# Quick Start Guide

Get your application integrated with this OIDC provider in 10 minutes.

---

## For the Impatient

```bash
# 1. Get credentials from admin panel
https://your-idp.com/admin/login

# 2. Add to your app (Python example)
pip install authlib flask

# 3. Copy this code
# (see Python example below)

# 4. Done! Users can now log in via OIDC
```

---

## Prerequisites

- ✅ OIDC Provider deployed and accessible
- ✅ Admin access to register your client
- ✅ A web application with a backend (Node.js, Python, PHP, etc.)

---

## Step 1: Register Your Application (2 minutes)

### Via Admin Panel

1. **Navigate** to: `https://your-idp.com/admin/login`
2. **Login** with admin credentials
3. **Go to** "Clients" → "Create New Client"
4. **Fill in**:
   - Client Name: `My App`
   - Redirect URIs: `http://localhost:3000/callback` (one per line)
   - Allowed Scopes: `openid, profile, email`
5. **Click** "Create"
6. **Copy** your credentials:
   ```
   Client ID: abc123def456
   Client Secret: xyz789... (⚠️ save this - shown only once!)
   ```

---

## Step 2: Choose Your Integration Method (1 minute)

Pick the method that matches your tech stack:

| If you use... | Go to |
|---------------|-------|
| Python + Flask | [Python Example](#python-flask) |
| Node.js + Express | [Node.js Example](#nodejs-express) |
| PHP + Laravel | [PHP Example](#php-laravel) |
| Any other | [Generic HTTP Flow](#generic-http-flow) |

---

## Python (Flask)

### Install Dependencies

```bash
pip install flask authlib requests
```

### Code (`app.py`)

```python
from flask import Flask, redirect, url_for, session, jsonify
from authlib.integrations.flask_client import OAuth
import os

app = Flask(__name__)
app.secret_key = os.urandom(24)

# Configure OIDC
oauth = OAuth(app)
oauth.register(
    name='myidp',
    client_id='YOUR_CLIENT_ID',
    client_secret='YOUR_CLIENT_SECRET',
    server_metadata_url='https://your-idp.com/.well-known/openid-configuration',
    client_kwargs={'scope': 'openid profile email'}
)

@app.route('/')
def index():
    user = session.get('user')
    if user:
        return jsonify(user)
    return '<a href="/login">Login with OIDC</a>'

@app.route('/login')
def login():
    redirect_uri = url_for('callback', _external=True)
    return oauth.myidp.authorize_redirect(redirect_uri)

@app.route('/callback')
def callback():
    token = oauth.myidp.authorize_access_token()
    session['user'] = token['userinfo']
    return redirect('/')

@app.route('/logout')
def logout():
    session.pop('user', None)
    return redirect('/')

if __name__ == '__main__':
    app.run(port=3000, debug=True)
```

### Run

```bash
python app.py
# Open http://localhost:3000
```

---

## Node.js (Express)

### Install Dependencies

```bash
npm install express express-session passport openid-client
```

### Code (`server.js`)

```javascript
const express = require('express');
const session = require('express-session');
const passport = require('passport');
const { Issuer, Strategy } = require('openid-client');

const app = express();

app.use(session({
  secret: 'keyboard cat',
  resave: false,
  saveUninitialized: true
}));

app.use(passport.initialize());
app.use(passport.session());

passport.serializeUser((user, done) => done(null, user));
passport.deserializeUser((user, done) => done(null, user));

// Discover and configure OIDC
Issuer.discover('https://your-idp.com/.well-known/openid-configuration')
  .then(issuer => {
    const client = new issuer.Client({
      client_id: 'YOUR_CLIENT_ID',
      client_secret: 'YOUR_CLIENT_SECRET',
      redirect_uris: ['http://localhost:3000/callback'],
      response_types: ['code'],
    });

    passport.use('oidc', new Strategy({ client }, (tokenSet, userinfo, done) => {
      return done(null, userinfo);
    }));

    // Routes
    app.get('/', (req, res) => {
      if (req.isAuthenticated()) {
        res.send(`<h1>Hello, ${req.user.name}!</h1><a href="/logout">Logout</a>`);
      } else {
        res.send('<a href="/login">Login with OIDC</a>');
      }
    });

    app.get('/login', passport.authenticate('oidc'));

    app.get('/callback',
      passport.authenticate('oidc', { failureRedirect: '/' }),
      (req, res) => res.redirect('/')
    );

    app.get('/logout', (req, res) => {
      req.logout(() => res.redirect('/'));
    });

    app.listen(3000, () => console.log('App running on http://localhost:3000'));
  });
```

