# Multi-OIDC Provider Implementation Status

**Branch:** `multi-login`  
**Date:** 2024  
**Status:** ✅ Backend Complete - Frontend In Progress

---

## Overview

This document tracks the implementation status of multiple OIDC provider support in API Explorer II, enabling users to choose from different identity providers (OBP-OIDC, Keycloak, Google, GitHub, etc.) at login time.

---

## Implementation Summary

### ✅ Completed (Backend)

#### 1. Type Definitions
- [x] **`server/types/oauth2.ts`**
  - `WellKnownUri` - Provider information from OBP API
  - `WellKnownResponse` - Response from `/obp/v5.1.0/well-known`
  - `ProviderStrategy` - Provider configuration
  - `ProviderStatus` - Provider health information
  - `OIDCConfiguration` - OpenID Connect discovery
  - `TokenResponse` - OAuth2 token response
  - `UserInfo` - OIDC UserInfo endpoint response

#### 2. Core Services
- [x] **`server/services/OAuth2ClientWithConfig.ts`**
  - Extends arctic `OAuth2Client` with OIDC discovery
  - Stores provider name and OIDC configuration
  - Methods:
    - `initOIDCConfig()` - Fetch and validate OIDC discovery document
    - `getAuthorizationEndpoint()` - Get auth endpoint from config
    - `getTokenEndpoint()` - Get token endpoint from config
    - `getUserInfoEndpoint()` - Get userinfo endpoint from config
    - `exchangeAuthorizationCode()` - Token exchange with PKCE
    - `refreshTokens()` - Refresh access token
    - `isInitialized()` - Check if config loaded

- [x] **`server/services/OAuth2ProviderFactory.ts`**
  - Strategy pattern for provider configurations
  - Loads strategies from environment variables
  - Supported providers:
    - OBP-OIDC (`VITE_OBP_OAUTH2_*`)
    - Keycloak (`VITE_KEYCLOAK_*`)
    - Google (`VITE_GOOGLE_*`)
    - GitHub (`VITE_GITHUB_*`)
    - Custom OIDC (`VITE_CUSTOM_OIDC_*`)
  - Methods:
    - `initializeProvider()` - Create and initialize OAuth2 client
    - `getConfiguredProviders()` - List available strategies
    - `hasStrategy()` - Check if provider configured

- [x] **`server/services/OAuth2ProviderManager.ts`**
  - Manages multiple OAuth2 providers
  - Fetches well-known URIs from OBP API
  - Tracks provider health status
  - Performs periodic health checks (60s intervals)
  - Methods:
    - `fetchWellKnownUris()` - Get providers from OBP API
    - `initializeProviders()` - Initialize all providers
    - `getProvider()` - Get OAuth2 client by name
    - `getAvailableProviders()` - List healthy providers
    - `getAllProviderStatus()` - Get status for all providers
    - `startHealthCheck()` - Start monitoring
    - `stopHealthCheck()` - Stop monitoring
    - `retryProvider()` - Retry failed provider

#### 3. Controllers
- [x] **`server/controllers/OAuth2ProvidersController.ts`**
  - New endpoint: `GET /api/oauth2/providers`
  - Returns list of available providers with status
  - Used by frontend for provider selection UI

- [x] **`server/controllers/OAuth2ConnectController.ts`** (Updated)
  - Updated: `GET /api/oauth2/connect?provider=<name>&redirect=<url>`
  - Supports both multi-provider and legacy single-provider mode
  - Multi-provider: Uses provider from query parameter
  - Legacy: Falls back to existing OAuth2Service
  - Generates PKCE parameters (code_verifier, code_challenge, state)
  - Stores provider name in session
  - Redirects to provider's authorization endpoint

- [x] **`server/controllers/OAuth2CallbackController.ts`** (Updated)
  - Updated: `GET /api/oauth2/callback?code=<code>&state=<state>`
  - Retrieves provider from session
  - Uses correct OAuth2 client for token exchange
  - Validates state (CSRF protection)
  - Exchanges authorization code for tokens
  - Fetches user info from provider
  - Stores tokens and user data in session
  - Supports both multi-provider and legacy modes

#### 4. Server Initialization
- [x] **`server/app.ts`** (Updated)
  - Initialize `OAuth2ProviderManager` on startup
  - Fetch providers from OBP API
  - Start health monitoring (60s intervals)
  - Register `OAuth2ProvidersController`
  - Maintain backward compatibility with legacy OAuth2Service

