freeswitch/src/mod/applications/mod_nibblebill/mod_nibblebill.c

/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005/2006, Anthony Minessale II <anthmct@yahoo.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthmct@yahoo.com>
 *
 * The Initial Developer of this module is
 * Darren Schreiber <d@d-man.org>
 *
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * Darren Schreiber <d@d-man.org>
 *
 * mod_nibblebill.c - Nibble Billing
 * Purpose is to allow real-time debiting of credit or cash from a database while calls are in progress. I had the following goals: 
 *
 * Debit credit/cash from accounts real-time 
 * Allow for billing at different rates during a single call 
 * Allow for warning callers when their balance is low (via audio, in-channel) 
 * Allow for disconnecting or re-routing calls when balance is depleted 
 * Allow for billing to function as listed above with multiple concurrent calls 
 * 
 * Thanks go to bandwidth.com for funding this work.
 *
 *
 * TODO: Fix what happens when the DB is not available
 * TODO: Fix what happens when the DB queries fail (right now, all are acting like success)
 * TODO: Add buffering abilities
 * TODO: Make error handling for database, such that when the database is down (or not installed) we just log to a text file
 * FUTURE: Possibly make the hooks not tied per-channel, and instead just do this as a supervision style application with one thread that watches all calls
 */

#include <switch.h>

#ifdef SWITCH_HAVE_ODBC
#include <switch_odbc.h>
#endif

/* Defaults */
#ifdef SWITCH_HAVE_ODBC
static char SQL_LOOKUP[] = "SELECT %s FROM %s WHERE %s='%s'";
static char SQL_SAVE[] = "UPDATE %s SET %s=%s-%f WHERE %s='%s'";
#endif

typedef struct
{
	switch_time_t lastts;	/* Last time we did any billing */
	float total;	/* Total amount billed so far */

	switch_time_t pausets;	/* Timestamp of when a pause action started. 0 if not paused */
	float bill_adjustments;	/* Adjustments to make to the next billing, based on pause/resume events */

} nibble_data_t;


typedef struct nibblebill_results
{
	float	balance;

	float	percall_max; /* Overrides global on a per-user level */
	float	lowbal_amt;  /*  ditto */
} nibblebill_results_t;


/* Keep track of our config, event hooks and database connection variables, for this module only */
static struct
{
	/* Memory */
        switch_memory_pool_t *pool;

	/* Event hooks */
	switch_event_node_t *node;

	/* Global mutex (don't touch a session when it's already being touched) */
	switch_mutex_t *mutex;

	/* Global billing config options */
	float	percall_max_amt;	/* Per-call billing limit (safety check, for fraud) */
	char	*percall_action;	/* Exceeded length of per-call action */
	float	lowbal_amt;		/* When we warn them they are near depletion */
	char	*lowbal_action;		/* Low balance action */
	float	nobal_amt;		/* Minimum amount that must remain in the account */
	char	*nobal_action;		/* Drop action */

	/* Other options */
	int	global_heartbeat;	/* Supervise and bill every X seconds, 0 means off */

	/* Database settings */
	char *db_username;
	char *db_password;
	char *db_dsn;
	char *db_table;
	char *db_column_cash;
	char *db_column_account;
#ifdef SWITCH_HAVE_ODBC
	switch_odbc_handle_t *master_odbc;
#else   
	void *padding1;  /* Keep structures same size */
#endif
} globals;

static void nibblebill_pause(switch_core_session_t *session);

/**************************
* Setup FreeSWITCH Macros *
**************************/
/* Define the module's load function */
SWITCH_MODULE_LOAD_FUNCTION(mod_nibblebill_load);

/* Define the module's shutdown function */
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_nibblebill_shutdown);

/* Define the module's name, load function, shutdown function and runtime function */
SWITCH_MODULE_DEFINITION(mod_nibblebill, mod_nibblebill_load, mod_nibblebill_shutdown, NULL);

/* String setting functions */
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_username, globals.db_username);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_password, globals.db_password);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_dsn, globals.db_dsn);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_table, globals.db_table);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_column_cash, globals.db_column_cash);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_db_column_account, globals.db_column_account);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_percall_action, globals.percall_action);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_lowbal_action, globals.lowbal_action);
SWITCH_DECLARE_GLOBAL_STRING_FUNC(set_global_nobal_action, globals.nobal_action);

