#!/bin/bash
# SEAMLESS MIGRATION STRATEGY
# Zero-Downtime Service Migration to Docker Swarm

set -e

echo "🎯 SEAMLESS MIGRATION STRATEGY - ZERO DOWNTIME"
echo "=============================================="

# Phase 1: Parallel Deployment (Zero Downtime)
echo ""
echo "📋 PHASE 1: PARALLEL DEPLOYMENT"
echo "-------------------------------"

echo "1. Deploy services to Docker Swarm alongside existing services"
echo "   - Keep existing services running"
echo "   - Deploy new services with different ports"
echo "   - Test new services thoroughly"

echo ""
echo "2. Update Caddyfile with new service endpoints"
echo "   - Add new service routes"
echo "   - Keep old routes as fallback"
echo "   - Test both old and new endpoints"

echo ""
echo "3. Gradual traffic migration"
echo "   - Start with low-traffic services"
echo "   - Monitor performance and stability"
echo "   - Gradually shift traffic to new services"

# Phase 2: Service Cutover (Minimal Downtime)
echo ""
echo "📋 PHASE 2: SERVICE CUTOVER"
echo "---------------------------"

echo "1. Update Caddyfile to point to new services"
echo "   - Change IP addresses to swarm endpoints"
echo "   - Reload Caddy configuration"
echo "   - Verify all services accessible"

echo ""
echo "2. Stop old services"
echo "   - Stop individual Docker containers"
echo "   - Stop native services"
echo "   - Verify no data loss"

# Phase 3: Validation & Cleanup
echo ""
echo "📋 PHASE 3: VALIDATION & CLEANUP"
echo "--------------------------------"

echo "1. Comprehensive testing"
echo "   - Test all service functionality"
echo "   - Verify data integrity"
echo "   - Check performance metrics"

echo ""
echo "2. Cleanup old infrastructure"
echo "   - Remove old containers"
echo "   - Clean up old configurations"
echo "   - Update documentation"

echo ""
echo "✅ MIGRATION COMPLETE - ALL SERVICES SEAMLESSLY MIGRATED"