### Run

```bash
node server.js
# Open http://localhost:3000
```

---

## PHP (Laravel)

### Install Socialite

```bash
composer require laravel/socialite
composer require socialiteproviders/oidc
```

### Configure (`config/services.php`)

```php
'oidc' => [
    'client_id' => env('OIDC_CLIENT_ID'),
    'client_secret' => env('OIDC_CLIENT_SECRET'),
    'redirect' => env('OIDC_REDIRECT_URI'),
    'base_url' => env('OIDC_ISSUER'),
],
```

### Environment (`.env`)

```bash
OIDC_CLIENT_ID=YOUR_CLIENT_ID
OIDC_CLIENT_SECRET=YOUR_CLIENT_SECRET
OIDC_REDIRECT_URI=http://localhost:8000/callback
OIDC_ISSUER=https://your-idp.com
```

### Routes (`routes/web.php`)

```php
use Laravel\Socialite\Facades\Socialite;
use Illuminate\Support\Facades\Auth;

Route::get('/login', function () {
    return Socialite::driver('oidc')->redirect();
});

Route::get('/callback', function () {
    $user = Socialite::driver('oidc')->user();

    // Find or create user in database
    $localUser = User::updateOrCreate(
        ['email' => $user->email],
        ['name' => $user->name]
    );

    Auth::login($localUser);

    return redirect('/dashboard');
});

Route::get('/logout', function () {
    Auth::logout();
    return redirect('/');
});
```

### Run

```bash
php artisan serve
# Open http://localhost:8000
```

---

## Generic HTTP Flow

If you can't use a library, here's the manual flow:

### Step 1: Redirect to Authorization Endpoint

```http
GET https://your-idp.com/authorize?
  client_id=YOUR_CLIENT_ID&
  redirect_uri=http://localhost:3000/callback&
  response_type=code&
  scope=openid%20profile%20email&
  state=RANDOM_STATE_TOKEN
```

### Step 2: Handle Callback

User is redirected back with a code:
```
http://localhost:3000/callback?code=ABC123&state=RANDOM_STATE_TOKEN
```

**Verify state token** to prevent CSRF!

### Step 3: Exchange Code for Token

```bash
curl -X POST https://your-idp.com/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=authorization_code" \
  -d "code=ABC123" \
  -d "redirect_uri=http://localhost:3000/callback" \
  -d "client_id=YOUR_CLIENT_ID" \
  -d "client_secret=YOUR_CLIENT_SECRET"
```

**Response:**
```json
{
  "access_token": "eyJhbGci...",
  "id_token": "eyJhbGci...",
  "token_type": "Bearer",
  "expires_in": 3600
}
```

### Step 4: Get User Info

```bash
curl https://your-idp.com/userinfo \
  -H "Authorization: Bearer ACCESS_TOKEN"
```

**Response:**
```json
{
  "sub": "user-123",
  "email": "john@example.com",
  "name": "John Doe",
  "preferred_username": "john"
}
```

---

## Testing Your Integration

### 1. Start Your App

```bash
# Your app should now be running on localhost
```

### 2. Click "Login"

Navigate to your app's login link. You should be redirected to:
```
https://your-idp.com/authorize?client_id=...
```

### 3. Login

Use test credentials:
```
Username: test
Password: test123
```

### 4. Verify

After login, you should:
- ✅ Be redirected back to your app
- ✅ See user information
- ✅ Have an active session

---

## Common Issues

### "Invalid Redirect URI"

**Problem**: Redirect URI doesn't match.

**Fix**:
1. Check exact match (including trailing slash)
2. Update in admin panel if needed

### "Invalid Client"

**Problem**: Wrong client ID or secret.

**Fix**:
1. Double-check credentials
2. No extra spaces or line breaks

### "Connection Refused"

**Problem**: OIDC provider not accessible.

**Fix**:
1. Verify provider is running: `curl https://your-idp.com/health`
2. Check network/firewall

### CORS Errors (for SPAs)

**Problem**: Browser blocks cross-origin requests.

**Solution**: Don't call OIDC endpoints from frontend. Use a backend proxy.

---

## Next Steps

Once basic login works:

1. **Add User Persistence**: Store user in your database
2. **Handle Logout**: Clear session and optionally redirect to IdP logout
3. **Refresh Tokens**: Implement token refresh (when available)
4. **Error Handling**: Add proper error pages
5. **Production Setup**: Use HTTPS, secure cookies

---

## Complete Examples

Check out complete example applications:

- **Python Flask**: `examples/python-flask/` (coming soon)
- **Node.js Express**: `examples/nodejs-express/` (coming soon)
- **PHP Laravel**: `examples/php-laravel/` (coming soon)

---

## Need Help?

- 📖 [Full API Guide](API_GUIDE.md)
- 🏗️ [Architecture](ARCHITECTURE.md)
- 🚀 [Deployment](deployment.md)
- 🐛 Report issues on GitHub

---

**You're all set!** 🎉

Your users can now log in via OIDC in just a few clicks.