#ifdef SWITCH_HAVE_ODBC
static int nibblebill_callback(void *pArg, int argc, char **argv, char **columnNames)
{
	nibblebill_results_t *cbt = (nibblebill_results_t *) pArg;

	cbt->balance = (float)atof(argv[0]);

	return 0;
}
#endif

static switch_status_t load_config(void)
{
	char *cf = "nibblebill.conf";
	switch_xml_t cfg, xml = NULL, param, settings;
	switch_status_t status = SWITCH_STATUS_SUCCESS;
	
	if (!(xml = switch_xml_open_cfg(cf, &cfg, NULL))) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "open of %s failed\n", cf);
		status = SWITCH_STATUS_SUCCESS;  /* We don't fail because we can still write to a text file or buffer */
		goto setdefaults;
	}
	
	if ((settings = switch_xml_child(cfg, "settings"))) {
		for (param = switch_xml_child(settings, "param"); param; param = param->next) {
			char *var = (char *) switch_xml_attr_soft(param, "name");
			char *val = (char *) switch_xml_attr_soft(param, "value");

			if (!strcasecmp(var, "db_username")) {
				set_global_db_username(val);
			} else if (!strcasecmp(var, "db_password")) {
				set_global_db_password(val);
			} else if (!strcasecmp(var, "db_dsn")) {
				set_global_db_dsn(val);
			} else if (!strcasecmp(var, "db_table")) {
				set_global_db_table(val);
			} else if (!strcasecmp(var, "db_column_cash")) {
				set_global_db_column_cash(val);
			} else if (!strcasecmp(var, "db_column_account")) {
				set_global_db_column_account(val);
			} else if (!strcasecmp(var, "percall_action")) {
				set_global_percall_action(val);
			} else if (!strcasecmp(var, "percall_max_amt")) {
				globals.percall_max_amt = (float)atof(val);
			} else if (!strcasecmp(var, "lowbal_action")) {
				set_global_lowbal_action(val);
			} else if (!strcasecmp(var, "lowbal_amt")) {
				globals.lowbal_amt = (float)atof(val);
			} else if (!strcasecmp(var, "nobal_action")) {
				set_global_nobal_action(val);
			} else if (!strcasecmp(var, "nobal_amt")) {
				globals.nobal_amt = (float)atof(val);
			} else if (!strcasecmp(var, "global_heartbeat")) {
				globals.global_heartbeat = atoi(val);
			}
		}
	}
	
/* Set defaults for any variables still not set */
setdefaults:
	if (switch_strlen_zero(globals.db_username)) {
		set_global_db_username("bandwidth.com");
	}
	if (switch_strlen_zero(globals.db_password)) {
		set_global_db_password("dev");
	}
	if (switch_strlen_zero(globals.db_dsn)) {
		set_global_db_dsn("bandwidth.com");
	}
	if (switch_strlen_zero(globals.percall_action)) {
		set_global_percall_action("hangup");
	}
	if (switch_strlen_zero(globals.lowbal_action)) {
		set_global_lowbal_action("play ding");
	}
	if (switch_strlen_zero(globals.nobal_action)) {
		set_global_nobal_action("hangup");
	}

#ifdef SWITCH_HAVE_ODBC
	if (globals.db_dsn) {
		if (!(globals.master_odbc = switch_odbc_handle_new(globals.db_dsn, globals.db_username, globals.db_password))) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Cannot create handle to ODBC Database!\n");
			status = SWITCH_STATUS_FALSE;
			goto done;
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Opened ODBC Database handle!\n");
		}

		if (switch_odbc_handle_connect(globals.master_odbc) != SWITCH_ODBC_SUCCESS) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Cannot connect to ODBC driver/database %s (user: %s / pass %s)!\n", globals.db_dsn, globals.db_username, globals.db_password);
			status = SWITCH_STATUS_FALSE;
			goto done;
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Opened ODBC Database!\n");
		}
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Connected ODBC DSN: %s\n", globals.db_dsn);
	} else {
#endif
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "ODBC does not appear to be installed in the core. You need to run ./configure --enable-core-odbc-support\n");
#ifdef SWITCH_HAVE_ODBC
	}
#endif

