#!/usr/bin/env bash

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

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

tmp_log_file="$(mktemp)"

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

MYSQL_CREDENTIALS_GIVEN=false

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
}

is_number() {

   return $(test ! -z "${1##*[!0-9]*}" > /dev/null 2>&1);

   # - also possible
   # -
   #[[ ! -z "${1##*[!0-9]*}" ]] && return 0 || return 1
   #return $([[ ! -z "${1##*[!0-9]*}" ]])
}

detect_mysql_version () {

   _MYSQLD_VERSION="$(mysqld -V 2>/dev/null)"

   if [[ -z "$_MYSQLD_VERSION" ]]; then
      fatal "No installed MySQL server or distribution found!"
   elif [[ -d "/usr/local/mysql" ]] && [[ "$(basename "$(realpath "/usr/local/mysql")")" =~ percona- ]]; then
      MYSQL_CUR_DISTRIBUTION="Percona"
   elif [[ "$_MYSQLD_VERSION" =~ MariaDB ]]; then
      MYSQL_CUR_DISTRIBUTION="MariaDB"
   elif [[ "$_MYSQLD_VERSION" =~ MySQL ]]; then
      MYSQL_CUR_DISTRIBUTION="MySQL"
   elif [[ -d "/usr/local/mysql" ]] && [[ "$(basename "$(realpath "/usr/local/mysql")")" =~ mysql- ]]; then
      MYSQL_CUR_DISTRIBUTION="MySQL"
   elif [[ -d "/usr/local/mysql" ]] && [[ "$(basename "$(realpath "/usr/local/mysql")")" =~ mariadb- ]]; then
      MYSQL_CUR_DISTRIBUTION="MariaDB"
   else
      error "MySQL Instalation found, but cannot determin the distribution!"

      MYSQL_CUR_DISTRIBUTION=
      echo ""
      echo "   Select the MySQL distribution to install."
      echo ""
      echo "   [1] MySQL (the original community edition)"
      echo "   [2] Percona Server for MySQL"
      echo "   [3] MariaDB"
      echo ""
      echononl "   Eingabe [1/2/3]: "

      while [ "$MYSQL_CUR_DISTRIBUTION" != "MySQL" -a "$MYSQL_CUR_DISTRIBUTION" != "MariaDB" -a "$MYSQL_CUR_DISTRIBUTION" != "Percona" ];do
         read OPTION
         case $OPTION in
               1)      MYSQL_CUR_DISTRIBUTION="MySQL"
               ;;
               2)      MYSQL_CUR_DISTRIBUTION="Percona"
               ;;
               3)      MYSQL_CUR_DISTRIBUTION="MariaDB"
               ;;
               *)    echo ""
                     echo -e "\tFalsche Eingabe ! [ 1 = MySQL ; 2 = Percona ; 3 = MariaDB ]"
                     echo ""
                     echononl "   Eingabe:"
               ;;
         esac
      done
   fi

   MYSQL_VERSION="$(echo $_MYSQLD_VERSION | grep -o -E "[0-9]+\.[0-9]+\.[0-9]+(-[0-9]+)?" | head -n 1)"
   MYSQL_MAJOR_VERSION="$(echo $MYSQL_VERSION | cut -d '.' -f1)"
   MYSQL_MINOR_VERSION="$(echo $MYSQL_VERSION | cut -d '.' -f2)"
   MYSQL_PATCH_LEVEL="$(echo $MYSQL_VERSION | cut -d '.' -f3)"
   MYSQL_MAIN_VERSION="$(echo $MYSQL_VERSION | cut -d '.' -f1,2)"

}


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


echononl "   Get MySQL command.."
mysql_command="$(which mysql)"
if [[ $? -eq 0 ]]; then
   echo_ok
else

   if [[ -x "/usr/local/mysql/bin/mysql" ]]; then
      mysql_command="/usr/local/mysql/bin/mysql"
      echo_ok
   else
      echo_failed
      fatal "$(cat $tmp_log_file)"
   fi
fi


if [[ -n "$DATABASE_NAME" ]] ; then
   if [[ -z "$DATABASE_USER" || -z "$DATABASE_PASSWD" ]] ; then
      read_file=""
      if [[ -f "${working_dir}/databases/$DATABASE_NAME" ]]; then
         read_file="${working_dir}/databases/$DATABASE_NAME"
      elif [[ -f "${working_dir}/databases/DELETED/$DATABASE_NAME" ]]; then
         read_file="${working_dir}/databases/DELETED/$DATABASE_NAME"
      fi

      if [[ -n "$read_file" ]]; 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 < "$read_file"
      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