---

### 🚧 In Progress (Frontend)

#### 5. Frontend Components
- [ ] **`src/components/HeaderNav.vue`** (To be updated)
  - Fetch available providers on mount
  - Display provider selection UI
  - Handle login with selected provider
  - Show provider availability status

- [ ] **`src/components/ProviderSelector.vue`** (To be created)
  - Modal/dropdown for provider selection
  - Display provider names and status
  - Trigger login with selected provider
  - Responsive design

---

### 📋 Not Started

#### 6. Testing
- [ ] Unit tests for `OAuth2ClientWithConfig`
- [ ] Unit tests for `OAuth2ProviderFactory`
- [ ] Unit tests for `OAuth2ProviderManager`
- [ ] Integration tests for multi-provider flow
- [ ] E2E tests for login flow

#### 7. Documentation
- [ ] Update README.md with multi-provider setup
- [ ] Update OAUTH2-README.md
- [ ] Create migration guide
- [ ] Update deployment documentation

---

## Architecture

### Data Flow

```
1. Server Startup
   ├─> OAuth2ProviderManager.initializeProviders()
   ├─> Fetch well-known URIs from OBP API (/obp/v5.1.0/well-known)
   ├─> For each provider:
   │   ├─> OAuth2ProviderFactory.initializeProvider()
   │   ├─> Create OAuth2ClientWithConfig
   │   ├─> Fetch .well-known/openid-configuration
   │   └─> Store in providers Map
   └─> Start health monitoring (60s intervals)

2. User Login Flow
   ├─> Frontend: Fetch available providers (GET /api/oauth2/providers)
   ├─> User selects provider (e.g., "obp-oidc")
   ├─> Redirect: /api/oauth2/connect?provider=obp-oidc&redirect=/resource-docs
   ├─> OAuth2ConnectController:
   │   ├─> Get OAuth2Client for selected provider
   │   ├─> Generate PKCE (code_verifier, code_challenge, state)
   │   ├─> Store in session (provider, code_verifier, state)
   │   └─> Redirect to provider's authorization endpoint
   ├─> User authenticates on OIDC provider
   ├─> Callback: /api/oauth2/callback?code=xxx&state=yyy
   └─> OAuth2CallbackController:
       ├─> Retrieve provider from session
       ├─> Get OAuth2Client for provider
       ├─> Validate state (CSRF protection)
       ├─> Exchange code for tokens (with PKCE)
       ├─> Fetch user info
       ├─> Store tokens and user in session
       └─> Redirect to original page

3. Health Monitoring
   └─> Every 60 seconds:
       ├─> For each provider:
       │   ├─> HEAD request to issuer endpoint
       │   └─> Update provider status (available/unavailable)
       └─> Frontend can query status via /api/oauth2/providers
```

---

## Configuration

### Environment Variables

```bash
# OBP-OIDC Provider (Required for OBP-OIDC)
VITE_OBP_OAUTH2_CLIENT_ID=48ac28e9-9ee3-47fd-8448-69a62764b779
VITE_OBP_OAUTH2_CLIENT_SECRET=fOTQF7jfg8C74u7ZhSjVQpoBYvD0KpWfM5UsEZBSFFM
VITE_OBP_OAUTH2_REDIRECT_URL=http://localhost:5173/api/oauth2/callback

# Keycloak Provider (Optional)
VITE_KEYCLOAK_CLIENT_ID=obp-api-explorer
VITE_KEYCLOAK_CLIENT_SECRET=your-keycloak-secret
VITE_KEYCLOAK_REDIRECT_URL=http://localhost:5173/api/oauth2/callback

# Google Provider (Optional)
# VITE_GOOGLE_CLIENT_ID=your-google-client-id
# VITE_GOOGLE_CLIENT_SECRET=your-google-client-secret
# VITE_GOOGLE_REDIRECT_URL=http://localhost:5173/api/oauth2/callback

# GitHub Provider (Optional)
# VITE_GITHUB_CLIENT_ID=your-github-client-id
# VITE_GITHUB_CLIENT_SECRET=your-github-client-secret
# VITE_GITHUB_REDIRECT_URL=http://localhost:5173/api/oauth2/callback

# Custom OIDC Provider (Optional)
# VITE_CUSTOM_OIDC_PROVIDER_NAME=my-provider
# VITE_CUSTOM_OIDC_CLIENT_ID=your-client-id
# VITE_CUSTOM_OIDC_CLIENT_SECRET=your-client-secret
# VITE_CUSTOM_OIDC_REDIRECT_URL=http://localhost:5173/api/oauth2/callback

# Legacy Single-Provider Mode (Backward Compatibility)
# VITE_OBP_OAUTH2_WELL_KNOWN_URL=http://127.0.0.1:9000/obp-oidc/.well-known/openid-configuration
```

