#!/bin/bash
# Script per il backup di database MS SQL Server
# Autore: Lorenzo Paciotti & Mattia Tadini
# Nome del file: mssql-backup.sh
# Revisione: 1.00

# Configuration
BACKUP_DIR="/zucchetti/backupdb/bkfiles"
SQLCMD="/opt/mssql-tools18/bin/sqlcmd"
USER="sa"
PASSWORD="DBP0l01nf0.."
HOST="localhost"
RETENTION=1  # Retention per i backup locali
REMOTE_RETENTION=2  # Retention per i backup remoti
DATE=$(LC_TIME=C date +%Y%m%d%H%M%S)  # Forza il formato della data
SERVER_NAME="DBSQL01"  # Identificativo del server fisico
LOG_FILE="/zucchetti/backupdb/backup_log.txt"
ERROR_LOG_FILE="/zucchetti/backupdb/backup_err.txt"
FTP_SERVER="terni.poloinformatico.it"
FTP_USER="backupmssqldb"
FTP_PASSWORD="!Li'D/i%2&*QkvK!"
REMOTE_DIR="/BackupDB"
SMTP_SERVER="smtp://relay.poloinformatico.it:587"
SMTP_USER="brass@relay.poloinformatico.it"
SMTP_PASS="DMKqP9vUYn8s"

# Check if a database name is provided as an argument
if [ -z "$1" ]; then
    echo "Usage: $0 <database_name>"
    exit 1
fi

DB_NAME=$1
LOCAL_DB_DIR="$BACKUP_DIR/$DB_NAME"
REMOTE_DB_DIR="$REMOTE_DIR/$DB_NAME"

# Create local backup directory if it doesn't exist
mkdir -p "$LOCAL_DB_DIR"
chown mssql:mssql "$LOCAL_DB_DIR"
# Create remote directory on FTP server if it doesn't exist
ftp -inv $FTP_SERVER <<EOF >> $LOG_FILE 2>> $ERROR_LOG_FILE
user $FTP_USER $FTP_PASSWORD
mkdir "$REMOTE_DB_DIR"
bye
EOF

BACKUP_FILE="$LOCAL_DB_DIR/${DB_NAME}_backup_$DATE.bak"
REMOTE_BACKUP_FILE="${DB_NAME}_backup_$DATE.bak"
LOCAL_STATUS=0
FTP_STATUS=0  # Indica lo stato dell'upload FTP (0: success, 1: failure)

# Function to send email with msmtp
send_email() {
    SUBJECT="Backup [${EMAIL_STATUS}] for $DB_NAME on $SERVER_NAME - $(LC_TIME=C date)"
    MESSAGE="Backup process completed. Check the details below:\n\n$(cat $LOG_FILE)"

    echo -e "Subject: $SUBJECT\nFrom: $SMTP_USER\nTo: $SMTP_USER\n\n$MESSAGE" | msmtp --debug --from="$SMTP_USER" -t
}

# Start time for the backup
START_TIME=$(date +%s)
echo "$(LC_TIME=C date): Starting backup for database: $DB_NAME on server $SERVER_NAME" > $LOG_FILE

# Perform database backup with CHECK option
$SQLCMD -S $HOST -U $USER -P $PASSWORD -Q "BACKUP DATABASE [$DB_NAME] TO DISK = N'$BACKUP_FILE' WITH CHECKSUM, COMPRESSION, INIT" -C >> $LOG_FILE 2>> $ERROR_LOG_FILE

# Check if the local backup was successful
if [ $? -eq 0 ]; then
    LOCAL_STATUS=0
    echo "$(LC_TIME=C date): Local backup completed successfully for $DB_NAME." >> $LOG_FILE
else
    LOCAL_STATUS=1
    echo "$(LC_TIME=C date): Error during local backup of $DB_NAME. Check error log." >> $LOG_FILE
fi

# End time and duration
END_TIME=$(date +%s)
DURATION=$((END_TIME - START_TIME))
echo "$(LC_TIME=C date): Backup ended for $DB_NAME." >> $LOG_FILE
echo "Start time: $(LC_TIME=C date -d @$START_TIME)" >> $LOG_FILE
echo "End time: $(LC_TIME=C date -d @$END_TIME)" >> $LOG_FILE
echo "Duration: $((DURATION / 60)) minutes and $((DURATION % 60)) seconds" >> $LOG_FILE

