#!/bin/bash
# Database Backup Script for Overseas Appointment System
# This script creates daily backups of the MySQL database

set -e

# Configuration
BACKUP_DIR="/backups/mysql"
RETENTION_DAYS=7
DATE=$(date +%Y%m%d_%H%M%S)
BACKUP_FILE="overseas_appointment_${DATE}.sql.gz"

# Database credentials (from environment or defaults)
DB_HOST="${DB_HOST:-mysql}"
DB_PORT="${DB_PORT:-3306}"
DB_NAME="${DB_NAME:-overseas_appointment}"
DB_USER="${DB_USER:-app_user}"
DB_PASSWORD="${DB_PASSWORD:-}"

# Create backup directory if it doesn't exist
mkdir -p "${BACKUP_DIR}"

echo "[$(date)] Starting database backup..."

# Create backup using mysqldump
mysqldump \
    --host="${DB_HOST}" \
    --port="${DB_PORT}" \
    --user="${DB_USER}" \
    --password="${DB_PASSWORD}" \
    --single-transaction \
    --routines \
    --triggers \
    --events \
    --add-drop-table \
    --complete-insert \
    "${DB_NAME}" | gzip > "${BACKUP_DIR}/${BACKUP_FILE}"

# Check if backup was successful
if [ $? -eq 0 ]; then
    echo "[$(date)] Backup completed successfully: ${BACKUP_FILE}"
    echo "[$(date)] Backup size: $(du -h ${BACKUP_DIR}/${BACKUP_FILE} | cut -f1)"
else
    echo "[$(date)] ERROR: Backup failed!"
    exit 1
fi

# Remove old backups (older than RETENTION_DAYS)
echo "[$(date)] Cleaning up old backups (older than ${RETENTION_DAYS} days)..."
find "${BACKUP_DIR}" -name "overseas_appointment_*.sql.gz" -type f -mtime +${RETENTION_DAYS} -delete

# List remaining backups
echo "[$(date)] Current backups:"
ls -lh "${BACKUP_DIR}"/*.sql.gz 2>/dev/null || echo "No backups found"

echo "[$(date)] Backup process completed."