Joining a session 'works' but neither the client nor the host reacts to one another, yet.

src/instance/game_instance.c

@@ -28,7 +28,7 @@ bool game_instance_host_session(Game_Instance *instance, const Game_Session_Sett
         return false;
     }
 
-    instance->game_session = (Game_Session *)calloc(1, sizeof(Game_Session));
+    instance->game_session = (Game_Session *)calloc(1, sizeof(Game_Session)); // LEAK
 
     if(settings.online) {
         if(instance->game_networking.api != NULL) {
@@ -57,7 +57,7 @@ bool game_instance_host_session(Game_Instance *instance, const Game_Session_Sett
 bool game_instance_join_session(Game_Instance *instance, const char *session_id) {
     assert(instance != NULL);
 
-    printf("Trying to join a session ...\n");
+    printf("Trying to join a session '%s' ...\n", session_id);
 
     if(instance->game_session != NULL) {
         printf("Failed. A session is already active.\n");
@@ -69,7 +69,13 @@ bool game_instance_join_session(Game_Instance *instance, const char *session_id)
         return false;
     }
 
-    return false;
+    instance->game_session = (Game_Session *)calloc(1, sizeof(Game_Session)); // LEAK
+
+    if(!networking_try_join(&instance->game_networking, instance->game_session, session_id)) {
+        return false;
+    }
+
+    return true;
 }
 
 bool game_instance_push_local_input(Game_Instance *instance, Simulation_Game_Input input) {

src/presentation/states/state_main_menu.c

@@ -90,6 +90,14 @@ static void state_render(Presentation_State *state) {
             }
             if (GuiButton((Rectangle){ 64, 64 + (BUTTON_HEIGHT * 1), 128, BUTTON_HEIGHT }, "Join")) {
                 ctx->mode = Main_Menu_Mode_Multiplayer_Join;
+
+                memset(&ctx->session_id_input, 0, sizeof(ctx->session_id_input));
+                ctx->session_id_input[0] = 'A';
+                ctx->session_id_input[1] = 'B';
+                ctx->session_id_input[2] = 'C';
+                ctx->session_id_input[3] = 'D';
+                ctx->session_id_input[4] = 'E';
+                ctx->session_id_input[5] = 'F';
             }
             if (GuiButton((Rectangle){ 64, 64 + (BUTTON_HEIGHT * 2), 128, BUTTON_HEIGHT }, "Back to Main Menu")) {
                 ctx->mode = Main_Menu_Mode_Home;
@@ -126,16 +134,35 @@ static void state_render(Presentation_State *state) {
             break;
         }
         case Main_Menu_Mode_Multiplayer_Join: {
-            // TODO: SS - Add text-input here so the player can specify what session to try connecting to.
+            // TODO: SS - Session-browser? Shows all available sessions and you can just press it to join? Maybe be prompted with a password if it's locked?
 
-            if (GuiButton((Rectangle){ 64, 64 + (BUTTON_HEIGHT * 1), 128, BUTTON_HEIGHT }, "Connect")) {
+            int pressed_button_index = GuiTextInputBox(
-                printf("TODO: SS - Connect to session id.\n");
+                (Rectangle) { 64, 64, 256, 128 }, // Bounds
-                const char *session_id = "TEMP00"; // TEMP
+                "Session-ID", // Title
-                game_instance_join_session(ctx->game_instance, session_id);
+                NULL, // Message
-            }
+                "Join", // Buttons
+                &ctx->session_id_input[0], // Text
+                sizeof(ctx->session_id_input) + 1, // Text max size
+                NULL // secret view active
+            );
 
-            if (GuiButton((Rectangle){ 64, 64 + (BUTTON_HEIGHT * 2), 128, BUTTON_HEIGHT }, "Cancel")) {
+            if(pressed_button_index >= 0) {
-                ctx->mode = Main_Menu_Mode_Multiplayer;
+                if(pressed_button_index == 0) {
+                    ctx->mode = Main_Menu_Mode_Multiplayer;
+                }
+                else if(pressed_button_index == 1) {
+                    if(game_instance_join_session(ctx->game_instance, &ctx->session_id_input[0])) {
+                        // Ok!
+                        ctx->ingame_ctx->game_instance = ctx->game_instance;
+                        presentation_state_machine_go_to(&presentation_state_ingame);
+                    }
+                    else {
+                        printf("Failed to join session '%s'.\n", &ctx->session_id_input[0]);
+                    }
+                }
+                else {
+                    assert(false);
+                }
             }
             
             break;

src/presentation/states/state_main_menu.h

@@ -24,6 +24,8 @@ typedef struct {
     bool *should_quit_game;
 
     Presentation_State_Ingame_Context *ingame_ctx;
+
+    char session_id_input[6];
 } Presentation_State_Main_Menu_Context;
 
 void presentation_state_main_menu_init(Presentation_State_Main_Menu_Context *ctx);

src/session/networking.c

@@ -4,6 +4,19 @@
 
 #define ONVO_IDENTIFIER "c2438167-831b-4bf7-8bdc-abcdefabcd00"
 
