/* C-Netz transaction handling
 *
 * (C) 2016 by Andreas Eversberg <jolly@eversberg.eu>
 * All Rights Reserved
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include "../common/debug.h"
#include "../common/timer.h"
#include "cnetz.h"
#include "telegramm.h"
#include "database.h"

const char *transaction2rufnummer(transaction_t *trans)
{
	static char rufnummer[9];

	sprintf(rufnummer, "%d%d%05d", trans->futln_nat, trans->futln_fuvst, trans->futln_rest);

	return rufnummer;
}

/* create transaction */
transaction_t *create_transaction(cnetz_t *cnetz, uint32_t state, uint8_t futln_nat, uint8_t futln_fuvst, uint16_t futln_rest, int extended)
{
	transaction_t *trans;

	/* search transaction for this subsriber */
	trans = search_transaction_number(cnetz, futln_nat, futln_fuvst, futln_rest);
	if (trans) {
		const char *rufnummer = transaction2rufnummer(trans);
		PDEBUG(DTRANS, DEBUG_NOTICE, "Found alredy pending transaction for subscriber '%s', deleting!\n", rufnummer);
		destroy_transaction(trans);
	}

	trans = calloc(1, sizeof(*trans));
	if (!trans) {
		PDEBUG(DTRANS, DEBUG_ERROR, "No memory!\n");
		return NULL;
	}

	timer_init(&trans->timer, transaction_timeout, trans);

	trans_new_state(trans, state);
	trans->futln_nat = futln_nat;
	trans->futln_fuvst = futln_fuvst;
	trans->futln_rest = futln_rest;

	if (state == TRANS_VWG)
		trans->mo_call = 1;
	if (state == TRANS_VAK)
		trans->mt_call = 1;

	const char *rufnummer = transaction2rufnummer(trans);
	PDEBUG(DTRANS, DEBUG_INFO, "Created transaction for subscriber '%s'\n", rufnummer);

	link_transaction(trans, cnetz);

	/* update database: now busy */
	trans->extended = update_db(cnetz, futln_nat, futln_fuvst, futln_rest, extended, 1, 0);

	return trans;
}

/* destroy transaction */
void destroy_transaction(transaction_t *trans)
{
	/* update database: now idle */
	update_db(trans->cnetz, trans->futln_nat, trans->futln_fuvst, trans->futln_rest, -1, 0, trans->ma_failed);

	unlink_transaction(trans);
	
	const char *rufnummer = transaction2rufnummer(trans);
	PDEBUG(DTRANS, DEBUG_INFO, "Destroying transaction for subscriber '%s'\n", rufnummer);

	timer_exit(&trans->timer);

	trans_new_state(trans, 0);

	free(trans);
}

/* link transaction to list */
void link_transaction(transaction_t *trans, cnetz_t *cnetz)
{
	transaction_t **transp;

	/* attach to end of list, so first transaction is served first */
	PDEBUG(DTRANS, DEBUG_DEBUG, "Linking transaction %p to cnetz %p\n", trans, cnetz);
	trans->cnetz = cnetz;
	trans->next = NULL;
	transp = &cnetz->trans_list;
	while (*transp)
		transp = &((*transp)->next);
	*transp = trans;
}

/* unlink transaction from list */
void unlink_transaction(transaction_t *trans)
{
	transaction_t **transp;

	/* unlink */
	PDEBUG(DTRANS, DEBUG_DEBUG, "Unlinking transaction %p from cnetz %p\n", trans, trans->cnetz);
	transp = &trans->cnetz->trans_list;
	while (*transp && *transp != trans)
		transp = &((*transp)->next);
	if (!(*transp)) {
		PDEBUG(DTRANS, DEBUG_ERROR, "Transaction not in list, please fix!!\n");
		abort();
	}
	*transp = trans->next;
	trans->cnetz = NULL;
}

transaction_t *search_transaction(cnetz_t *cnetz, uint32_t state_mask)
{
	transaction_t *trans = cnetz->trans_list;

	while (trans) {
		if ((trans->state & state_mask)) {
			const char *rufnummer = transaction2rufnummer(trans);
			PDEBUG(DTRANS, DEBUG_DEBUG, "Found transaction for subscriber '%s'\n", rufnummer);
			return trans;
		}
		trans = trans->next;
	}

	return NULL;
}

transaction_t *search_transaction_number(cnetz_t *cnetz, uint8_t futln_nat, uint8_t futln_fuvst, uint16_t futln_rest)
{
	transaction_t *trans = cnetz->trans_list;

	while (trans) {
		if (trans->futln_nat == futln_nat
		 && trans->futln_fuvst == futln_fuvst
		 && trans->futln_rest == futln_rest) {
			const char *rufnummer = transaction2rufnummer(trans);
			PDEBUG(DTRANS, DEBUG_DEBUG, "Found transaction for subscriber '%s'\n", rufnummer);
			return trans;
		}
		trans = trans->next;
	}

	return NULL;
}

transaction_t *search_transaction_callref(cnetz_t *cnetz, int callref)
{
	transaction_t *trans = cnetz->trans_list;

	/* just in case, this should not happen */
	if (!callref)
		return NULL;
	while (trans) {
		if (trans->callref == callref) {
			const char *rufnummer = transaction2rufnummer(trans);
			PDEBUG(DTRANS, DEBUG_DEBUG, "Found transaction for subscriber '%s'\n", rufnummer);
			return trans;
		}
		trans = trans->next;
	}

	return NULL;
}

static const char *trans_state_name(int state)
{
	switch (state) {
	case 0:
		return "IDLE";
	case TRANS_EM:
		return "EM";
	case TRANS_UM:
		return "UM";
	case TRANS_MA:
		return "MA";
	case TRANS_MFT:
		return "MFT";
	case TRANS_VWG:
		return "VWG";
	case TRANS_WAF:
		return "WAF";
	case TRANS_WBP:
		return "WBP";
	case TRANS_WBN:
		return "WBN";
	case TRANS_VAG:
		return "VAG";
	case TRANS_VAK:
		return "VAK";
	case TRANS_BQ:
		return "BQ";
	case TRANS_VHQ:
		return "VHQ";
	case TRANS_RTA:
		return "RTA";
	case TRANS_DS:
		return "DS";
	case TRANS_AHQ:
		return "AHQ";
	case TRANS_AF:
		return "AF";
	case TRANS_AT:
		return "AT";
	default:
		return "<invald transaction state>";
	}
}

void trans_new_state(transaction_t *trans, int state)
{
	PDEBUG(DTRANS, DEBUG_INFO, "Transaction state %s -> %s\n", trans_state_name(trans->state), trans_state_name(state));
	trans->state = state;
}

void cnetz_flush_other_transactions(cnetz_t *cnetz, transaction_t *trans)
{
	/* flush after this very trans */
	while (trans->next) {
		PDEBUG(DTRANS, DEBUG_NOTICE, "Kicking other pending transaction\n");
		destroy_transaction(trans->next);
	}
	/* flush before this very trans */
	while (cnetz->trans_list != trans) {
		PDEBUG(DTRANS, DEBUG_NOTICE, "Kicking other pending transaction\n");
		destroy_transaction(cnetz->trans_list);
	}
}