1 files changed, 65 insertions, 0 deletions
diff --git a/data.c b/data.c
new file mode 100644
index 0000000..e9c4039
--- /dev/null
+++ b/data.c
@@ -0,0 +1,65 @@
+
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "gui.h"
+
+
+// https://www.rfc-editor.org/rfc/rfc6121#section-2.1.2.5
+typedef enum {
+	SUB_NONE,
+	SUB_TO,
+	SUB_FROM,
+	SUB_BOTH
+} subscription_t;
+
+typedef struct _roster_item_t {
+	const char* name;
+	const char* jid;
+	subscription_t sub;
+	void* widget;  // GUI widget as generic void*
+	struct _roster_item_t* next;
+} roster_item_t;
+
+
+// the RAM-stored data payload
+static roster_item_t* roster = NULL;
+
+
+void add_roster_item(const char* jid, const char* subscription, const char* name) {
+
+	// parse roster item
+	roster_item_t* item = malloc(sizeof(roster_item_t));
+	item->name = name;
+	item->jid = jid;
+	if (strcmp(subscription, "none") == 0) {
+		item->sub = SUB_NONE;
+	} else if (strcmp(subscription, "to") == 0) {
+		item->sub = SUB_TO;
+	} else if (strcmp(subscription, "from") == 0) {
+		item->sub = SUB_FROM;
+	} else if (strcmp(subscription, "both") == 0) {
+		item->sub = SUB_BOTH;
+	} else {
+		printf("Invalid subscription '%s'!\n", subscription);
+		return;
+	}
+	item->next = NULL;
+
+	// add item to roster datastructure
+	if (roster == NULL) {
+		roster = item;
+	} else {
+		roster_item_t* current = roster;
+		while (current->next != NULL)     // loop until end of linked list
+			current = current->next;
+		current->next = item;
+	}
+
+	// notify GUI
+	void* widget = gui_add_roster_item(jid, subscription, name);
+	item->widget = widget;  // adds pointer to GUI widget to roster_item_t
+
+}