#ifdef SWITCH_HAVE_ODBC
done:
#endif

	if (xml) {
		switch_xml_free(xml);
	}
	return status;
}

void debug_event_handler(switch_event_t *event)
{
	 if (!event) {
		return;
	}

	/* Print out all event headers, for fun */
	if (event->headers) {
		switch_event_header_t *event_header = NULL;
		for (event_header = event->headers; event_header; event_header = event_header->next) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Header info: %s => %s\n", event_header->name, event_header->value);
		}
	}
}


static void transfer_call(switch_core_session_t *session, char *destination)
{
	char *argv[4] = { 0 };
	const char *uuid;
	switch_channel_t *channel = switch_core_session_get_channel(session);
	char *mydup;

	if (!destination) {
		return;
	}

	mydup = strdup(destination);
	switch_assert(mydup);
	switch_separate_string(mydup, ' ', argv, (sizeof(argv) / sizeof(argv[0])));

	/* Find the uuid of our B leg. If it exists, transfer it first */
	if ((uuid = switch_channel_get_variable(channel, SWITCH_SIGNAL_BOND_VARIABLE))) {
		switch_core_session_t *b_session;

		/* Get info on the B leg */
		if ((b_session = switch_core_session_locate(uuid))) {
			/* Make sure we are in the media path on B leg */
			switch_ivr_media(uuid, SMF_REBRIDGE);

			/* Transfer the B leg */
			switch_ivr_session_transfer(b_session, argv[0], argv[1], argv[2]);
			switch_core_session_rwunlock(b_session);
		}
	}

	/* Make sure we are in the media path on A leg */
	uuid = switch_core_session_get_uuid(session);
	switch_ivr_media(uuid, SMF_REBRIDGE);

	/* Transfer the A leg */
	switch_ivr_session_transfer(session, argv[0], argv[1], argv[2]);
	free(mydup);
}


/* At this time, billing never succeeds if you don't have a database. */
static switch_status_t bill_event(float billamount, const char *billaccount)
{
#ifdef SWITCH_HAVE_ODBC
	char sql[1024] = "";
	SQLHSTMT stmt;

	switch_snprintf(sql, 1024, SQL_SAVE, globals.db_table, globals.db_column_cash, globals.db_column_cash, billamount, globals.db_column_account, billaccount);
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG,  "Doing update query\n[%s]\n", sql);

	if (switch_odbc_handle_exec(globals.master_odbc, sql, &stmt) != SWITCH_ODBC_SUCCESS) {
		char *err_str;
		err_str = switch_odbc_handle_get_error(globals.master_odbc, stmt);
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "ERR: [%s]\n[%s]\n", sql, switch_str_nil(err_str));
		switch_safe_free(err_str);
	} else {
#endif
		/* TODO: Failover to a flat/text file if DB is unavailable */

		return SWITCH_STATUS_SUCCESS;
#ifdef SWITCH_HAVE_ODBC
	}

	SQLFreeHandle(SQL_HANDLE_STMT, stmt);
#endif
	return SWITCH_STATUS_SUCCESS;
}


static float get_balance(const char *billaccount)
{
#ifdef SWITCH_HAVE_ODBC
	char sql[1024] = "";
	nibblebill_results_t pdata;
	float balance = 0.00f;

	memset(&pdata, 0, sizeof(pdata));
	snprintf(sql, 1024, SQL_LOOKUP, globals.db_column_cash, globals.db_table, globals.db_column_account, billaccount);

	if (switch_odbc_handle_callback_exec(globals.master_odbc, sql, nibblebill_callback, &pdata) != SWITCH_ODBC_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error running this query: [%s]\n", sql);
#endif
		/* Return -1 for safety */

		return -1.00;
#ifdef SWITCH_HAVE_ODBC
	} else {
		/* Successfully retrieved! */
		balance = pdata.balance;

		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG,  "Retrieved current balance for account %s (balance = %f)\n", billaccount, balance);
	}
	
	return balance;
#endif
}

/* This is where we actually charge the guy 
  This can be called anytime a call is in progress or at the end of a call before the session is destroyed */
static switch_status_t do_billing(switch_core_session_t *session)
{
	/* FS vars we will use */
	switch_channel_t *channel;
	switch_caller_profile_t *profile;

	/* Local vars */
	nibble_data_t *nibble_data;
	switch_time_t ts = switch_micro_time_now();
	float billamount;
	char date[80] = "";
	char *uuid;
	switch_size_t retsize;
	switch_time_exp_t tm;
	const char *billrate;
	const char *billaccount;
	float balance;

	if (!session) {
		/* Why are we here? */
		return SWITCH_STATUS_SUCCESS;
	}

	uuid = switch_core_session_get_uuid(session);

