#!/bin/bash
# Automated database backup script
# Supports full and incremental backups

set -e

BACKUP_DIR="${BACKUP_DIR:-/backups}"
DB_NAME="${DB_NAME:-theorder}"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
BACKUP_TYPE="${1:-full}" # full or incremental

echo "📦 Starting database backup (type: $BACKUP_TYPE)..."

mkdir -p "$BACKUP_DIR"

if [ "$BACKUP_TYPE" = "full" ]; then
  BACKUP_FILE="$BACKUP_DIR/full_backup_${TIMESTAMP}.sql.gz"
  echo "Creating full backup..."
  pg_dump "$DATABASE_URL" | gzip > "$BACKUP_FILE"
  echo "✅ Full backup created: $BACKUP_FILE"
  
  # Keep only last 7 full backups
  ls -t "$BACKUP_DIR"/full_backup_*.sql.gz | tail -n +8 | xargs rm -f || true
elif [ "$BACKUP_TYPE" = "incremental" ]; then
  BACKUP_FILE="$BACKUP_DIR/incremental_backup_${TIMESTAMP}.sql.gz"
  echo "Creating incremental backup..."
  # For PostgreSQL, we use WAL archiving for true incremental backups
  # This is a simplified version using pg_dump with --data-only
  pg_dump "$DATABASE_URL" --data-only | gzip > "$BACKUP_FILE"
  echo "✅ Incremental backup created: $BACKUP_FILE"
  
  # Keep only last 24 incremental backups
  ls -t "$BACKUP_DIR"/incremental_backup_*.sql.gz | tail -n +25 | xargs rm -f || true
fi

# Upload to cloud storage if configured
if [ -n "$BACKUP_STORAGE_BUCKET" ]; then
  echo "Uploading backup to cloud storage..."
  if command -v aws &> /dev/null; then
    aws s3 cp "$BACKUP_FILE" "s3://$BACKUP_STORAGE_BUCKET/$(basename $BACKUP_FILE)" || true
  elif command -v az &> /dev/null; then
    az storage blob upload --file "$BACKUP_FILE" --container-name backups --name "$(basename $BACKUP_FILE)" --account-name "$AZURE_STORAGE_ACCOUNT" || true
  fi
fi

echo "✅ Backup complete!"