Add JWT auth, token service & Neutrino endpoint

API/Controllers/Neutrino/NeutrinoController.cs

@@ -0,0 +1,82 @@
+using System.Security.Claims;
+using System.Text.Json;
+using API.Contracts.Neutrino.Enums;
+using API.Contracts.Neutrino.Requests;
+using API.Contracts.Neutrino.Responses;
+using Microsoft.AspNetCore.Mvc;
+using RecNet.Domain.Repositories;
+using RecNet.Domain.Services.Tokens;
+
+namespace API.Controllers.Neutrino;
+
+[Route("[controller]")]
+[ApiController]
+public class NeutrinoController(
+    IProfileRepository profileRepository,
+    ITokenService tokenService) : ControllerBase
+{
+    // This route will be kind of abysmal so bare with it.
+    [Route("authorize")]
+    public async Task<ActionResult<NeutrinoAuthenticateResponse>> AuthorizeNeutrinoAsync()
+    {
+        // Photon sends the request with Content-Type: text/plain instead of application/json
+        // This is a really janky workaround since we can't use [FromBody] to automatically parse the data.
+        using var reader = new StreamReader(Request.Body);
+        string rawText = await reader.ReadToEndAsync();
+
+        NeutrinoAuthenticateRequest? request;
+
+        try
+        {
+            request = JsonSerializer.Deserialize<NeutrinoAuthenticateRequest>(rawText, new JsonSerializerOptions
+            {
+                IncludeFields = true,
+                PropertyNameCaseInsensitive = true
+            });
+        }
+        catch
+        {
+            return Ok(
+                NeutrinoAuthenticateResponse.Failure(
+                    AuthenticationResultCode.InvalidParameters));
+        }
+
+        // 1. Check if request parameters aren't empty
+        if (request is null ||
+            request.ProfileId == Guid.Empty ||
+            string.IsNullOrWhiteSpace(request.AccessToken))
+            return Ok(
+                NeutrinoAuthenticateResponse.Failure(
+                    AuthenticationResultCode.InvalidParameters));
+
+        // 2. Verify accessToken is valid
+        var tokenVerifyResult = tokenService.VerifyToken(request.AccessToken);
+        if (tokenVerifyResult.IsError || !TryGetProfileId(tokenVerifyResult.Claims, out var tokenAccountId))
+            return Ok(
+                NeutrinoAuthenticateResponse.Failure(
+                    AuthenticationResultCode.AuthenticationFailedWrongCredentials));
+
+        // 3. Verify that the accountId from the request matches the one from the token
+        if (tokenAccountId != request.ProfileId)
+            return Ok(
+                NeutrinoAuthenticateResponse.Failure(
+                    AuthenticationResultCode.AuthenticationFailedWrongCredentials));
+
+        // 4. Get the profile to check if it exists, and for the name
+        var profile = await profileRepository.GetByIdAsync(request.ProfileId);
+        if (profile is null)
+            return Ok(
+                NeutrinoAuthenticateResponse.Failure(
+                    AuthenticationResultCode.AuthenticationFailedWrongCredentials));
+
+        return Ok(
+            NeutrinoAuthenticateResponse.Success(
+                userId: request.ProfileId.ToString(),
+                nickname: profile.Name
+            )
+        );
+    }
+
+    private static bool TryGetProfileId(IEnumerable<Claim> claims, out Guid accountId)
+        => Guid.TryParse(claims.FirstOrDefault(c => c.Type == "sub")?.Value, out accountId);
+}