# - Clear Screen
# -
clear


# -------------
# - Load Settings from configuration file mysql_credetials.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

if [[ -n "$mysql_credential_args" ]]; then
   MYSQL_CREDENTIAL_ARGS="$mysql_credential_args"
   MYSQL_CREDENTIALS_GIVEN=true
fi


if ! $NON_INTERACTIVE_MODE ; then

   declare -i index_arr=0

   # - Get MySQL Version
   # -
   if [[ ${#mysql_credential_args_arr[@]} -gt 0 ]] ; then

      echo ""
      echo -e "\033[32m--\033[m"
      echo ""
      echo "Which Installation should be used for dropping database?"
      echo ""
      echo ""

      declare -a _tmp_arr=()
      #for _val in ${mysql_credential_args_arr[@]} ; do
      while [[ $index_arr -lt ${#mysql_credential_args_arr[@]} ]] ; do

         #IFS=':' read -a _val_arr <<< "${_val}"
         IFS=':' read -a _val_arr <<< "${mysql_credential_args_arr[$index_arr]}"

         mysql_version="${_val_arr[0]}"
         mysql_credential_args="${_val_arr[1]}"
         mysql_dist_string="$(${mysql_command} $mysql_credential_args -N -s -e "SELECT VERSION()" 2> ${tmp_log_file})"
         if [[ $? -ne 0 ]] ; then
            if [[ "$(cat $tmp_log_file)" =~ "unknown variable 'login-path" ]] ; then
               if [[ -x "/usr/local/mysql/bin/mysql" ]] ; then
                  mysql_dist_string="$(/usr/local/mysql/bin/mysql $mysql_credential_args -N -s -e "SELECT VERSION()" 2> /dev/null)"
               fi
            fi
         fi

         if [[ "$mysql_dist_string" =~ MariaDB ]]; then
            mysql_dist="MariaDB $mysql_version"
         else
            mysql_dist="MySQL/Percona $mysql_version"
         fi
         echo "   [$index_arr] $mysql_dist"
         _temp_arr[${index_arr}]="$mysql_credential_args"
         #_temp_arr+=("$mysql_credential_args")
         (( index_arr++ ))
      done

      _OK=false
      echo ""
      echononl "Eingabe: "
      while ! $_OK ; do
         read _IN
         if is_number "$_IN" && [[ -n ${_temp_arr[$_IN]} ]]; then

            MYSQL_CREDENTIAL_ARGS="${_temp_arr[$_IN]}"
            _OK=true
         else
            echo ""  
            echo -e "\tFalsche Eingabe !"
            echo ""
            echononl "Eingabe: "
         fi
      done

      MYSQL_CREDENTIALS_GIVEN=true

   fi


   if $DATABASE_NAME_NEEDED ; then
      echo ""
      echo -e "\033[32m--\033[m"
      echo ""
      echo "Insert Database name which should be deleted.."
      echo ""
      echo ""
      echononl "Database name: "
      read DATABASE_NAME
      while [ "X$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 $MYSQL_CREDENTIALS_GIVEN ; then

   # - Get MySQL Version
   # -
   echo ""
   echo -e "\033[32m--\033[m"
   echo ""
   echononl "   Get MySQL Version"
   _version="$(mysql $MYSQL_CREDENTIAL_ARGS -N -s -e "SELECT VERSION()" 2> $tmp_log_file)"
   if [[ $? -ne 0 ]] ; then
      if [[ "$(cat $tmp_log_file)" =~ "unknown variable 'login-path" ]] ; then
         if [[ -x "/usr/local/mysql/bin/mysql" ]] ; then
            mysql_command="/usr/local/mysql/bin/mysql"
         else
            echo_failed
            fatal "$(cat $tmp_log_file)"
         fi

         _version="$(${mysql_command} $MYSQL_CREDENTIAL_ARGS -N -s -e "SELECT VERSION()" 2> $tmp_log_file)"
         if [[ $? -ne 0 ]] ; then
            echo_failed
            fatal "$(cat $tmp_log_file)"
         else
            echo_ok
         fi
      else
         echo_failed
         fatal "$(cat $tmp_log_file)"
      fi

   else
      echo_ok
   fi

   IFS='.' read -r -a version_arr <<< "$_version"
   declare -i MAJOR_VERSION="${version_arr[0]}"
   declare -i MINOR_VERSION="${version_arr[1]}"
   _path_level="${version_arr[2]}"
   declare -i PATCH_LEVEL="${_path_level%%-*}"

