aa_composer.js

/*jslint node: true */
"use strict";
var Decimal = require('decimal.js');
var _ = require('lodash');
var async = require('async');
var constants = require('./constants.js');
var string_utils = require("./string_utils.js");
var storage = require('./storage.js');
var db = require('./db.js');
var ValidationUtils = require("./validation_utils.js");
var objectLength = require("./object_length.js");
var objectHash = require("./object_hash.js");
var validation = require("./validation.js");
var formulaParser = require('./formula/evaluation.js');
var kvstore = require('./kvstore.js');
var eventBus = require('./event_bus.js');
var mutex = require('./mutex.js');
var writer = require('./writer.js');
var conf = require('./conf.js');

var getFormula = require('./formula/common.js').getFormula;
var hasCases = require('./formula/common.js').hasCases;
var assignField = require('./formula/common.js').assignField;
var assignObject = require('./formula/common.js').assignObject;
var wrappedObject = formulaParser.wrappedObject;
var toJsType = formulaParser.toJsType;

var isNonnegativeInteger = ValidationUtils.isNonnegativeInteger;
var isNonemptyArray = ValidationUtils.isNonemptyArray;
var isNonemptyObject = ValidationUtils.isNonemptyObject;
var isEmptyObjectOrArray = ValidationUtils.isEmptyObjectOrArray;

var testnetAAsDefinedByAAsAreActiveImmediatelyUpgradeMci = 1167000;

var TRANSFER_INPUT_SIZE = 0 // type: "transfer" omitted
	+ 44 // unit
	+ 8 // message_index
	+ 8; // output_index
var TRANSFER_INPUT_KEYS_SIZE = "unit".length + "message_index".length + "output_index".length;

var OUTPUT_SIZE = 32 + 8; // address + amount
var OUTPUT_KEYS_SIZE = "address".length + "amount".length;

const CHECK_BALANCES_INTERVAL = conf.CHECK_BALANCES_INTERVAL || 600 * 1000;

/*
eventBus.on('new_aa_triggers', function () {
	mutex.lock(["write"], function (unlock) {
		unlock(); // we don't need to block writes, we requested the lock just to wait that the current write completes
		handleAATriggers();
	});
});*/

function handleAATriggers(onDone) {
	if (!onDone)
		return new Promise(resolve => handleAATriggers(resolve));
	mutex.lock(['aa_triggers'], function (unlock) {
		db.query(
			"SELECT aa_triggers.mci, aa_triggers.unit, address, definition \n\
			FROM aa_triggers \n\
			CROSS JOIN units USING(unit) \n\
			CROSS JOIN aa_addresses USING(address) \n\
			ORDER BY aa_triggers.mci, level, aa_triggers.unit, address",
			function (rows) {
				var arrPostedUnits = [];
				async.eachSeries(
					rows,
					function (row, cb) {
						console.log('handleAATriggers', row.unit, row.mci, row.address);
						var arrDefinition = JSON.parse(row.definition);
						handlePrimaryAATrigger(row.mci, row.unit, row.address, arrDefinition, arrPostedUnits, cb);
					},
					function () {
						arrPostedUnits.forEach(function (objUnit) {
							eventBus.emit('new_aa_unit', objUnit);
						});
						unlock();
						onDone();
					}
				);
			}
		);
	});
}

function handlePrimaryAATrigger(mci, unit, address, arrDefinition, arrPostedUnits, onDone) {
	db.takeConnectionFromPool(function (conn) {
		conn.query("BEGIN", function () {
			var batch = kvstore.batch();
			readMcUnit(conn, mci, function (objMcUnit) {
				readUnit(conn, unit, function (objUnit) {
					var arrResponses = [];
					var trigger = getTrigger(objUnit, address);
					trigger.initial_address = trigger.address;
					trigger.initial_unit = trigger.unit;
					handleTrigger(conn, batch, trigger, {}, {}, arrDefinition, address, mci, objMcUnit, false, arrResponses, function(){
						conn.query("DELETE FROM aa_triggers WHERE mci=? AND unit=? AND address=?", [mci, unit, address], async function(){
							await conn.query("UPDATE units SET count_aa_responses=IFNULL(count_aa_responses, 0)+? WHERE unit=?", [arrResponses.length, unit]);
							let objUnitProps = storage.assocStableUnits[unit];
							if (!objUnitProps)
								throw Error(`handlePrimaryAATrigger: unit ${unit} not found in cache`);
							if (!objUnitProps.count_aa_responses)
								objUnitProps.count_aa_responses = 0;
							objUnitProps.count_aa_responses += arrResponses.length;
							var batch_start_time = Date.now();
							batch.write({ sync: true }, function(err){
								console.log("AA batch write took "+(Date.now()-batch_start_time)+'ms');
								if (err)
									throw Error("AA composer: batch write failed: "+err);
								conn.query("COMMIT", function () {
									conn.release();
									if (arrResponses.length > 1) {
										// copy updatedStateVars to all responses
										if (arrResponses[0].updatedStateVars)
											for (var i = 1; i < arrResponses.length; i++)
												arrResponses[i].updatedStateVars = arrResponses[0].updatedStateVars;
										// merge all changes of balances if the same AA was called more than once
										let assocBalances = {};
										for (let { aa_address, balances } of arrResponses)
											assocBalances[aa_address] = balances; // overwrite if repeated
										for (let r of arrResponses) {
											r.balances = assocBalances[r.aa_address];
											r.allBalances = assocBalances;
										}
									}
									else
										arrResponses[0].allBalances = { [address]: arrResponses[0].balances };
									arrResponses.forEach(function (objAAResponse) {
										if (objAAResponse.objResponseUnit)
											arrPostedUnits.push(objAAResponse.objResponseUnit);
										eventBus.emit('aa_response', objAAResponse);
										eventBus.emit('aa_response_to_unit-'+objAAResponse.trigger_unit, objAAResponse);
										eventBus.emit('aa_response_to_address-'+objAAResponse.trigger_address, objAAResponse);
										eventBus.emit('aa_response_from_aa-'+objAAResponse.aa_address, objAAResponse);
									});
									onDone();
								});
							});
						});
					});
				});
			});
		});
	});
}

// estimates the effects of an AA trigger before it gets stable.
// stateVars and assocBalances are updated after the function returns.
// The estimation is not 100% accurate, e.g. storage_size is ignored, unit validation errors are not caught
function estimatePrimaryAATrigger(objUnit, address, stateVars, assocBalances, onDone) {
	if (!onDone)
		return new Promise(resolve => estimatePrimaryAATrigger(objUnit, address, stateVars, assocBalances, resolve));
	db.takeConnectionFromPool(function (conn) {
		conn.query("BEGIN", function () {
			storage.readAADefinition(conn, address, arrDefinition => {
				if (!arrDefinition)
					throw Error("AA not found: " + address)
				readLastUnit(conn, function (objMcUnit) {
					// rewrite timestamp in case our last unit is old (light or unsynced full)
					objMcUnit.timestamp = objUnit.timestamp || Math.round(Date.now() / 1000);
					if (objUnit.main_chain_index)
						objMcUnit.main_chain_index = objUnit.main_chain_index;
					var mci = objMcUnit.main_chain_index;
					var arrResponses = [];
					var trigger = getTrigger(objUnit, address);
					trigger.initial_address = trigger.address;
					trigger.initial_unit = trigger.unit;
					var trigger_opts = {
						bAir: true,
						conn,
						trigger,
						params: {},
						stateVars,
						assocBalances, // balances _before_ the trigger, not including the coins received in the trigger
						arrDefinition,
						address,
						mci,
						objMcUnit,
						arrResponses,
						onDone: function () {
							// remove the 'updated' flag for future triggers
							for (var aa in stateVars) {
								var addressVars = stateVars[aa];
								for (var var_name in addressVars) {
									var state = addressVars[var_name];
									if (state.updated) {
										delete state.updated;
										state.old_value = state.value;
										state.original_old_value = state.value;
									}
								}
							}
							conn.query("ROLLBACK", function () {
								conn.release();
								// copy updatedStateVars to all responses
								if (arrResponses.length > 1 && arrResponses[0].updatedStateVars)
									for (var i = 1; i < arrResponses.length; i++)
										arrResponses[i].updatedStateVars = arrResponses[0].updatedStateVars;
								onDone(arrResponses);
							});
						},
					}
					handleTrigger(trigger_opts);
				});
			});
		});
	});
}

var lightBatch = {
	put: function () { },
	del: function () { },
	clear: function () { },
	write: function () {
		throw Error("attempting to write a batch in a light client");
	}
};

function validateAATriggerObject(trigger, handle) {
	if (!ValidationUtils.isNonemptyObject(trigger))
		return handle("no trigger");
	if (!ValidationUtils.isNonemptyObject(trigger.outputs))
		return handle("no trigger outputs");
	if (!ValidationUtils.isValidAddress(trigger.address))
		return handle("bad trigger address");
	var arrAssets = Object.keys(trigger.outputs).filter(function(asset) {return asset !== 'base'});
	if (arrAssets.length >= constants.MAX_MESSAGES_PER_UNIT)
		return handle("too many assets");
	if (!ValidationUtils.isPositiveInteger(trigger.outputs.base))
		return handle("no base payment");
	if (arrAssets.length === 0)
		return handle();
	if (!arrAssets.every(function(asset){return ValidationUtils.isPositiveInteger(trigger.outputs[asset])}))
		return handle("invalid output amount")
	// we have to check that assets exist otherwise foreign key constraint would fail when inserting fake outputs
	db.query("SELECT 1 FROM assets WHERE unit IN (?)", [arrAssets], function(rows) {
		if (rows.length !== arrAssets.length)
			return handle("unknown asset");
		else
			return handle();
	});
}

