1 files changed, 105 insertions, 0 deletions

diff --git a/rss.c b/rss.c
new file mode 100644
index 0000000..61620fa
--- /dev/null
+++ b/rss.c
@@ -0,0 +1,105 @@
+/* snac - A simple, minimalistic ActivityPub instance */
+/* copyright (c) 2025 grunfink et al. / MIT license */
+
+#include "xs.h"
+#include "xs_html.h"
+#include "xs_regex.h"
+#include "xs_time.h"
+
+#include "snac.h"
+
+xs_str *rss_from_timeline(snac *user, const xs_list *timeline,
+                        const char *title, const char *link, const char *desc)
+/* converts a timeline to rss */
+{
+    xs_html *rss = xs_html_tag("rss",
+        xs_html_attr("xmlns:content", "http:/" "/purl.org/rss/1.0/modules/content/"),
+        xs_html_attr("version",       "2.0"),
+        xs_html_attr("xmlns:atom",    "http:/" "/www.w3.org/2005/Atom"));
+
+    xs_html *channel = xs_html_tag("channel",
+        xs_html_tag("title",
+            xs_html_text(title)),
+        xs_html_tag("language",
+            xs_html_text("en")),
+        xs_html_tag("link",
+            xs_html_text(link)),
+        xs_html_sctag("atom:link",
+            xs_html_attr("href", link),
+            xs_html_attr("rel", "self"),
+            xs_html_attr("type", "application/rss+xml")),
+        xs_html_tag("generator",
+            xs_html_text(USER_AGENT)),
+        xs_html_tag("description",
+            xs_html_text(desc)));
+
+    xs_html_add(rss, channel);
+
+    int cnt = 0;
+    const char *v;
+
+    xs_list_foreach(timeline, v) {
+        xs *msg = NULL;
+
+        if (user) {
+            if (!valid_status(timeline_get_by_md5(user, v, &msg)))
+                continue;
+        }
+        else {
+            if (!valid_status(object_get_by_md5(v, &msg)))
+                continue;
+        }
+
+        const char *id = xs_dict_get(msg, "id");
+        const char *content = xs_dict_get(msg, "content");
+        const char *published = xs_dict_get(msg, "published");
+
+        if (user && !xs_startswith(id, user->actor))
+            continue;
+
+        if (!id || !content || !published)
+            continue;
+
+        /* create a title with the first line of the content */
+        xs *title = xs_replace(content, "<br>", "\n");
+        title = xs_regex_replace_i(title, "<[^>]+>", " ");
+        title = xs_regex_replace_i(title, "&[^;]+;", " ");
+        int i;
+
+        for (i = 0; title[i] && title[i] != '\n' && i < 50; i++);
+
+        if (title[i] != '\0') {
+            title[i] = '\0';
+            title = xs_str_cat(title, "...");
+        }
+
+        title = xs_strip_i(title);
+
+        /* convert the date */
+        time_t t = xs_parse_iso_date(published, 0);
+        xs *rss_date = xs_str_utctime(t, "%a, %d %b %Y %T +0000");
+
+        /* if it's the first one, add it to the header */
+        if (cnt == 0)
+            xs_html_add(channel,
+                xs_html_tag("lastBuildDate",
+                    xs_html_text(rss_date)));
+
+        xs_html_add(channel,
+            xs_html_tag("item",
+                xs_html_tag("title",
+                    xs_html_text(title)),
+                xs_html_tag("link",
+                    xs_html_text(id)),
+                xs_html_tag("guid",
+                    xs_html_text(id)),
+                xs_html_tag("pubDate",
+                    xs_html_text(rss_date)),
+                xs_html_tag("description",
+                    xs_html_text(content))));
+
+        cnt++;
+    }
+
+    return xs_html_render_s(rss, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
+}