Add implementation status document

- Document completed backend implementation
- List remaining frontend and testing tasks
- Include architecture diagrams and data flow
- Document configuration and endpoints
- Track session data structure
- Note backward compatibility approach

Author: simonredfern

MULTI-OIDC-IMPLEMENTATION-STATUS.md

@@ -0,0 +1,361 @@
+# 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 ✅