#!/bin/bash

DB_HOST=$1
DB_PORT=$2
DB_USER=$3
DB_PASS=$4
DB_NAME=$5
DUMP_DIR=$6
DUMP_TRAIN=$7
DUMP_PREFIX=$8
DUMP_STAMP=$(date +%d.%m.%Y_%H.%M.%S)

function usage {
        echo 'Usage dumper.sh DB_HOST DB_PORT DB_USER DB_PASS DB_NAME DUMP_DIRECTORY [DUMP_TRAIN, DUMP_PREFIX]'
        echo 'Where optional'
        echo '  DUMP_TRAIN    - number of stored files, should >0 (rest will be deleted)'
        echo '  DUMP_PREFIX   - prefix dump files'
        exit 1
}

([[ -z "${DB_HOST}" ]] || [[ -z "${DB_PORT}" ]] || [[ -z "${DB_USER}" ]] || [[ -z "${DB_PASS}" ]] || [[ -z "${DB_NAME}" ]] || [[ -z "${DUMP_DIR}" ]]) && usage
[[ -d ${DUMP_DIR} ]] || mkdir -p ${DUMP_DIR} || exit 2

DUMP_DIR=${DUMP_DIR%/}
DUMP_FILE=${DUMP_DIR}/${DUMP_PREFIX}${DUMP_STAMP}-${DB_NAME}.sql

mysqldump\
  --host=${DB_HOST}\
  --port=${DB_PORT}\
  --user=${DB_USER}\
  --password=${DB_PASS}\
  ${DB_NAME} > ${DUMP_FILE}

if ! [ -z "${DUMP_TRAIN}" ] && [ ${DUMP_TRAIN} -gt 0 ]; then
        DUMP_TRAIN=$((${DUMP_TRAIN} + 1));
        OLD_DUMPS=$(ls -t ${DUMP_DIR} | grep -E "${DUMP_PREFIX}.*${DB_NAME}.sql" | tail -n +${DUMP_TRAIN});
        for file in ${OLD_DUMPS}; do
                rm "${DUMP_DIR}/${file}"
        done
fi

c=$(echo "${OLD_DUMPS}" | wc -l)
echo "[$(date +'%d.%m.%Y %H:%M:%S')] dump \"${DB_NAME}\" from [${DB_USER}@${DB_HOST}] to ${DUMP_FILE} and removed ${c} files: "${OLD_DUMPS} >> ~/.dumper.log