### OBP API Configuration

The multi-provider system fetches available providers from:
```
GET /obp/v5.1.0/well-known
```

**Expected Response:**
```json
{
  "well_known_uris": [
    {
      "provider": "obp-oidc",
      "url": "http://127.0.0.1:9000/obp-oidc/.well-known/openid-configuration"
    },
    {
      "provider": "keycloak",
      "url": "http://127.0.0.1:8180/realms/obp/.well-known/openid-configuration"
    }
  ]
}
```

---

## Endpoints

### New Endpoints

| Method | Path | Description |
|--------|------|-------------|
| GET | `/api/oauth2/providers` | List available OIDC providers with status |

### Updated Endpoints

| Method | Path | Query Parameters | Description |
|--------|------|------------------|-------------|
| GET | `/api/oauth2/connect` | `provider` (optional), `redirect` (optional) | Initiate OAuth2 flow with selected provider |
| GET | `/api/oauth2/callback` | `code`, `state`, `error` (optional) | Handle OAuth2 callback from any provider |

---

## Session Data

### Login Initiation
```javascript
session = {
  oauth2_provider: "obp-oidc",           // Provider name
  oauth2_code_verifier: "...",           // PKCE code verifier
  oauth2_state: "...",                   // CSRF state token
  oauth2_redirect_page: "/resource-docs" // Redirect after auth
}
```

### After Token Exchange
```javascript
session = {
  oauth2_provider: "obp-oidc",      // Provider used
  oauth2_access_token: "...",       // Access token
  oauth2_refresh_token: "...",      // Refresh token
  oauth2_id_token: "...",           // ID token (JWT)
  user: {
    username: "john.doe",
    email: "john@example.com",
    name: "John Doe",
    provider: "obp-oidc",
    sub: "uuid-1234"
  }
}
```

---

## Backward Compatibility

The implementation maintains full backward compatibility with the existing single-provider OAuth2 system:

1. **Legacy Environment Variable**: `VITE_OBP_OAUTH2_WELL_KNOWN_URL` still works
2. **Fallback Behavior**: If no provider parameter is specified, falls back to legacy OAuth2Service
3. **No Breaking Changes**: Existing deployments continue to work without changes
4. **Gradual Migration**: Can enable multi-provider incrementally

---

## Benefits

1. ✅ **User Choice** - Users select their preferred identity provider
2. ✅ **Dynamic Discovery** - Providers discovered from OBP API automatically
3. ✅ **Health Monitoring** - Real-time provider availability tracking
4. ✅ **Extensibility** - Add new providers via environment variables only
5. ✅ **Resilience** - Fallback to available providers if one fails
6. ✅ **Backward Compatible** - No breaking changes for existing deployments

---

## Next Steps

### Priority 1: Frontend Implementation
1. Update `HeaderNav.vue` to fetch and display available providers
2. Create `ProviderSelector.vue` component for provider selection
3. Test login flow with multiple providers
4. Handle error states gracefully

### Priority 2: Testing
1. Write unit tests for all new services
2. Create integration tests for multi-provider flow
3. Add E2E tests for login scenarios

### Priority 3: Documentation
1. Update README.md with setup instructions
2. Document environment variables for each provider
3. Create migration guide from single to multi-provider
4. Update deployment documentation

---

## Known Issues

- None currently identified

---

## References

- **Implementation Guide**: `MULTI-OIDC-PROVIDER-IMPLEMENTATION.md`
- **Executive Summary**: `MULTI-OIDC-PROVIDER-SUMMARY.md`
- **Flow Diagrams**: `MULTI-OIDC-FLOW-DIAGRAM.md`
- **OBP-Portal Reference**: `~/Documents/workspace_2024/OBP-Portal`
- **Branch**: `multi-login`

---

## Commits

1. `3dadca8` - Add multi-OIDC provider backend services
2. `8b90bb4` - Add multi-OIDC provider controllers and update app initialization
3. `755dc70` - Fix TypeScript compilation errors in multi-provider implementation

---

**Last Updated**: 2024  
**Status**: Backend implementation complete ✅