#!/bin/bash

set -e

migration_command="puppetdb config-migration"

#############
# FUNCTIONS #
#############

# Display usage information and exit
#
# This function simply displays the usage information to the screen and exits
# with exit code 0.
#
# Example:
#
#   usage
#
function usage() {
  echo "Usage: ${migration_command}"
  echo "Configuration helper for migrating config files for PuppetDB upgrade."
  echo
  echo "This tool will attempt to copy the necessary PuppetDB config files into "\
       "place for use by the PuppetDB HTTPS service. It updates the pathing of "\
       "the files to align with new path expectations in the PuppetDB 3 series. "\
       "It will ensure the config files contain either existing edits or up "\
       "to date default settings. If the default settings are changed, the script "\
       "will also migrate any associated data into the new default location."
  echo
  echo "Options:"
  echo " -h  Help"
  exit 0
}

# Backs up a file, if it hasn't already been backed up
#
# $1 - file to backup
#
# Example:
#
#   backupfile "/etc/myconfig"
#
function backupfile {
  # Create the global array if it doesn't already exist
  if [ -z "$backupfile_list" ]; then
    backupfile_list=()
  fi

  # We check the array to make sure the file isn't already backed up
  if ! contains ${backupfile_list[@]} "$1"; then
    local backup_path="$1.bak.$(date +%s)"
    echo "Backing up $1 to ${backup_path} before making changes"
    cp -p "$1" "$backup_path"

    # Append to the array, so we don't need to back it up again later
    backupfile_list+=($1)
  fi
}

# This function searches for an element in an array returning 1 if it exists.
#
# $1 - array
# $2 - item to search for
#
# Example:
#
#   myarray=('element1', 'element2')
#   if contains ${myarray[@]}, "element1'; then
#     echo "element1 exists in the array"
#   fi
#
function contains {
  local n=$#
  local value=${!n}
  for ((i=1;i < $#;i++)); do
    if [ "${!i}" == "${value}" ]; then
      return 0
    fi
  done
  return 1
}

# This function wraps sed for a line focused search and replace.
#
# * Makes sure its atomic by writing to a temp file and moving it _after_
# * Escapes any forward slashes and ampersands on the RHS for you
#
# $1 - regexp to match
# $2 - line to replace
# $3 - file to operate on
#
# Example:
#
#    replaceline "^$mysetting.*" "mysetting = myvalue" /etc/myconfig
#
function replaceline {
  backupfile "$3"
  tmp="$3.tmp.$(date +%s)"
  sed "s/$1/$(echo "$2" | sed -e 's/[\/&]/\\&/g')/g" "$3" > "$tmp"
  mv "$tmp" "$3"
  chmod 644 "$3"
}

# This funtion gives a generic error message if a given path or file isn't found
#
# $1 - missing path
#
function path_not_found {
  echo "Warning: Unable to find the path to copy"
  echo
  echo "  This tool requires the following to exist:"
  echo
  echo "  * $1"
  echo
  echo "  Re-run this tool then restart PuppetDB to complete the config"
  echo "  setup:"
  echo
  echo "      ${migration_command}"
}


# This function copies the give file to the given destination
#
# $1 - file or directory to be moved
# $2 - destination
#
# Example:
#
#    migrate_file "/etc/puppetdb/conf.d/config.ini" "/etc/puppetlabs/puppetdb/conf.d"
#
function migrate {
  origin=$1
  destination=$2
  if [ "${destination##*/}" = "${origin##*/}" ] ; then
    destination_path="${destination%/*}"
  else
    destination_path="$destination"
    destination="${destination}/${origin##*/}"
  fi
  if [ ! -e "$origin" ]; then
    path_not_found "$origin"
  else
    if [ -e "$destination" ] ; then
      echo "Replacing: ${destination} with ${origin}"
      cp -pr "$origin" "$destination_path"
    else
      echo "Copying: ${origin} to ${destination}"
      mkdir -p "$destination_path"
      cp -pr "$origin" "$destination_path"
    fi
  fi
}

########
# MAIN #
########

# Gather command line options
while getopts "h" opt;
do
  case $opt in
    h)
      usage ;;
    *)
      usage ;;
  esac
done


# Figure out where the config files are we want to deal with
# Either they exist in the archive created by the preinst script
# during the upgrade, or the user is running this script by hand
# and they exist in the PDB 2 series location
if [ -e '/tmp/puppetdb-upgrade-config-files.tgz' ] ; then
  orig_config_dir=/tmp/puppetdb-orig-configs
  mkdir -p $orig_config_dir
  tar -xzf '/tmp/puppetdb-upgrade-config-files.tgz' -C $orig_config_dir
elif [ -e '/etc/puppetdb/conf.d/config.ini' -a -e '/etc/puppetdb/conf.d/database.ini' -a -e '/etc/puppetdb/conf.d/jetty.ini' ] ; then
  orig_config_dir=/etc/puppetdb/conf.d
else
  echo "Config archive not found. Not proceeding with migration"
  exit 0
fi

orig_jetty_file=${orig_config_dir}/jetty.ini
orig_database_file=${orig_config_dir}/database.ini
orig_config_file=${orig_config_dir}/config.ini
orig_ini_files=($orig_jetty_file $orig_database_file $orig_config_file)

config_dir=/etc/puppetlabs/puppetdb/conf.d
database_file=${config_dir}/database.ini
jetty_file=${config_dir}/jetty.ini
config_file=${config_dir}/config.ini
ini_files=($config_file $jetty_file $database_file)


echo "Migrating configuration files ${orig_ini_files[*]} to ${config_dir}"
for orig_ini_file in "${orig_ini_files[@]}" ; do
  migrate "$orig_ini_file" "$config_dir"
done

echo "Checking to see if we need to update default settings"
for ini_file in "${ini_files[@]}"; do
  if [ -f "${ini_file}" ] ; then

