added webserver

software/pc_client/src/wsserver.c

@@ -0,0 +1,106 @@
+#include "wsserver.h"
+
+/*
+ * This section provides a web server to controll the
+ * device manager through web sockets
+ * 
+ * by Dennis Gunia - 2025 - www.dennisgunia.de
+ */
+
+json_object *(*commandparser_func)(json_object *);
+
+// this sections handles ws connections and communications
+// called on opening websocket client
+void onopen(ws_cli_conn_t client)
+{
+    char *cli;
+    cli = ws_getaddress(client);
+    printf("Connection opened, addr: %s\n", cli);
+}
+
+// called on closing websocket client
+void onclose(ws_cli_conn_t client)
+{
+    char *cli;
+    cli = ws_getaddress(client);
+    printf("Connection closed, addr: %s\n", cli);
+}
+
+// called on receiving websocket message
+void onmessage(ws_cli_conn_t client, const unsigned char *msg, uint64_t size, int type)
+{
+    char *cli = ws_getaddress(client);
+    printf("received message: %s (%zu), from: %s\n", msg, size, cli);
+
+    json_tokener *tok = json_tokener_new();
+    json_object *req = json_tokener_parse_ex(tok, msg, size);
+    enum json_tokener_error jerr;
+    jerr = json_tokener_get_error(tok);
+    if (jerr != json_tokener_success)
+    {
+        // check if request can be parsed, if not retrun error
+        send_json_error(client, "parsing error", json_tokener_error_desc(jerr));
+    }
+    else
+    {
+        // if it can be parsed, get command.
+        json_object *commandObj = json_object_object_get(req, "command");
+        printf("test");
+        if (commandObj != NULL)
+        {
+            char *command = json_object_to_json_string(commandObj);
+            // get key
+            json_object *res = commandparser_func(req);
+            if (res == NULL)
+            {
+                send_json_error(client, "internal error", "");
+            }
+            else
+            {
+                send_json_response(client, res);
+            }
+            free(res);
+        }
+        else
+        {
+            // if key is missing, send error
+            send_json_error(client, "format error", "missing key: command");
+        }
+    }
+    free(tok); // always free tokenizer, to prevent memory leak
+}
+
+void send_json_response(ws_cli_conn_t client, json_object *res)
+{
+    char *message = json_object_to_json_string_ext(res, JSON_C_TO_STRING_PRETTY);
+    ws_sendframe_txt(client, message);
+}
+
+void send_json_error(ws_cli_conn_t client, char *error, char *detail)
+{
+    json_object *root = json_object_new_object();
+    json_object_object_add(root, "error", json_object_new_string(error));
+    json_object_object_add(root, "detail", json_object_new_string(detail));
+    send_json_response(client, root);
+}
+
+// starting webserver
+int start_webserver(json_object *(*commandparser_func_ptr)(json_object *))
+{
+    commandparser_func = commandparser_func_ptr;
+    ws_socket(&(struct ws_server){/*
+         * Bind host, such as:
+         * localhost -> localhost/127.0.0.1
+         * 0.0.0.0   -> global IPv4
+         * ::        -> global IPv4+IPv6 (Dual stack)
+         */
+                                  .host = WS_SERVER_ADDR,
+                                  .port = WS_SERVER_PORT,
+                                  .thread_loop = 0,
+                                  .timeout_ms = 1000,
+                                  .evs.onopen = &onopen,
+                                  .evs.onclose = &onclose,
+                                  .evs.onmessage = &onmessage});
+
+    return (0);
+}