stabilizaiton work - projects rework for maintenanceability and ui livening

src/__Libraries/StellaOps.Provcache.Api/ProvcacheEndpointExtensions.GetEvidenceChunks.cs

@@ -0,0 +1,95 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging;
+using System.Globalization;
+
+namespace StellaOps.Provcache.Api;
+
+public static partial class ProvcacheEndpointExtensions
+{
+    /// <summary>
+    /// GET /v1/provcache/proofs/{proofRoot}
+    /// </summary>
+    private static async Task<IResult> GetEvidenceChunksAsync(
+        string proofRoot,
+        int? offset,
+        int? limit,
+        bool? includeData,
+        [FromServices] IEvidenceChunkRepository chunkRepository,
+        ILogger<ProofsApiEndpoints> logger,
+        CancellationToken cancellationToken)
+    {
+        logger.LogDebug("GET /v1/provcache/proofs/{ProofRoot} offset={Offset} limit={Limit}", proofRoot, offset, limit);
+
+        try
+        {
+            if (offset is < 0)
+            {
+                return BadRequest("Offset must be zero or greater.", "Invalid pagination");
+            }
+
+            if (limit is <= 0)
+            {
+                return BadRequest("Limit must be greater than zero.", "Invalid pagination");
+            }
+
+            var startIndex = offset ?? 0;
+            var pageSize = Math.Min(limit ?? DefaultPageSize, MaxPageSize);
+
+            // Get manifest for total count
+            var manifest = await chunkRepository.GetManifestAsync(proofRoot, cancellationToken);
+            if (manifest is null)
+            {
+                return Results.NotFound();
+            }
+
+            if (startIndex >= manifest.TotalChunks)
+            {
+                return Results.Ok(new ProofEvidenceResponse
+                {
+                    ProofRoot = proofRoot,
+                    TotalChunks = manifest.TotalChunks,
+                    TotalSize = manifest.TotalSize,
+                    Chunks = [],
+                    NextCursor = null,
+                    HasMore = false
+                });
+            }
+
+            // Get chunk range
+            var chunks = await chunkRepository.GetChunkRangeAsync(proofRoot, startIndex, pageSize, cancellationToken);
+
+            var chunkResponses = chunks
+                .OrderBy(c => c.ChunkIndex)
+                .Select(c => new ProofChunkResponse
+                {
+                    ChunkId = c.ChunkId,
+                    Index = c.ChunkIndex,
+                    Hash = c.ChunkHash,
+                    Size = c.BlobSize,
+                    ContentType = c.ContentType,
+                    Data = includeData == true ? Convert.ToBase64String(c.Blob) : null
+                }).ToList();
+
+            var hasMore = startIndex + chunks.Count < manifest.TotalChunks;
+            var nextCursor = hasMore
+                ? (startIndex + pageSize).ToString(CultureInfo.InvariantCulture)
+                : null;
+
+            return Results.Ok(new ProofEvidenceResponse
+            {
+                ProofRoot = proofRoot,
+                TotalChunks = manifest.TotalChunks,
+                TotalSize = manifest.TotalSize,
+                Chunks = chunkResponses,
+                NextCursor = nextCursor,
+                HasMore = hasMore
+            });
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "Error getting evidence chunks for proof root {ProofRoot}", proofRoot);
+            return InternalError("Evidence retrieval failed");
+        }
+    }
+}