIL"
  local letsencrypt_account_email=$read_config_result
  if [ -z $letsencrypt_account_email ]
  then
      letsencrypt_account_email="me@example.com"
  fi
  if [ "$letsencrypt_account_email" = "me@example.com" ]
  then
      local letsencrypt_status="ENTER to skip"
  else
    local letsencrypt_status="Enter 'OFF' to disable."
  fi

  read_config "DISCOURSE_HOSTNAME"
  hostname=$read_config_result

  local new_value=""
  local config_ok="n"
  local update_ok="y"

  echo ""

  while [[ "$config_ok" == "n" ]]
  do
    if [ ! -z "$hostname" ]
    then
      read -p "Hostname for your Discourse? [$hostname]: " new_value
      if [ ! -z "$new_value" ]
      then
          hostname="$new_value"
      fi
      if [[ $hostname =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]
      then
        echo
        echo "Discourse requires a DNS hostname. IP addresses are unsupported and will not work."
        echo
        hostname="discourse.example.com"
      fi
    fi

    if [ ! -z "$developer_emails" ]
    then
      read -p "Email address for admin account(s)? [$developer_emails]: " new_value
      if [ ! -z "$new_value" ]
      then
          developer_emails="$new_value"
      fi
    fi

    if [ ! -z "$smtp_address" ]
    then
      read -p "SMTP server address? [$smtp_address]: " new_value
      if [ ! -z "$new_value" ]
      then
        smtp_address="$new_value"
      fi
    fi

    if [ ! -z "$smtp_port" ]
    then
      read -p "SMTP port? [$smtp_port]: " new_value
      if [ ! -z "$new_value" ]
      then
        smtp_port="$new_value"
      fi
    fi

    ##
    ## automatically set correct user name based on common mail providers unless it's been set
    ##
    if [ "$smtp_user_name" == "user@example.com" ]
    then
      if [ "$smtp_address" == "smtp.sparkpostmail.com" ]
      then
      	smtp_user_name="SMTP_Injection"
      fi
      if [ "$smtp_address" == "smtp.sendgrid.net" ]
      then
  	    smtp_user_name="apikey"
      fi
      if [ "$smtp_address" == "smtp.mailgun.org" ]
      then
  	    smtp_user_name="postmaster@$hostname"
      fi
    fi

    if [ ! -z "$smtp_user_name" ]
    then
      read -p "SMTP user name? [$smtp_user_name]: " new_value
      if [ ! -z "$new_value" ]
      then
          smtp_user_name="$new_value"
      fi
    fi

    read -p "SMTP password? [$smtp_password]: " new_value
    if [ ! -z "$new_value" ]
    then
        smtp_password="$new_value"
    fi

    if [ ! -z $letsencrypt_account_email ]
    then
      read -p "Optional email address for setting up Let's Encrypt? ($letsencrypt_status) [$letsencrypt_account_email]: " new_value
      if [ ! -z "$new_value" ]
      then
          letsencrypt_account_email="$new_value"
          if [ "${new_value,,}" = "off" ]
          then
            letsencrypt_status="ENTER to skip"
          else
            letsencrypt_status="Enter 'OFF' to disable."
          fi
      fi
    fi

    if [ "$letsencrypt_status" == "Enter 'OFF' to disable." ]
    then
       check_IP_match $hostname
    fi

    echo -e "\nDoes this look right?\n"
    echo "Hostname      : $hostname"
    echo "Email         : $developer_emails"
    echo "SMTP address  : $smtp_address"
    echo "SMTP port     : $smtp_port"
    echo "SMTP username : $smtp_user_name"
    echo "SMTP password : $smtp_password"

    if [ "$letsencrypt_status" == "Enter 'OFF' to disable." ]
    then
      echo "Let's Encrypt : $letsencrypt_account_email"
    fi


    echo ""
    read -p "ENTER to continue, 'n' to try again, Ctrl+C to exit: " config_ok
  done

  sed -i -e "s/^  DISCOURSE_HOSTNAME:.*/  DISCOURSE_HOSTNAME: $hostname/w $changelog" $web_file
  if [ -s $changelog ]
  then
    rm $changelog
  else
    echo "DISCOURSE_HOSTNAME change failed."
    update_ok="n"
  fi

  sed -i -e "s/^  DISCOURSE_DEVELOPER_EMAILS:.*/  DISCOURSE_DEVELOPER_EMAILS: \'$developer_emails\'/w $changelog" $web_file
  if [ -s $changelog ]
  then
    rm $changelog
  else
    echo "DISCOURSE_DEVELOPER_EMAILS change failed."
    update_ok="n"
  fi

