#!/usr/bin/env bash

working_dir="$(dirname $(realpath $0))"
log_dir="${working_dir}/log"

conf_file="${working_dir}/conf/create_drop_database.conf"

tmp_log_file="$(mktemp)"

# -------------
# - Variable settings
# -------------

#DEFAULT_ACTION='create'
DEFAULT_MYSQL_CREDENTIAL_ARGS="--login-path=local"

DATABASE_NAME=""
DATABASE_USER=""
DATABASE_NAME_NEEDED=true
DATABASE_USER_NEEDED=true
DO_NOT_DELTE_USER=false
QUIET_MODE=false
NON_INTERACTIVE_MODE=false


# -------------
# --- Some functions
# -------------

usage() {
   echo 
      [ -n  "$1" ] && echo -e "Error: $1\n"

      cat<<EOF

   Usage: $(basename $0) [Options]

      Script drops an existing MySQL database. The database name is either given on 
      command line using parameter '-d' or will be asked for otherwise.

      If a user is given or

   

      Options:

      -d <db-name>
            The name of the domain, which is requested for deletion. If not set, script
            will ask for the database name.

      -I
            Non-interactive mode. Script will act in non-interactice mode. At least the
            database name must be given using parameter '-d'. Default is acting in 
            interactive mode
      -q
            Be quiet. Setting this parameter implies non-interactive mode (parameter -I). So 
            if '-q' is set, at least the database name must be given using parameter '-d'.

      -u <db-user>   
            The name of the database user who will be granted full access to the given 
            database. If not set, script looks for a file 'databases/<db-name>'. If 
            found, script reads database settings (user/password) from that file. If not 
            running in quiet mode, you will be asked to confirm or set the db-user.

      -U 
            No User will be deleted from table mysql.user. 

EOF
clean_up 1
}


clean_up() {

   # Perform program exit housekeeping
   rm -f $tmp_log_file
   exit $1
}

fatal(){
   echo ""
   if $terminal ; then
      if [[ -n "$*" ]] ; then
         echo -e "   [ \033[31m\033[1mFatal\033[m ]: $*"
      else
         echo "   \033[31m\033[1mFatal error\033[m:"
      fi
      echo ""
      echo -e "              \033[31m\033[1mScript will be interrupted.\033[m\033[m"
   else
      if [[ -n "$*" ]] ; then
         echo "   [ Fatal ]: $*"
      else
         echo "   Fatal error:"
      fi
      echo ""
      echo "              Script was terminated...."
   fi
   echo ""
   clean_up 1
}

echononl(){
   if $terminal && ! $QUIET_MODE ; then
      echo X\\c > /tmp/shprompt$$
      if [ `wc -c /tmp/shprompt$$ | awk '{print $1}'` -eq 1 ]; then
         echo -e -n "$*\\c" 1>&2
      else
         echo -e -n "$*" 1>&2
      fi
      rm /tmp/shprompt$$
   fi
}

error(){
   echo ""
   if $terminal ; then
      echo -e "   [ \033[31m\033[1mError\033[m ]: $*"
   else
      echo "Error: $*"
   fi
   echo ""
}

warn (){
   if $terminal && ! $QUIET_MODE ; then
      echo ""
      echo -e "   [ \033[33m\033[1mWarning\033[m ]: $*"
      echo ""
   fi
}

info (){
   if $terminal && ! $QUIET_MODE ; then
      echo ""
      echo -e "   [ \033[32m\033[1mInfo\033[m ]: $*"
      echo ""
   fi
}

echo_ok() {
   if $terminal && ! $QUIET_MODE ; then
      echo -e "\033[80G[ \033[32mok\033[m ]"
   fi
}
echo_failed(){
   if $terminal && ! $QUIET_MODE ; then
      echo -e "\033[80G[ \033[1;31mfailed\033[m ]"
   fi
}
echo_skipped() {
   if $terminal && ! $QUIET_MODE ; then
      echo -e "\033[80G[ \033[37mskipped\033[m ]"
   fi
}


