Convert backend to Drogon HTTP API server

Co-authored-by: johndoe6345789 <224850594+johndoe6345789@users.noreply.github.com>

BUILD.md

@@ -19,7 +19,7 @@ WizardMerge/
 
 ### C++ Backend
 
-The backend implements the core three-way merge algorithm.
+The backend implements the core three-way merge algorithm with an HTTP API server using Drogon.
 
 **Prerequisites:**
 - C++17 compiler (GCC 7+, Clang 6+, MSVC 2017+)
@@ -33,11 +33,13 @@ cd backend
 ./build.sh
 ```
 
-**Usage:**
+**Run the server:**
 ```bash
-./build/wizardmerge-cli base.txt ours.txt theirs.txt output.txt
+./build/wizardmerge-cli
 ```
 
+The HTTP server will start on port 8080. Use the POST /api/merge endpoint to perform merges.
+
 See [backend/README.md](backend/README.md) for details.
 
 ### TypeScript Frontend

README.md

@@ -14,7 +14,8 @@ WizardMerge uses a multi-frontend architecture with a high-performance C++ backe
 - **Location**: `backend/`
 - **Build System**: CMake + Ninja
 - **Package Manager**: Conan
-- **Features**: Three-way merge algorithm, conflict detection, auto-resolution
+- **Web Framework**: Drogon
+- **Features**: Three-way merge algorithm, conflict detection, auto-resolution, HTTP API
 
 ### Frontend (TypeScript/Next.js)
 - **Location**: `frontend/`

backend/CMakeLists.txt

@@ -7,6 +7,7 @@ set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 # Find dependencies via Conan
+find_package(Drogon CONFIG REQUIRED)
 find_package(GTest QUIET)
 
 # Library sources
@@ -23,9 +24,10 @@ target_include_directories(wizardmerge
 # Executable
 add_executable(wizardmerge-cli
     src/main.cpp
+    src/controllers/MergeController.cc
 )
 
-target_link_libraries(wizardmerge-cli PRIVATE wizardmerge)
+target_link_libraries(wizardmerge-cli PRIVATE wizardmerge Drogon::Drogon)
 
 # Tests (if GTest is available)
 if(GTest_FOUND)

backend/README.md

@@ -1,6 +1,6 @@
 # WizardMerge C++ Backend
 
-This is the C++ backend for WizardMerge implementing the core merge algorithms.
+This is the C++ backend for WizardMerge implementing the core merge algorithms with a Drogon-based HTTP API.
 
 ## Build System
 
@@ -8,6 +8,7 @@ This is the C++ backend for WizardMerge implementing the core merge algorithms.
 - **Package Manager**: Conan
 - **CMake**: Version 3.15+
 - **C++ Standard**: C++17
+- **Web Framework**: Drogon
 
 ## Building
 
@@ -36,8 +37,8 @@ cd build
 cmake .. -G Ninja -DCMAKE_TOOLCHAIN_FILE=conan_toolchain.cmake -DCMAKE_BUILD_TYPE=Release
 ninja
 
-# Run the executable
-./wizardmerge-cli base.txt ours.txt theirs.txt output.txt
+# Run the HTTP server
+./wizardmerge-cli
 ```
 
 ## Testing
@@ -53,12 +54,16 @@ ninja test
 backend/
 ├── CMakeLists.txt       # CMake build configuration
 ├── conanfile.py         # Conan package definition
+├── config.json          # Drogon server configuration
 ├── include/             # Public headers
 │   └── wizardmerge/
 │       └── merge/
 │           └── three_way_merge.h
 ├── src/                 # Implementation files
 │   ├── main.cpp
+│   ├── controllers/
+│   │   ├── MergeController.h
+│   │   └── MergeController.cc
 │   └── merge/
 │       └── three_way_merge.cpp
 └── tests/               # Unit tests
@@ -69,16 +74,48 @@ backend/
 - Three-way merge algorithm (Phase 1.1 from ROADMAP)
 - Conflict detection and marking
 - Auto-resolution of common patterns
-- Command-line interface
+- HTTP API server using Drogon framework
+- JSON-based request/response
 
