/*
 * checkUsage() checks the remaining usage units and time elapsed
 * If either does not meet threshold requirements, nlapiYieldScript() is called to reset usage
 * and continue where the script left off.
 *
 * Author: Jon Allen
 */
function checkUsage(usage_threshold, message) {
	time_threshold = 55; // maximum script running time in minutes
	usage_threshold = (usage_threshold || 100) + 100;
	message = message || '';
	var remaining_usage = global_context.getRemainingUsage();
	var current_time = new Date();
	var elapsed_time = ((current_time - global_start_time) / 60000).toFixed(2); // elapsed time in minutes
	if (remaining_usage < usage_threshold || elapsed_time >= time_threshold) {
		s_log.audit({title: 'Usage Remaining is Below Set Threshold of ' + usage_threshold, details: 'remaining_usage: ' + remaining_usage + (message ? ' message: ' + message : '') + '  --  elapsed_time: ' + elapsed_time + ' minutes' })
		global_start_time = new Date();
		setRecoveryPoint();
		s_log.debug({title: 'nlapiYieldScript', details: 'Attempting to Yield Script...'});
		var state = nlapiYieldScript();
		// state.status will never be SUCCESS because a success would imply a yield has occurred. The equivalent response would be yield
		if (state.status == 'FAILURE') {
			s_log.error({title: 'nlapiYieldScript', details: "Failed to yield script, exiting: Reason = " + state.reason + " / Size = " + state.size});
			throw "Failed to yield script";
		} else if (state.status == 'RESUME') {
			s_log.audit({title: 'nlapiYieldScript', details: 'Resuming script because of ' + state.reason + '.  Size = ' + state.size});
		}
	}
	return {points: remaining_usage, minutes: elapsed_time};
}

function setRecoveryPoint() {
	if (typeof SCRIPT_RESCHEDULED != 'undefined'){
		SCRIPT_RESCHEDULED = true;
	}
		s_log.debug({title: 'setRecoveryPoint', details: 'Setting Recovery Point...'});
	var state = nlapiSetRecoveryPoint(); //100 point governance
	if (state.status == 'SUCCESS') return; //we successfully create a new recovery point
	if (state.status == 'RESUME') { //a recovery point was previously set, we are resuming due to some unforeseen error
		s_log.error({title: 'Resuming script because of ' + state.reason + '. Size = ' + state.size});
		handleRecoveryFailure(state);
	} else if (state.status == 'FAILURE') { //we failed to create a new recovery point
		s_log.debug({title: 'Failed to create recovery point', details: state.reason + " / Size = " + state.size});
		handleRecoveryFailure(state);
	}
}

function handleRecoveryFailure(failure) {

	s_log.error({title: 'handleRecoveryFailure', details: 'Failed: ' + JSON.stringify(failure)});
	if (failure.reason == 'SS_MAJOR_RELEASE') throw "Major Update of NetSuite in progress, shutting down all processes";
	if (failure.reason == 'SS_CANCELLED') throw "Script Cancelled due to UI interaction";
	if (failure.reason == 'SS_EXCESSIVE_MEMORY_FOOTPRINT') throw "Exceeded Memory Footprint";
	if (failure.reason == 'SS_DISALLOWED_OBJECT_REFERENCE') throw "Could not set recovery point because of a reference to a non-recoverable object: " + failure.information;
}