function dryRunPrimaryAATrigger(trigger, address, arrDefinition, onDone) {
	db.takeConnectionFromPool(function (conn) {
		conn.query("BEGIN", function () {
			var batch = conf.bLight ? lightBatch : kvstore.batch();
			readLastStableMcUnit(conn, function (mci, objMcUnit) {
				trigger.unit = objMcUnit.unit;
				if (!trigger.address)
					trigger.address = objMcUnit.authors[0].address;
				trigger.initial_address = trigger.address;
				trigger.initial_unit = trigger.unit;
				var fPrepare = function (cb) {
					insertFakeOutputsIntoMcUnit(conn, objMcUnit, trigger.outputs, address, cb);
				};
				fPrepare(function () {
					var arrResponses = [];
					handleTrigger(conn, batch, trigger, {}, {}, arrDefinition, address, mci, objMcUnit, false, arrResponses, function () {
						revertResponsesInCaches(arrResponses);
						batch.clear();
						conn.query("ROLLBACK", function () {
							conn.release();
							onDone(arrResponses);
						});
					});
				});
			});
		});
	});
}

function readLastStableMcUnit(conn, handleMciAndUnit) {
	conn.query(
		"SELECT unit, main_chain_index FROM units WHERE +is_on_main_chain=1 AND +is_stable=1 \n\
		ORDER BY main_chain_index DESC LIMIT 1",
		function (rows) {
			if (rows.length !== 1)
				throw Error("found " + rows.length + " last stable MC units");
			var row = rows[0];
			readUnit(conn, row.unit, function (objUnit) {
				handleMciAndUnit(row.main_chain_index, objUnit);
			});
		}
	);
}

function insertFakeOutputsIntoMcUnit(conn, objMcUnit, outputs, address, onDone) {
	// this ensures we have the funds on AA address in case the response unit tries to send the received funds somewhere else
	console.log('inserting fake outputs into unit ' + objMcUnit.unit);
	var arrQueries = [];
	var message_index = objMcUnit.messages.length;
	for (var asset in outputs) {
		conn.addQuery(arrQueries,
			"INSERT INTO outputs (unit, message_index, output_index, asset, address, amount) VALUES(?, ?,0, ?, ?, ?)",
			[objMcUnit.unit, message_index, asset === 'base' ? null : asset, address, outputs[asset]]);
		message_index++;
	}
	async.series(arrQueries, onDone);
}

function readMcUnit(conn, mci, handleUnit) {
	conn.query("SELECT unit FROM units WHERE main_chain_index=? AND is_on_main_chain=1", [mci], function (rows) {
		if (rows.length !== 1)
			throw Error("found " + rows.length + " MC units on MCI " + mci);
		readUnit(conn, rows[0].unit, handleUnit);
	});
}

function readLastUnit(conn, handleUnit) {
	conn.query("SELECT unit, main_chain_index FROM units ORDER BY main_chain_index DESC LIMIT 1", function (rows) {
		if (rows.length !== 1 || !rows[0].main_chain_index) {
			if (!conf.bLight)
				throw Error("found " + rows.length + " last units");
			var objMcUnit = {
				unit: 'mcunit',
				witness_list_unit: 'mcwitnesslistunit',
				last_ball_unit: 'mclastballunit',
				last_ball: 'mclastball',
				timestamp: Math.round(Date.now() / 1000),
				main_chain_index: 1e9,
			};
			return handleUnit(objMcUnit);
		}
		readUnit(conn, rows[0].unit, handleUnit);
	});
}

function readUnit(conn, unit, handleUnit) {
	storage.readJoint(conn, unit, {
		ifNotFound: function () {
			throw Error("unit not found: " + unit);
		},
		ifFound: function (objJoint) {
			handleUnit(objJoint.unit);
		}
	});
}

function getTrigger(objUnit, receiving_address) {
	var trigger = { address: objUnit.authors[0].address, unit: objUnit.unit, outputs: {} };
	if ("max_aa_responses" in objUnit)
		trigger.max_aa_responses = objUnit.max_aa_responses;
	objUnit.messages.forEach(function (message) {
		if (message.app === 'data' && !trigger.data) // use the first data message, ignore the subsequent ones
			trigger.data = message.payload;
		else if (message.app === 'payment') {
			var payload = message.payload;
			var asset = payload.asset || 'base';
			payload.outputs.forEach(function (output) {
				if (output.address === receiving_address) {
					if (!trigger.outputs[asset])
						trigger.outputs[asset] = 0;
					trigger.outputs[asset] += output.amount; // in case there are several outputs
				}
			});
		}
	});
	if (Object.keys(trigger.outputs).length === 0)
		throw Error("no outputs to " + receiving_address);
	return trigger;
}

// the result is onDone(objResponseUnit, bBounced)
function handleTrigger(conn, batch, trigger, params, stateVars, arrDefinition, address, mci, objMcUnit, bSecondary, arrResponses, onDone) {
	var trigger_opts;
	if (arguments.length === 1) {
		trigger_opts = conn;
		conn = trigger_opts.conn;
		batch = trigger_opts.batch;
		trigger = trigger_opts.trigger;
		params = trigger_opts.params;
		stateVars = trigger_opts.stateVars;
		arrDefinition = trigger_opts.arrDefinition;
		address = trigger_opts.address;
		mci = trigger_opts.mci;
		objMcUnit = trigger_opts.objMcUnit;
		bSecondary = trigger_opts.bSecondary;
		arrResponses = trigger_opts.arrResponses;
		onDone = trigger_opts.onDone;
		// extra options:
		// trigger_opts.bAir
		// trigger_opts.assocBalances
		if (!!trigger_opts.bAir !== !!trigger_opts.assocBalances)
			throw Error("assocBalances and bAir do not match");
	}
	else
		trigger_opts = { conn, batch, trigger, params, stateVars, arrDefinition, address, mci, objMcUnit, bSecondary, arrResponses, onDone };
	if (arrDefinition[0] !== 'autonomous agent')
		throw Error('bad AA definition ' + arrDefinition);
	if (!trigger.initial_address)
		trigger.initial_address = trigger.address;
	if (!trigger.initial_unit)
		trigger.initial_unit = trigger.unit;
	var error_message = '';
	var responseVars = {};
	var template = arrDefinition[1];
	if (template.base_aa) { // parameterized AA
		if (params && Object.keys(params).length > 0)
			throw Error("unexpected params");
		storage.readAADefinition(conn, template.base_aa, function (arrBaseDefinition) {
			if (!arrBaseDefinition)
				throw Error("base AA not found: " + template.base_aa);
			console.log("redirecting to base AA " + template.base_aa + " with params " + JSON.stringify(template.params));
			trigger_opts.params = template.params;
			trigger_opts.arrDefinition = arrBaseDefinition;
			handleTrigger(trigger_opts);
		});
		return;
	}
	var bounce_fees = template.bounce_fees || {base: constants.MIN_BYTES_BOUNCE_FEE};
	if (!bounce_fees.base)
		bounce_fees.base = constants.MIN_BYTES_BOUNCE_FEE;
//	console.log('===== trigger.outputs', trigger.outputs);
	var objValidationState = {
		last_ball_mci: mci,
		last_ball_timestamp: objMcUnit.timestamp,
		mc_unit: objMcUnit.unit,
		assocBalances: {},
		number_of_responses: arrResponses.length,
		arrPreviousAAResponses: arrResponses.map(objAAResponse => ({
			unit_obj: objAAResponse.objResponseUnit || false,
			trigger_unit: objAAResponse.trigger_unit,
			trigger_address: objAAResponse.trigger_address,
			aa_address: objAAResponse.aa_address,
		})),
	};
	var bWithKeys = (mci >= constants.includeKeySizesUpgradeMci);
	var FULL_TRANSFER_INPUT_SIZE = TRANSFER_INPUT_SIZE + (bWithKeys ? TRANSFER_INPUT_KEYS_SIZE : 0);
	var byte_balance;
	var storage_size;
	var objStateUpdate;
	var count = 0;
	var originalStateVars = _.cloneDeep(stateVars);
	var originalBalances;
	if (bSecondary)
		updateOriginalOldValues();