	/* Get channel var */
	if (!(channel = switch_core_session_get_channel(session))) {
		return SWITCH_STATUS_SUCCESS;
	}

	/* Variables kept in FS but relevant only to this module */
	billrate = switch_channel_get_variable(channel, "nibble_rate");
	billaccount = switch_channel_get_variable(channel, "nibble_account");

	/* Return if there's no billing information on this session */
	if (!billrate || !billaccount) {
		return SWITCH_STATUS_SUCCESS;
	}

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Attempting to bill at $%s per minute to account %s\n", billrate, billaccount);

	/* Get caller profile info from channel */
	profile = switch_channel_get_caller_profile(channel);

	if (!profile || !profile->times) {
		/* No caller profile (why would this happen?) */
		return SWITCH_STATUS_SUCCESS;
	}

	if (profile->times->answered < 1) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Not billing %s - call is not in answered state\n", billaccount);

		/* See if this person has enough money left to continue the call */
		balance = get_balance(billaccount);
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Comparing %f to hangup balance of %f\n", balance, globals.nobal_amt);
		if (balance <= globals.nobal_amt) {
			/* Not enough money - reroute call to nobal location */
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Balance of %f fell below allowed amount of %f! (Account %s)\n", balance, globals.nobal_amt, billaccount);

			transfer_call(session, globals.nobal_action);
		}

		return SWITCH_STATUS_SUCCESS;
	}

	/* Lock this session's data for this module while we tinker with it */
	if (globals.mutex) {
		switch_mutex_lock(globals.mutex);
	}

	/* Get our nibble data var. This will be NULL if it's our first call here for this session */
	nibble_data = (nibble_data_t *) switch_channel_get_private(channel, "_nibble_data_");

	/* Are we in paused mode? If so, we don't do anything here - go back! */
	if (nibble_data && (nibble_data->pausets > 0)) {
		if (globals.mutex) {
			switch_mutex_unlock(globals.mutex);
		}
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Received heartbeat, but we're paused - ignoring\n");
		return SWITCH_STATUS_SUCCESS;
	}

	/* Have we done any billing on this channel yet? If no, set up vars for doing so */
	if (!nibble_data) {
		nibble_data = switch_core_session_alloc(session, sizeof(*nibble_data));
		memset(nibble_data, 0, sizeof(*nibble_data));

		/* Setup new billing data (based on call answer time, in case this module started late with active calls) */
		nibble_data->lastts = profile->times->answered;		/* Set the initial answer time to match when the call was really answered */
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Beginning new billing on %s\n", uuid);
	} else {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Last successful billing time was %s\n", date);
	}

	switch_time_exp_lt(&tm, nibble_data->lastts);
	switch_strftime_nocheck(date, &retsize, sizeof(date), "%Y-%m-%d %T", &tm);

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "%d seconds passed since last bill time of %s\n", (int) ((ts - nibble_data->lastts) / 1000000), date);

	if ((ts - nibble_data->lastts) >= 0) {
		/* Convert billrate into microseconds and multiply by # of microseconds that have passed since last *successful* bill */
		billamount = ((float)atof(billrate) / 1000000 / 60) * ((ts - nibble_data->lastts)) - nibble_data->bill_adjustments;

		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Billing $%f to %s (Call: %s / %f so far)\n", billamount, billaccount, uuid, nibble_data->total);

		/* DO ODBC BILLING HERE and reset counters if it's successful! */
		if (bill_event(billamount, billaccount) == SWITCH_STATUS_SUCCESS) {
			/* Increment total cost */
			nibble_data->total += billamount;

			/* Reset manual billing adjustments from pausing */
			nibble_data->bill_adjustments = 0;

			/* Update channel variable with current billing */
			switch_channel_set_variable_printf(channel, "nibble_total_billed", "%f", nibble_data->total);
		} else {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Failed to log to database!\n");
		}
	} else {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "Just tried to bill %s negative minutes! That should be impossible.\n", uuid);
	}

	/* Update the last time we billed */
	nibble_data->lastts = ts;

	/* Save this location, but only if the channel/session are not hungup (otherwise, we're done) */
	if (channel && switch_channel_get_state(channel) != CS_HANGUP) {
		switch_channel_set_private(channel, "_nibble_data_", nibble_data);