    # Check settings are correct and fix or warn. Do not move vardir behind
    # subname.
    orig_settings=(
      "vardir:/var/lib/puppetdb"
      "logging-config:/etc/puppetdb/logback.xml"
      "subname:file:/var/lib/puppetdb/db/db;hsqldb.tx=mvcc;sql.syntax_pgs=true"
      "ssl-key:/etc/puppetdb/ssl/private.pem"
      "ssl-cert:/etc/puppetdb/ssl/public.pem"
      "ssl-ca-cert:/etc/puppetdb/ssl/ca.pem"
    )
    new_settings=(
      "vardir:/opt/puppetlabs/server/data/puppetdb"
      "logging-config:/etc/puppetlabs/puppetdb/logback.xml"
      "subname:file:/opt/puppetlabs/server/data/puppetdb/db/db;hsqldb.tx=mvcc;sql.syntax_pgs=true"
      "ssl-key:/etc/puppetlabs/puppetdb/ssl/private.pem"
      "ssl-cert:/etc/puppetlabs/puppetdb/ssl/public.pem"
      "ssl-ca-cert:/etc/puppetlabs/puppetdb/ssl/ca.pem"
    )

    for i in "${orig_settings[@]}"; do
      setting="${i%%:*}"
      orig_value="${i#*:}"
      for j in "${new_settings[@]}"; do
        if [ "${j%%:*}" == "${setting}" ] ; then
          new_value="${j#*:}"
          if grep -qe "^${setting}" "$ini_file"; then
            if grep -qe "^${setting}[[:space:]]*=[[:space:]]*${orig_value}$" "$ini_file"; then
              replaceline "^${setting}.*" "${setting} = ${new_value}" "$ini_file"
              echo "Updated setting ${setting} in ${ini_file}."
              case "$setting" in
                vardir|ssl-*)
                  migrate "$orig_value" "$new_value"
                  rm -rf "$orig_value"
                  ;;
                subname)
                  orig_hsql_path="${orig_value#file:}"
                  orig_hsql_dir="${orig_hsql_path%/db;hsqldb.tx=mvcc;sql.syntax_pgs=true}"
                  new_hsql_path="${new_value#file:}"
                  new_hsql_dir="${new_hsql_path%/db;hsqldb.tx=mvcc;sql.syntax_pgs=true}"
                  ## if the default vardir still exists, then the vardir was
                  ## changed, but the subname still points to the default
                  ## vardir.
                  if [ -e "$orig_hsql_dir" ] ; then
                    echo "Copying over the contents of ${orig_hsql_dir} to ${new_hsql_dir}"
                    migrate "$orig_hsql_dir" "$new_hsql_dir"
                    rm -rf "$orig_hsql_dir"
                  fi
                  ;;
              esac
            else
              echo "Setting ${setting} in ${ini_file} has been changed from the default, so will not be updated."
            fi
          else
            if grep -qE "^# ?${setting} = <[A-Za-z_]+>$" "$ini_file"; then
              replaceline "^# ?${setting}.*" "${setting} = ${new_value}" "$ini_file"
              echo "Updated default settings from package installation for ${setting} in ${ini_file}."
            fi
          fi
        fi
      done
    done
  else
    echo "Error: Unable to find PuppetDB configuration file at ${ini_file} so unable to provide automatic configuration for that file."
    echo
    echo "   Confirm the file exists before running the tool again."
    echo "   The file should have been created automatically when"
    echo "   the package was installed."
  fi
done
echo "cleaning up old config files"
old_config_dir=/etc/puppetdb/conf.d
old_jetty_file=${old_config_dir}/jetty.ini
old_database_file=${old_config_dir}/database.ini
old_config_file=${old_config_dir}/config.ini
old_ini_files=($old_jetty_file $old_database_file $old_config_file)

for old_ini_file in "${old_ini_files[@]}" ; do
  if [ -e "$old_ini_file" ] ; then
    echo "Removing $old_ini_file"
    rm "$old_ini_file"
  fi
  if [ -e "${old_ini_file}.rpmsave" ] ; then
    echo "Removing ${old_ini_file}.rpmsave"
    rm "${old_ini_file}.rpmsave"
  fi
done

echo "Modifications may have been made to PuppetDB config files. To ensure these changes have been picked up, please do the following: "
echo "  1) upgrade the puppetdb-termini package"
echo "  2) restart the puppetdb service"
echo "  3) restart the puppetserver service"