Support DELETE for Mastodon subscriptions

While testing Mona, I noticed that after deleting my account entry for
my snac server, Mona would repeatedly try to delete the subscription it
thought it had created, resulting in many unhandled DELETE calls.

This accepts the call and returns 200 for it, which makes Mona happy.

httpd.c

@@ -344,6 +344,14 @@ void httpd_connection(FILE *f)
     if (strcmp(method, "OPTIONS") == 0) {
         status = 200;
     }
+    else
+    if (strcmp(method, "DELETE") == 0) {
+#ifndef NO_MASTODON_API
+        if (status == 0)
+            status = mastoapi_delete_handler(req, q_path,
+                    &body, &b_size, &ctype);
+#endif
+    }
 
     /* unattended? it's an error */
     if (status == 0) {

mastoapi.c

@@ -2484,6 +2484,22 @@ int mastoapi_post_handler(const xs_dict *req, const char *q_path,
 }
 
 
+int mastoapi_delete_handler(const xs_dict *req, const char *q_path,
+                             char **body, int *b_size, char **ctype) {
+
+    if (!xs_startswith(q_path, "/api/v1/") && !xs_startswith(q_path, "/api/v2/"))
+        return 0;
+
+    srv_debug(1, xs_fmt("mastoapi_delete_handler %s", q_path));
+    xs *cmd = xs_replace_n(q_path, "/api", "", 1);
+    if (xs_startswith(cmd, "/v1/push/subscription") || xs_startswith(cmd, "/v2/push/subscription")) { /** **/
+        // pretend we deleted it, since it doesn't exist anyway
+        return 200;
+    }
+    return 0;
+}
+
+
 int mastoapi_put_handler(const xs_dict *req, const char *q_path,
                           const char *payload, int p_size,
                           char **body, int *b_size, char **ctype)

snac.h

@@ -312,6 +312,8 @@ int oauth_post_handler(const xs_dict *req, const char *q_path,
                        char **body, int *b_size, char **ctype);
 int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                          char **body, int *b_size, char **ctype);
+int mastoapi_delete_handler(const xs_dict *req, const char *q_path,
+                         char **body, int *b_size, char **ctype);
 int mastoapi_post_handler(const xs_dict *req, const char *q_path,
                           const char *payload, int p_size,
                           char **body, int *b_size, char **ctype);