	// add the coins received in the trigger
	function updateInitialAABalances(cb) {
		if (trigger_opts.assocBalances) {
			if (!trigger_opts.assocBalances[address])
				trigger_opts.assocBalances[address] = {};
			originalBalances = _.cloneDeep(trigger_opts.assocBalances);
			for (var asset in trigger.outputs)
				trigger_opts.assocBalances[address][asset] = (trigger_opts.assocBalances[address][asset] || 0) + trigger.outputs[asset];
			objValidationState.assocBalances = trigger_opts.assocBalances;
			byte_balance = trigger_opts.assocBalances[address].base || 0;
			storage_size = 0;
			return cb();
		}
		objValidationState.assocBalances[address] = {};
		var arrAssets = Object.keys(trigger.outputs);
		conn.query(
			"SELECT asset, balance FROM aa_balances WHERE address=?",
			[address],
			function (rows) {
				var arrQueries = [];
				// 1. update balances of existing assets
				rows.forEach(function (row) {
					if (constants.bTestnet && mci < testnetAAsDefinedByAAsAreActiveImmediatelyUpgradeMci)
						reintroduceBalanceBug(address, row);
					if (!trigger.outputs[row.asset]) {
						objValidationState.assocBalances[address][row.asset] = row.balance;
						return;
					}
					conn.addQuery(
						arrQueries,
						"UPDATE aa_balances SET balance=balance+? WHERE address=? AND asset=? ",
						[trigger.outputs[row.asset], address, row.asset]
					);
					objValidationState.assocBalances[address][row.asset] = row.balance + trigger.outputs[row.asset];
				});
				// 2. insert balances of new assets
				var arrExistingAssets = rows.map(function (row) { return row.asset; });
				var arrNewAssets = _.difference(arrAssets, arrExistingAssets);
				if (arrNewAssets.length > 0) {
					var arrValues = arrNewAssets.map(function (asset) {
						objValidationState.assocBalances[address][asset] = trigger.outputs[asset];
						return "(" + conn.escape(address) + ", " + conn.escape(asset) + ", " + trigger.outputs[asset] + ")"
					});
					conn.addQuery(arrQueries, "INSERT INTO aa_balances (address, asset, balance) VALUES "+arrValues.join(', '));
				}
				byte_balance = objValidationState.assocBalances[address].base;
				if (trigger.outputs.base === undefined && mci < constants.aa3UpgradeMci) // bug-compatible
					byte_balance = undefined;
				if (!bSecondary)
					conn.addQuery(arrQueries, "SAVEPOINT initial_balances");
				async.series(arrQueries, function () {
					conn.query("SELECT storage_size FROM aa_addresses WHERE address=?", [address], function (rows) {
						if (rows.length === 0)
							throw Error("AA not found? " + address);
						storage_size = rows[0].storage_size;
						objValidationState.storage_size = storage_size;
						cb();
					});
				});
			}
		);
	}

	function updateFinalAABalances(arrConsumedOutputs, objUnit, cb) {
		if (trigger_opts.bAir)
			throw Error("updateFinalAABalances shouldn't be called with bAir");
		var assocDeltas = {};
		var arrNewAssets = [];
		arrConsumedOutputs.forEach(function (output) {
			if (!assocDeltas[output.asset])
				assocDeltas[output.asset] = 0;
			assocDeltas[output.asset] -= output.amount;
			// this might happen if there is another pending invocation of our AA that created the outputs we are spending now
			if (!objValidationState.assocBalances[address][output.asset])
				arrNewAssets.push(output.asset);
		});
		objUnit.messages.forEach(function (message) {
			if (message.app !== 'payment')
				return;
			var payload = message.payload;
			var asset = payload.asset || 'base';
			payload.outputs.forEach(function (output) {
				if (output.address !== address)
					return;
				if (!assocDeltas[asset]) { // it can happen if the asset was issued by AA
					assocDeltas[asset] = 0;
					arrNewAssets.push(asset);
				}
				assocDeltas[asset] += output.amount;
			});
		});
		var arrQueries = [];
		if (arrNewAssets.length > 0) {
			var arrValues = arrNewAssets.map(function (asset) { return "(" + conn.escape(address) + ", " + conn.escape(asset) + ", 0)"; });
			conn.addQuery(arrQueries, "INSERT "+conn.getIgnore()+" INTO aa_balances (address, asset, balance) VALUES "+arrValues.join(', '));
		}
		for (var asset in assocDeltas) {
			if (assocDeltas[asset]) {
				conn.addQuery(arrQueries, "UPDATE aa_balances SET balance=balance+? WHERE address=? AND asset=?", [assocDeltas[asset], address, asset]);
				if (!objValidationState.assocBalances[address][asset])
					objValidationState.assocBalances[address][asset] = 0;
				objValidationState.assocBalances[address][asset] += assocDeltas[asset];
			}
		}
		if (assocDeltas.base)
			byte_balance += assocDeltas.base;
		async.series(arrQueries, cb);
	}
	
	function evaluateAA(arrDefinition, cb) {
		var locals = {};
		var f = getFormula(arrDefinition[1].getters);
		if (f === null) // no getters
			return replace(arrDefinition, 1, '', locals, cb);
		// evaluate getters before everything else as they can define a few functions
		delete arrDefinition[1].getters;
		var opts = {
			conn: conn,
			formula: f,
			trigger: trigger,
			params: params,
			locals: locals,
			stateVars: stateVars,
			responseVars: responseVars,
			bStatementsOnly: true,
			bGetters: true,
			objValidationState: objValidationState,
			address: address
		};
		formulaParser.evaluate(opts, function (err, res) {
			if (res === null)
				return cb(err.bounce_message || "formula " + f + " failed: " + err);
			replace(arrDefinition, 1, '', locals, cb);
		});
	}

	// note that app=definition is also replaced using the current trigger and vars, its code has to generate "{}"-formulas in order to be dynamic
	function replace(obj, name, path, locals, cb) {
		count++;
		if (count % 100 === 0) // interrupt the call stack
			return setImmediate(replace, obj, name, path, locals, cb);
		locals = _.clone(locals);
		var value = obj[name];
		if (typeof name === 'string') {
			var f = getFormula(name);
			if (f !== null) {
				var opts = {
					conn: conn,
					formula: f,
					trigger: trigger,
					params: params,
					locals: _.clone(locals),
					stateVars: stateVars,
					responseVars: responseVars,
					objValidationState: objValidationState,
					address: address
				};
				return formulaParser.evaluate(opts, function (err, res) {
					if (res === null)
						return cb(err.bounce_message || "formula " + f + " failed: "+err);
					delete obj[name];
					if (res === '')
						return cb(); // the key is just removed from the object
					if (typeof res !== 'string')
						return cb("result of formula " + name + " is not a string: " + res);
					if (ValidationUtils.hasOwnProperty(obj, res))
						return cb("duplicate key " + res + " calculated from " + name);
					if (getFormula(res) !== null)
						return cb("calculated value of " + name + " looks like a formula again: " + res);
					assignField(obj, res, value);
					replace(obj, res, path, locals, cb);
				});
			}
		}
		if (typeof value === 'number' || typeof value === 'boolean')
			return cb();
		if (typeof value === 'string') {
			var f = getFormula(value);
			if (f === null)
				return cb();
		//	console.log('path', path, 'name', name, 'f', f);
			var bStateUpdates = (path === '/messages/state');
			if (bStateUpdates) {
				if (objStateUpdate)
					return cb("second state update formula: " + f + ", existing: " + objStateUpdate.formula);
				objStateUpdate = {formula: f, locals: locals};
				return cb();
			}
			var opts = {
				conn: conn,
				formula: f,
				trigger: trigger,
				params: params,
				locals: locals,
				stateVars: stateVars,
				responseVars: responseVars,
				objValidationState: objValidationState,
				address: address,
				bObjectResultAllowed: true
			};
			formulaParser.evaluate(opts, function (err, res) {
			//	console.log('--- f', f, '=', res, typeof res);
				if (res === null)
					return cb(err.bounce_message || "formula " + f + " failed: "+err);
				if (res === '' || isEmptyObjectOrArray(res)) { // signals that the key should be removed (only empty string or array or object, cannot be false as it is a valid value for asset properties)
					if (typeof name === 'string')
						delete obj[name];
					else
						assignField(obj, name, null);
				}
				else
					assignField(obj, name, res);
				cb();
			});
		}
		else if (hasCases(value)) {
			var thecase;
			async.eachSeries(
				value.cases,
				function (acase, cb2) {
					if (!("if" in acase)) {
						thecase = acase;
						return cb2('done');
					}
					var f = getFormula(acase.if);
					if (f === null)
						return cb2("case if is not a formula: " + acase.if);
					var locals_tmp = _.clone(locals); // separate copy for each iteration of eachSeries
					var opts = {
						conn: conn,
						formula: f,
						trigger: trigger,
						params: params,
						locals: locals_tmp,
						stateVars: stateVars,
						responseVars: responseVars,
						objValidationState: objValidationState,
						address: address
					};
					formulaParser.evaluate(opts, function (err, res) {
						if (res === null)
							return cb2(err.bounce_message || "formula " + acase.if + " failed: " + err);
						if (res) {
							thecase = acase;
							locals = locals_tmp;
							return cb2('done');
						}
						cb2(); // try next
					});
				},
				function (err) {
					if (!err)
						return cb("neither case is true in " + name);
					if (err !== 'done')
						return cb(err);
					var replacement_value = thecase[name];
					if (!replacement_value)
						throw Error("a case was selected but no replacement value in " + name);
					assignField(obj, name, replacement_value);
					if (!thecase.init)
						return replace(obj, name, path, locals, cb);
					var f = getFormula(thecase.init);
					if (f === null)
						return cb("case init is not a formula: " + thecase.init);
					var opts = {
						conn: conn,
						formula: f,
						trigger: trigger,
						params: params,
						locals: locals,
						stateVars: stateVars,
						responseVars: responseVars,
						bStatementsOnly: true,
						objValidationState: objValidationState,
						address: address
					};
					formulaParser.evaluate(opts, function (err, res) {
						if (res === null)
							return cb(err.bounce_message || "formula " + f + " failed: " + err);
						replace(obj, name, path, locals, cb);
					});
				}
			);
		}
		else if (typeof value === 'object' && (typeof value.if === 'string' || typeof value.init === 'string')) {
			function evaluateIf(cb2) {
				if (typeof value.if !== 'string')
					return cb2();
				var f = getFormula(value.if);
				if (f === null)
					return cb("if is not a formula: " + value.if);
				var opts = {
					conn: conn,
					formula: f,
					trigger: trigger,
					params: params,
					locals: locals,
					stateVars: stateVars,
					responseVars: responseVars,
					objValidationState: objValidationState,
					address: address
				};
				formulaParser.evaluate(opts, function (err, res) {
					if (res === null)
						return cb(err.bounce_message || "formula " + value.if + " failed: " + err);
					if (!res) {
						if (typeof name === 'string')
							delete obj[name];
						else
							assignField(obj, name, null); // will be removed
						return cb();
					}
					delete value.if;
					cb2();
				});
			}
			evaluateIf(function () {
				if (typeof value.init !== 'string')
					return replace(obj, name, path, locals, cb);
				var f = getFormula(value.init);
				if (f === null)
					return cb("init is not a formula: " + value.init);
				var opts = {
					conn: conn,
					formula: f,
					trigger: trigger,
					params: params,
					locals: locals,
					stateVars: stateVars,
					responseVars: responseVars,
					bStatementsOnly: true,
					objValidationState: objValidationState,
					address: address
				};
				formulaParser.evaluate(opts, function (err, res) {
					if (res === null)
						return cb(err.bounce_message || "formula " + value.init + " failed: " + err);
					delete value.init;
					replace(obj, name, path, locals, cb);
				});
			});
		}
		else if (Array.isArray(value)) {
			async.eachOfSeries(
				value,
				function (elem, i, cb2) {
					replace(value, i, path, _.clone(locals), cb2);
				},
				function (err) {
					if (err)
						return cb(err);
					var replacement_value = value.filter(function (elem) { return (elem !== null); });
					if (replacement_value.length === 0) {
						if (typeof name === 'string')
							delete obj[name];
						else
							assignField(obj, name, null); // to be removed
						return cb();
					}
					assignField(obj, name, replacement_value);
					cb();
				}
			);
		}
		else if (isNonemptyObject(value)) {
			async.eachSeries(
				Object.keys(value),
				function (key, cb2) {
					replace(value, key, path + '/' + key, _.clone(locals), cb2);
				},
				function (err) {
					if (err)
						return cb(err);
					if (Object.keys(value).length === 0) {
						if (typeof name === 'string')
							delete obj[name];
						else
							assignField(obj, name, null); // to be removed
						return cb();
					}
					cb();
				}
			);
		}
		else
			throw Error('unknown type of value in ' + name);
	}

