fix(modem): Add support for URC handler into C-API

Closes #180

components/esp_modem/include/esp_modem_c_api_types.h

@@ -141,6 +141,21 @@ esp_err_t esp_modem_command(esp_modem_dce_t *dce, const char *command, esp_err_t
  */
 esp_err_t esp_modem_set_apn(esp_modem_dce_t *dce, const char *apn);
 
+#ifdef CONFIG_ESP_MODEM_URC_HANDLER
+/**
+ * @brief Sets a handler for unsolicited result codes (URCs) from the modem
+ *
+ * This function registers a callback that is triggered whenever an unsolicited
+ * result code (URC) is received from the modem. URCs are typically sent by the
+ * modem without a prior command to notify the host about certain events or status changes.
+ *
+ * @param dce Modem DCE handle
+ * @param got_line_cb Callback function which is called whenever a URC line is received
+ * @return ESP_OK on success, ESP_FAIL on failure
+ */
+esp_err_t esp_modem_set_urc(esp_modem_dce_t *dce, esp_err_t(*got_line_cb)(uint8_t *data, size_t len));
+#endif
+
 /**
  * @}
  */

components/esp_modem/src/esp_modem_c_api.cpp

@@ -451,3 +451,27 @@ extern "C" esp_err_t esp_modem_set_apn(esp_modem_dce_t *dce_wrap, const char *ap
     dce_wrap->dce->get_module()->configure_pdp_context(std::move(new_pdp));
     return ESP_OK;
 }
+
+#ifdef CONFIG_ESP_MODEM_URC_HANDLER
+extern "C" esp_err_t esp_modem_set_urc(esp_modem_dce_t *dce_wrap, esp_err_t(*got_line_fn)(uint8_t *data, size_t len))
+{
+    if (dce_wrap == nullptr || dce_wrap->dce == nullptr) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (got_line_fn == nullptr) {
+        dce_wrap->dce->set_urc(nullptr);
+        return ESP_OK;
+    }
+    dce_wrap->dce->set_urc([got_line_fn](uint8_t *data, size_t len) {
+        switch (got_line_fn(data, len)) {
+        case ESP_OK:
+            return command_result::OK;
+        case ESP_FAIL:
+            return command_result::FAIL;
+        default:
+            return command_result::TIMEOUT;
+        }
+    });
+    return ESP_OK;
+}
+#endif

components/esp_modem/src/esp_modem_uart.cpp

@@ -72,6 +72,7 @@ class UartTerminal : public Terminal {
     {
         auto t = static_cast<UartTerminal *>(task_param);
         t->task();
+        t->task_handle.task_handle = nullptr;
         vTaskDelete(nullptr);
     }