feat(backend): start authentication controllers

Foxnouns.Backend/Controllers/Authentication/AuthController.cs

@@ -0,0 +1,38 @@
+using System.Web;
+using Foxnouns.Backend.Services;
+using Microsoft.AspNetCore.Mvc;
+using NodaTime;
+
+namespace Foxnouns.Backend.Controllers.Authentication;
+
+[Route("/api/v2/auth")]
+public class AuthController(Config config, KeyCacheService keyCacheSvc) : ApiControllerBase
+{   
+    [HttpPost("urls")]
+    [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(UrlsResponse))]
+    public async Task<IActionResult> UrlsAsync()
+    {
+        var state = HttpUtility.UrlEncode(await keyCacheSvc.GenerateAuthStateAsync());
+        string? discord = null;
+        if (config.DiscordAuth.ClientId != null && config.DiscordAuth.ClientSecret != null)
+            discord =
+                $"https://discord.com/oauth2/authorize?response_type=code" +
+                $"&client_id={config.DiscordAuth.ClientId}&scope=identify" +
+                $"&prompt=none&state={state}" +
+                $"&redirect_uri={HttpUtility.UrlEncode($"{config.BaseUrl}/auth/login/discord")}";
+
+        return Ok(new UrlsResponse(discord, null, null));
+    }
+
+    private record UrlsResponse(
+        string? Discord,
+        string? Google,
+        string? Tumblr
+    );
+
+    internal record AuthResponse(
+        UserRendererService.UserResponse User,
+        string Token,
+        Instant ExpiresAt
+    );
+}

Foxnouns.Backend/Controllers/Authentication/DiscordAuthController.cs

@@ -6,9 +6,11 @@ namespace Foxnouns.Backend.Controllers.Authentication;
 [Route("/api/v2/auth/discord")]
 public class DiscordAuthController(Config config, DatabaseContext db) : ApiControllerBase
 {
-    [HttpPost("url")]
-    public async Task<IActionResult> AuthenticationUrl()
+    private void CheckRequirements()
     {
-        throw new NotImplementedException();
+        if (config.DiscordAuth.ClientId == null || config.DiscordAuth.ClientSecret == null)
+        {
+            throw new ApiError.BadRequest("Discord authentication is not enabled on this instance.");
+        }
     }
 }

Foxnouns.Backend/Controllers/Authentication/EmailAuthController.cs

@@ -0,0 +1,31 @@
+using Foxnouns.Backend.Database;
+using Foxnouns.Backend.Services;
+using Microsoft.AspNetCore.Mvc;
+using NodaTime;
+
+namespace Foxnouns.Backend.Controllers.Authentication;
+
+[Route("/api/v2/auth/email")]
+public class EmailAuthController(DatabaseContext db, AuthService authSvc, UserRendererService userRendererSvc, IClock clock, ILogger logger) : ApiControllerBase
+{
+    [HttpPost("login")]
+    public async Task<IActionResult> LoginAsync([FromBody] LoginRequest req)
+    {
+        var user = await authSvc.AuthenticateUserAsync(req.Email, req.Password);
+        var frontendApp = await db.GetFrontendApplicationAsync();
+        
+        var (tokenStr, token) =
+            authSvc.GenerateToken(user, frontendApp, ["*"], clock.GetCurrentInstant() + Duration.FromDays(365));
+        db.Add(token);
+
+        await db.SaveChangesAsync();
+
+        return Ok(new AuthController.AuthResponse(
+            await userRendererSvc.RenderUserAsync(user, selfUser: user, renderMembers: false),
+            tokenStr,
+            token.ExpiresAt
+        ));
+    }
+
+    public record LoginRequest(string Email, string Password);
+}