	function pickParents(handleParents) {
		if (trigger_opts.bAir)
			throw Error("pickParents shouldn't be called with bAir");
		// first look for a chain of AAs stemming from the MC unit
		conn.query(
			"SELECT units.unit \n\
			FROM units CROSS JOIN unit_authors USING(unit) CROSS JOIN aa_addresses USING(address) \n\
			WHERE latest_included_mc_index=? AND aa_addresses.mci<=? \n\
			ORDER BY level DESC LIMIT 1",
			[mci, mci],
			function (rows) {
				if (rows.length > 0)
					return handleParents([rows[0].unit]);
				// next, check if there is an AA stemming from a recent MCI
				conn.query(
					"SELECT units.unit, latest_included_mc_index \n\
					FROM units CROSS JOIN unit_authors USING(unit) CROSS JOIN aa_addresses USING(address) \n\
					WHERE (main_chain_index>? OR main_chain_index IS NULL) AND aa_addresses.mci<=? \n\
					ORDER BY latest_included_mc_index DESC, level DESC LIMIT 1",
					[mci, mci],
					function (rows) {
						if (rows.length > 0) {
							var row = rows[0];
							if (row.latest_included_mc_index >= mci)
								throw Error("limci of last AA > mci");
							return handleParents([row.unit, objMcUnit.unit].sort());
						}
						handleParents([objMcUnit.unit]);
					}
				);
			}
		);
	}

	var bBouncing = false;
	function bounce(error) {
		console.log('bouncing with error', error, new Error().stack);
		objStateUpdate = null;
		error_message = error_message ? (error_message + ', then ' + error) : error;
		if (trigger_opts.bAir) {
			assignObject(stateVars, originalStateVars); // restore state vars
			assignObject(trigger_opts.assocBalances, originalBalances); // restore balances
			if (!bSecondary) {
				for (let a in trigger.outputs)
					if (bounce_fees[a])
						trigger_opts.assocBalances[address][a] = (trigger_opts.assocBalances[address][a] || 0) + bounce_fees[a];
			}
		}
		if (bBouncing)
			return finish(null);
		bBouncing = true;
		if (bSecondary)
			return finish(null);
		if ((trigger.outputs.base || 0) < bounce_fees.base)
			return finish(null);
		var messages = [];
		for (var asset in trigger.outputs) {
			var amount = trigger.outputs[asset];
			var fee = bounce_fees[asset] || 0;
			if (fee > amount)
				return finish(null);
			if (fee === amount)
				continue;
			var bounced_amount = amount - fee;
			messages.push({app: 'payment', payload: {asset: asset, outputs: [{address: trigger.address, amount: bounced_amount}]}});
		}
		if (messages.length === 0)
			return finish(null);
		sendUnit(messages);
	}

	// with bAir option, we don't send or save a real unit
	function sendDummyUnit(messages) {
		console.log('AA ' + address + ': send dummy unit with messages', JSON.stringify(messages, null, '\t'));
		var objUnit = messages.length ? {
			unit: 'dummy' + Date.now(),
			authors: [{ address: address }],
			messages: messages,
		} : null;
		executeStateUpdateFormula(objUnit, function (err) {
			if (err)
				return bounce(err);
			// update balances
			var arrOutputAddresses = [];
			messages.forEach(message => {
				if (message.app !== 'payment')
					return;
				var asset = message.payload.asset || 'base';
				message.payload.outputs.forEach(output => {
					if (output.amount !== 0 && arrOutputAddresses.indexOf(output.address) === -1)
						arrOutputAddresses.push(output.address);
					if (!trigger_opts.assocBalances[address][asset])
						trigger_opts.assocBalances[address][asset] = 0;
					if (output.amount === undefined) // send all
						output.amount = trigger_opts.assocBalances[address][asset];
					// deduct from this AA's balance. It can get negative if we are issuing coins but in this case balance[] is probably meaningless
					trigger_opts.assocBalances[address][asset] -= output.amount;
				});
			});
			if (arrOutputAddresses.length === 0)
				return finish(objUnit);
			if (trigger_opts.assocBalances[address].base < 0)
				return bounce("not enough balance in base");
			let arrAssetsWithNegativeBalances = [];
			for (let asset in trigger_opts.assocBalances[address])
				if (asset !== 'base' && trigger_opts.assocBalances[address][asset] < 0)
					arrAssetsWithNegativeBalances.push(asset);
			async.eachSeries(
				arrAssetsWithNegativeBalances,
				function (asset, cb) {
					storage.loadAssetWithListOfAttestedAuthors(conn, asset, mci, [address], true, function (err, objAsset) {
						if (err)
							return cb(err);
						if (objAsset.issued_by_definer_only && address !== objAsset.definer_address)
							return cb("not enough balance in " + asset); // and we are not the issuer
						cb();
					});
				},
				function (err) {
					if (err)
						return bounce(err);
					fixStateVars();
					addResponse(objUnit, function () {
						handleSecondaryTriggers(objUnit, arrOutputAddresses);
					});
				}
			);
		});
	}

	function sendUnit(messages) {
		if (trigger_opts.bAir)
			return sendDummyUnit(messages);
		console.log('send unit with messages', JSON.stringify(messages, null, '\t'));
		var arrUsedOutputIds = [];
		var arrConsumedOutputs = [];

		function completeMessage(message) {
			message.payload_location = 'inline';
			message.payload_hash = objectHash.getBase64Hash(message.payload, true);
		}

		function completePaymentPayload(payload, size, cb) {
			var asset = payload.asset || null;
			var is_base = (asset === null) ? 1 : 0;
			if (!payload.inputs && bWithKeys && is_base)
				size += "inputs".length;
			payload.inputs = [];
			var total_amount = 0;

			var send_all_outputs = payload.outputs.filter(function (output) { return (output.amount === undefined); });
			if (send_all_outputs.length > 1)
				return cb(send_all_outputs.length + " send-all outputs");
			var send_all_output = send_all_outputs[0];
			// send-all output looks like {address: "BASE32"}, its size is 32 since it has no amount.
			// remove the send-all output from size calculation, it might be added later
			if (send_all_output && is_base){
				size -= 32 + (bWithKeys ? "address".length : 0);
				// we add a change output to AA to keep balance above storage_size
				if (storage_size > FULL_TRANSFER_INPUT_SIZE && mci >= constants.aaStorageSizeUpgradeMci){
					size += OUTPUT_SIZE + (bWithKeys ? OUTPUT_KEYS_SIZE : 0);
					payload.outputs.push({ address: address, amount: storage_size });
				}
			}
			const paid_temp_data_fee = objectLength.getPaidTempDataFee({ messages });
			var net_target_amount = payload.outputs.reduce(function (acc, output) { return acc + (output.amount || 0); }, size);
			let target_amount = net_target_amount + getOversizeFee(size);
			var bFound = false;