# Upload backup to remote FTP server
echo "$(LC_TIME=C date): Starting FTP upload for $DB_NAME." >> $LOG_FILE
ftp -inv $FTP_SERVER >> $LOG_FILE 2>> $ERROR_LOG_FILE <<EOF
user $FTP_USER $FTP_PASSWORD
cd $REMOTE_DB_DIR
put $BACKUP_FILE $REMOTE_BACKUP_FILE
bye
EOF

# Check FTP status
if [ $? -eq 0 ]; then
    FTP_STATUS=0
    echo "$(LC_TIME=C date): FTP upload completed successfully for $DB_NAME." >> $LOG_FILE
else
    FTP_STATUS=1
    echo "$(LC_TIME=C date): Error during FTP upload for $DB_NAME. Check error log." >> $LOG_FILE
fi

# Local retention policy
ls -1tr $LOCAL_DB_DIR/${DB_NAME}_backup_*.bak | head -n -$RETENTION | xargs -d '\n' rm -f >> $LOG_FILE 2>> $ERROR_LOG_FILE

# Remote retention policy
echo "$(LC_TIME=C date): Performing remote retention check." >> $LOG_FILE

# Otteniamo la lista dei file remoti (escludiamo informazioni non rilevanti come dati FTP)
ftp -inv $FTP_SERVER <<EOF > /tmp/ftp_file_list.txt 2>> $ERROR_LOG_FILE
user $FTP_USER $FTP_PASSWORD
cd $REMOTE_DB_DIR
ls
bye
EOF

# Filtriamo la lista per estrarre solo i nomi dei file (ignoriamo righe di tipo 'drwxr-xr-x', 'total', etc.)
grep -E -o '\S+_backup_[0-9]{14}\.bak' /tmp/ftp_file_list.txt | while read -r file; do
    # Verifica se il nome del file contiene il nome del database
    if [[ "$file" =~ ^$DB_NAME ]]; then
        # Estrai la data dal nome del file (formato DBNAME_backup_DATE.bak)
        file_date=$(echo "$file" | sed -n 's/.*_backup_\([0-9]\{14\}\)\.bak/\1/p')

        # Verifica che la data sia stata estratta correttamente
        if [ -n "$file_date" ]; then
            # Aggiungi un messaggio di debug per verificare la data estratta
            echo "$(LC_TIME=C date): Data estratta dal file remoto $file: $file_date" >> $LOG_FILE

            # Confrontiamo direttamente la data come numeri (formato YYYYMMDDHHMMSS)
            retention_date=$(LC_TIME=C date -d "-$REMOTE_RETENTION days" +%Y%m%d%H%M%S)

            # Verifica se la data estratta è più vecchia della retention
            if [ "$file_date" -lt "$retention_date" ]; then
                # Elimina il file remoto se è troppo vecchio
                ftp -inv $FTP_SERVER <<EOF >> $LOG_FILE 2>> $ERROR_LOG_FILE
                user $FTP_USER $FTP_PASSWORD
                cd $REMOTE_DB_DIR
                delete "$file"
                bye
EOF
                echo "$(LC_TIME=C date): File remoto $file eliminato perché più vecchio di $REMOTE_RETENTION giorni." >> $LOG_FILE
            fi
        else
            echo "$(LC_TIME=C date): Data non estratta correttamente dal nome del file remoto $file. Skipping file." >> $LOG_FILE
        fi
    else
        echo "$(LC_TIME=C date): Il file remoto $file non appartiene al database $DB_NAME. Skipping file." >> $LOG_FILE
    fi
done

# Determine email status
if [ $LOCAL_STATUS -eq 0 ] && [ $FTP_STATUS -eq 0 ]; then
    EMAIL_STATUS="SUCCESS"
elif [ $LOCAL_STATUS -eq 1 ] || [ $FTP_STATUS -eq 1 ]; then
    EMAIL_STATUS="FAILED"
else
    EMAIL_STATUS="WARNING"
fi

# Send the email with the log
send_email

# Remove the log file after sending the email
rm -f $LOG_FILE

echo "Backup process complete, local status: $LOCAL_STATUS, FTP status: $FTP_STATUS, and email sent."