network/docs/ARCHITECTURE.md

# Orama Network Architecture

## Overview

Orama Network is a high-performance API Gateway and Reverse Proxy designed for a decentralized ecosystem. It serves as a unified entry point that orchestrates traffic between clients and various backend services.

## Architecture Pattern

**Modular Gateway / Edge Proxy Architecture**

The system follows a clean, layered architecture with clear separation of concerns:

```
┌─────────────────────────────────────────────────────────────┐
│                        Clients                               │
│              (Web, Mobile, CLI, SDKs)                        │
└────────────────────────┬────────────────────────────────────┘
                         │
                         │ HTTPS/WSS
                         ▼
┌─────────────────────────────────────────────────────────────┐
│                   API Gateway (Port 443)                     │
│  ┌──────────────────────────────────────────────────────┐   │
│  │  Handlers Layer (HTTP/WebSocket)                     │   │
│  │  - Auth handlers    - Storage handlers               │   │
│  │  - Cache handlers   - PubSub handlers                │   │
│  │  - Serverless       - Database handlers              │   │
│  └──────────────────────┬───────────────────────────────┘   │
│                         │                                    │
│  ┌──────────────────────▼───────────────────────────────┐   │
│  │  Middleware (Security, Auth, Logging)                │   │
│  └──────────────────────┬───────────────────────────────┘   │
│                         │                                    │
│  ┌──────────────────────▼───────────────────────────────┐   │
│  │  Service Coordination (Gateway Core)                 │   │
│  └──────────────────────┬───────────────────────────────┘   │
└─────────────────────────┼────────────────────────────────────┘
                          │
        ┌─────────────────┼─────────────────┐
        │                 │                 │
        ▼                 ▼                 ▼
┌──────────────┐  ┌──────────────┐  ┌──────────────┐
│   RQLite     │  │    Olric     │  │     IPFS     │
│  (Database)  │  │   (Cache)    │  │  (Storage)   │
│              │  │              │  │              │
│  Port 5001   │  │  Port 3320   │  │  Port 4501   │
└──────────────┘  └──────────────┘  └──────────────┘

        ┌─────────────────┐         ┌──────────────┐
        │  IPFS Cluster   │         │  Serverless  │
        │   (Pinning)     │         │    (WASM)    │
        │                 │         │              │
        │  Port 9094      │         │   In-Process │
        └─────────────────┘         └──────────────┘
```

## Core Components

### 1. API Gateway (`pkg/gateway/`)

The gateway is the main entry point for all client requests. It coordinates between various backend services.

**Key Files:**
- `gateway.go` - Core gateway struct and routing
- `dependencies.go` - Service initialization and dependency injection
- `lifecycle.go` - Start/stop/health lifecycle management
- `middleware.go` - Authentication, logging, error handling
- `routes.go` - HTTP route registration

**Handler Packages:**
- `handlers/auth/` - Authentication (JWT, API keys, wallet signatures)
- `handlers/storage/` - IPFS storage operations
- `handlers/cache/` - Distributed cache operations
- `handlers/pubsub/` - Pub/sub messaging
- `handlers/serverless/` - Serverless function deployment and execution

### 2. Client SDK (`pkg/client/`)

Provides a clean Go SDK for interacting with the Orama Network.

**Architecture:**
```go
// Main client interface
type NetworkClient interface {
    Storage() StorageClient
    Cache() CacheClient
    Database() DatabaseClient
    PubSub() PubSubClient
    Serverless() ServerlessClient
    Auth() AuthClient
}
```

**Key Files:**
- `client.go` - Main client orchestration
- `config.go` - Client configuration
- `storage_client.go` - IPFS storage client
- `cache_client.go` - Olric cache client
- `database_client.go` - RQLite database client
- `pubsub_bridge.go` - Pub/sub messaging client
- `transport.go` - HTTP transport layer
- `errors.go` - Client-specific errors

**Usage Example:**
```go
import "github.com/DeBrosOfficial/network/pkg/client"

// Create client
cfg := client.DefaultClientConfig()
cfg.GatewayURL = "https://api.orama.network"
cfg.APIKey = "your-api-key"

c := client.NewNetworkClient(cfg)

// Use storage
resp, err := c.Storage().Upload(ctx, data, "file.txt")

// Use cache
err = c.Cache().Set(ctx, "key", value, 0)

// Query database
rows, err := c.Database().Query(ctx, "SELECT * FROM users")

// Publish message
err = c.PubSub().Publish(ctx, "chat", []byte("hello"))

// Deploy function
fn, err := c.Serverless().Deploy(ctx, def, wasmBytes)

// Invoke function
result, err := c.Serverless().Invoke(ctx, "function-name", input)
```

### 3. Database Layer (`pkg/rqlite/`)

ORM-like interface over RQLite distributed SQL database.

