Step 90: LSP client core

editor/src/LSPClient.h

@@ -0,0 +1,71 @@
+#pragma once
+// Step 90: LSP client core
+//
+// Minimal JSON-RPC LSP client with injectable transport.
+
+#include <string>
+#include <memory>
+#include <vector>
+#include <nlohmann/json.hpp>
+
+class LSPTransport {
+public:
+    virtual ~LSPTransport() = default;
+    virtual void send(const std::string& msg) = 0;
+    virtual bool receive(std::string& out) = 0;
+    virtual bool isOpen() const = 0;
+    virtual void close() = 0;
+};
+
+class LSPClient {
+public:
+    explicit LSPClient(std::shared_ptr<LSPTransport> transport)
+        : transport_(std::move(transport)) {}
+
+    void initialize(const std::string& rootUri,
+                    const std::string& clientName,
+                    int processId) {
+        nlohmann::json params;
+        params["processId"] = processId;
+        params["rootUri"] = rootUri;
+        params["clientInfo"] = { {"name", clientName}, {"version", "0.1"} };
+        params["capabilities"] = nlohmann::json::object();
+        sendRequest("initialize", params);
+        sendNotification("initialized", nlohmann::json::object());
+    }
+
+    void shutdown() {
+        sendRequest("shutdown", nlohmann::json::object());
+        sendNotification("exit", nlohmann::json::object());
+        if (transport_) transport_->close();
+    }
+
+    void sendNotification(const std::string& method, const nlohmann::json& params) {
+        nlohmann::json msg;
+        msg["jsonrpc"] = "2.0";
+        msg["method"] = method;
+        msg["params"] = params;
+        sendMessage(msg);
+    }
+
+    int sendRequest(const std::string& method, const nlohmann::json& params) {
+        nlohmann::json msg;
+        msg["jsonrpc"] = "2.0";
+        msg["id"] = nextId_++;
+        msg["method"] = method;
+        msg["params"] = params;
+        sendMessage(msg);
+        return msg["id"].get<int>();
+    }
+
+private:
+    void sendMessage(const nlohmann::json& msg) {
+        if (!transport_) return;
+        std::string body = msg.dump();
+        std::string header = "Content-Length: " + std::to_string(body.size()) + "\r\n\r\n";
+        transport_->send(header + body);
+    }
+
+    std::shared_ptr<LSPTransport> transport_;
+    int nextId_ = 1;
+};