-## Usage
+## API Usage
+
+### Start the server
 
 ```sh
-wizardmerge-cli <base> <ours> <theirs> <output>
+./wizardmerge-cli [config.json]
 ```
 
-Arguments:
-- `base`: Common ancestor version
-- `ours`: Current branch version
-- `theirs`: Branch being merged
-- `output`: Output file for merged result
+The server will start on port 8080 by default (configurable in config.json).
+
+### POST /api/merge
+
+Perform a three-way merge operation.
+
+**Request:**
+```json
+{
+  "base": ["line1", "line2", "line3"],
+  "ours": ["line1", "line2_modified", "line3"],
+  "theirs": ["line1", "line2", "line3_modified"]
+}
+```
+
+**Response:**
+```json
+{
+  "merged": ["line1", "line2_modified", "line3_modified"],
+  "conflicts": [],
+  "has_conflicts": false
+}
+```
+
+**Example with curl:**
+```sh
+curl -X POST http://localhost:8080/api/merge \
+  -H "Content-Type: application/json" \
+  -d '{
+    "base": ["line1", "line2", "line3"],
+    "ours": ["line1", "line2_ours", "line3"],
+    "theirs": ["line1", "line2_theirs", "line3"]
+  }'
+```

backend/conanfile.py

@@ -18,7 +18,7 @@ class WizardMergeConan(ConanFile):
     exports_sources = "CMakeLists.txt", "src/*", "include/*"
     
     # Dependencies
-    requires = []
+    requires = ["drogon/1.9.3"]
     
     generators = "CMakeDeps", "CMakeToolchain"
     

backend/config.json

@@ -0,0 +1,43 @@
+{
+  "app": {
+    "threads_num": 4,
+    "enable_session": false,
+    "session_timeout": 0,
+    "document_root": "",
+    "upload_path": "./uploads",
+    "file_types": [
+      "json"
+    ],
+    "max_connections": 100000,
+    "max_connections_per_ip": 0,
+    "load_libs": [],
+    "log": {
+      "log_path": "./logs",
+      "logfile_base_name": "wizardmerge",
+      "log_size_limit": 100000000,
+      "log_level": "INFO"
+    },
+    "run_as_daemon": false,
+    "relaunch_on_error": false,
+    "use_sendfile": true,
+    "use_gzip": true,
+    "use_brotli": false,
+    "static_files_cache_time": 0,
+    "simple_controllers_map": [],
+    "idle_connection_timeout": 60,
+    "server_header_field": "WizardMerge/0.1.0",
+    "enable_server_header": true,
+    "keepalive_requests": 0,
+    "pipelining_requests": 0,
+    "client_max_body_size": "10M",
+    "client_max_memory_body_size": "10M",
+    "client_max_websocket_message_size": "128K"
+  },
+  "listeners": [
+    {
+      "address": "0.0.0.0",
+      "port": 8080,
+      "https": false
+    }
+  ]
+}