**Key Files:**
- `client.go` - Main ORM client
- `orm_types.go` - Interfaces (Client, Tx, Repository[T])
- `query_builder.go` - Fluent query builder
- `repository.go` - Generic repository pattern
- `scanner.go` - Reflection-based row scanning
- `transaction.go` - Transaction support

**Features:**
- Fluent query builder
- Generic repository pattern with type safety
- Automatic struct mapping
- Transaction support
- Connection pooling with retry

**Example:**
```go
// Query builder
users, err := client.CreateQueryBuilder("users").
    Select("id", "name", "email").
    Where("age > ?", 18).
    OrderBy("name ASC").
    Limit(10).
    GetMany(ctx, &users)

// Repository pattern
type User struct {
    ID    int    `db:"id"`
    Name  string `db:"name"`
    Email string `db:"email"`
}

repo := client.Repository("users")
user := &User{Name: "Alice", Email: "alice@example.com"}
err := repo.Save(ctx, user)
```

### 4. Serverless Engine (`pkg/serverless/`)

WebAssembly (WASM) function execution engine with host functions.

**Architecture:**
```
pkg/serverless/
├── engine.go              - Core WASM engine
├── execution/             - Function execution
│   ├── executor.go
│   └── lifecycle.go
├── cache/                 - Module caching
│   └── module_cache.go
├── registry/              - Function metadata
│   ├── registry.go
│   ├── function_store.go
│   ├── ipfs_store.go
│   └── invocation_logger.go
└── hostfunctions/         - Host functions by domain
    ├── cache.go           - Cache operations
    ├── storage.go         - Storage operations
    ├── database.go        - Database queries
    ├── pubsub.go          - Messaging
    ├── http.go            - HTTP requests
    └── logging.go         - Logging
```

**Features:**
- Secure WASM execution sandbox
- Memory and CPU limits
- Host function injection (cache, storage, DB, HTTP)
- Function versioning
- Invocation logging
- Hot module reloading

### 5. Configuration System (`pkg/config/`)

Domain-specific configuration with validation.

**Structure:**
```
pkg/config/
├── config.go              - Main config aggregator
├── loader.go              - YAML loading
├── node_config.go         - Node settings
├── database_config.go     - Database settings
├── gateway_config.go      - Gateway settings
└── validate/              - Validation
    ├── validators.go
    ├── node.go
    ├── database.go
    └── gateway.go
```

### 6. Shared Utilities

**HTTP Utilities (`pkg/httputil/`):**
- Request parsing and validation
- JSON response writers
- Error handling
- Authentication extraction

**Error Handling (`pkg/errors/`):**
- Typed errors (ValidationError, NotFoundError, etc.)
- HTTP status code mapping
- Error wrapping with context
- Stack traces

**Contracts (`pkg/contracts/`):**
- Interface definitions for all services
- Enables dependency injection
- Clean abstractions

## Data Flow

### 1. HTTP Request Flow

```
Client Request
    ↓
[HTTPS Termination]
    ↓
[Authentication Middleware]
    ↓
[Route Handler]
    ↓
[Service Layer]
    ↓
[Backend Service] (RQLite/Olric/IPFS)
    ↓
[Response Formatting]
    ↓
Client Response
```

### 2. WebSocket Flow (Pub/Sub)

```
Client WebSocket Connect
    ↓
[Upgrade to WebSocket]
    ↓
[Authentication]
    ↓
[Subscribe to Topic]
    ↓
[LibP2P PubSub] ←→ [Local Subscribers]
    ↓
[Message Broadcasting]
    ↓
Client Receives Messages
```

