smartproxy/readme.hints.md

# SmartProxy Project Hints

## Project Overview
- Package: `@push.rocks/smartproxy` – high-performance proxy supporting HTTP(S), TCP, WebSocket, and ACME integration.
- Written in TypeScript, compiled output in `dist_ts/`, uses ESM with NodeNext resolution.

## Important: ACME Configuration in v19.0.0
- **Breaking Change**: ACME configuration must be placed within individual route TLS settings, not at the top level
- Route-level ACME config is the ONLY way to enable SmartAcme initialization
- SmartCertManager requires email in route config for certificate acquisition
- Top-level ACME configuration is ignored in v19.0.0

## Repository Structure
- `ts/` – TypeScript source files:
  - `index.ts` exports main modules.
  - `plugins.ts` centralizes native and third-party imports.
  - Subdirectories: `networkproxy/`, `nftablesproxy/`, `port80handler/`, `redirect/`, `smartproxy/`.
  - Key classes: `ProxyRouter` (`classes.router.ts`), `SmartProxy` (`classes.smartproxy.ts`), plus handlers/managers.
- `dist_ts/` – transpiled `.js` and `.d.ts` files mirroring `ts/` structure.
- `test/` – test suites in TypeScript:
  - `test.router.ts` – routing logic (hostname matching, wildcards, path parameters, config management).
  - `test.smartproxy.ts` – proxy behavior tests (TCP forwarding, SNI handling, concurrency, chaining, timeouts).
  - `test/helpers/` – utilities (e.g., certificates).
- `assets/certs/` – placeholder certificates for ACME and TLS.

## Development Setup
- Requires `pnpm` (v10+).
- Install dependencies: `pnpm install`.
- Build: `pnpm build` (runs `tsbuild --web --allowimplicitany`).
- Test: `pnpm test` (runs `tstest test/`).
- Format: `pnpm format` (runs `gitzone format`).

## Testing Framework
- Uses `@push.rocks/tapbundle` (`tap`, `expect`, `expactAsync`).
- Test files: must start with `test.` and use `.ts` extension.
- Run specific tests via `tsx`, e.g., `tsx test/test.router.ts`.

## Coding Conventions
- Import modules via `plugins.ts`:
  ```ts
  import * as plugins from './plugins.ts';
  const server = new plugins.http.Server();
  ```
- Reference plugins with full path: `plugins.acme`, `plugins.smartdelay`, `plugins.minimatch`, etc.
- Path patterns support globs (`*`) and parameters (`:param`) in `ProxyRouter`.
- Wildcard hostname matching leverages `minimatch` patterns.

## Key Components
- **ProxyRouter**
  - Methods: `routeReq`, `routeReqWithDetails`.
  - Hostname matching: case-insensitive, strips port, supports exact, wildcard, TLD, complex patterns.
  - Path routing: exact, wildcard, parameter extraction (`pathParams`), returns `pathMatch` and `pathRemainder`.
  - Config API: `setNewProxyConfigs`, `addProxyConfig`, `removeProxyConfig`, `getHostnames`, `getProxyConfigs`.
- **SmartProxy**
  - Manages one or more `net.Server` instances to forward TCP streams.
  - Options: `preserveSourceIP`, `defaultAllowedIPs`, `globalPortRanges`, `sniEnabled`.
  - DomainConfigManager: round-robin selection for multiple target IPs.
  - Graceful shutdown in `stop()`, ensures no lingering servers or sockets.

## Notable Points
- **TSConfig**: `module: NodeNext`, `verbatimModuleSyntax`, allows `.js` extension imports in TS.
- Mermaid diagrams and architecture flows in `readme.md` illustrate component interactions and protocol flows.
- CLI entrypoint (`cli.js`) supports command-line usage (ACME, proxy controls).
- ACME and certificate handling via `Port80Handler` and `helpers.certificates.ts`.