trap clean_up SIGHUP SIGINT SIGTERM




# -------------
# - Read Commandline Parameters
# -------------

while getopts d:hIqu:U opt ; do
   case $opt in
      d) DATABASE_NAME="$OPTARG"
         DATABASE_NAME_NEEDED=false
         ;;
      I) NON_INTERACTIVE_MODE=true
         ;;
      q) QUIET_MODE=true
         NON_INTERACTIVE_MODE=true
         ;;
      u) DATABASE_USER="$OPTARG"
         DATABASE_USER_NEEDED=false
         ;;
      U) DO_NOT_DELTE_USER=true
         DATABASE_USER_NEEDED=false
         ;;
      h) usage
          ;;
      *) usage
   esac
done

shift $(expr $OPTIND - 1)
[[ "$#" -gt 0 ]] && usage "Wrong number of arguments given!"

# - If not running in a terminal, be silent and non-interactive
# -
if [[ -t 1 ]] ; then
      terminal=true
else
   terminal=false
   QUIET_MODE=true
   NON_INTERACTIVE_MODE=true
fi

if [[ -z "$DATABASE_NAME" ]] ; then
   DATABASE_USER_NEEDED=true
   DATABASE_PASSWD_NEEDED=true
fi

if $NON_INTERACTIVE_MODE && [[ -z "$DATABASE_NAME" ]]; then
   fatal "In quiet mode at least the database name must ibe given on th command line!"
fi


if [[ -n "$DATABASE_NAME" ]] ; then
   if [[ -z "$DATABASE_USER" || -z "$DATABASE_PASSWD" ]] ; then
      if [[ -f "${working_dir}/databases/$DATABASE_NAME" ]]; then
         while read -r _db_name _db_user _db_pass ; do

            # - if var '_db_name' begins with '#', that means the readed line
            # - is a comment line, then empty this variable
            # - 
            # - 
            _db_name="$(echo $_db_name | grep -vE "^\s*#")"

            # - Do not consider empty lines or commented lines
            # -
            [[ -z "$_db_name" ]] && continue

            if [[ "$_db_name" = "$DATABASE_NAME" ]]; then
               [[ -z "$DATABASE_USER" ]] && DATABASE_USER="$_db_user"
               [[ -z "$DATABASE_PASSWD" ]] && DATABASE_PASSWD="$_db_pass"
               break
            fi

         done < "${working_dir}/databases/$DATABASE_NAME"
      fi
   fi
fi

if $NON_INTERACTIVE_MODE ; then
   if [[ -z "$DATABASE_USER" ]]; then
      fatal "Database user not given. Maybe missing or wrong file '${working_dir}/databases/$DATABASE_NAME'."
   fi
   if [[ -z "$DATABASE_PASSWD" ]]; then
      fatal "Database user's password nit given. Maybe missing or wrong file '${working_dir}/databases/$DATABASE_NAME'."
   fi

fi



# -------------
# - Load Settings from configuration file create_drop_database.conf
# -------------

if ! $QUIET_MODE ; then
   echo ""
fi
echononl "   Loading configuration settings from $(basename ${conf_file}).."
if [[ -f "$conf_file" ]]; then
   source "$conf_file" > $tmp_log_file 2>&1
   if [[ $? -eq 0 ]]; then
      echo_ok
   else
      echo_failed
      fatal "$(cat $tmp_log_file)"
   fi
else
   echo_skipped
   warn "No Configuration File found. Loading defaults.."
fi

[[ -n "$MYSQL_CREDENTIAL_ARGS" ]] || MYSQL_CREDENTIAL_ARGS="$DEFAULT_MYSQL_CREDENTIAL_ARGS"
#[[ -n "$ACTION" ]] || ACTION="$DEFAULT_ACTION"
   

if ! $NON_INTERACTIVE_MODE ; then

   clear
   if $DATABASE_NAME_NEEDED ; then
      echo ""
      echo -e "\033[32m--\033[m"
      echo ""
      echo "Insert Database name which should be created.."
      echo ""
      echo ""
      echononl "Database name: "
      read DATABASE_NAME
      while [ "X$DATABASE_NAME" = "X" ] ; do
         echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
         echononl "Database name: "
         read DATABASE_NAME
      done
   fi