### 3. Serverless Invocation Flow

```
Function Deployment:
    Upload WASM → Store in IPFS → Save Metadata (RQLite) → Compile Module

Function Invocation:
    Request → Load Metadata → Get WASM from IPFS →
    Execute in Sandbox → Return Result → Log Invocation
```

## Security Architecture

### Authentication Methods

1. **Wallet Signatures** (Ethereum-style)
   - Challenge/response flow
   - Nonce-based to prevent replay attacks
   - Issues JWT tokens after verification

2. **API Keys**
   - Long-lived credentials
   - Stored in RQLite
   - Namespace-scoped

3. **JWT Tokens**
   - Short-lived (15 min default)
   - Refresh token support
   - Claims-based authorization

### TLS/HTTPS

- Automatic ACME (Let's Encrypt) certificate management
- TLS 1.3 support
- HTTP/2 enabled
- Certificate caching

### Middleware Stack

1. **Logger** - Request/response logging
2. **CORS** - Cross-origin resource sharing
3. **Authentication** - JWT/API key validation
4. **Authorization** - Namespace access control
5. **Rate Limiting** - Per-client rate limits
6. **Error Handling** - Consistent error responses

## Scalability

### Horizontal Scaling

- **Gateway:** Stateless, can run multiple instances behind load balancer
- **RQLite:** Multi-node cluster with Raft consensus
- **IPFS:** Distributed storage across nodes
- **Olric:** Distributed cache with consistent hashing

### Caching Strategy

1. **WASM Module Cache** - Compiled modules cached in memory
2. **Olric Distributed Cache** - Shared cache across nodes
3. **Local Cache** - Per-gateway request caching

### High Availability

- **Database:** RQLite cluster with automatic leader election
- **Storage:** IPFS replication factor configurable
- **Cache:** Olric replication and eventual consistency
- **Gateway:** Stateless, multiple replicas supported

## Monitoring & Observability

### Health Checks

- `/health` - Liveness probe
- `/v1/status` - Detailed status with service checks

### Metrics

- Prometheus-compatible metrics endpoint
- Request counts, latencies, error rates
- Service-specific metrics (cache hit ratio, DB query times)

### Logging

- Structured logging (JSON format)
- Log levels: DEBUG, INFO, WARN, ERROR
- Correlation IDs for request tracing

## Development Patterns

### SOLID Principles

- **Single Responsibility:** Each handler/service has one focus
- **Open/Closed:** Interface-based design for extensibility
- **Liskov Substitution:** All implementations conform to contracts
- **Interface Segregation:** Small, focused interfaces
- **Dependency Inversion:** Depend on abstractions, not implementations

### Code Organization

- **Average file size:** ~150 lines
- **Package structure:** Domain-driven, feature-focused
- **Testing:** Unit tests for logic, E2E tests for integration
- **Documentation:** Godoc comments on all public APIs

## Deployment

### Development

```bash
make dev       # Start 5-node cluster
make stop      # Stop all services
make test      # Run unit tests
make test-e2e  # Run E2E tests
```

### Production

```bash
# First node (creates cluster)
sudo orama install --vps-ip <IP> --domain node1.example.com

# Additional nodes (join cluster)
sudo orama install --vps-ip <IP> --domain node2.example.com \
    --peers /dns4/node1.example.com/tcp/4001/p2p/<PEER_ID> \
    --join <node1-ip>:7002 \
    --cluster-secret <secret> \
    --swarm-key <key>
```

### Docker (Future)

Planned containerization with Docker Compose and Kubernetes support.

## Future Enhancements

1. **GraphQL Support** - GraphQL gateway alongside REST
2. **gRPC Support** - gRPC protocol support
3. **Event Sourcing** - Event-driven architecture
4. **Kubernetes Operator** - Native K8s deployment
5. **Observability** - OpenTelemetry integration
6. **Multi-tenancy** - Enhanced namespace isolation

## Resources

- [RQLite Documentation](https://rqlite.io/docs/)
- [IPFS Documentation](https://docs.ipfs.tech/)
- [LibP2P Documentation](https://docs.libp2p.io/)
- [WebAssembly (WASM)](https://webassembly.org/)