		/* See if this person has enough money left to continue the call */
		balance = get_balance(billaccount);
		if (balance <= globals.nobal_amt) {
			/* Not enough money - reroute call to nobal location */
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Balance of %f fell below allowed amount of %f! (Account %s)\n", balance, globals.nobal_amt, billaccount);

			/* IMPORTANT: Billing must be paused before the transfer occurs! This prevents infinite loops, since the transfer will result */
			/* in nibblebill checking the call again in the routing process for an allowed balance! */
			/* If you intend to give the user the option to re-up their balance, you must clear & resume billing once the balance is updated! */
			nibblebill_pause(session);
			transfer_call(session, globals.nobal_action);
		}
        }


	/* Done changing - release lock */
	if (globals.mutex) {
		switch_mutex_unlock(globals.mutex);
	}

	/* Go check if this call is allowed to continue */

	return SWITCH_STATUS_SUCCESS;
}

/* You can turn on session heartbeat on a channel to have us check billing more often */
static void event_handler(switch_event_t *event)
{
	switch_core_session_t *session;
	char *uuid;

	if (!event){
		/* We should never get here - it means an event came in without the event info */
		return;
	}

	/* Make sure everything is sane */
	if (!(uuid = switch_event_get_header(event, "Unique-ID"))){
		/* Donde esta channel? */
		return;
	}

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Received request via %s!\n", switch_event_name (event->event_id));

	/* Display debugging info */
	if (switch_event_get_header(event, "nibble_debug")) {
		debug_event_handler(event);
	}

	/* Get session var */
	if (!(session = switch_core_session_locate(uuid))) {
		return;
	}

	/* Go bill */
	do_billing(session);

	switch_core_session_rwunlock(session);
}

static void nibblebill_pause(switch_core_session_t *session)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	switch_time_t ts = switch_micro_time_now();
	nibble_data_t *nibble_data;

	if (!channel) {
		return;
	}

	/* Lock this session's data for this module while we tinker with it */
	if (globals.mutex) {
		switch_mutex_lock(globals.mutex);
	}

	/* Get our nibble data var. This will be NULL if it's our first call here for this session */
	nibble_data = (nibble_data_t *) switch_channel_get_private(channel, "_nibble_data_");

	if (!nibble_data) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Can't pause - channel is not initialized for billing!\n");
		return;
	}

	/* Set pause counter if not already set */
	if (nibble_data->pausets == 0)
		nibble_data->pausets = ts;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Paused billing timestamp!\n");

	/* Done checking - release lock */
	if (globals.mutex) {
		switch_mutex_unlock(globals.mutex);
	}
}

static void nibblebill_resume(switch_core_session_t *session)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	switch_time_t ts = switch_micro_time_now();
	nibble_data_t *nibble_data;
	const char *billrate;

	if (!channel) {
		return;
	}

	/* Get our nibble data var. This will be NULL if it's our first call here for this session */
	nibble_data = (nibble_data_t *) switch_channel_get_private(channel, "_nibble_data_");

	if (!nibble_data) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Can't resume - channel is not initialized for billing (This is expected at hangup time)!\n");
		return;
	}

	if (nibble_data->pausets == 0) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Can't resume - channel is not paused! (This is expected at hangup time)\n");
		return;
	}

	/* Lock this session's data for this module while we tinker with it */
	if (globals.mutex) {
		switch_mutex_lock(globals.mutex);
	}

	billrate = switch_channel_get_variable(channel, "nibble_rate");

	/* Calculate how much was "lost" to billings during pause - we do this here because you never know when the billrate may change during a call */
	nibble_data->bill_adjustments += ((float)atof(billrate) / 1000000 / 60) * ((ts - nibble_data->pausets));
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Resumed billing! Subtracted %f from this billing cycle.\n", (atof(billrate) / 1000000 / 60) * ((ts - nibble_data->pausets)));

	nibble_data->pausets = 0;

	/* Done checking - release lock */
	if (globals.mutex) {
		switch_mutex_unlock(globals.mutex);
	}
}

static void nibblebill_reset(switch_core_session_t *session)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	switch_time_t ts = switch_micro_time_now();
	nibble_data_t *nibble_data;

	if (!channel) {
		return;
	}

	/* Get our nibble data var. This will be NULL if it's our first call here for this session */
	nibble_data = (nibble_data_t *) switch_channel_get_private(channel, "_nibble_data_");

	if (!nibble_data) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Can't reset - channel is not initialized for billing!\n");
		return;
	}

