Add plagiarism detection for contest submissions

src/CodeClash.API/Controllers/Contests/ContestController.cs

@@ -3,6 +3,7 @@
 using CodeClash.Application.Contests.GetAllContests;
 using CodeClash.Application.Contests.GetContest;
 using CodeClash.Application.Contests.RegisterInContest;
+using CodeClash.Application.Plagiarism.GetContestPlagiarismCases;
 using CodeClash.Domain.Premitives.Responses;
 using MediatR;
 using Microsoft.AspNetCore.Authorization;
@@ -36,15 +37,15 @@ public async Task<IActionResult> GetAllContests(
         var result = await sender.Send(new GetAllContestsQuery(), cancellationToken);
 
         return result.IsSuccess
-            ? Ok(result.Value)
+            ? Ok(result)
             : BadRequest(result.Error);
     }
 
 
     [Authorize]
     [HttpPost]
     public async Task<IActionResult> CreateContest(
-    CreateContestCommand command,
+    [FromBody] CreateContestCommand command,
     CancellationToken cancellationToken)
     {
         var result = await sender.Send(command, cancellationToken);
@@ -69,11 +70,11 @@ public async Task<IActionResult> RegisterInContest(
             : BadRequest(result);
     }
 
-    [HttpPost("{contestId:guid}/problems/{problemId:guid}")]
     [Authorize]
+    [HttpPost("{contestId:guid}/problems/{problemId:guid}")]
     public async Task<IActionResult> AddProblem(
-        Guid contestId,
-        Guid problemId,
+        [FromRoute] Guid contestId,
+        [FromRoute] Guid problemId,
         CancellationToken cancellationToken)
     {
         var result = await sender.Send(
@@ -97,4 +98,22 @@ public async Task<IActionResult> AddProblem(
             _ => BadRequest(result)
         };
     }
+
+    [Authorize]
+    [HttpGet("{contestId:guid}/plagiarisms")]
+    [ProducesResponseType(typeof(GetContestPlagiarismCasesResponse), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> GetPlagiarismCases(
+    [FromRoute] Guid contestId,
+    [FromQuery] decimal threshold,
+    [FromQuery] List<Guid> problemIds,
+    CancellationToken cancellationToken)
+    {
+        var query = new GetContestPlagiarismCasesQuery(contestId, threshold, problemIds);
+        var result = await sender.Send(query, cancellationToken);
+
+        return result.IsSuccess
+            ? Ok(result)
+            : NotFound(result);
+    }
 }

src/CodeClash.API/Controllers/Plagiarisms/PlagiarismController.cs

@@ -0,0 +1,19 @@
+using CodeClash.Application.Abstractions.Plagiarism;
+using CodeClash.Domain.Requests;
+using Microsoft.AspNetCore.Mvc;
+
+namespace CodeClash.API.Controllers.Plagiarisms;
+
+[ApiController]
+[Route("plagiarisms")]
+public sealed class PlagiarismController(
+    IPlagiarismService plagiarismService) : ControllerBase
+{
+    [HttpPost("similarity")]
+    [ProducesResponseType(typeof(CodeSimilarityRequest), StatusCodes.Status200OK)]
+    public IActionResult GetSimilarity([FromBody] CodeSimilarityRequest request)
+    {
+        var similarity = plagiarismService.GetSimilarity(request.Code1, request.Code2);
+        return Ok(similarity);
+    }
+}

src/CodeClash.API/Extensions/SeedDataExtension.cs

@@ -205,7 +205,10 @@ private static async Task SeedElasticAsync(
 
         if (success)
         {
-            logger.LogInformation("Seeded {Count} problems into Elasticsearch.", documents.Count);
+            if (logger.IsEnabled(LogLevel.Information))
+            {
+                logger.LogInformation("Seeded {Count} problems into Elasticsearch.", documents.Count);
+            }
         }
         else
         {

