#!/bin/bash
#
# Basil Backup Script for Standalone PostgreSQL
# Place on database server and run via cron
#
# Cron example (daily at 2 AM):
# 0 2 * * * /path/to/backup-standalone-postgres.sh

set -e

# Configuration
DB_HOST="localhost"
DB_PORT="5432"
DB_NAME="basil"
DB_USER="basil"
BACKUP_DIR="/var/backups/basil"
RETENTION_DAYS=30

# Create backup directories
mkdir -p "$BACKUP_DIR/daily"
mkdir -p "$BACKUP_DIR/weekly"
mkdir -p "$BACKUP_DIR/monthly"

# Timestamp
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
DATE=$(date +%Y%m%d)
DAY_OF_WEEK=$(date +%u)  # 1=Monday, 7=Sunday
DAY_OF_MONTH=$(date +%d)

# Daily backup
echo "Starting daily backup: $TIMESTAMP"
DAILY_BACKUP="$BACKUP_DIR/daily/basil-$DATE.sql.gz"
pg_dump -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" "$DB_NAME" | gzip > "$DAILY_BACKUP"
echo "Daily backup completed: $DAILY_BACKUP"

# Weekly backup (on Sundays)
if [ "$DAY_OF_WEEK" -eq 7 ]; then
    echo "Creating weekly backup"
    WEEK=$(date +%V)
    WEEKLY_BACKUP="$BACKUP_DIR/weekly/basil-week$WEEK-$DATE.sql.gz"
    cp "$DAILY_BACKUP" "$WEEKLY_BACKUP"
    echo "Weekly backup completed: $WEEKLY_BACKUP"
fi

# Monthly backup (on 1st of month)
if [ "$DAY_OF_MONTH" -eq 01 ]; then
    echo "Creating monthly backup"
    MONTH=$(date +%Y%m)
    MONTHLY_BACKUP="$BACKUP_DIR/monthly/basil-$MONTH.sql.gz"
    cp "$DAILY_BACKUP" "$MONTHLY_BACKUP"
    echo "Monthly backup completed: $MONTHLY_BACKUP"
fi

# Cleanup old backups
echo "Cleaning up old backups..."
find "$BACKUP_DIR/daily" -name "basil-*.sql.gz" -mtime +$RETENTION_DAYS -delete
find "$BACKUP_DIR/weekly" -name "basil-*.sql.gz" -mtime +90 -delete
find "$BACKUP_DIR/monthly" -name "basil-*.sql.gz" -mtime +365 -delete

# Verify backup integrity
echo "Verifying backup integrity..."
if gzip -t "$DAILY_BACKUP"; then
    BACKUP_SIZE=$(du -h "$DAILY_BACKUP" | cut -f1)
    echo "Backup verification successful. Size: $BACKUP_SIZE"
else
    echo "ERROR: Backup verification failed!" >&2
    exit 1
fi

# Optional: Send notification (uncomment to enable)
# echo "Basil backup completed successfully on $(hostname) at $(date)" | \
#   mail -s "Basil Backup Success" your-email@example.com

echo "Backup process completed successfully"