cli: move to HTTP-based implementation

tools/cli/cli-client.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include "ggml.h"
+
+#define JSON_ASSERT GGML_ASSERT
+#include <nlohmann/json.hpp>
+
+#include <functional>
+#include <string>
+
+using json = nlohmann::ordered_json;
+
+// openai-like client for CLI
+struct cli_client {
+    std::string server_base; // base url, for example "http://127.0.0.1:8080"
+    std::string last_error;  // set when wait_health() fails
+
+    // simple GET request, returns the response json
+    // throws std::runtime_error on transport error or non-2xx status
+    json get(const std::string & path);
+
+    // simple POST request, returns the response json
+    // throws std::runtime_error on transport error or non-2xx status
+    json post(const std::string & path, const json & body);
+
+    // POST request with an SSE streaming response; on_data is invoked once
+    // per "data:" event; the function returns after the stream is finished:
+    // a null json on graceful exit (incl. cancellation via should_stop),
+    // the error response json otherwise
+    json post_sse(const std::string & path,
+                  const json & body,
+                  const std::function<bool()> & should_stop,
+                  const std::function<void(const json &)> & on_data);
+
+    // poll /health until the server is ready to accept requests
+    // returns false if is_aborted returned true or the server is unreachable
+    bool wait_health(const std::function<bool()> & is_aborted);
+
+    //
+    // higher-level wrappers
+    //
+
+    json create_chat_completion(const json & request,
+                                const std::function<bool()> & should_stop,
+                                const std::function<void(const json &)> & on_data) {
+        return post_sse("/v1/chat/completions", request, should_stop, on_data);
+    }
+
+    json get_props() {
+        return get("/props");
+    }
+};