/*
 * lwftp_mod.h
 *
 *  Created on: Feb 14, 2024
 *      Author: SeungJu Lim
 */

/** Process newly connected PCB
 * @param pointer to lwftp session data
 * @param pointer to PCB
 * @param state of connection
 */
static err_t lwftp_control_connected(void *arg, struct tcp_pcb *tpcb, err_t err) {
	lwftp_session_t *s = (lwftp_session_t*) arg;

	if (err == ERR_OK) {
		LWIP_DEBUGF(LWFTP_STATE, ("lwftp:connected to server\n"));
		s->control_state = LWFTP_CONNECTED;
	} else {
		LWIP_DEBUGF(LWFTP_WARNING,
				("lwftp:err in control_connected (%s)\n", lwip_strerr(err)));
	}
	return err;
}

/** Close control connection
 * @param pointer to lwftp session data
 * @param result to pass to callback fn (if called)
 */
static void lwftp_control_close(lwftp_session_t *s, int result) {
	if (s->data_pcb) {
		lwftp_pcb_close(s->data_pcb);
		s->data_pcb = NULL;
	}
	if (s->control_pcb) {
		lwftp_pcb_close(s->control_pcb);
		s->control_pcb = NULL;
	}
	s->control_state = LWFTP_CLOSED;
	if ((result >= 0) && s->done_fn) {
		s->done_fn(s->handle, result);
	}
}

/** Process newly connected PCB
 * @param pointer to lwftp session data
 * @param pointer to PCB
 * @param state of connection
 */
static err_t lwftp_control_connected(void *arg, struct tcp_pcb *tpcb, err_t err) {
	lwftp_session_t *s = (lwftp_session_t*) arg;

	if (err == ERR_OK) {
		LWIP_DEBUGF(LWFTP_STATE, ("lwftp: connected to server\n"));
		s->control_state = LWFTP_CONNECTED;
	} else {
		LWIP_DEBUGF(LWFTP_WARNING,
				("lwftp: err in control_connected (%s)\n", lwip_strerr(err)));
	}
	return err;
}

/** Handle control connection error
 * @param pointer to lwftp session data
 * @param state of connection
 */
static void lwftp_control_err(void *arg, err_t err) {
	LWIP_UNUSED_ARG(err);
	if (arg != NULL) {
		lwftp_session_t *s = (lwftp_session_t*) arg;
		int result;
		if (s->control_state == LWFTP_CLOSED) {
			LWIP_DEBUGF(LWFTP_WARNING,
					("lwftp: failed to connect to server (%s)\n", lwip_strerr(err)));
			result = LWFTP_RESULT_ERR_CONNECT;
		} else {
			LWIP_DEBUGF(LWFTP_WARNING, ("lwftp: connection closed by remote host\n"));
			result = LWFTP_RESULT_ERR_CLOSED;
		}
		s->control_pcb = NULL; // No need to de-allocate PCB
		lwftp_control_close(s, result);
	}
}

/** Handle control connection incoming data
 * @param pointer to lwftp session data
 * @param pointer to PCB
 * @param pointer to incoming pbuf
 * @param state of incoming process
 */
static err_t lwftp_control_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p,
		err_t err) {
	lwftp_session_t *s = (lwftp_session_t*) arg;

	if (err == ERR_OK) {
		if (p) {
			tcp_recved(tpcb, p->tot_len);
			lwftp_control_process(s, tpcb, p);
		} else {
			LWIP_DEBUGF(LWFTP_WARNING, ("lwftp: connection closed by remote host\n"));
			lwftp_control_close(s, LWFTP_RESULT_ERR_CLOSED);
		}
	} else {
		LWIP_DEBUGF(LWFTP_SERIOUS,
				("lwftp: failed to receive (%s)\n", lwip_strerr(err)));
		lwftp_control_close(s, LWFTP_RESULT_ERR_UNKNOWN);
	}
	return err;
}

/** Handle control connection acknowledge of sent data
 * @param pointer to lwftp session data
 * @param pointer to PCB
 * @param number of bytes sent
 */
static err_t lwftp_control_sent(void *arg, struct tcp_pcb *tpcb, u16_t len) {
	LWIP_DEBUGF(LWFTP_TRACE, ("lwftp: successfully sent %d bytes\n", len));
	return ERR_OK;
}