Feat: add gandi api methods

src/gandi.h

@@ -0,0 +1,47 @@
+#ifndef GANDI_H
+#define GANDI_H
+
+#define GANDI_MAX_IP_LEN 46
+
+/*
+ * Stores the API key internally.
+ * Must be called once at startup before calling other gandi methods.
+ *
+ * Returns 0 on success.
+ * Returns -1 if api_key is NULL or empty.
+ */
+int gandi_init(const char *api_key);
+
+/*
+ * Fetches the current IPv4 addr from the special gandi fqdn
+ *
+ * Returns 0 on success.
+ * Returns -1 on network or curl error.
+ * Returns -2 on API auth error (401/403).
+ * Returns -3 if the record was not found or has no values.
+ */
+int gandi_get_self_ip(const char *domain, const char *record_name, char *out_ip);
+
+/*
+ * Fetches all records of all domains,
+ * looks for all A records where rrset_value
+ * is set to `old_ip` and patches each one to `new_ip`.
+ *
+ * Returns 0 on success (all records updated).
+ * Returns -1 on network or curl error, or if any patch failed.
+ * Returns -2 on API auth error (401/403).
+ * Returns -3 if no A records had old_ip.
+ */
+int gandi_update_domains(const char *fqdn, const char *old_ip, const char *new_ip);
+
+/*
+ * Patches an A record's rrset_value from `old_ip` to `new_ip`.
+ *
+ * Returns 0 on success.
+ * Returns -1 on network or curl error.
+ * Returns -2 on API auth error (401/403).
+ */
+int gandi_update_record(const char *domain, const char *record_name,
+                        const char *old_ip, const char *new_ip);
+
+#endif /* GANDI_H */