src/CodeClash.Application/Abstractions/Plagiarism/IPlagiarismService.cs

@@ -0,0 +1,15 @@
+using CodeClash.Application.DTO;
+
+namespace CodeClash.Application.Abstractions.Plagiarism;
+
+public interface IPlagiarismService
+{
+    Task<IEnumerable<PlagiarismCaseDto>> GetPlagiarismCases(
+        Guid contestId,
+        List<Guid> ProblemIds,
+        decimal threshold);
+
+    decimal GetSimilarity(
+        string code1,
+        string code2); // for testing purposes
+}

src/CodeClash.Application/Behaviors/LoggingBehavior.cs

@@ -39,6 +39,7 @@ public async Task<TResponse> Handle(
 
         try
         {
+#pragma warning disable CA1873
             // Log command execution start
             logger.LogInformation("Executing request {Request}", name);
 

src/CodeClash.Application/DTO/PlagiarismCaseDto.cs

@@ -0,0 +1,9 @@
+namespace CodeClash.Application.DTO;
+
+public sealed class PlagiarismCaseDto
+{
+    public SubmitDto FirstSubmission { get; set; }
+    public SubmitDto SecondSubmission { get; set; }
+    public decimal Similarity { get; set; }
+    public Guid ProblemId { get; set; }
+}

src/CodeClash.Application/DTO/SubmissionDto.cs

@@ -0,0 +1,11 @@
+using CodeClash.Domain.Premitives;
+
+namespace CodeClash.Application.DTO;
+
+public sealed class SubmissionDto
+{
+    public string UserId { get; set; }
+    public string Code { get; set; }
+    public DateTime SubmissionDate { get; set; }
+    public Language Language { get; set; }
+}

src/CodeClash.Application/DTO/SubmitDto.cs

@@ -0,0 +1,14 @@
+using CodeClash.Domain.Premitives;
+
+namespace CodeClash.Application.DTO;
+
+public sealed class SubmitDto
+{
+    public string UserId { get; set; }
+    public Guid ProblemId { get; set; }
+    public Guid? ContestId { get; set; }
+    public string Code { get; set; }
+    public Language Language { get; set; }
+    public DateTime SubmissionDate { get; set; }
+    public SubmissionResult Result { get; set; }
+}

src/CodeClash.Application/Mapping/PlagiarismMappings.cs

@@ -0,0 +1,18 @@
+using CodeClash.Application.DTO;
+using CodeClash.Domain.Models.Submits;
+
+namespace CodeClash.Application.Mapping;
+
+public static class PlagiarismMappings
+{
+    public static SubmitDto ToDto(this Submit submit) => new()
+    {
+        UserId = submit.UserId,
+        ProblemId = submit.ProblemId,
+        ContestId = submit.ContestId,
+        Code = submit.Code,
+        Language = submit.Language,
+        SubmissionDate = submit.SubmissionDate,
+        Result = submit.Result
+    };
+}

src/CodeClash.Application/Plagiarism/GetContestPlagiarismCases/GetContestPlagiarismCasesHandler.cs

@@ -0,0 +1,25 @@
+using CodeClash.Application.Abstractions.Messaging;
+using CodeClash.Application.Abstractions.Plagiarism;
+using CodeClash.Domain.Premitives;
+
+namespace CodeClash.Application.Plagiarism.GetContestPlagiarismCases;
+
+internal sealed class GetContestPlagiarismCasesHandler(
+    IPlagiarismService plagiarismService) : IQueryHandler<GetContestPlagiarismCasesQuery, GetContestPlagiarismCasesResponse>
+{
+    public async Task<Result<GetContestPlagiarismCasesResponse>> Handle(
+        GetContestPlagiarismCasesQuery request,
+        CancellationToken cancellationToken)
+    {
+        var cases = (await plagiarismService.GetPlagiarismCases(
+            request.ContestId,
+            request.ProblemIds,
+            request.Threshold)).ToList();
+
+        return Result.Success(new GetContestPlagiarismCasesResponse(
+            request.ContestId,
+            request.Threshold,
+            request.ProblemIds,
+            cases));
+    }
+}

src/CodeClash.Application/Plagiarism/GetContestPlagiarismCases/GetContestPlagiarismCasesQuery.cs

