#!/bin/bash

# Username to connect to database as.  Will default to "postgres" if none specified.
USERNAME=postgres

# This dir will be created if it doesn't exist.  This must be writable by the user the script is
# running as.
BACKUP_DIR=/var/rhizo_backups/postgresql/

# Will produce a custom-format backup if set to "yes"
ENABLE_CUSTOM_BACKUPS=no

# Will produce a gzipped plain-format backup if set to "yes"
ENABLE_PLAIN_BACKUPS=yes

# Which day to take the weekly backup from (1-7 = Monday-Sunday)
DAY_OF_WEEK_TO_KEEP=6

# Number of days to keep daily backups
DAYS_TO_KEEP=7

# How many weeks to keep weekly backups
WEEKS_TO_KEEP=5


function perform_backups()
{
    SUFFIX=$1
    FINAL_BACKUP_DIR=$BACKUP_DIR"`date +\%Y-\%m-\%d`$SUFFIX/"

    EX_TABLES = ""
    if [ $SUFFIX = "-daily" ] ; then
        EX_TABLES=" -T cdr -T sms -T prefix_mexico -T rates "
    fi

    echo "Making backup directory in $FINAL_BACKUP_DIR"

    if ! mkdir -p $FINAL_BACKUP_DIR; then
        echo "Cannot create backup directory in $FINAL_BACKUP_DIR. Go and fix it!" 1>&2
        exit 1;
    fi;


    ###########################
    ###### FULL BACKUPS #######
    ###########################

    FULL_BACKUP_QUERY="select datname from pg_database where not datistemplate and datallowconn order by datname;"

    echo -e "\n\nPerforming full backups"
    echo -e "--------------------------------------------\n"

    for DATABASE in `psql -U "$USERNAME" -At -c "$FULL_BACKUP_QUERY" postgres`
    do
        if [ $ENABLE_PLAIN_BACKUPS = "yes" ]
        then
            echo "Plain backup of $DATABASE"

            if ! pg_dump -Fp -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress; then
                echo "[!!ERROR!!] Failed to produce plain backup database $DATABASE" 1>&2
            else
                mv $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE".sql.gz
            fi
        fi

        if [ $ENABLE_CUSTOM_BACKUPS = "yes" ]
        then
            echo "Custom backup of $DATABASE"

            if ! pg_dump -Fc -U "$USERNAME" "$DATABASE" -f $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress; then
                echo "[!!ERROR!!] Failed to produce custom backup database $DATABASE"
            else
                mv $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress $FINAL_BACKUP_DIR"$DATABASE".custom
            fi
        fi

    done

    echo -e "\nAll database backups complete!"
}

# MONTHLY BACKUPS

DAY_OF_MONTH=`date +%d`

if [ $DAY_OF_MONTH -eq 1 ];
then
    # Delete all expired monthly directories
    find $BACKUP_DIR -maxdepth 1 -name "*-monthly" -exec rm -rf '{}' ';'

    perform_backups "-monthly"

    exit 0;
fi

# WEEKLY BACKUPS

DAY_OF_WEEK=`date +%u` #1-7 (Monday-Sunday)
EXPIRED_DAYS=`expr $((($WEEKS_TO_KEEP * 7) + 1))`

if [ $DAY_OF_WEEK = $DAY_OF_WEEK_TO_KEEP ];
then
    # Delete all expired weekly directories
    find $BACKUP_DIR -maxdepth 1 -mtime +$EXPIRED_DAYS -name "*-weekly" -exec rm -rf '{}' ';'

    perform_backups "-weekly"

    exit 0;
fi

# DAILY BACKUPS

# Delete daily backups 7 days old or more
find $BACKUP_DIR -maxdepth 1 -mtime +$DAYS_TO_KEEP -name "*-daily" -exec rm -rf '{}' ';'

perform_backups "-daily"