   ## - Get current MySQL Distribution
   ## -
   echononl "   Get current MySQL distribution .."
   if [[ -z "$_version" ]]; then
      echo_failed
      fatal "No installed MySQL server or distribution found!"
   elif [[ "$_version" =~ MariaDB ]]; then
      MYSQL_CUR_DISTRIBUTION="MariaDB"
   else
      MYSQL_CUR_DISTRIBUTION="MySQL"
   fi
   echo_ok
   echo ""
   echo -e "\033[32m--\033[m"
   echo ""

else

   detect_mysql_version

   MAJOR_VERSION="$MYSQL_MAJOR_VERSION"
   MINOR_VERSION="$MYSQL_MINOR_VERSION"
   PATCH_LEVEL="$MYSQL_PATCH_LEVEL"

   if [[ "$MYSQL_CUR_DISTRIBUTION" = "MariaDB" ]] && ([[ $MAJOR_VERSION -gt 10 ]] \
         || ( [[ $MAJOR_VERSION -eq 10 ]] && [[ $MINOR_VERSION -gt 3 ]] )) ; then
      if [[ -S "/tmp/mysql.sock" ]]; then
         MYSQL_CREDENTIAL_ARGS="-u root -S /tmp/mysql.sock"
      elif [[ -S "/run/mysqld/mysqld.sock" ]]; then
         MYSQL_CREDENTIAL_ARGS="-u root -S /run/mysqld/mysqld.sock"
      elif [[ -S "/var/run/mysqld/mysqld.sock" ]]; then
         MYSQL_CREDENTIAL_ARGS="-u root -S /var/run/mysqld/mysqld.sock"
      else
         fatal "Parameter 'MYSQL_CREDENTIAL_ARGS' cannot be determined automated. 

              Use configuration file "$conf_file" to set 
              parameter manually."
      fi
   else
      if $(${mysql_command} --login-path=local  -e ";" > /dev/null 2>&1) ; then
         MYSQL_CREDENTIAL_ARGS="--login-path=local"
      elif [[ -f "/usr/local/mysql/sys-maint.cnf" ]] ; then
         MYSQL_CREDENTIAL_ARGS="--defaults-file=/usr/local/mysql/sys-maint.cnf"
      elif [[ -f "/etc/mysql/debian.cnf" ]] ; then
         MYSQL_CREDENTIAL_ARGS="--defaults-file=/etc/mysql/debian.cnf"
      else
         fatal "Parameter 'MYSQL_CREDENTIAL_ARGS' cannot be determined automated. 

              Use configuration file "$conf_file" to set 
              parameter manually."
      fi
   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 "   MySQL Distribution...........: $MYSQL_CUR_DISTRIBUTION"
   echo "   MySQL Version................: ${MAJOR_VERSION}.${MINOR_VERSION}.${PATCH_LEVEL}"
   echo "   MySQL Credentials............: $MYSQL_CREDENTIAL_ARGS"
   echo ""
   echo "   MySQL commnd.................: ${mysql_command}"
   echo ""
   echo "   Drop Database................: $DATABASE_NAME"
   if $DO_NOT_DELTE_USER ; then
      echo -e "   Drop Database user...........: \033[33mNone\033[m"
   else
      echo "   Drop 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_command} $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_command} $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
   "DELETE FROM db WHERE Db = '$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_command} $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
   "SELECT count(User) FROM db WHERE User = '$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_command} $MYSQL_CREDENTIAL_ARGS mysql -N -s -e \
         "DELETE FROM user WHERE User = '$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_command} $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

echononl "   Create directory '${working_dir}/databases/DELETED'.."
if [[ -d "${working_dir}/databases/DELETED" ]]; then
   echo_skipped
else
   mkdir -p "${working_dir}/databases/DELETED" > $tmp_log_file 2>&1
   if [[ $? -ne 0 ]] ; then
      echo_failed
      error "$(cat $tmp_log_file)"
   else
      echo_ok
   fi
fi

echononl "   Remove file '${working_dir}/databases/$DATABASE_NAME'"
if [[ -f "${working_dir}/databases/$DATABASE_NAME" ]] ; then
   mv "${working_dir}/databases/$DATABASE_NAME" "${working_dir}/databases/DELETED/" > $tmp_log_file 2>&1
   if [[ $? -ne 0 ]] ; then
      echo_failed
      error "$(cat $tmp_log_file)"
   else
      echo_ok
   fi
else
   echo_skipped
fi

echononl "   Create file '${working_dir}/databases/DELETED/$DATABASE_NAME'"
if [[ -f "${working_dir}/databases/DELETED/$DATABASE_NAME" ]]; then
   echo_skipped
else
   cat <<EOF > "${working_dir}/databases/DELETED/$DATABASE_NAME" 2> $tmp_log_file 2>&1
# <db-name> <db-user> <dp-pass>
$DATABASE_NAME $DATABASE_USER $DATABASE_PASSWD
EOF
   if [[ $? -ne 0 ]] ; then
      echo_failed
      error "$(cat $tmp_log_file)"
   else
      echo_ok
   fi
fi


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