			function getOversizeFee(s) {
				return (mci >= constants.v4UpgradeMci && is_base) ? storage.getOversizeFee(s - paid_temp_data_fee, mci) : 0;
			}

			function iterateUnspentOutputs(rows) {
				for (var i = 0; i < rows.length; i++){
					var row = rows[i];
					var input = { unit: row.unit, message_index: row.message_index, output_index: row.output_index };
					arrUsedOutputIds.push(row.output_id);
					arrConsumedOutputs.push({asset: asset || 'base', amount: row.amount});
					payload.inputs.push(input);
					total_amount += row.amount;
					if (is_base) {
						net_target_amount += FULL_TRANSFER_INPUT_SIZE;
						size += FULL_TRANSFER_INPUT_SIZE;
						target_amount = net_target_amount + getOversizeFee(size);
					}
					if (total_amount < target_amount)
						continue;
					if (total_amount === target_amount && payload.outputs.length > 0) {
						bFound = true;
						if (send_all_output)
							continue;
						else
							break;
					}
					var additional_output_size = is_base ? OUTPUT_SIZE + (bWithKeys ? OUTPUT_KEYS_SIZE : 0) : 0; // the same for send-all
					var change_amount = total_amount - (net_target_amount + additional_output_size + getOversizeFee(size + additional_output_size));
					if (change_amount > 0) {
						bFound = true;
						if (send_all_output) {
							console.log("change " + change_amount + ", storage_size " + storage_size);
							send_all_output.amount = change_amount;
						}
						else {
							payload.outputs.push({ address: address, amount: change_amount });
							break;
						}
					}
				}
			}

			function readStableOutputs(handleRows) {
			//	console.log('--- readStableOutputs');
				// byte outputs less than 60 bytes (which are net negative) are ignored to prevent dust attack: spamming the AA with very small outputs so that the AA spends all its money for fees when it tries to respond
				conn.query(
					"SELECT unit, message_index, output_index, amount, output_id \n\
					FROM outputs \n\
					CROSS JOIN units USING(unit) \n\
					WHERE address=? AND asset"+(asset ? "="+conn.escape(asset) : " IS NULL AND amount>=" + FULL_TRANSFER_INPUT_SIZE)+" AND is_spent=0 \n\
						AND sequence='good' AND main_chain_index<=? \n\
						AND output_id NOT IN("+(arrUsedOutputIds.length === 0 ? "-1" : arrUsedOutputIds.join(', '))+") \n\
					ORDER BY main_chain_index, unit, output_index", // sort order must be deterministic
					[address, mci], handleRows
				);
			}

			function readUnstableOutputsSentByAAs(handleRows) {
			//	console.log('--- readUnstableOutputsSentByAAs');
				conn.query(
					"SELECT outputs.unit, message_index, output_index, amount, output_id \n\
					FROM outputs \n\
					CROSS JOIN units USING(unit) \n\
					CROSS JOIN unit_authors USING(unit) \n\
					CROSS JOIN aa_addresses ON unit_authors.address=aa_addresses.address \n\
					WHERE outputs.address=? AND asset"+(asset ? "="+conn.escape(asset) : " IS NULL AND amount>="+FULL_TRANSFER_INPUT_SIZE)+" AND is_spent=0 \n\
						AND sequence='good' AND (main_chain_index>? OR main_chain_index IS NULL) \n\
						AND output_id NOT IN("+(arrUsedOutputIds.length === 0 ? "-1" : arrUsedOutputIds.join(', '))+") \n\
					ORDER BY latest_included_mc_index, level, outputs.unit, output_index", // sort order must be deterministic
					[address, mci], handleRows
				);
			}

			function issueAsset(cb2) {
				var objAsset = assetInfos[asset];
				if (objAsset.issued_by_definer_only && address !== objAsset.definer_address)
					return cb2("not a definer");
				var issue_amount = objAsset.cap || (target_amount - total_amount);

				function addIssueInput(serial_number){
					var input = {
						type: "issue",
						amount: issue_amount,
						serial_number: serial_number
					};
					payload.inputs.unshift(input);
					total_amount += issue_amount;
					var change_amount = total_amount - target_amount;
					if (change_amount > 0)
						payload.outputs.push({ address: address, amount: change_amount });
					cb2();
				}
				
				if (objAsset.cap) {
					conn.query("SELECT 1 FROM inputs WHERE type='issue' AND asset=?", [asset], function(rows){
						if (rows.length > 0) // already issued
							return cb2('already issued');
						addIssueInput(1);
					});
				}
				else{
					conn.query(
						"SELECT MAX(serial_number) AS max_serial_number FROM inputs WHERE type='issue' AND asset=? AND address=?",
						[asset, address],
						function(rows){
							var max_serial_number = (rows.length === 0) ? 0 : rows[0].max_serial_number;
							addIssueInput(max_serial_number+1);
						}
					);
				}
			}

			function sortOutputsAndReturn() {
				if (send_all_output && send_all_output.amount === undefined)
					_.pull(payload.outputs, send_all_output);
				if (payload.outputs.find(output => typeof output.address !== 'string'))
					return cb("some addresses are not strings");
				payload.outputs.sort(sortOutputs);
				cb();
			}

			readStableOutputs(function (rows) {
				iterateUnspentOutputs(rows);
				if (bFound && !send_all_output)
					return sortOutputsAndReturn();
				readUnstableOutputsSentByAAs(function (rows2) {
					iterateUnspentOutputs(rows2);
					if (bFound)
						return sortOutputsAndReturn();
					if (!asset)
						return cb('not enough funds for ' + target_amount + ' bytes');
					var bSelfIssueForSendAll = mci < (constants.bTestnet ? 2080483 : constants.aa3UpgradeMci);
					if (!bSelfIssueForSendAll && send_all_output && payload.outputs.length === 1) // send-all is the only output - don't issue for it
						return sortOutputsAndReturn();
					issueAsset(function (err) {
						if (err) {
							console.log("issue failed: " + err);
							return cb('not enough funds for ' + target_amount + ' of asset ' + asset);
						}
						sortOutputsAndReturn();
					});
				});
			});
		}

		for (var i = 0; i < messages.length; i++){
			var message = messages[i];
			if (message.app !== 'payment')
				continue;
			var payload = message.payload;
			if (!isNonemptyObject(payload))
				return bounce("payload must be nonempty object");
			if (!Array.isArray(payload.outputs))
				return bounce("outputs must be array"); // empty array is okay
			// negative or fractional
			if (!payload.outputs.every(function (output) { return (isNonnegativeInteger(output.amount) || output.amount === undefined); }))
				return bounce("negative or fractional amounts");
			// filter out 0-outputs
			payload.outputs = payload.outputs.filter(function (output) { return (output.amount > 0 || output.amount === undefined); });
		}
		// remove messages with no outputs
		messages = messages.filter(function (message) { return (message.app !== 'payment' || message.payload.outputs.length > 0); });
		if (messages.length === 0) {
			error_message = 'no messages after removing 0-outputs';
			console.log(error_message);
			return handleSuccessfulEmptyResponseUnit(null);
		}
		var objBasePaymentMessage;
		var arrOutputAddresses = [];
		var assetInfos = {};
		async.eachSeries(
			messages,
			function (message, cb) {
				if (message.app !== 'payment') {
					try {
						if (message.app === 'definition')
							message.payload.address = objectHash.getChash160(message.payload.definition);
						completeMessage(message);
					}
					catch (e) { // may error if there are empty objects or arrays inside
						return cb("some hashes failed: " + e.toString());
					}
					return cb();
				}
				var payload = message.payload;
				var addOutputAddresses = () => {
					payload.outputs.forEach(function (output) {
						if (output.address !== address && arrOutputAddresses.indexOf(output.address) === -1)
							arrOutputAddresses.push(output.address);
					});
				};
				if (payload.asset === 'base')
					delete payload.asset;
				var asset = payload.asset || null;
				if (asset === null) {
					if (objBasePaymentMessage)
						return cb("already have base payment");
					objBasePaymentMessage = message;
					addOutputAddresses();
					return cb(); // skip it for now, we can estimate the fees only after all other messages are in place
				}
				storage.loadAssetWithListOfAttestedAuthors(conn, asset, mci, [address], true, function (err, objAsset) {
					if (err)
						return cb(err);
					assetInfos[asset] = objAsset;
					if (objAsset.fixed_denominations) // will skip it later
						return cb();
					completePaymentPayload(payload, 0, function (err) {
						if (err)
							return cb(err);
						addOutputAddresses();
						if (payload.outputs.length > 0) // send-all output might get removed while being the only output
							completeMessage(message);
						cb();
					});
				});
			},
			function (err) {
				if (err)
					return bounce(err);
				// remove messages with no outputs again (send-all outputs might get removed if nothing found for them)
				messages = messages.filter(function (message) { return (message.app !== 'payment' || message.payload.outputs.length > 0); });
				if (messages.length === 0) {
					error_message = 'no messages after removing 0-outputs (2nd pass)';
					console.log(error_message);
					return handleSuccessfulEmptyResponseUnit(null);
				}
				messages = messages.filter(function (message) { return (message.app !== 'payment' || !message.payload.asset || !assetInfos[message.payload.asset].fixed_denominations); });
				if (messages.length === 0) {
					error_message = 'no messages after removing fixed denominations';
					console.log(error_message);
					return handleSuccessfulEmptyResponseUnit(null);
				}
				if (!objBasePaymentMessage) {
					objBasePaymentMessage = { app: 'payment', payload: { outputs: [] } };
					messages.push(objBasePaymentMessage);
				}
				// add payload_location and wrong payload_hash
				objBasePaymentMessage.payload_location = 'inline';
				objBasePaymentMessage.payload_hash = '-'.repeat(44);
				var objUnit = {
					version: mci >= constants.v4UpgradeMci ? constants.version : (bWithKeys ? constants.version3 : constants.versionWithoutKeySizes), // we should actually use last_ball_mci
					alt: constants.alt,
					timestamp: objMcUnit.timestamp,
					messages: messages,
					authors: [{ address: address }],
					last_ball_unit: objMcUnit.last_ball_unit,
					last_ball: objMcUnit.last_ball,
				};
				if (mci < constants.v4UpgradeMci)
					objUnit.witness_list_unit = objMcUnit.witnesses ? objMcUnit.unit : objMcUnit.witness_list_unit;
			//	else
			//		objUnit.tps_fee = 0;
				pickParents(function (parent_units) {
					objUnit.parent_units = parent_units;
					objUnit.headers_commission = objectLength.getHeadersSize(objUnit);
					objUnit.payload_commission = objectLength.getTotalPayloadSize(objUnit);
					var size = objUnit.headers_commission + objUnit.payload_commission;
					console.log('unit before completing bytes payment', JSON.stringify(objUnit, null, '\t'));
					completePaymentPayload(objBasePaymentMessage.payload, size, function (err) {
					//	console.log('--- completePaymentPayload', err);
						if (err)
							return bounce(err);
						completeMessage(objBasePaymentMessage); // fixes payload_hash
						objUnit.payload_commission = objectLength.getTotalPayloadSize(objUnit);
						const oversize_fee = (mci >= constants.v4UpgradeMci) ? storage.getOversizeFee(objUnit, mci) : 0;
						if (oversize_fee)
							objUnit.oversize_fee = oversize_fee;
						objUnit.unit = objectHash.getUnitHash(objUnit);
						console.log('unit', JSON.stringify(objUnit, null, '\t'))
						executeStateUpdateFormula(objUnit, function (err) {
							if (err)
								return bounce(err);
							validateAndSaveUnit(objUnit, function (err) {
								if (err)
									return bounce(err);
								updateFinalAABalances(arrConsumedOutputs, objUnit, function () {
									if (arrOutputAddresses.length === 0)
										return finish(objUnit);
									fixStateVars();
									addResponse(objUnit, function () {
										updateStorageSize(function (err) {
											if (err)
												return revert(err);
											handleSecondaryTriggers(objUnit, arrOutputAddresses);
										});
									});
								});
							});
						});
					});
				});
			}
		);
	}