   if $DATABASE_USER_NEEDED ; then
      echo ""
      echo -e "\033[32m--\033[m"
      echo ""
      echo "Insert Database user who will grant full access to database '${DATABASE_NAME}'.."
      echo ""
      echo -e "Type \"\033[33mNone\033[m\" if no Database user should be deleted"
      echo ""
      echo ""
      if [ -z "$DATABASE_USER" ]; then
         echononl "Database user for database '${DATABASE_NAME}': "
         read DATABASE_USER
         while [ "X$DATABASE_USER" = "X" ] ; do
            echo -e "\n\t\033[33m\033[1mEingabe erforderlich.\033[m\n"
            echononl "Database user for database '${DATABASE_NAME}': "
            read DATABASE_USER
         done
      else
         _DATABASE_USER="$DATABASE_USER"
         echononl "Database user for database '${DATABASE_NAME}' [${_DATABASE_USER}]: "
         read DATABASE_USER
         if [[ "X$DATABASE_USER" = "X" ]]; then
            DATABASE_USER=$_DATABASE_USER
         fi
      fi
   fi

   if [[ "${DATABASE_USER,,}" = "none" ]]; then
      DO_NOT_DELTE_USER=true
   fi

fi

if ! $QUIET_MODE ; then
   echo ""
   echo ""
   echo -e "\033[32m\033[1m====================\033[m"
   echo "Drop MySQL Database settings"
   echo -e "\033[32m\033[1m====================\033[m"
   echo ""
   echo "   Database name................: $DATABASE_NAME"
   if $DO_NOT_DELTE_USER ; then
      echo -e "   Database user................: \033[33mNone\033[m"
   else
      echo "   Database user................: $DATABASE_USER"
   fi
   echo ""
   echo ""
fi

if ! $NON_INTERACTIVE_MODE ; then

   info "To Continue dropping database \033[1m$DATABASE_NAME\033[m type uppercase 'YES'"
   echo -e -n "\033[1mContinue:\033[m "
   read OK

   if [[ "$OK" != "YES" ]] ; then
      fatal "Abort by user request - Answer as not 'YES'"
   fi

fi


if ! $QUIET_MODE ; then
   echo ""
   echo ""
   echo -e "   Processing database \033[1m$DATABASE_NAME\033[m"
   echo ""
fi

echononl "   Drop database '$DATABASE_NAME'.."
mysql $MYSQL_CREDENTIAL_ARGS -N -s -e "DROP DATABASE $DATABASE_NAME" > $tmp_log_file 2>&1
if [[ $? -ne 0 ]] ; then
   echo_failed
   fatal "$(cat $tmp_log_file)"
else
   echo_ok
fi

echononl "   Delete all entries for database '$DATABASE_NAME' from table mysql.db .."
mysql $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
   "DELETE FROM db WHERE Db = '$DATABASE_NAME'" > $tmp_log_file 2>&1
if [[ $? -ne 0 ]] ; then
   echo_failed
   fatal "$(cat $tmp_log_file)"
else
   echo_ok
fi


# - Test if given user is associated with another database
# -
echononl "   Check if db user '$DATABASE_USER' is also associated with another database"
_count_user="$(mysql $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
   "SELECT count(User) FROM db WHERE User = '$DATABASE_USER'" 2> $tmp_log_file)"
if [[ -z "$_count_user" ]]; then
   echo_failed
   error $(cat "$tmp_log_file")
else
   echo_ok
   if [[ $_count_user -gt 0 ]]; then
      warn "Db user '$DATABASE_USER' is already in use.\n                So user will not be deleted from table 'mysql.user'."
   else
      echononl "   Delete username '$DATABASE_USER' from table mysql.user"
      mysql $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
         "DELETE FROM user WHERE User = '$DATABASE_USER'" > $tmp_log_file 2>&1
      if [[ $? -ne 0 ]] ; then
         echo_failed
         fatal "$(cat $tmp_log_file)"
      else
         echo_ok
      fi
   fi
fi


echononl "   Flush Privileges.."
mysql $MYSQL_CREDENTIAL_ARGS -N -s -e "FLUSH PRIVILEGES" > $tmp_log_file 2>&1
if [[ $? -ne 0 ]] ; then
   echo_failed
   error "$(cat $tmp_log_file)"
else
   echo_ok
fi


if ! $QUIET_MODE ; then
   echo ""
fi
clean_up 0