#!/bin/bash
# =============================================================================
# IGNY8 Database Restore Script
# =============================================================================
# Usage: ./restore-db.sh <backup_file> [target_db]
# Restores database from a backup file (.sql or .sql.gz)
# =============================================================================

set -e

# Configuration
BACKUP_FILE="${1}"
TARGET_DB="${2:-igny8_db}"
DB_CONTAINER="postgres"
DB_USER="igny8"

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log() {
    echo -e "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
}

log_success() {
    log "${GREEN}✅ $1${NC}"
}

log_warn() {
    log "${YELLOW}⚠️  $1${NC}"
}

log_error() {
    log "${RED}❌ $1${NC}"
}

# Validate input
if [[ -z "${BACKUP_FILE}" ]]; then
    echo "Usage: ./restore-db.sh <backup_file> [target_db]"
    echo ""
    echo "Arguments:"
    echo "  backup_file  Path to backup file (.sql or .sql.gz)"
    echo "  target_db    Target database (default: igny8_db)"
    echo ""
    echo "Available backups:"
    ls -la /data/backups/latest_db.sql.gz 2>/dev/null || echo "  No latest backup found"
    echo ""
    find /data/backups -name "*.sql.gz" -type f 2>/dev/null | head -10
    exit 1
fi

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

echo "=========================================="
echo "IGNY8 Database Restore"
echo "=========================================="
echo ""
echo "Backup file: ${BACKUP_FILE}"
echo "Target DB:   ${TARGET_DB}"
echo ""

# Safety confirmation
log_warn "This will REPLACE the database '${TARGET_DB}' with backup data!"
read -p "Are you sure? Type 'yes' to continue: " confirm
if [[ "${confirm}" != "yes" ]]; then
    log "Restore cancelled"
    exit 0
fi

# Check if postgres container is running
if ! docker ps --format '{{.Names}}' | grep -q "^${DB_CONTAINER}$"; then
    log_error "PostgreSQL container '${DB_CONTAINER}' is not running"
    exit 1
fi

# Create pre-restore backup
log "Creating pre-restore backup of current database..."
PRE_RESTORE_BACKUP="/data/backups/pre-restore_${TARGET_DB}_$(date +%Y%m%d_%H%M%S).sql.gz"
if docker exec "${DB_CONTAINER}" pg_dump -U "${DB_USER}" "${TARGET_DB}" 2>/dev/null | gzip > "${PRE_RESTORE_BACKUP}"; then
    log_success "Pre-restore backup: ${PRE_RESTORE_BACKUP}"
else
    log_warn "Could not create pre-restore backup (database might not exist)"
fi

# Stop application containers to prevent connections
log "Stopping application containers..."
docker compose -f /data/app/igny8/docker-compose.app.yml -p igny8-app stop igny8_backend igny8_celery_worker igny8_celery_beat 2>/dev/null || true

# Drop and recreate database
log "Dropping existing database..."
docker exec "${DB_CONTAINER}" psql -U postgres -c "DROP DATABASE IF EXISTS ${TARGET_DB};" || true

log "Creating fresh database..."
docker exec "${DB_CONTAINER}" psql -U postgres -c "CREATE DATABASE ${TARGET_DB} OWNER ${DB_USER};"

# Restore from backup
log "Restoring database from backup..."
if [[ "${BACKUP_FILE}" == *.gz ]]; then
    # Compressed backup
    gunzip -c "${BACKUP_FILE}" | docker exec -i "${DB_CONTAINER}" psql -U "${DB_USER}" -d "${TARGET_DB}"
else
    # Uncompressed backup
    docker exec -i "${DB_CONTAINER}" psql -U "${DB_USER}" -d "${TARGET_DB}" < "${BACKUP_FILE}"
fi

if [[ $? -eq 0 ]]; then
    log_success "Database restore complete"
else
    log_error "Database restore failed"
    exit 1
fi

# Restart application containers
log "Restarting application containers..."
docker compose -f /data/app/igny8/docker-compose.app.yml -p igny8-app start igny8_backend igny8_celery_worker igny8_celery_beat 2>/dev/null || true

# Wait for backend to be healthy
log "Waiting for backend to be healthy..."
sleep 10

# Verify restoration
log "Verifying database..."
TABLE_COUNT=$(docker exec "${DB_CONTAINER}" psql -U "${DB_USER}" -d "${TARGET_DB}" -t -c "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'public';")
log_success "Database restored with ${TABLE_COUNT} tables"

echo ""
echo "=========================================="
echo "RESTORE COMPLETE"
echo "=========================================="
echo "Database '${TARGET_DB}' has been restored"
echo ""
echo "Pre-restore backup saved to:"
echo "  ${PRE_RESTORE_BACKUP}"
echo ""
echo "To rollback this restore, run:"
echo "  ./restore-db.sh ${PRE_RESTORE_BACKUP} ${TARGET_DB}"
echo "=========================================="