# Tenant Migration Implementation - Complete

## ✅ Implementation Summary

All tenant migration functionality has been successfully added to the backend. This implementation provides comprehensive tools for managing database schema changes across all tenants in the multi-tenant platform.

## 📁 Files Created

### Scripts Directory: `/root/neo/backend/scripts/`

1. **`migrate-tenant.ts`** (167 lines)
   - Migrates a single tenant by slug or ID
   - Handles password decryption
   - Provides detailed progress output
   - Usage: `npm run migrate:tenant <slug-or-id>`

2. **`migrate-all-tenants.ts`** (170 lines)
   - Migrates all active tenants in sequence
   - Collects success/failure statistics
   - Provides comprehensive summary
   - Exits with error code if any tenant fails
   - Usage: `npm run migrate:all-tenants`

3. **`check-migration-status.ts`** (181 lines)
   - Checks migration status across all tenants
   - Shows completed and pending migrations
   - Identifies which tenants need updates
   - Usage: `npm run migrate:status`

4. **`README.md`** (Comprehensive documentation)
   - Detailed usage instructions
   - Security notes on password encryption
   - Troubleshooting guide
   - Best practices
   - Example workflows

### Documentation Files

5. **`/root/neo/TENANT_MIGRATION_GUIDE.md`** (Root level guide)
   - Quick start guide
   - Architecture diagrams
   - Complete workflow examples
   - CI/CD integration examples
   - Security documentation

### Updated Files

6. **`/root/neo/backend/package.json`**
   - Added 6 new migration scripts to the `scripts` section

## 🚀 Available Commands

| Command | Description |
|---------|-------------|
| `npm run migrate:make <name>` | Create a new migration file in `migrations/tenant/` |
| `npm run migrate:status` | Check migration status for all tenants |
| `npm run migrate:tenant <slug>` | Run pending migrations for a specific tenant |
| `npm run migrate:all-tenants` | Run pending migrations for all active tenants |
| `npm run migrate:latest` | Run migrations on default database (rarely used) |
| `npm run migrate:rollback` | Rollback last migration on default database |

## 🔧 How It Works

### Architecture

```
┌─────────────────────────────────────────────────────────┐
│                    Central Database                      │
│                                                          │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐             │
│  │  Tenant  │  │  Tenant  │  │  Tenant  │             │
│  │    1     │  │    2     │  │    N     │             │
│  └──────────┘  └──────────┘  └──────────┘             │
│       │              │              │                   │
│       │ (encrypted   │              │                   │
│       │  password)   │              │                   │
└───────┼──────────────┼──────────────┼───────────────────┘
        │              │              │
        ▼              ▼              ▼
┌───────────┐  ┌───────────┐  ┌───────────┐
│  Tenant   │  │  Tenant   │  │  Tenant   │
│  DB 1     │  │  DB 2     │  │  DB N     │
│           │  │           │  │           │
│ Migrations│  │ Migrations│  │ Migrations│
│  Applied  │  │  Applied  │  │  Applied  │
└───────────┘  └───────────┘  └───────────┘
```

### Migration Flow

1. **Creating a Migration**
   ```bash
   npm run migrate:make add_custom_fields
   # Creates: migrations/tenant/20250127123456_add_custom_fields.js
   ```

2. **Testing on Single Tenant**
   ```bash
   npm run migrate:tenant acme-corp
   # Output:
   # 📋 Tenant: Acme Corp (acme-corp)
   # 📊 Database: acme_corp_db
   # 🔄 Running migrations...
   # ✅ Ran 1 migration(s):
   #    - 20250127123456_add_custom_fields.js
   ```

3. **Checking Status**
   ```bash
   npm run migrate:status
   # Shows which tenants have pending migrations
   ```

4. **Applying to All Tenants**
   ```bash
   npm run migrate:all-tenants
   # Migrates all active tenants sequentially
   # Provides summary of successes/failures
   ```

## 🔐 Security Features

### Password Encryption
- Tenant database passwords are encrypted using **AES-256-CBC**
- Stored encrypted in central database
- Automatically decrypted during migration
- Requires `DB_ENCRYPTION_KEY` environment variable

### Environment Setup
```bash
# Required for migration scripts
export DB_ENCRYPTION_KEY="your-32-character-secret-key!!"
```

This key must match the key used by `TenantService` for encryption/decryption.

## 📋 Example Workflows

### Scenario 1: Adding a Field to All Tenants

```bash
# 1. Create migration
npm run migrate:make add_priority_field

# 2. Edit the generated file
# migrations/tenant/20250127120000_add_priority_field.js

# 3. Test on one tenant
npm run migrate:tenant test-company

# 4. Check status
npm run migrate:status

# 5. Apply to all
npm run migrate:all-tenants
```

### Scenario 2: Checking Migration Status

```bash
npm run migrate:status

# Output:
# 📋 Found 3 active tenant(s)
# 
# 📦 Acme Corp (acme-corp)
#    Database: acme_corp_db
#    Completed: 5 migration(s)
#    ✅ Up to date
#
# 📦 TechStart (techstart)
#    Database: techstart_db
#    Completed: 4 migration(s)
#    ⚠️  Pending: 1 migration(s)
#       - 20250127120000_add_priority_field.js
#
# 💡 Run: npm run migrate:all-tenants
```

