Implemented missing file handling endpoints

Added contract update endpoint

PostFundManagement.Application/Abstractions/S3ServiceBase.cs

@@ -10,14 +10,55 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
     protected abstract string BucketName { get; }
     protected abstract string CdnBaseUrl { get; }
 
-    public virtual async ValueTask<Result<string>> UploadFileAsync(string fileName, Stream fileStream, string contentType, CancellationToken cancellationToken = default) =>
+    public string GenerateCdnUrl(string fileKey) => $"{CdnBaseUrl}/{fileKey}";
+
+    public virtual async ValueTask<Result<string>> GeneratePresignedUrlAsync(string fileKey, TimeSpan duration, string? contentType = null, CancellationToken cancellationToken = default) =>
         await Result.Try((Func<ValueTask<Result<string>>>)(async () =>
         {
             if (string.IsNullOrWhiteSpace(BucketName))
-                return Result.Fail<string>(Domain.Errors.ValidationError.Create("Bucket name is not configured."));
+                return Result.Fail(ValidationError.Create("Bucket name is not configured."));
+
+            if (string.IsNullOrWhiteSpace(fileKey))
+                return Result.Fail(ValidationError.Create("File key is required."));
+
+            var request = new GetPreSignedUrlRequest
+            {
+                BucketName = BucketName,
+                Key = fileKey,
+                Expires = DateTime.UtcNow.Add(duration),
+                Verb = HttpVerb.GET
+            };
+
+            if (!string.IsNullOrWhiteSpace(contentType))
+            {
+                request.ResponseHeaderOverrides.ContentType = contentType;
+                request.ResponseHeaderOverrides.ContentDisposition = "inline";
+            }
+
+            var presignedUrl = await Client.GetPreSignedURLAsync(request);
+
+            return Result.FailIf(string.IsNullOrWhiteSpace(presignedUrl),
+                CreateError.Create("Failed to create presigned URL"))
+                    .ToResult(presignedUrl);
+        }));
+        
+    private static string CreateFileKey(string path, string fileName, string fileHash)
+    {
+        var cleanSubPath = path.Replace('\\', '/').Trim('/');
+
+        return string.IsNullOrWhiteSpace(cleanSubPath)
+            ? $"{fileHash.ToLower(CultureInfo.InvariantCulture)}_{fileName}"
+            : $"{cleanSubPath}/{fileHash.ToLower(CultureInfo.InvariantCulture)}_{fileName}";
+    }
+
+    public virtual async ValueTask<Result<string>> UploadFileAsync(string fileName, string subPath, Stream fileStream, string contentType, CancellationToken cancellationToken = default) =>
+        await Result.Try((Func<ValueTask<Result<string>>>)(async () =>
+        {
+            if (string.IsNullOrWhiteSpace(BucketName))
+                return Result.Fail<string>(ValidationError.Create("Bucket name is not configured."));
 
             if (string.IsNullOrWhiteSpace(CdnBaseUrl))
-                return Result.Fail<string>(Domain.Errors.ValidationError.Create("CDN base URL is not configured."));
+                return Result.Fail<string>(ValidationError.Create("CDN base URL is not configured."));
 
             await using var stream = new MemoryStream();
 
@@ -31,7 +72,7 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
             if (string.IsNullOrWhiteSpace(fileHash))
                 return Result.Fail<string>(CreateError.Create("Failed to compute file hash."));
 
-            var fileKey = $"{fileHash.ToLower(CultureInfo.InvariantCulture)}{Path.GetExtension(fileName)}";
+            var fileKey = CreateFileKey(subPath, fileName, fileHash);
 
             var putRequest = new PutObjectRequest
             {
@@ -48,7 +89,7 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
 
             return response.HttpStatusCode != HttpStatusCode.OK
                 ? Result.Fail<string>(CreateError.Create($"Failed to upload {fileName} to S3."))
-                : Result.Ok($"{CdnBaseUrl}/{fileKey}");
+                : Result.Ok(fileKey);
         }));
 
     public virtual async ValueTask<Result> DeleteFileAsync(string fileKey, CancellationToken cancellationToken = default) =>
@@ -63,7 +104,7 @@ public abstract class S3ServiceBase(IAmazonS3 amazonS3)
                 Key = fileKey
             }, cancellationToken);
 
-            return Result.FailIf(response.HttpStatusCode == HttpStatusCode.NoContent, 
+            return Result.FailIf(response.HttpStatusCode == HttpStatusCode.NoContent,
                 UpdateError.Create($"Failed to delete {fileKey} from S3."));
         }));
 }

PostFundManagement.Application/Abstractions/Services/IEvidenceService.cs

@@ -27,4 +27,6 @@ public interface IEvidenceService
     ValueTask<Result<Evidence[]>> GetProjectEvidencesAsync(string projectIdHash, CancellationToken cancellationToken = default);
 
     ValueTask<Result> UpdateEvidenceAsync(UpdateEvidenceRequest request, Guid userId, CancellationToken cancellationToken = default);
+
+    ValueTask<Result<string>> GetEvidenceUrlAsync(string evidenceIdHash, CancellationToken cancellationToken = default);
 }

PostFundManagement.Application/Abstractions/Services/IGrantsService.cs

@@ -25,4 +25,10 @@ public interface IGrantsService
     ValueTask<Result> CreateBudgetAsync(CreateBudgetRequest request, Guid userId, CancellationToken cancellationToken = default);
 
     ValueTask<Result> CreateAwardAsync(CreateAwardRequest request, Guid userId, CancellationToken cancellationToken = default);
+
+    ValueTask<Result<string>> GetContractUrlAsync(string contractIdHash, CancellationToken cancellationToken = default);
+    
+    ValueTask<Result> UploadContractAsync(string contractIdHash, Guid userId, IFormFile file, CancellationToken cancellationToken = default);
+    
+    ValueTask<Result> UpdateContractAsync(UpdateContractRequest request, CancellationToken cancellationToken = default);
 }