@@ -0,0 +1,8 @@
+using CodeClash.Application.Abstractions.Messaging;
+
+namespace CodeClash.Application.Plagiarism.GetContestPlagiarismCases;
+
+public sealed record GetContestPlagiarismCasesQuery(
+    Guid ContestId,
+    decimal Threshold,
+    List<Guid> ProblemIds) : IQuery<GetContestPlagiarismCasesResponse>;

src/CodeClash.Application/Plagiarism/GetContestPlagiarismCases/GetContestPlagiarismCasesResponse.cs

@@ -0,0 +1,9 @@
+using CodeClash.Application.DTO;
+
+namespace CodeClash.Application.Plagiarism.GetContestPlagiarismCases;
+
+public sealed record GetContestPlagiarismCasesResponse(
+    Guid ContestId,
+    decimal Threshold,
+    List<Guid> ProblemIds,
+    List<PlagiarismCaseDto> Cases);

src/CodeClash.Domain/Abstractions/ISubmissionRepository.cs

@@ -2,6 +2,7 @@
 using CodeClash.Domain.Premitives;
 
 namespace CodeClash.Domain.Abstractions;
+
 public interface ISubmissionRepository
 {
     Task<Submit?> GetByIdAsync(Guid id);
@@ -17,4 +18,6 @@ public interface ISubmissionRepository
     Task<Dictionary<Guid, SubmissionResult>> GetUserSubmissionsAsync(string userId);
 
     Task<Submit?> GetSubmissionIfAuthorized(string userId, Guid submissionId);
+
+    Task<List<Submit>> GetContestACSubmissionsByProblemIdsAsync(Guid contestId, List<Guid> problemIds);
 }

src/CodeClash.Domain/Requests/CodeSimilarityRequest.cs

@@ -0,0 +1,7 @@
+namespace CodeClash.Domain.Requests;
+
+public sealed class CodeSimilarityRequest
+{
+    public string Code1 { get; set; }
+    public string Code2 { get; set; }
+}

src/CodeClash.Infrastructure/DependencyInjection.cs

@@ -7,6 +7,7 @@
 using CodeClash.Application.Abstractions.Execution;
 using CodeClash.Application.Abstractions.File;
 using CodeClash.Application.Abstractions.Identity;
+using CodeClash.Application.Abstractions.Plagiarism;
 using CodeClash.Application.Abstractions.Roles;
 using CodeClash.Application.Helpers;
 using CodeClash.Domain.Abstractions;
@@ -26,6 +27,7 @@
 using StackExchange.Redis;
 
 namespace CodeClash.Infrastructure;
+
 public static class DependencyInjection
 {
     public static IServiceCollection AddInfrastructure(
@@ -64,6 +66,8 @@ public static IServiceCollection AddInfrastructure(
 
         services.AddScoped<IExecutionService, ExecutionService>();
 
+        services.AddScoped<IPlagiarismService, PlagiarismService>();
+
         services.AddScoped<IEmailService, EmailService>();
 
         services.AddScoped<IElasticService, ElasticService>();

src/CodeClash.Infrastructure/Implementation/ElasticService.cs

@@ -7,6 +7,7 @@
 using Nest;
 
 namespace CodeClash.Infrastructure.Implementation;
+
 internal sealed class ElasticService : IElasticService
 {
     private readonly ElasticClient _client;
@@ -98,6 +99,7 @@ private async Task EnsureIndexAsync<T>(string indexName) where T : class
         }
         else
         {
+#pragma warning disable CA1873
             _logger.LogInformation("Index '{IndexName}' created successfully.", indexName);
         }
     }