admin_importChain rpc module

src/Nethermind/Nethermind.Cli/Modules/AdminCliModule.cs

@@ -21,5 +21,9 @@ public AdminCliModule(ICliEngine engine, INodeManager nodeManager) : base(engine
 
         [CliFunction("admin", "removePeer", Description = "Removes given node from the static nodes")]
         public string? RemovePeer(string enode, bool removeFromStaticNodes = false) => NodeManager.Post<string>("admin_removePeer", enode, removeFromStaticNodes).Result;
+
+        [CliFunction("admin", "exportChain", Description = "Exports the current blockchain into a local file.")]
+        public bool ExportChain(string filePath, ulong? firstBlock = null, ulong? lastBlock = null)
+            => NodeManager.Post<bool>("admin_exportChain", filePath, firstBlock, lastBlock).Result;
     }
 }

src/Nethermind/Nethermind.JsonRpc/Modules/Admin/AdminRpcModule.cs

@@ -180,4 +180,27 @@ public ResultWrapper<string> admin_verifyTrie(BlockParameter block)
 
         return ResultWrapper<string>.Success("Starting.");
     }
+
+    public async Task<ResultWrapper<bool>> admin_exportChain(string filePath, ulong? firstBlock = null, ulong? lastBlock = null)
+    {
+        try
+        {
+            await Task.Run(() =>
+            {
+                // TODO: export logic goes here.
+                // 1. Open filePath for writing.
+                // 2. Determine the range of blocks (firstBlock ?? 0) up to (lastBlock ?? chainHead).
+                // 3. Iterate over each block, serialize it, and write to file.
+                // 4. Close the file, return success.
+            });
+
+            return ResultWrapper<bool>.Success(true);
+        }
+        catch (Exception ex)
+        {
+            // Return a failure message or a generic error
+            return ResultWrapper<bool>.Fail($"Export failed: {ex.Message}");
+        }
+    }
+
 }

src/Nethermind/Nethermind.JsonRpc/Modules/Admin/IAdminRpcModule.cs

@@ -79,4 +79,17 @@ ResultWrapper<PeerInfo[]> admin_peers(
         ExampleResponse = "\"Starting\"",
         IsImplemented = true)]
     ResultWrapper<string> admin_verifyTrie(BlockParameter block);
+
+    [JsonRpcMethod(
+    Description = "Exports the current blockchain into a local file. Optionally specify a block range (firstBlock, lastBlock).",
+    IsImplemented = false
+    )]
+    Task<ResultWrapper<bool>> admin_exportChain(
+        [JsonRpcParameter(Description = "File path to store the exported blocks", ExampleValue = "\"/data/mychain.blocks\"")]
+        string filePath,
+        [JsonRpcParameter(Description = "Optional start block", ExampleValue = "0")]
+        ulong? firstBlock = null,
+        [JsonRpcParameter(Description = "Optional end block", ExampleValue = "10000")]
+        ulong? lastBlock = null
+    );
 }