#!/bin/bash

source "$(dirname $(realpath $BASH_SOURCE))/config/backup.sh"

readonly LOCK="/var/lock/backup"
readonly MOUNT_POINT=$(dirname $REPOSITORY)

function main()
{
    mount | grep -q $MOUNT_POINT || mount $MOUNT_POINT

    if [[ -e /var/run/mysqld/mysqld.sock ]]
    then
        mysql_backup
    fi

    postgersql_backup

    borg create --compression zlib,6 --exclude-from "$(dirname $(realpath $BASH_SOURCE))/config/exclude.txt" "$REPOSITORY::cuddles-$(date +%Y-%m-%d_%H:%M:%S)" $BACKUP_FILES

    borg prune --keep-daily=7 --keep-weekly=4 --keep-monthly=-1 "$REPOSITORY"

    postgresql_test

    umount $MOUNT_POINT
}

function mysql_backup()
{
    ensure_directory '/media/data/mysql_dump' 'mysql'
    rm /media/data/mysql_dump/*.dump

    for database in $(mysql_get_databases)
    do
        if [[ "$database" != "information_schema" && "$database" != "performance_schema" ]]
        then
            mysqldump --user "$MYSQL_USER" --password="$MYSQL_PASSWORD" "$database" > "/media/data/mysql_dump/$database.dump"
        fi
    done
}

function mysql_get_databases()
{
    echo 'SHOW DATABASES;' | mysql --user "$MYSQL_USER" --password="$MYSQL_PASSWORD" --silent
}

function postgersql_backup()
{
    ensure_directory '/media/data/pgsql_dump' 'postgres'
    sudo -u postgres rm /media/data/pgsql_dump/*.dump

    sudo -u postgres pg_dumpall --roles-only > '/media/data/pgsql_dump/_roles.dump'
    sed -i 's/^\(CREATE ROLE postgres;\)$/-- \1/' '/media/data/pgsql_dump/_roles.dump'
    for database in $(postgresql_get_databases)
    do
        sudo -u postgres pg_dump --file "/media/data/pgsql_dump/$database.dump" "$database"
    done
}

function postgresql_get_databases()
{
    sudo -u postgres psql --pset tuples_only --command 'SELECT datname FROM pg_database WHERE datistemplate = false;'
}

function postgresql_test()
{
    readonly CLUSTER_DIR="/var/lib/postgresql/$PGSQL_VERSION/backup"
    readonly TEST_DIR="$CLUSTER_DIR/tests"

    sudo -u postgres pg_createcluster "$PGSQL_VERSION" backup -d "$CLUSTER_DIR" > /dev/null
    sudo -u postgres pg_ctlcluster "$PGSQL_VERSION" backup start
    sudo -u postgres psql --port 5433 --output /dev/null --quiet --command '\i /media/data/pgsql_dump/_roles.dump'

    for database in $(postgresql_get_databases)
    do
        if [[ "$database" != "postgres" ]]
        then
            sudo -u postgres psql --port 5433 --output /dev/null --quiet --command "CREATE DATABASE $database;"
            sudo -u postgres psql --port 5433 --output /dev/null --quiet --command "\i /media/data/pgsql_dump/$database.dump" "$database"
        fi
    done

    sudo -u postgres pg_ctlcluster --mode immediate "$PGSQL_VERSION" backup stop
    sudo -u postgres pg_dropcluster "$PGSQL_VERSION" backup
}

function ensure_directory()
{
    local name=$1
    local user=$2
    local group=${3-$user}

    if [[ ! -d "$name" ]]
    then
        mkdir --parent "$name"
        chown "$user:$group" "$name"
    fi
}

if [[ ! -f "$LOCK" ]]
then
    touch "$LOCK"
    trap 'rm -f "$LOCK"' EXIT
    main
fi