	function executeStateUpdateFormula(objResponseUnit, cb) {
		if (bBouncing)
			return cb();
		if (!objStateUpdate) {
			const rv_len = getResponseVarsLength();
			if (rv_len > constants.MAX_RESPONSE_VARS_LENGTH)
				return cb(`response vars too long: ${rv_len}`);
			return cb();
		}
		var opts = {
			conn: conn,
			formula: objStateUpdate.formula,
			trigger: trigger,
			params: params,
			locals: objStateUpdate.locals,
			stateVars: stateVars,
			responseVars: responseVars,
			bStateVarAssignmentAllowed: true,
			bStatementsOnly: true,
			objValidationState: objValidationState,
			address: address,
			objResponseUnit: objResponseUnit
		};
		formulaParser.evaluate(opts, function (err, res) {
		//	console.log('--- state update formula', objStateUpdate.formula, '=', res);
			if (res === null)
				return cb(err.bounce_message || "formula " + objStateUpdate.formula + " failed: "+err);
			const rv_len = getResponseVarsLength();
			if (rv_len > constants.MAX_RESPONSE_VARS_LENGTH)
				return cb(`response vars too long: ${rv_len}`);
			cb();
		});
	}

	function getResponseVarsLength() {
		if (mci < constants.v4UpgradeMci)
			return 0;
		const serializedResponseVars = JSON.stringify(responseVars);
		return serializedResponseVars.length;
	}

	function fixStateVars() {
		if (bBouncing)
			return;
		for (var address in stateVars) {
			var addressVars = stateVars[address];
			for (var var_name in addressVars) {
				var state = addressVars[var_name];
				if (!state.updated)
					continue;
				if (state.value === true)
					state.value = 1; // affects secondary triggers that execute after ours
			}
		}
	}

	function saveStateVars() {
		if (bSecondary || bBouncing || trigger_opts.bAir)
			return;
		for (var address in stateVars) {
			var addressVars = stateVars[address];
			for (var var_name in addressVars) {
				var state = addressVars[var_name];
				if (!state.updated)
					continue;
				var key = "st\n" + address + "\n" + var_name;
				if (state.value === false) // false value signals that the var should be deleted
					batch.del(key);
				else
					batch.put(key, getTypeAndValue(state.value)); // Decimal converted to string, object to json
			}
		}
	}

	function getTypeAndValue(value) {
		if (typeof value === 'string')
			return 's\n' + value;
		else if (typeof value === 'number' || Decimal.isDecimal(value))
			return 'n\n' + value.toString();
		else if (value instanceof wrappedObject)
			return 'j\n' + string_utils.getJsonSourceString(value.obj, true);
		else
			throw Error("state var of unknown type: " + value);	
	}

	function getValueSize(value) {
		if (typeof value === 'string')
			return value.length;
		else if (typeof value === 'number' || Decimal.isDecimal(value))
			return value.toString().length;
		else if (value instanceof wrappedObject)
			return string_utils.getJsonSourceString(value.obj, true).length;
		else
			throw Error("state var of unknown type: " + value);		
	}

	function updateStorageSize(cb) {
		if (bBouncing || trigger_opts.bAir)
			return cb();
		var delta_storage_size = 0;
		var addressVars = stateVars[address] || {};
		for (var var_name in addressVars) {
			var state = addressVars[var_name];
			if (!state.updated)
				continue;
			if (state.value === false) { // false value signals that the var should be deleted
				if (state.original_old_value !== undefined)
					delta_storage_size -= var_name.length + getValueSize(state.original_old_value);
			}
			else {
				if (state.original_old_value !== undefined)
					delta_storage_size += getValueSize(state.value) - getValueSize(state.original_old_value);
				else
					delta_storage_size += var_name.length + getValueSize(state.value);
			}
		}
		console.log('storage size = ' + storage_size + ' + ' + delta_storage_size + ', byte_balance = ' + byte_balance);
		var new_storage_size = storage_size + delta_storage_size;
		if (new_storage_size < 0)
			throw Error("storage size would become negative: " + new_storage_size);
		if (byte_balance < new_storage_size && new_storage_size > FULL_TRANSFER_INPUT_SIZE && mci >= constants.aaStorageSizeUpgradeMci)
			return cb("byte balance " + byte_balance + " would drop below new storage size " + new_storage_size);
		if (delta_storage_size === 0)
			return cb();
		conn.query("UPDATE aa_addresses SET storage_size=? WHERE address=?", [new_storage_size, address], function () {
			cb();
		});
	}

	function updateOriginalOldValues() {
		if (!bSecondary || !stateVars[address])
			return;
		var addressVars = stateVars[address];
		for (var var_name in addressVars) {
			var state = addressVars[var_name];
			if (state.updated)
				state.original_old_value = (state.value === false) ? undefined : state.value;
		}
	}

	function handleSuccessfulEmptyResponseUnit() {
		if (!objStateUpdate)
			return bounce("no state changes");
		executeStateUpdateFormula(null, function (err) {
			if (err) {
				error_message = undefined; // remove error message like 'no messages after filtering'
				return bounce(err);
			}
			finish(null);
		});
	}

	var bAddedResponse = false;
	function addResponse(objResponseUnit, cb) {
		var response_unit = objResponseUnit ? objResponseUnit.unit : null;
		var response = {};
		if (!bBouncing && Object.keys(responseVars).length > 0)
			response.responseVars = responseVars;
		if (error_message) {
			if (bBouncing)
				response.error = error_message;
			else
				response.info = error_message;
		}
		var objAAResponse = {
			mci: mci,
			timestamp: objMcUnit.timestamp,
			trigger_address: trigger.address,
			trigger_initial_address: trigger.initial_address,
			trigger_unit: trigger.unit,
			trigger_initial_unit: trigger.initial_unit,
			aa_address: address,
			bounced: bBouncing,
			response_unit: response_unit,
			objResponseUnit: objResponseUnit,
			response: response,
			balances: objValidationState.assocBalances[address],
		};
		if (objValidationState.logs)
			objAAResponse.logs = objValidationState.logs;
		arrResponses.push(objAAResponse);
		bAddedResponse = true;
		if (trigger_opts.bAir)
			return cb();
		conn.query(
			"INSERT INTO aa_responses (mci, trigger_address, aa_address, trigger_unit, bounced, response_unit, response) \n\
			VALUES (?, ?,?,?, ?,?,?)",
			[mci, trigger.address, address, trigger.unit, bBouncing ? 1 : 0, response_unit, JSON.stringify(response)],
			function (res) {
				storage.last_aa_response_id = res.insertId;
				cb();
			}
		);
	}