	/* Lock this session's data for this module while we tinker with it */
	if (globals.mutex) {
		switch_mutex_lock(globals.mutex);
	}

	/* Update the last time we billed */
	nibble_data->lastts = ts;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Reset last billing timestamp marker to right now!\n");

	/* Done checking - release lock */
	if (globals.mutex) {
		switch_mutex_unlock(globals.mutex);
	}
}

static float nibblebill_check(switch_core_session_t *session)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	nibble_data_t *nibble_data;
	float amount = 0;

	if (!channel) {
		return -99999;
	}

	/* Get our nibble data var. This will be NULL if it's our first call here for this session */
	nibble_data = (nibble_data_t *) switch_channel_get_private(channel, "_nibble_data_");

	if (!nibble_data) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Can't check - channel is not initialized for billing!\n");
		return -99999;
	}

	/* Lock this session's data for this module while we tinker with it */
	if (globals.mutex) {
		switch_mutex_lock(globals.mutex);
	}

	amount = nibble_data->total;

	/* Done checking - release lock */
	if (globals.mutex) {
		switch_mutex_unlock(globals.mutex);
	}

	return amount;
}

static void nibblebill_adjust(switch_core_session_t *session, float amount)
{
	switch_channel_t *channel = switch_core_session_get_channel(session);
	const char *billaccount;

	if (!channel) {
		return;
	}

	/* Variables kept in FS but relevant only to this module */
	
	billaccount = switch_channel_get_variable(channel, "nibble_account");

	/* Return if there's no billing information on this session */
	if (!billaccount) {
		return;
	}

	/* Add or remove amount from adjusted billing here. Note, we bill the OPPOSITE */
	if (bill_event(-amount, billaccount) == SWITCH_STATUS_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Recorded adjustment to %s for $%f\n", billaccount, amount);
	} else {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed to record adjustment to %s for $%f\n", billaccount, amount);
	}
}

#define APP_SYNTAX "pause | resume | reset | adjust <amount> | heartbeat <seconds> | check"
SWITCH_STANDARD_APP(nibblebill_app_function)
{
	int argc = 0;
	char *lbuf = NULL;
	char *argv[3] = { 0 };

	if (!switch_strlen_zero(data) && (lbuf = strdup(data))
		&& (argc = switch_separate_string(lbuf, ' ', argv, (sizeof(argv) / sizeof(argv[0]))))) {
		if (!strcasecmp(argv[0], "adjust") && argc == 2) {
			nibblebill_adjust(session, (float)atof(argv[1]));
		} else if (!strcasecmp(argv[0], "flush")) {
			do_billing(session);
		} else if (!strcasecmp(argv[0], "pause")) {
			nibblebill_pause(session);
		} else if (!strcasecmp(argv[0], "resume")) {
			nibblebill_resume(session);
		} else if (!strcasecmp(argv[0], "check")) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Current billing is at $%f\n", nibblebill_check(session));
		} else if (!strcasecmp(argv[0], "reset")) {
			nibblebill_reset(session);
		} else if (!strcasecmp(argv[0], "heartbeat") && argc == 2) {
			switch_core_session_enable_heartbeat(session, atoi(argv[1]));
		}
	}
	switch_safe_free(lbuf);
}

/* We get here from the API only (theoretically) */
#define API_SYNTAX "<uuid> [pause | resume | reset | adjust <amount> | heartbeat <seconds> | check]"
SWITCH_STANDARD_API(nibblebill_api_function)
{
	switch_core_session_t *psession = NULL;
	char *mycmd = NULL, *argv[3] = { 0 };
	int argc = 0;

	if (!switch_strlen_zero(cmd) && (mycmd = strdup(cmd))) {
		argc = switch_separate_string(mycmd, ' ', argv, (sizeof(argv) / sizeof(argv[0])));
		if ((argc == 2 || argc == 3) && !switch_strlen_zero(argv[0])) {
			char *uuid = argv[0];
			if ((psession = switch_core_session_locate(uuid))) {
				switch_channel_t *channel;
				channel = switch_core_session_get_channel(psession);

