#!/bin/sh
set -e

# Configuration
BACKUP_DIR="/backups"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
BACKUP_FILE="${BACKUP_DIR}/postgres_${POSTGRES_DB}_${TIMESTAMP}.sql.gz"
RETENTION_DAYS=${BACKUP_RETENTION_DAYS:-7}

echo "======================================"
echo "PostgreSQL Backup - $(date)"
echo "======================================"

# Wait for PostgreSQL to be ready
until PGPASSWORD="${POSTGRES_PASSWORD}" pg_isready -h "${POSTGRES_HOST}" -U "${POSTGRES_USER}" -d "${POSTGRES_DB}"; do
  echo "⏳ Waiting for PostgreSQL..."
  sleep 5
done

echo "✅ PostgreSQL is ready"

# Create backup
echo "📦 Creating backup: ${BACKUP_FILE}"
PGPASSWORD="${POSTGRES_PASSWORD}" pg_dump \
  -h "${POSTGRES_HOST}" \
  -U "${POSTGRES_USER}" \
  -d "${POSTGRES_DB}" \
  --clean \
  --if-exists \
  --create \
  --no-owner \
  --no-privileges \
  | gzip > "${BACKUP_FILE}"

# Verify backup was created
if [ -f "${BACKUP_FILE}" ]; then
  BACKUP_SIZE=$(du -h "${BACKUP_FILE}" | cut -f1)
  echo "✅ Backup created successfully: ${BACKUP_SIZE}"
else
  echo "❌ Backup failed!"
  exit 1
fi

# Cleanup old backups
echo "🗑️  Cleaning up backups older than ${RETENTION_DAYS} days..."
find "${BACKUP_DIR}" -name "postgres_*.sql.gz" -type f -mtime +${RETENTION_DAYS} -delete

# List current backups
echo ""
echo "📊 Current backups:"
ls -lh "${BACKUP_DIR}"/postgres_*.sql.gz 2>/dev/null || echo "No backups found"

echo ""
echo "✅ Backup completed successfully"
echo "======================================"