	function addUpdatedStateVarsIntoPrimaryResponse() {
		if (bSecondary || bBouncing)
			return;
		var updatedStateVars = {};
		for (var var_address in stateVars) {
			var addressVars = stateVars[var_address];
			for (var var_name in addressVars) {
				var state = addressVars[var_name];
				if (!state.updated)
					continue;
				if (!updatedStateVars[var_address])
					updatedStateVars[var_address] = {};
				var varInfo = {
					value: toJsType(state.value),
				};
				if (state.old_value !== undefined)
					varInfo.old_value = toJsType(state.old_value);
				if (typeof varInfo.value === 'number') {
					if (typeof varInfo.old_value === 'number')
						varInfo.delta = varInfo.value - varInfo.old_value;
				//	else if (varInfo.old_value === undefined || varInfo.old_value === false)
				//		varInfo.delta = varInfo.value;
				}
				assignField(updatedStateVars[var_address], var_name, varInfo);
				if (state.value === false) // deleted variable
					delete addressVars[var_name];
			}
		}
		arrResponses[0].updatedStateVars = updatedStateVars;
	}

	function finish(objResponseUnit) {
		if (bBouncing && bSecondary) {
			if (objResponseUnit)
				throw Error('response_unit with bouncing a secondary AA');
			if (!bAddedResponse && objValidationState.logs) // add the logs from the final bouncing unit
				arrResponses.push({ logs: objValidationState.logs });
			return onDone(null, address + ': ' + error_message);
		}
		fixStateVars();
		saveStateVars();
		addResponse(objResponseUnit, function () {
			updateStorageSize(function (err) {
				if (err)
					return revert(err);
				addUpdatedStateVarsIntoPrimaryResponse();
				onDone(objResponseUnit, bBouncing ? error_message : false);
			});
		});
	}

	function handleSecondaryTriggers(objUnit, arrOutputAddresses) {
		conn.query("SELECT address, definition FROM aa_addresses WHERE address IN(?) AND mci<=? ORDER BY address", [arrOutputAddresses, mci], function (rows) {
			if (rows.length > 0 && constants.bTestnet && mci < testnetAAsDefinedByAAsAreActiveImmediatelyUpgradeMci)
				rows = rows.filter(function (row) {
					var len = storage.getUnconfirmedAADefinitionsPostedByAAs([row.address]).length;
					if (len > 0)
						console.log("not calling secondary trigger from unit " + objUnit.unit + " to AA " + row.address);
					return (len === 0);
				});
			if (rows.length === 0) {
				saveStateVars();
				addUpdatedStateVarsIntoPrimaryResponse();
				return onDone(objUnit, bBouncing ? error_message : false);
			}
			if (bBouncing)
				throw Error("secondary triggers while bouncing");
			async.eachSeries(
				rows,
				function (row, cb) {
					var child_trigger = getTrigger(objUnit, row.address);
					child_trigger.initial_address = trigger.initial_address;
					child_trigger.initial_unit = trigger.initial_unit;
					var arrChildDefinition = JSON.parse(row.definition);

					var child_trigger_opts = Object.assign({}, trigger_opts);
					child_trigger_opts.trigger = child_trigger;
					child_trigger_opts.params = {};
					child_trigger_opts.arrDefinition = arrChildDefinition;
					child_trigger_opts.address = row.address;
					child_trigger_opts.bSecondary = true;
					child_trigger_opts.onDone = function (objSecondaryUnit, bounce_message) {
						if (bounce_message)
							return cb(bounce_message);
						cb();
					};
					handleTrigger(child_trigger_opts);
				},
				function (err) {
					if (err) {
						// revert
						if (bSecondary)
							return bounce(err);
						return revert("one of secondary AAs bounced with error: " + err);
					}
					saveStateVars();
					addUpdatedStateVarsIntoPrimaryResponse();
					onDone(objUnit, bBouncing ? error_message : false);
				}
			);
		});
	}

	function revert(err) {
		console.log('will revert: ' + err);
		if (bSecondary)
			return bounce(err);
		if (!trigger_opts.bAir)
			revertResponsesInCaches(arrResponses);
		
		// copy all logs
		var logs = [];
		arrResponses.forEach(objAAResponse => {
			if (objAAResponse.logs)
				logs = logs.concat(objAAResponse.logs);
		});
		if (logs.length > 0)
			objValidationState.logs = logs;
		
		arrResponses.splice(0, arrResponses.length); // start over
		if (trigger_opts.bAir)
			return bounce(err);
		Object.keys(stateVars).forEach(function (address) { delete stateVars[address]; });
		batch.clear();
		conn.query("ROLLBACK TO SAVEPOINT initial_balances", function () {
			console.log('done revert: ' + err);
			bounce(err);
		});
		/*
		conn.query("ROLLBACK", function () {
			conn.query("BEGIN", function () {
				// initial AA balances were rolled back, we have to add them again
				if (!fPrepare)
					fPrepare = function (cb) { cb(); };
				fPrepare(function () {
					updateInitialAABalances(function () {
						console.log('done revert: ' + err);
						bounce(err);
					});
				});
			});
		});*/
	}

	function validateAndSaveUnit(objUnit, cb) {
		var objJoint = { unit: objUnit, aa: true };
		validation.validate(objJoint, {
			ifJointError: function (err) {
				throw Error("AA validation joint error: " + err);
			},
			ifUnitError: function (err) {
				console.log("AA validation unit error: " + err);
				return cb(err);
			},
			ifTransientError: function (err) {
				throw Error("AA validation transient error: " + err);
			},
			ifNeedHashTree: function () {
				throw Error("AA validation unexpected need hash tree");
			},
			ifNeedParentUnits: function (arrMissingUnits) {
				throw Error("AA validation unexpected dependencies: " + arrMissingUnits.join(", "));
			},
			ifOkUnsigned: function () {
				throw Error("AA validation returned ok unsigned");
			},
			ifOk: function (objAAValidationState, validation_unlock) {
				if (objAAValidationState.sequence !== 'good')
					throw Error("nonserial AA");
				validation_unlock();
				objAAValidationState.bUnderWriteLock = true;
				objAAValidationState.conn = conn;
				objAAValidationState.batch = batch;
				objAAValidationState.initial_trigger_mci = mci;
				writer.saveJoint(objJoint, objAAValidationState, null, function(err){
					if (err)
						throw Error('AA writer returned error: ' + err);
					cb();
				});
			}
		}, conn);
	}


	updateInitialAABalances(function () {

		// these errors must be thrown after updating the balances
		if (arrResponses.length >= constants.MAX_RESPONSES_PER_PRIMARY_TRIGGER) // max number of responses per primary trigger, over all branches stemming from the primary trigger
			return bounce("max number of responses per trigger exceeded");
		if ("max_aa_responses" in trigger && arrResponses.length >= trigger.max_aa_responses)
			return bounce(`max_aa_responses ${trigger.max_aa_responses} exceeded`);
		// being able to pay for bounce fees is not required for secondary triggers as they never actually send any bounce response or change state when bounced
		if (!bSecondary) {
			if ((trigger.outputs.base || 0) < bounce_fees.base) {
				return bounce('received bytes are not enough to cover bounce fees');
			}
			for (var asset in trigger.outputs) { // if not enough asset received to pay for bounce fees, ignore silently
				if (bounce_fees[asset] && trigger.outputs[asset] < bounce_fees[asset]) {
					return bounce('received ' + asset + ' is not enough to cover bounce fees');
				}
			}
		}

		evaluateAA(arrDefinition, function (err) {
			if (err)
				return bounce(err);
			var messages = template.messages;
			if (!messages)
				return bounce('no messages');
			// this will also filter out the special message that performs the state changes
			messages = messages.filter(function (message) { return ('payload' in message && (message.app !== 'payment' || 'outputs' in message.payload)); });
			if (messages.length === 0) { // eat the received coins and send no response, state changes are still performed
				error_message = 'no messages after filtering';
				console.log(error_message);
				return handleSuccessfulEmptyResponseUnit(null);
			}
			messages.forEach(function (message) {
				var payload = message.payload;
				if (message.app === 'asset' && isNonemptyArray(payload.denominations))
					payload.denominations.sort(sortDenominations);
				if ((message.app === 'asset' || message.app === 'asset_attestors') && isNonemptyArray(payload.attestors))
					payload.attestors.sort();
			});
			sendUnit(messages);
		});
	});