backend/src/controllers/MergeController.cc

@@ -0,0 +1,112 @@
+/**
+ * @file MergeController.cc
+ * @brief Implementation of HTTP controller for merge operations
+ */
+
+#include "MergeController.h"
+#include "wizardmerge/merge/three_way_merge.h"
+#include <json/json.h>
+
+using namespace wizardmerge::controllers;
+using namespace wizardmerge::merge;
+
+void MergeController::merge(
+    const HttpRequestPtr &req,
+    std::function<void(const HttpResponsePtr &)> &&callback) {
+    
+    // Parse request JSON
+    auto jsonPtr = req->getJsonObject();
+    if (!jsonPtr) {
+        Json::Value error;
+        error["error"] = "Invalid JSON in request body";
+        auto resp = HttpResponse::newHttpJsonResponse(error);
+        resp->setStatusCode(k400BadRequest);
+        callback(resp);
+        return;
+    }
+
+    const auto &json = *jsonPtr;
+    
+    // Validate required fields
+    if (!json.isMember("base") || !json.isMember("ours") || !json.isMember("theirs")) {
+        Json::Value error;
+        error["error"] = "Missing required fields: base, ours, theirs";
+        auto resp = HttpResponse::newHttpJsonResponse(error);
+        resp->setStatusCode(k400BadRequest);
+        callback(resp);
+        return;
+    }
+
+    // Convert JSON arrays to std::vector<std::string>
+    std::vector<std::string> base;
+    std::vector<std::string> ours;
+    std::vector<std::string> theirs;
+
+    try {
+        for (const auto &line : json["base"]) {
+            base.push_back(line.asString());
+        }
+        for (const auto &line : json["ours"]) {
+            ours.push_back(line.asString());
+        }
+        for (const auto &line : json["theirs"]) {
+            theirs.push_back(line.asString());
+        }
+    } catch (const std::exception &e) {
+        Json::Value error;
+        error["error"] = "Invalid array format in request";
+        auto resp = HttpResponse::newHttpJsonResponse(error);
+        resp->setStatusCode(k400BadRequest);
+        callback(resp);
+        return;
+    }
+
+    // Perform merge
+    auto result = three_way_merge(base, ours, theirs);
+    
+    // Auto-resolve simple conflicts
+    result = auto_resolve(result);
+
+    // Build response JSON
+    Json::Value response;
+    Json::Value mergedArray(Json::arrayValue);
+    for (const auto &line : result.merged_lines) {
+        mergedArray.append(line.content);
+    }
+    response["merged"] = mergedArray;
+
+    // Add conflicts information
+    Json::Value conflictsArray(Json::arrayValue);
+    for (const auto &conflict : result.conflicts) {
+        Json::Value conflictObj;
+        conflictObj["start_line"] = Json::Value::UInt64(conflict.start_line);
+        conflictObj["end_line"] = Json::Value::UInt64(conflict.end_line);
+        
+        Json::Value baseLines(Json::arrayValue);
+        for (const auto &line : conflict.base_lines) {
+            baseLines.append(line.content);
+        }
+        conflictObj["base_lines"] = baseLines;
+        
+        Json::Value ourLines(Json::arrayValue);
+        for (const auto &line : conflict.our_lines) {
+            ourLines.append(line.content);
+        }
+        conflictObj["our_lines"] = ourLines;
+        
+        Json::Value theirLines(Json::arrayValue);
+        for (const auto &line : conflict.their_lines) {
+            theirLines.append(line.content);
+        }
+        conflictObj["their_lines"] = theirLines;
+        
+        conflictsArray.append(conflictObj);
+    }
+    response["conflicts"] = conflictsArray;
+    response["has_conflicts"] = result.has_conflicts();
+
+    // Return successful response
+    auto resp = HttpResponse::newHttpJsonResponse(response);
+    resp->setStatusCode(k200OK);
+    callback(resp);
+}

backend/src/controllers/MergeController.h

@@ -0,0 +1,49 @@
+/**
+ * @file MergeController.h
+ * @brief HTTP controller for merge operations
+ */
+
+#ifndef WIZARDMERGE_CONTROLLERS_MERGE_CONTROLLER_H
+#define WIZARDMERGE_CONTROLLERS_MERGE_CONTROLLER_H
+
+#include <drogon/HttpController.h>
+
+using namespace drogon;
+
+namespace wizardmerge {
+namespace controllers {
+
+/**
+ * @brief HTTP controller for three-way merge API
+ */
+class MergeController : public HttpController<MergeController> {
+  public:
+    METHOD_LIST_BEGIN
+    // POST /api/merge - Perform three-way merge
+    ADD_METHOD_TO(MergeController::merge, "/api/merge", Post);
+    METHOD_LIST_END
+
+    /**
+     * @brief Perform three-way merge operation
+     * 
+     * Request body should be JSON:
+     * {
+     *   "base": ["line1", "line2", ...],
+     *   "ours": ["line1", "line2", ...],
+     *   "theirs": ["line1", "line2", ...]
+     * }
+     * 
+     * Response:
+     * {
+     *   "merged": ["line1", "line2", ...],
+     *   "conflicts": [...]
+     * }
+     */
+    void merge(const HttpRequestPtr &req,
+              std::function<void(const HttpResponsePtr &)> &&callback);
+};
+
+}  // namespace controllers
+}  // namespace wizardmerge
+
+#endif  // WIZARDMERGE_CONTROLLERS_MERGE_CONTROLLER_H

backend/src/main.cpp

@@ -1,83 +1,43 @@
 /**
  * @file main.cpp
- * @brief Command-line interface for WizardMerge
+ * @brief HTTP API server for WizardMerge using Drogon framework
  */
 
