# Task 10: Add OAuth Client Management

## Task Description

**Files:**
- Create: `src/Fengling.AuthService/Models/OAuthApplication.cs`
- Create: `src/Fengling.AuthService/Controllers/OAuthClientsController.cs`
- Modify: `src/Fengling.AuthService/Data/ApplicationDbContext.cs`

## Implementation Steps

### Step 1: Create OAuthApplication model

Create: `src/Fengling.AuthService/Models/OAuthApplication.cs`

```csharp
namespace Fengling.AuthService.Models;

public class OAuthApplication
{
    public long Id { get; set; }
    public string ClientId { get; set; } = string.Empty;
    public string? ClientSecret { get; set; }
    public string DisplayName { get; set; } = string.Empty;
    public string[] RedirectUris { get; set; } = Array.Empty<string>();
    public string[] PostLogoutRedirectUris { get; set; } = Array.Empty<string>();
    public string[] Scopes { get; set; } = Array.Empty<string>();
    public string[] GrantTypes { get; set; } = Array.Empty<string>();
    public string ClientType { get; set; } = "public";
    public string ConsentType { get; set; } = "implicit";
    public string Status { get; set; } = "active";
    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
    public DateTime? UpdatedAt { get; set; }
}
```

### Step 2: Update ApplicationDbContext

Edit: `src/Fengling.AuthService/Data/ApplicationDbContext.cs`

Add to context:
```csharp
public DbSet<OAuthApplication> OAuthApplications { get; set; }
```

Add to OnModelCreating:
```csharp
builder.Entity<OAuthApplication>(entity =>
{
    entity.HasKey(e => e.Id);
    entity.HasIndex(e => e.ClientId).IsUnique();
    entity.Property(e => e.ClientId).HasMaxLength(100);
    entity.Property(e => e.ClientSecret).HasMaxLength(200);
    entity.Property(e => e.DisplayName).HasMaxLength(100);
    entity.Property(e => e.ClientType).HasMaxLength(20);
    entity.Property(e => e.ConsentType).HasMaxLength(20);
    entity.Property(e => e.Status).HasMaxLength(20);
});
```

### Step 3: Add migration

Run:
```bash
dotnet ef migrations add AddOAuthApplications
dotnet ef database update
```

### Step 4: Create OAuthClientsController

Create: `src/Fengling.AuthService/Controllers/OAuthClientsController.cs`

```csharp
using Fengling.AuthService.Data;
using Fengling.AuthService.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace Fengling.AuthService.Controllers;

[ApiController]
[Route("api/[controller]")]
public class OAuthClientsController : ControllerBase
{
    private readonly ApplicationDbContext _context;
    private readonly ILogger<OAuthClientsController> _logger;

    public OAuthClientsController(
        ApplicationDbContext context,
        ILogger<OAuthClientsController> logger)
    {
        _context = context;
        _logger = logger;
    }

    [HttpGet]
    public async Task<ActionResult<IEnumerable<OAuthApplication>>> GetClients()
    {
        return await _context.OAuthApplications.ToListAsync();
    }

    [HttpGet("{id}")]
    public async Task<ActionResult<OAuthApplication>> GetClient(long id)
    {
        var client = await _context.OAuthApplications.FindAsync(id);
        if (client == null)
        {
            return NotFound();
        }
        return client;
    }

    [HttpPost]
    public async Task<ActionResult<OAuthApplication>> CreateClient(OAuthApplication application)
    {
        _context.OAuthApplications.Add(application);
        await _context.SaveChangesAsync();
        return CreatedAtAction(nameof(GetClient), new { id = application.Id }, application);
    }

    [HttpPut("{id}")]
    public async Task<IActionResult> UpdateClient(long id, OAuthApplication application)
    {
        if (id != application.Id)
        {
            return BadRequest();
        }

        _context.Entry(application).State = EntityState.Modified;
        await _context.SaveChangesAsync();
        return NoContent();
    }

    [HttpDelete("{id}")]
    public async Task<IActionResult> DeleteClient(long id)
    {
        var client = await _context.OAuthApplications.FindAsync(id);
        if (client == null)
        {
            return NotFound();
        }

        _context.OAuthApplications.Remove(client);
        await _context.SaveChangesAsync();
        return NoContent();
    }
}
```

### Step 5: Commit

```bash
git add src/Fengling.AuthService/Models/ src/Fengling.AuthService/Controllers/ src/Fengling.AuthService/Data/
git commit -m "feat(auth): add OAuth client management API"
```

## Context

This task adds OAuth client management functionality for managing OAuth applications. This will be used by Fengling.Console to register and manage clients.

**Tech Stack**: EF Core, ASP.NET Core Controllers

## Verification

- [ ] OAuthApplication model created
- [ ] DbSet added to ApplicationDbContext
- [ ] Migration generated and applied
- [ ] CRUD API endpoints created
- [ ] Build succeeds
- [ ] Committed to git

## Notes

- Clients can be registered through this API
- Fengling.Console will be pre-registered in Task 11
- Status field enables client enable/disable