+static void listen_callback(
+    const char *event,      /* "joined", "leaved", "game" */
+    int64_t messageId,      /* sekventiellt meddelande‑ID (från host) */
+    const char *clientId,   /* avsändarens klient‑ID (eller NULL) */
+    json_t *data,           /* JSON‑objekt med godtycklig speldata */
+    void *context         /* godtycklig pekare som skickas vidare */
+) {
+    printf("#%li :: Event: '%s' from '%s'.\n", messageId, event, clientId);
+
+    Game_Networking *networking = (Game_Networking *)context;
+
+}
+
 static inline bool setup_api(Game_Networking *networking) {
     assert(networking != NULL);
 
@@ -22,6 +35,28 @@ static inline bool setup_api(Game_Networking *networking) {
     return true;
 }
 
+static bool start_listening(Game_Networking *networking) {
+    assert(networking != NULL);
+    assert(networking->api != NULL);
+    
+    int listener_id = mp_api_listen(networking->api, listen_callback, (void *)networking); // TODO: SS - Change context.
+    if(listener_id < 0) {
+        return false;
+    }
+
+    networking->listener_id = (uint32_t)listener_id;
+
+    return true;
+}
+
+static bool stop_listening(Game_Networking *networking) {
+    assert(networking != NULL);
+    assert(networking->api != NULL);
+    assert(networking->listener_id >= 0);
+
+    mp_api_unlisten(networking->api, (int)networking->listener_id);
+}
+
 bool networking_try_host(Game_Networking *networking, Game_Session *session, Game_Session_Settings settings) {
     assert(networking != NULL);
 
@@ -47,6 +82,7 @@ bool networking_try_host(Game_Networking *networking, Game_Session *session, Gam
     );
     if(host_result != MP_API_OK) {
         printf("Failed to host; Got result: %i.\n", host_result);
+        // TODO: SS - Shutdown API.
         return false;
     }
     
@@ -54,7 +90,7 @@ bool networking_try_host(Game_Networking *networking, Game_Session *session, Gam
     networking->session_id = session_id;
     networking->local_client_id = local_client_id;
 
-    // TODO: SS - Start listening.
+    assert(start_listening(networking));
 
     // Set up session.
     game_session_init(
@@ -70,15 +106,60 @@ bool networking_try_host(Game_Networking *networking, Game_Session *session, Gam
     return true;
 }
 
-bool networking_try_join(Game_Networking *networking, const char *session_id) {
+bool networking_try_join(Game_Networking *networking, Game_Session *session, const char *session_id) {
     assert(networking != NULL);
 
+    if(strlen(session_id) == 0) {
+        return false;
+    }
+    
     if(!setup_api(networking)) {
         printf("Failed to join; API is already set up.\n");
         return false;
     }
     
-    printf("Trying to join session with id: '%s' ...\n", session_id);
+    printf("Trying to join session using code: '%s' ...\n", session_id);
+
+    char *result_session_id;
+    char *local_client_id;
+    json_t *received_json;
+    int join_result = mp_api_join(
+        networking->api, // API.
+        session_id, // Session-code.
+        NULL, // JSON-data to send. // TODO: SS - Send information about you as a player (username, ..).
+        &result_session_id, // Received Session-id. I assume it should be the same as 'session_id'.
+        &local_client_id, // Received client-id.
+        &received_json // Received JSON-data.
+    );
+    if(join_result != MP_API_OK) {
+        // TODO: SS - Shutdown API.
+        printf("Failed to join; Got result: %i.\n", join_result);
+        return false;
+    }
+    assert(strcmp(result_session_id, session_id) == 0); // TODO: SS - Ask Robin why mp_api_join() returns a session_id. Is it to support 'abcdef' => 'ABCDEF'?
+
+    printf("Joined session '%s', local_client_id is '%s'.\n", result_session_id, local_client_id);
+    networking->session_id = result_session_id;
+    networking->local_client_id = local_client_id;
+
+    // TODO: SS - Decide how to network this..
+    // Should we just receive the session's settings as well as a long list of commands of what has happened throughout the match - at least one per tick?
+    // Or, should this client receive the current state of the session?
+
+    if(received_json != NULL) {
+        // TODO: SS - Read this json because it might contain valuable information.
+        json_decref(received_json);
+    }
+    
+    // TODO: SS - Stop listening.
+    assert(start_listening(networking));
+
+    // TODO: SS - Set up session based on what we got in the json.
+    // game_session_init(
+    //     session,
+    //     settings
+    // );
+
     return true;
 }
 
@@ -89,14 +170,18 @@ bool networking_stop_hosting(Game_Networking *networking) {
         return false;
     }
 
+    assert(stop_listening(networking));
+
     mp_api_destroy(networking->api);
     networking->api = NULL;
 
     if(networking->session_id != NULL) {
         free(networking->session_id);
+        networking->session_id = NULL;
     }
     if(networking->local_client_id != NULL) {
         free(networking->local_client_id);
+        networking->local_client_id = NULL;
     }
     
     printf("Stopped hosting.\n");

src/session/networking.h

@@ -9,10 +9,12 @@ typedef struct {
 
     char *session_id;
     char *local_client_id;
+
+    uint32_t listener_id;
 } Game_Networking;
 
 bool networking_try_host(Game_Networking *networking, Game_Session *session, Game_Session_Settings settings);
-bool networking_try_join(Game_Networking *networking, const char *session_id);
+bool networking_try_join(Game_Networking *networking, Game_Session *session, const char *session_id);
 
 bool networking_stop_hosting(Game_Networking *networking);