### Scenario 3: New Tenant Provisioning (Automatic)

When a new tenant is created via the API:
```typescript
// Happens automatically in TenantProvisioningService
POST /tenants
{
  "name": "New Company",
  "slug": "new-company"
}

// Backend automatically:
// 1. Creates database
// 2. Runs all migrations
// 3. Sets tenant status to ACTIVE
```

## 🛠️ Technical Implementation

### Script Structure

All scripts follow this pattern:

1. **Import Dependencies**
   ```typescript
   import { PrismaClient as CentralPrismaClient } from '../prisma/generated-central/client';
   import knex, { Knex } from 'knex';
   import { createDecipheriv } from 'crypto';
   ```

2. **Decrypt Password**
   ```typescript
   function decryptPassword(encryptedPassword: string): string {
     // AES-256-CBC decryption
   }
   ```

3. **Create Tenant Connection**
   ```typescript
   function createTenantKnexConnection(tenant: any): Knex {
     const decryptedPassword = decryptPassword(tenant.dbPassword);
     return knex({ /* config */ });
   }
   ```

4. **Run Migrations**
   ```typescript
   const [batchNo, log] = await tenantKnex.migrate.latest();
   ```

5. **Report Results**
   ```typescript
   console.log(`✅ Ran ${log.length} migrations`);
   ```

## 🧪 Testing the Implementation

### 1. Verify Scripts Are Available
```bash
cd /root/neo/backend
npm run | grep migrate
```

Expected output:
```
migrate:make
migrate:latest
migrate:rollback
migrate:status
migrate:tenant
migrate:all-tenants
```

### 2. Test Creating a Migration
```bash
npm run migrate:make test_migration
```

Should create a file in `migrations/tenant/`

### 3. Check Status (if tenants exist)
```bash
npm run migrate:status
```

### 4. Test Single Tenant Migration (if tenants exist)
```bash
npm run migrate:tenant <your-tenant-slug>
```

## 📚 Documentation Locations

- **Quick Reference**: `/root/neo/TENANT_MIGRATION_GUIDE.md`
- **Detailed Scripts Docs**: `/root/neo/backend/scripts/README.md`
- **Architecture Overview**: `/root/neo/MULTI_TENANT_IMPLEMENTATION.md`

## 🎯 Key Features

✅ **Single Tenant Migration** - Target specific tenants for testing
✅ **Bulk Migration** - Update all tenants at once
✅ **Status Checking** - See which tenants need updates
✅ **Progress Tracking** - Detailed output for each operation
✅ **Error Handling** - Graceful failure with detailed error messages
✅ **Security** - Encrypted password storage and decryption
✅ **Comprehensive Docs** - Multiple levels of documentation

## 🔄 Integration Points

### With Existing Code

1. **TenantProvisioningService**
   - Already uses `runTenantMigrations()` method
   - New scripts complement automatic provisioning
   - Same migration directory: `migrations/tenant/`

2. **Knex Configuration**
   - Uses existing `knexfile.js`
   - Same migration table: `knex_migrations`
   - Compatible with existing migrations

3. **Prisma Central Client**
   - Scripts use central DB to fetch tenant list
   - Same encryption/decryption logic as backend services

## 🚦 Next Steps

### To Use This Implementation:

1. **Ensure Environment Variables**
   ```bash
   export DB_ENCRYPTION_KEY="your-32-character-secret-key!!"
   ```

2. **Generate Prisma Client** (if not already done)
   ```bash
   cd /root/neo/backend
   npx prisma generate --schema=prisma/schema-central.prisma
   ```

3. **Check Current Status**
   ```bash
   npm run migrate:status
   ```

4. **Create Your First Migration**
   ```bash
   npm run migrate:make add_my_feature
   ```

5. **Test and Apply**
   ```bash
   # Test on one tenant
   npm run migrate:tenant <slug>
   
   # Apply to all
   npm run migrate:all-tenants
   ```

## 📊 Complete File List

```
/root/neo/
├── TENANT_MIGRATION_GUIDE.md          (new)
└── backend/
    ├── package.json                    (updated - 6 new scripts)
    ├── knexfile.js                     (existing)
    ├── migrations/
    │   └── tenant/                     (existing)
    │       ├── 20250126000001_create_users_and_rbac.js
    │       ├── 20250126000002_create_object_definitions.js
    │       ├── 20250126000003_create_apps.js
    │       ├── 20250126000004_create_standard_objects.js
    │       └── 20250126000005_add_ui_metadata_to_fields.js
    ├── scripts/                        (new directory)
    │   ├── README.md                   (new)
    │   ├── migrate-tenant.ts           (new)
    │   ├── migrate-all-tenants.ts      (new)
    │   └── check-migration-status.ts   (new)
    └── src/
        └── tenant/
            └── tenant-provisioning.service.ts (existing - uses migrations)
```

## ✨ Summary

The tenant migration system is now fully implemented with:
- ✅ 3 TypeScript migration scripts
- ✅ 6 npm commands
- ✅ 2 comprehensive documentation files
- ✅ Full integration with existing architecture
- ✅ Security features (password encryption)
- ✅ Error handling and progress reporting
- ✅ Status checking capabilities

You can now manage database migrations across all tenants efficiently and safely! 🎉