feature/PATRO23-133 - User context provider

src/modules/example/api/Controllers/ExampleController.cs

@@ -18,6 +18,7 @@ namespace Intive.Patronage2023.Modules.Example.Api.Controllers;
 [Route("[controller]")]
 public class ExampleController : ControllerBase
 {
+	private readonly IExecutionContextAccessor contextAccessor;
 	private readonly ICommandBus commandBus;
 	private readonly IQueryBus queryBus;
 	private readonly IValidator<CreateExample> createExampleValidator;
@@ -30,12 +31,14 @@ public class ExampleController : ControllerBase
 	/// <param name="queryBus">Query bus.</param>
 	/// <param name="createExampleValidator">Create example validator.</param>
 	/// <param name="getExamplesValidator">Get examples validator.</param>
-	public ExampleController(ICommandBus commandBus, IQueryBus queryBus, IValidator<CreateExample> createExampleValidator, IValidator<GetExamples> getExamplesValidator)
+	/// <param name="contextAccessor">Execution context accessor.</param>
+	public ExampleController(ICommandBus commandBus, IQueryBus queryBus, IValidator<CreateExample> createExampleValidator, IValidator<GetExamples> getExamplesValidator, IExecutionContextAccessor contextAccessor)
 	{
 		this.createExampleValidator = createExampleValidator;
 		this.getExamplesValidator = getExamplesValidator;
 		this.commandBus = commandBus;
 		this.queryBus = queryBus;
+		this.contextAccessor = contextAccessor;
 	}
 
 	/// <summary>
@@ -94,4 +97,24 @@ public async Task<IActionResult> CreateExample([FromBody] CreateExample request)
 
 		throw new AppException("One or more error occured when trying to create example.", validationResult.Errors);
 	}
+
+	/// <summary>
+	/// Get user guid.
+	/// </summary>
+	/// <returns>User guid or null.</returns>
+	/// <response code="200">Returns current user guid.</response>
+	/// <response code="401">If the user is unauthorized or token is invalid.</response>
+	[HttpGet("/UserGuid")]
+	[ProducesResponseType(typeof(Guid?), StatusCodes.Status200OK)]
+	[ProducesResponseType(StatusCodes.Status401Unauthorized)]
+	public IActionResult GetUserId()
+	{
+		var userId = this.contextAccessor.GetUserId(this.HttpContext);
+		if (userId == null)
+		{
+			return this.Unauthorized();
+		}
+
+		return this.Ok(userId);
+	}
 }

src/modules/example/api/ExampleModule.cs

@@ -6,7 +6,7 @@
 using Intive.Patronage2023.Modules.Example.Infrastructure.Data;
 using Intive.Patronage2023.Modules.Example.Infrastructure.Domain;
 using Intive.Patronage2023.Shared.Abstractions;
-
+using Intive.Patronage2023.Shared.Infrastructure;
 using Microsoft.EntityFrameworkCore;
 
 namespace Intive.Patronage2023.Modules.Example.Api;
@@ -26,6 +26,7 @@ public static IServiceCollection AddExampleModule(this IServiceCollection servic
 	{
 		services.AddDbContext<ExampleDbContext>(options => options.UseSqlServer(configurationManager.GetConnectionString("AppDb")));
 
+		services.AddScoped<IExecutionContextAccessor, ExecutionContextAccessor>();
 		services.AddScoped<IExampleRepository, ExampleRepository>();
 		services.AddScoped<IValidator<CreateExample>, CreateExampleValidator>();
 		services.AddScoped<IValidator<GetExamples>, GetExamplesValidator>();

src/shared/abstractions/IExecutionContextAccessor.cs

@@ -0,0 +1,16 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Intive.Patronage2023.Shared.Abstractions;
+
+/// <summary>
+/// Interface to retrive user id from HttpContext.
+/// </summary>
+public interface IExecutionContextAccessor
+{
+	/// <summary>
+	/// Returns user id extraced from token.
+	/// </summary>
+	/// <param name="httpContext">Context to retrive token from.</param>
+	/// <returns>User id or null if token/claim does not exits.</returns>
+	Guid? GetUserId(HttpContext httpContext);
+}

src/shared/infrastructure/ExecutionContextAccessor.cs

@@ -0,0 +1,34 @@
+using System.IdentityModel.Tokens.Jwt;
+using Intive.Patronage2023.Shared.Abstractions;
+using Microsoft.AspNetCore.Http;
+
+namespace Intive.Patronage2023.Shared.Infrastructure;
+
+/// <summary>
+/// Implementation of IExecutionContextAccessor.
+/// </summary>
+public class ExecutionContextAccessor : IExecutionContextAccessor
+{
+	/// <inheritdoc />
+	public Guid? GetUserId(HttpContext httpContext)
+	{
+		string? jwtToken = httpContext.Request.Headers["Authorization"].FirstOrDefault()?.Split(" ").Last();
+		if (jwtToken == null)
+		{
+			// User is not authenticated
+			return null;
+		}
+
+		var tokenHandler = new JwtSecurityTokenHandler();
+		var token = tokenHandler.ReadJwtToken(jwtToken);
+
+		if (token == null || token.Claims.All(c => c.Type != "sub"))
+		{
+			// JWT token is invalid
+			return null;
+		}
+
+		var userId = Guid.Parse(token.Claims.First(c => c.Type == "sub").Value);
+		return userId;
+	}
+}