				if (!strcasecmp(argv[1], "adjust") && argc == 3) {
					nibblebill_adjust(psession, (float)atof(argv[2]));
				} else if (!strcasecmp(argv[1], "flush")) {
					do_billing(psession);
				} else if (!strcasecmp(argv[1], "pause")) {
					nibblebill_pause(psession);
				} else if (!strcasecmp(argv[1], "resume")) {
					nibblebill_resume(psession);
				} else if (!strcasecmp(argv[1], "check")) {
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Current billing is at $%f\n", nibblebill_check(psession));
				} else if (!strcasecmp(argv[1], "reset")) {
					nibblebill_reset(psession);
				} else if (!strcasecmp(argv[1], "heartbeat") && argc == 3) {
					switch_core_session_enable_heartbeat(psession, atoi(argv[2]));
				}

				switch_core_session_rwunlock(psession);
			} else {
				stream->write_function(stream, "-ERR No Such Channel!\n");
			}
		} else {
			stream->write_function(stream, "-USAGE: %s\n", API_SYNTAX);
		}
	}
	switch_safe_free(mycmd);
	return SWITCH_STATUS_SUCCESS;
}

/* Check if session has variable "billrate" set. If it does, activate the heartbeat variable
 switch_core_session_enable_heartbeat(switch_core_session_t *session, uint32_t seconds)
 switch_core_session_sched_heartbeat(switch_core_session_t *session, uint32_t seconds)*/

static switch_status_t sched_billing(switch_core_session_t *session)
{
	if (globals.global_heartbeat > 0) {
		switch_core_session_enable_heartbeat(session, globals.global_heartbeat);
	}

	/* TODO: Check account balance here */

	return SWITCH_STATUS_SUCCESS;
}

static switch_status_t process_hangup(switch_core_session_t *session)
{
	/* Resume any paused billings, just in case */
	//	nibblebill_resume(session);

	/* Now go handle like normal billing */
	do_billing(session);

	return SWITCH_STATUS_SUCCESS;
}

switch_state_handler_table_t nibble_state_handler =
{
	/* on_init */   	NULL,
	/* on_routing */   	process_hangup,	/* Need to add a check here for anything in their account before routing */
	/* on_execute */   	sched_billing,  /* Turn on heartbeat for this session and do an initial account check */
	/* on_hangup */   	process_hangup, /* On hangup - most important place to go bill */
	/* on_exch_media */   	sched_billing,
	/* on_soft_exec */   	NULL,
	/* on_consume_med */   	NULL,
	/* on_hibernate */   	NULL,
	/* on_reset */   	NULL
};

SWITCH_MODULE_LOAD_FUNCTION(mod_nibblebill_load)
{
	switch_api_interface_t *api_interface;
	switch_application_interface_t *app_interface;

	/* Set every byte in this structure to 0 */	
	memset(&globals, 0, sizeof(globals));
	globals.pool = pool;
	switch_mutex_init(&globals.mutex, SWITCH_MUTEX_NESTED, globals.pool);

	load_config();
	
	/* connect my internal structure to the blank pointer passed to me */
	*module_interface = switch_loadable_module_create_module_interface(pool, modname);

	/* Add API and CLI commands */
	SWITCH_ADD_API(api_interface, "nibblebill", "Manage billing parameters for a channel/call", nibblebill_api_function, API_SYNTAX);

	/* Add dialplan applications */
	SWITCH_ADD_APP(app_interface, "nibblebill", "Handle billing for the current channel/call", "Pause, resume, reset, adjust, flush, heartbeat commands to handle billing.", nibblebill_app_function, APP_SYNTAX, SAF_NONE);

	/* register state handlers for billing */
	switch_core_add_state_handler(&nibble_state_handler);

	/* bind to heartbeat events */
	if (switch_event_bind_removable(modname, SWITCH_EVENT_SESSION_HEARTBEAT, SWITCH_EVENT_SUBCLASS_ANY, event_handler, NULL, &globals.node) != SWITCH_STATUS_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't bind event to monitor for session heartbeats!\n");
		return SWITCH_STATUS_GENERR;
	}

	/* indicate that the module should continue to be loaded */
	return SWITCH_STATUS_SUCCESS;
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_nibblebill_shutdown)
{	
	switch_event_unbind(&globals.node);
	switch_core_remove_state_handler(&nibble_state_handler);

#ifdef SWITCH_HAVE_ODBC
	switch_odbc_handle_disconnect(globals.master_odbc);
#endif

	return SWITCH_STATUS_UNLOAD;
}

/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
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 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 expandtab:
 */