## ACME/Certificate Configuration Example (v19.0.0)
```typescript
const proxy = new SmartProxy({
  routes: [{
    name: 'example.com',
    match: { domains: 'example.com', ports: 443 },
    action: {
      type: 'forward',
      target: { host: 'localhost', port: 8080 },
      tls: {
        mode: 'terminate',
        certificate: 'auto',
        acme: {  // ACME config MUST be here, not at top level
          email: 'ssl@example.com',
          useProduction: false,
          challengePort: 80
        }
      }
    }
  }]
});
```

## TODOs / Considerations
- Ensure import extensions in source match build outputs (`.ts` vs `.js`).
- Update `plugins.ts` when adding new dependencies.
- Maintain test coverage for new routing or proxy features.
- Keep `ts/` and `dist_ts/` in sync after refactors.
- Consider implementing top-level ACME config support for backward compatibility

## HTTP-01 ACME Challenge Fix (v19.3.8)

### Issue
Non-TLS connections on ports configured in `useHttpProxy` were not being forwarded to HttpProxy. This caused ACME HTTP-01 challenges to fail when the ACME port (usually 80) was included in `useHttpProxy`.

### Root Cause
In the `RouteConnectionHandler.handleForwardAction` method, only connections with TLS settings (mode: 'terminate' or 'terminate-and-reencrypt') were being forwarded to HttpProxy. Non-TLS connections were always handled as direct connections, even when the port was configured for HttpProxy.

### Solution
Added a check for non-TLS connections on ports listed in `useHttpProxy`:
```typescript
// No TLS settings - check if this port should use HttpProxy
const isHttpProxyPort = this.settings.useHttpProxy?.includes(record.localPort);

if (isHttpProxyPort && this.httpProxyBridge.getHttpProxy()) {
  // Forward non-TLS connections to HttpProxy if configured
  this.httpProxyBridge.forwardToHttpProxy(/*...*/);
  return;
}
```

### Test Coverage
- `test/test.http-fix-unit.ts` - Unit tests verifying the fix
- Tests confirm that non-TLS connections on HttpProxy ports are properly forwarded
- Tests verify that non-HttpProxy ports still use direct connections

### Configuration Example
```typescript
const proxy = new SmartProxy({
  useHttpProxy: [80], // Enable HttpProxy for port 80
  httpProxyPort: 8443,
  acme: {
    email: 'ssl@example.com',
    port: 80
  },
  routes: [
    // Your routes here
  ]
});
```

## ACME Certificate Provisioning Timing Fix (v19.3.9)

### Issue
Certificate provisioning would start before ports were listening, causing ACME HTTP-01 challenges to fail with connection refused errors.

### Root Cause
SmartProxy initialization sequence:
1. Certificate manager initialized → immediately starts provisioning
2. Ports start listening (too late for ACME challenges)

### Solution
Deferred certificate provisioning until after ports are ready:
```typescript
// SmartCertManager.initialize() now skips automatic provisioning
// SmartProxy.start() calls provisionAllCertificates() directly after ports are listening
```

### Test Coverage
- `test/test.acme-timing-simple.ts` - Verifies proper timing sequence

### Migration
Update to v19.3.9+, no configuration changes needed.

## Socket Handler Race Condition Fix (v19.5.0)

### Issue
Initial data chunks were being emitted before async socket handlers had completed setup, causing data loss when handlers performed async operations before setting up data listeners.

### Root Cause
The `handleSocketHandlerAction` method was using `process.nextTick` to emit initial chunks regardless of whether the handler was sync or async. This created a race condition where async handlers might not have their listeners ready when the initial data was emitted.

### Solution
Differentiated between sync and async handlers:
```typescript
const result = route.action.socketHandler(socket);

if (result instanceof Promise) {
  // Async handler - wait for completion before emitting initial data
  result.then(() => {
    if (initialChunk && initialChunk.length > 0) {
      socket.emit('data', initialChunk);
    }
  }).catch(/*...*/);
} else {
  // Sync handler - use process.nextTick as before
  if (initialChunk && initialChunk.length > 0) {
    process.nextTick(() => {
      socket.emit('data', initialChunk);
    });
  }
}
```

### Test Coverage
- `test/test.socket-handler-race.ts` - Specifically tests async handlers with delayed listener setup
- Verifies that initial data is received even when handler sets up listeners after async work

### Usage Note
Socket handlers require initial data from the client to trigger routing (not just a TLS handshake). Clients must send at least one byte of data for the handler to be invoked.