  sed -i -e "s/^  DISCOURSE_SMTP_ADDRESS:.*/  DISCOURSE_SMTP_ADDRESS: $smtp_address/w $changelog" $web_file
  if [ -s $changelog ]
  then
    rm $changelog
  else
    echo "DISCOURSE_SMTP_ADDRESS change failed."
    update_ok="n"
  fi

  sed -i -e "s/^  #\?DISCOURSE_SMTP_PORT:.*/  DISCOURSE_SMTP_PORT: $smtp_port/w $changelog" $web_file
  if [ -s $changelog ]
  then
    rm $changelog
  else
    echo "DISCOURSE_SMTP_PORT change failed."
    update_ok="n"
  fi

  sed -i -e "s/^  #\?DISCOURSE_SMTP_USER_NAME:.*/  DISCOURSE_SMTP_USER_NAME: $smtp_user_name/w $changelog" $web_file
  if [ -s $changelog ]
  then
    rm $changelog
  else
    echo "DISCOURSE_SMTP_USER_NAME change failed."
    update_ok="n"
  fi

  if [[ "$smtp_password" == *"\""* ]]
  then
    SLASH="BROKEN"
    echo "========================================"
    echo "WARNING!!!"
    echo "Your password contains a quote (\")"
    echo "Your SMTP Password will not be set. You will need to edit app.yml to enter it."
    echo "========================================"
    update_ok="n"
  else
    SLASH="|"
    if [[ "$smtp_password" == *"$SLASH"* ]]
    then SLASH="+"
      if [[ "$smtp_password" == *"$SLASH"* ]]
      then
        SLASH="Q"
        if [[ "$smtp_password" == *"$SLASH"* ]]
	then
	  SLASH="BROKEN"
          echo "========================================"
          echo "WARNING!!!"
          echo "Your password contains all available delimiters (+, |, and Q). "
          echo "Your SMTP Password will not be set. You will need to edit app.yml to enter it."
          echo "========================================"
          update_ok="n"
         fi
       fi
    fi
  fi
  if [[ "$SLASH" != "BROKEN" ]]
  then
    sed -i -e "s${SLASH}^  #\?DISCOURSE_SMTP_PASSWORD:.*${SLASH}  DISCOURSE_SMTP_PASSWORD: \"${smtp_password}\"${SLASH}w $changelog" $web_file

    if [ -s $changelog ]
    then
      rm $changelog
    else
      echo "DISCOURSE_SMTP_PASSWORD change failed."
      update_ok="n"
    fi
  fi
  if [ "$letsencrypt_status" = "ENTER to skip" ]
  then
      local src='^  #\?- "templates\/web.ssl.template.yml"'
      local dst='  #\- "templates\/web.ssl.template.yml"'
      sed -i -e "s/$src/$dst/w $changelog" $web_file
      if [ ! -s $changelog ]
      then
        update_ok="n"
        echo "web.ssl.template.yml NOT DISABLED--Are you using a non-standard template?"
      fi
      local src='^  #\?- "templates\/web.letsencrypt.ssl.template.yml"'
      local dst='  #- "templates\/web.letsencrypt.ssl.template.yml"'

      sed -i -e "s/$src/$dst/w $changelog" $web_file
      if [ ! -s $changelog ]
      then
        update_ok="n"
        echo "web.ssl.template.yml NOT DISABLED--Are you using a non-standard template?"
      fi
  else # enable let's encrypt
    echo "Let's Encrypt will be enabled for $letsencrypt_account_email"
      sed -i -e "s/^  #\?LETSENCRYPT_ACCOUNT_EMAIL:.*/  LETSENCRYPT_ACCOUNT_EMAIL: $letsencrypt_account_email/w $changelog" $web_file
      if [ -s $changelog ]
      then
        rm $changelog
      else
        echo "LETSENCRYPT_ACCOUNT_EMAIL change failed."
        update_ok="n"
      fi
      local src='^  #\?- "templates\/web.ssl.template.yml"'
      local dst='  \- "templates\/web.ssl.template.yml"'
      sed -i -e "s/$src/$dst/w $changelog" $web_file
      if [ -s $changelog ]
      then
	  echo "web.ssl.template.yml enabled"
      else
        update_ok="n"
        echo "web.ssl.template.yml NOT ENABLED--was it on already?"
      fi
      local src='^  #\?- "templates\/web.letsencrypt.ssl.template.yml"'
      local dst='  - "templates\/web.letsencrypt.ssl.template.yml"'

      sed -i -e "s/$src/$dst/w $changelog" $web_file
      if [ -s $changelog ]
      then
	      echo "letsencrypt.ssl.template.yml enabled"
      else
        update_ok="n"
        echo "letsencrypt.ssl.template.yml NOT ENABLED -- was it on already?"
      fi
  fi

  if [ "$update_ok" == "y" ]
  then
    echo -e "\nConfiguration file at $config_file updated successfully!\n"
  else
    echo -e "\nUnfortunately, there was an error changing $config_file\n"
    echo -d "This may happen if you have made unexpected changes."
    exit 1
  fi
}

