#!/usr/bin/env bash
set -euo pipefail

# AgentHub Postgres Restore Script
# Restores a pg_dump backup file to a Postgres database
#
# Usage:
#   ./restore.sh <backup-file> [target-database]
#
# Examples:
#   # Restore to default database (from env or 'agenthub')
#   ./restore.sh /backups/agenthub_20260430_030000.dump
#
#   # Restore to specific database
#   ./restore.sh /backups/agenthub_20260430_030000.dump agenthub_restore_test
#
# Environment variables:
#   PGHOST, PGPORT, PGUSER, PGPASSWORD - Postgres connection params
#   SKIP_CONFIRMATION - Set to 'yes' to skip interactive confirmation

BACKUP_FILE="${1:-}"
TARGET_DB="${2:-${PGDATABASE:-agenthub}}"

if [[ -z "${BACKUP_FILE}" ]]; then
  echo "Usage: $0 <backup-file> [target-database]"
  echo ""
  echo "Example:"
  echo "  $0 /backups/agenthub_20260430_030000.dump"
  exit 1
fi

if [[ ! -f "${BACKUP_FILE}" ]]; then
  echo "ERROR: Backup file not found: ${BACKUP_FILE}"
  exit 1
fi

# Postgres connection from env
PGHOST="${PGHOST:-localhost}"
PGPORT="${PGPORT:-5432}"
PGUSER="${PGUSER:-agenthub}"

echo "========================================="
echo "AgentHub Database Restore"
echo "========================================="
echo "Backup file:     ${BACKUP_FILE}"
echo "Target database: ${TARGET_DB}"
echo "Host:            ${PGHOST}:${PGPORT}"
echo "User:            ${PGUSER}"
echo "========================================="
echo ""

# Get backup file info
BACKUP_SIZE=$(stat -f%z "${BACKUP_FILE}" 2>/dev/null || stat -c%s "${BACKUP_FILE}")
echo "Backup size: $((BACKUP_SIZE / 1024 / 1024)) MB"

# Confirm before proceeding
if [[ "${SKIP_CONFIRMATION:-}" != "yes" ]]; then
  echo ""
  echo "WARNING: This will DROP and recreate the target database."
  echo "All existing data in '${TARGET_DB}' will be LOST."
  echo ""
  read -p "Continue? (yes/no): " CONFIRM
  if [[ "${CONFIRM}" != "yes" ]]; then
    echo "Restore cancelled."
    exit 0
  fi
fi

echo ""
echo "[$(date -Iseconds)] Starting restore..."

# Drop and recreate database
echo "[$(date -Iseconds)] Dropping and recreating database '${TARGET_DB}'"
psql -h "${PGHOST}" -p "${PGPORT}" -U "${PGUSER}" -d postgres <<SQL
DROP DATABASE IF EXISTS ${TARGET_DB};
CREATE DATABASE ${TARGET_DB} OWNER ${PGUSER};
SQL

# Restore from backup
echo "[$(date -Iseconds)] Restoring from backup file"
pg_restore -h "${PGHOST}" -p "${PGPORT}" -U "${PGUSER}" -d "${TARGET_DB}" \
  --verbose \
  --no-owner \
  --no-acl \
  "${BACKUP_FILE}"

echo "[$(date -Iseconds)] Restore completed"

# Verify restoration
echo ""
echo "[$(date -Iseconds)] Verifying restore..."
TABLE_COUNT=$(psql -h "${PGHOST}" -p "${PGPORT}" -U "${PGUSER}" -d "${TARGET_DB}" -t -c "
  SELECT COUNT(*) FROM information_schema.tables
  WHERE table_schema = 'public' AND table_type = 'BASE TABLE';
")

echo "Tables restored: ${TABLE_COUNT}"

if [[ "${TABLE_COUNT}" -lt 1 ]]; then
  echo "WARNING: No tables found in restored database"
  exit 1
fi

echo ""
echo "========================================="
echo "Restore successful!"
echo "========================================="
echo "Database '${TARGET_DB}' has been restored from:"
echo "  ${BACKUP_FILE}"
echo ""
echo "Next steps:"
echo "  - Verify data integrity"
echo "  - Run application smoke tests"
echo "  - If restoring to production, update connection strings"