 #include <iostream>
-#include <fstream>
-#include <sstream>
-#include <vector>
-#include "wizardmerge/merge/three_way_merge.h"
+#include <drogon/drogon.h>
+#include "controllers/MergeController.h"
 
-using namespace wizardmerge::merge;
-
-/**
- * @brief Read lines from a file
- */
-std::vector<std::string> read_file(const std::string& filename) {
-    std::vector<std::string> lines;
-    std::ifstream file(filename);
-    std::string line;
-    
-    while (std::getline(file, line)) {
-        lines.push_back(line);
-    }
-    
-    return lines;
-}
-
-/**
- * @brief Write lines to a file
- */
-void write_file(const std::string& filename, const std::vector<Line>& lines) {
-    std::ofstream file(filename);
-    for (const auto& line : lines) {
-        file << line.content << '\n';
-    }
-}
+using namespace drogon;
 
 int main(int argc, char* argv[]) {
-    if (argc != 5) {
-        std::cerr << "Usage: " << argv[0] << " <base> <ours> <theirs> <output>\n";
-        std::cerr << "Performs three-way merge on three file versions.\n";
+    std::cout << "WizardMerge - Intelligent Merge Conflict Resolution API\n";
+    std::cout << "======================================================\n";
+    std::cout << "Starting HTTP server...\n\n";
+    
+    // Load configuration from file
+    std::string config_file = "config.json";
+    if (argc > 1) {
+        config_file = argv[1];
+    }
+    
+    try {
+        // Load configuration and start server
+        app().loadConfigFile(config_file);
+        
+        std::cout << "Server will listen on port " 
+                  << app().getListeners()[0].toPort << "\n";
+        std::cout << "Available endpoints:\n";
+        std::cout << "  POST /api/merge - Three-way merge API\n";
+        std::cout << "\nPress Ctrl+C to stop the server.\n\n";
+        
+        // Run the application
+        app().run();
+    } catch (const std::exception& e) {
+        std::cerr << "Error: " << e.what() << '\n';
+        std::cerr << "Failed to load config file: " << config_file << '\n';
+        std::cerr << "Usage: " << argv[0] << " [config.json]\n";
         return 1;
     }
     
-    std::string base_file = argv[1];
-    std::string ours_file = argv[2];
-    std::string theirs_file = argv[3];
-    std::string output_file = argv[4];
-    
-    std::cout << "WizardMerge - Intelligent Merge Conflict Resolution\n";
-    std::cout << "===================================================\n";
-    std::cout << "Base:   " << base_file << '\n';
-    std::cout << "Ours:   " << ours_file << '\n';
-    std::cout << "Theirs: " << theirs_file << '\n';
-    std::cout << "Output: " << output_file << '\n';
-    std::cout << '\n';
-    
-    // Read input files
-    auto base = read_file(base_file);
-    auto ours = read_file(ours_file);
-    auto theirs = read_file(theirs_file);
-    
-    // Perform merge
-    auto result = three_way_merge(base, ours, theirs);
-    
-    // Auto-resolve simple conflicts
-    result = auto_resolve(result);
-    
-    // Write output
-    write_file(output_file, result.merged_lines);
-    
-    // Report results
-    if (result.has_conflicts()) {
-        std::cout << "Merge completed with " << result.conflicts.size() 
-                  << " conflict(s).\n";
-        std::cout << "Please review and resolve conflicts in: " << output_file << '\n';
-        return 1;
-    } else {
-        std::cout << "Merge completed successfully with no conflicts.\n";
-        return 0;
-    }
+    return 0;
 }