##
## is our config file valid? Does it have the required fields set?
##
validate_config() {

  valid_config="y"

  for x in DISCOURSE_SMTP_ADDRESS DISCOURSE_SMTP_USER_NAME DISCOURSE_SMTP_PASSWORD \
           DISCOURSE_DEVELOPER_EMAILS DISCOURSE_HOSTNAME
  do
    read_config $x
    local result=$read_config_result
    read_default $x
    local default=$read_default_result

    if [ ! -z "$result" ]
    then
      if [[ "$config_line" = *"$default"* ]]
      then
        echo "$x left at incorrect default of $default"
        valid_config="n"
      fi
      config_val=`echo $config_line | awk '{print $2}'`
      if [ -z $config_val ]
      then
        echo "$x was not configured"
        valid_config="n"
      fi
    else
      echo "$x not present"
      valid_config="n"
    fi
  done

  if [ "$valid_config" != "y" ]; then
    echo -e "\nSorry, these $web_file settings aren't valid -- can't continue!"
    echo "If you have unusual requirements, edit $web_file and then: "
    echo "./launcher bootstrap $app_name"
    exit 1
  fi
}


##
## template file names
##

if [ "$1" == "2container" ]
then
    app_name=web_only
    data_name=data
    web_template=samples/web_only.yml
    data_template=samples/data.yml
    web_file=containers/$app_name.yml
    data_file=containers/$data_name.yml
else
  app_name=app
  data_name=app
  web_template=samples/standalone.yml
  data_template=""
  web_file=containers/$app_name.yml
  data_file=containers/$app_name.yml
fi
    changelog=/tmp/changelog

##
## Check requirements before creating a copy of a config file we won't edit
##
check_root
check_and_install_docker
check_disk_and_memory

if [ -a "$web_file" ]
then
  echo "The configuration file $web_file already exists!"
  echo
  echo ". . . reconfiguring . . ."
  echo
  echo
  DATE=`date +"%Y-%m-%d-%H%M%S"`
  BACKUP=$app_name.yml.$DATE.bak
  echo Saving old file as $BACKUP
  cp $web_file containers/$BACKUP
  echo "Stopping existing container in 5 seconds or Control-C to cancel."
  sleep 5
  ./launcher stop app
  echo
else
  check_ports
  cp -v $web_template $web_file
  if [ "$data_name" == "data" ]
  then
      echo "--------------------------------------------------"
      echo "This two container setup is currently unsupported. Use at your own risk!"
      echo "--------------------------------------------------"
      DISCOURSE_DB_PASSWORD=`date +%s | sha256sum | base64 | head -c 20`

     sed -i -e "s/DISCOURSE_DB_PASSWORD: SOME_SECRET/DISCOURSE_DB_PASSWORD: $DISCOURSE_DB_PASSWORD/w $changelog" $web_file
     if  [ -s $changelog ]
     then
	 rm $changelog
     else
       echo "Problem changing DISCOURSE_DB_PASSWORD" in $web_file
     fi

     cp -v $data_template $data_file
     quote=\'
     sed -i -e "s/password ${quote}SOME_SECRET${quote}/password '$DISCOURSE_DB_PASSWORD'/w $changelog" $data_file
     if  [ -s $changelog ]
     then
	 rm $changelog
     else
       echo "Problem changing DISCOURSE_DB_PASSWORD" in $data_file
     fi
  fi
fi

scale_ram_and_cpu
ask_user_for_config
validate_config

##
## if we reach this point without exiting, OK to proceed
## rebuild won't fail if there's nothing to rebuild and does the restart
##
echo "Updates successful. Rebuilding in 5 seconds."
sleep 5 # Just a chance to ^C in case they were too fast on the draw
if [ "$data_name" == "$app_name" ]
then
    echo Building $app_name
    ./launcher rebuild $app_name
else
    echo Building $data_name now . . .
    ./launcher rebuild $data_name
    echo Building $app_name now . . .
    ./launcher rebuild $app_name
fi