}

function sortOutputs(a,b){
	var addr_comparison = a.address.localeCompare(b.address);
	return addr_comparison ? addr_comparison : (a.amount - b.amount);
}

function sortDenominations(a,b){
	return (a.denomination - b.denomination);
}

function revertResponsesInCaches(arrResponses) {
	// remove the rolled back units from caches and correct is_free of their parents if necessary
	console.log('will revert responses ' + JSON.stringify(arrResponses, null, '\t'));
	var arrResponseUnits = [];
	arrResponses.forEach(function (objAAResponse) {
		if (objAAResponse.response_unit)
			arrResponseUnits.push(objAAResponse.response_unit);
	});
	console.log('will revert response units ' + arrResponseUnits.join(', '));
	if (arrResponseUnits.length > 0) {
		var first_unit = arrResponseUnits[0];
		var objFirstUnit = storage.assocUnstableUnits[first_unit];
		var parent_units = objFirstUnit.parent_units;
		arrResponseUnits.forEach(storage.forgetUnit);
		storage.fixIsFreeAfterForgettingUnit(parent_units);
	}
}

function checkStorageSizes() {
	mutex.lockOrSkip(['checkStorageSizes'], function (unlock) {
		db.takeConnectionFromPool(function (conn) { // block conection for the entire duration of the check
			var options = {};
			options.gte = "st\n";
			options.lte = "st\n\uFFFF";

			var assocSizes = {};
			var handleData = function (data) {
				var address = data.key.substr(3, 32);
				var var_name = data.key.substr(36);
				if (!assocSizes[address])
					assocSizes[address] = 0;
				assocSizes[address] += var_name.length + data.value.length - 2; // -2 for type and \n
			}
			var stream = kvstore.createReadStream(options);
			stream.on('data', handleData)
				.on('end', function () {
					conn.query("SELECT address, storage_size FROM aa_addresses", function (rows) {
						rows.forEach(function (row) {
							if (!assocSizes[row.address])
								assocSizes[row.address] = 0;
							if (row.storage_size !== assocSizes[row.address])
								throw Error("storage size mismatch on " + row.address + ": db=" + row.storage_size + ", kv=" + assocSizes[row.address]);
						});
						conn.release();
						unlock();
					});
				})
				.on('error', function (error) {
					throw Error('error from data stream: ' + error);
				});
		});
	});
}

function checkBalances() {
	mutex.lockOrSkip(['checkBalances'], function (unlock) {
		db.takeConnectionFromPool(function (conn) { // block conection for the entire duration of the check
			conn.query("SELECT 1 FROM aa_triggers", function (rows) {
				if (rows.length > 0) {
					console.log("skipping checkBalances because there are unhandled triggers");
					conn.release();
					return unlock();
				}
				var sql_create_temp = "CREATE TEMPORARY TABLE aa_outputs_balances ( \n\
					address CHAR(32) NOT NULL, \n\
					asset CHAR(44) NOT NULL, \n\
					calculated_balance BIGINT NOT NULL, \n\
					PRIMARY KEY (address, asset) \n\
				)" + (conf.storage === 'mysql' ? " ENGINE=MEMORY DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci" : "");
				var sql_fill_temp = "INSERT INTO aa_outputs_balances (address, asset, calculated_balance) \n\
					SELECT address, IFNULL(asset, 'base'), SUM(amount) \n\
					FROM aa_addresses \n\
					CROSS JOIN outputs USING(address) \n\
					CROSS JOIN units ON outputs.unit=units.unit \n\
					WHERE is_spent=0 AND ( \n\
						is_stable=1 \n\
						OR is_stable=0 AND EXISTS (SELECT 1 FROM unit_authors CROSS JOIN aa_addresses USING(address) WHERE unit_authors.unit=outputs.unit) \n\
					) \n\
					GROUP BY address, asset";
				var sql_balances_to_outputs = "SELECT aa_balances.address, aa_balances.asset, balance, calculated_balance \n\
				FROM aa_balances \n\
				LEFT JOIN aa_outputs_balances USING(address, asset) \n\
				GROUP BY aa_balances.address, aa_balances.asset \n\
				HAVING balance != calculated_balance";
				var sql_outputs_to_balances = "SELECT aa_outputs_balances.address, aa_outputs_balances.asset, balance, calculated_balance \n\
				FROM aa_outputs_balances \n\
				LEFT JOIN aa_balances USING(address, asset) \n\
				GROUP BY aa_outputs_balances.address, aa_outputs_balances.asset \n\
				HAVING balance != calculated_balance";
				var sql_drop_temp = db.dropTemporaryTable("aa_outputs_balances");
				
				var stable_or_from_aa = "( \n\
					(SELECT is_stable FROM units WHERE units.unit=outputs.unit)=1 \n\
					OR EXISTS (SELECT 1 FROM unit_authors CROSS JOIN aa_addresses USING(address) WHERE unit_authors.unit=outputs.unit) \n\
				)";
				var sql_base = "SELECT aa_addresses.address, balance, SUM(amount) AS calculated_balance \n\
					FROM aa_addresses \n\
					LEFT JOIN aa_balances ON aa_addresses.address = aa_balances.address AND aa_balances.asset = 'base' \n\
					LEFT JOIN outputs \n\
						ON aa_addresses.address = outputs.address AND is_spent = 0 AND outputs.asset IS NULL \n\
						AND " + stable_or_from_aa + " \n\
					GROUP BY aa_addresses.address \n\
					HAVING balance != calculated_balance";
				var sql_assets_balances_to_outputs = "SELECT aa_balances.address, aa_balances.asset, balance, SUM(amount) AS calculated_balance \n\
					FROM aa_balances \n\
					LEFT JOIN outputs " + db.forceIndex('outputsByAddressSpent') + " \n\
						ON aa_balances.address=outputs.address AND is_spent=0 AND outputs.asset=aa_balances.asset \n\
						AND " + stable_or_from_aa + " \n\
					WHERE aa_balances.asset!='base' \n\
					GROUP BY aa_balances.address, aa_balances.asset \n\
					HAVING balance != calculated_balance";
				var sql_assets_outputs_to_balances = "SELECT aa_addresses.address, outputs.asset, balance, SUM(amount) AS calculated_balance \n\
					FROM aa_addresses \n\
					CROSS JOIN outputs \n\
						ON aa_addresses.address=outputs.address AND is_spent=0 \n\
						AND " + stable_or_from_aa + " \n\
					LEFT JOIN aa_balances ON aa_addresses.address=aa_balances.address AND aa_balances.asset=outputs.asset \n\
					WHERE outputs.asset IS NOT NULL \n\
					GROUP BY aa_addresses.address, outputs.asset \n\
					HAVING balance != calculated_balance";
				async.eachSeries(
				//	[sql_base, sql_assets_balances_to_outputs, sql_assets_outputs_to_balances],
					[sql_create_temp, sql_fill_temp, sql_balances_to_outputs, sql_outputs_to_balances, sql_drop_temp],
					function (sql, cb) {
						conn.query(sql, function (rows) {
							if (!Array.isArray(rows))
								return cb();
							// ignore discrepancies that result from limited precision of js numbers
							rows = rows.filter(row => {
								if (row.balance <= Number.MAX_SAFE_INTEGER || row.calculated_balance <= Number.MAX_SAFE_INTEGER)
									return true;
								var diff = Math.abs(row.balance - row.calculated_balance);
								if (diff > row.balance * 1e-5) // large relative difference cannot result from precision loss
									return true;
								console.log("ignoring balance difference in", row);
								return false;
							});
							if (rows.length > 0)
								throw Error("checkBalances failed: sql:\n" + sql + "\n\nrows:\n" + JSON.stringify(rows, null, '\t'));
							cb();
						});
					},
					function () {
						conn.release();
						unlock();
					}
				);
			});
		});
	});
}

function reintroduceBalanceBug(address, row) {
	if (address === 'XM3EMLR3D3VLKDNPSZSJTSKPKFFXDDHV') row.balance -= 3125;
	if (address === 'FSEIUKVQNYNF5BQE5S46R7ERQDVROVJL') row.balance -= 3337;
	if (address === 'BCHGVAJRLHS3HMA7NMKZ4BO6JQKUW3Q5') row.balance -= 2173;
	if (address === 'H4KE7UKFJOMMBXSQ6YPWNF66AK4WCIHI') row.balance -= 2200;
	if (address === 'W4BXAP5B6CB3VUBTTEWILHDLBH32GW77') row.balance -= 2200;
	if (address === '5MUADPAHD5HODQ2H2I4VJK7LIJP2UWEM') row.balance -= 2173;
	if (address === 'R5XIX3LV56SXLDL2RRU3MTMDEX7KMG7E') row.balance -= 2096;
	if (address === '5G6AIA2SNEKZCHL4CWGRCG6U4YJEMMEG') row.balance -= 2123;
	if (address === 'DVPC3PRVQ52DDBSHMRFOFRDDPG5CUKKG') row.balance -= 2055;
	if (address === 'ZZEC7WHPGVAPHB6TZY5EQNDFMRA3PBFB') row.balance -= 2028;
	if (address === 'X5ZRXFN27AS5AXALITEBJGJAJCGB3HFK') row.balance -= 2019;
	if (address === 'CPTSL3OUMDIEKQ2LJWRO2BDJVRUTH7TZ') row.balance -= 1992;
	if (address === 'AE7RCCPDR2DOSEOSTQA4XP7CSR5SY3WM') row.balance -= 1959;
	if (address === '7SBOUY5ERICX4XHFS42FJJVVAN4YJ3BZ') row.balance -= 1932;
}

if (!conf.bLight) {
	setTimeout(checkStorageSizes, 1000);
	setInterval(checkStorageSizes, 600 * 1000);
	if (typeof window !== 'undefined')
		eventBus.once('app_ready', checkBalances);
	else
		setTimeout(checkBalances, 2000);
	setInterval(checkBalances, CHECK_BALANCES_INTERVAL);
}

exports.getTrigger = getTrigger;
exports.handleAATriggers = handleAATriggers;
exports.handleTrigger = handleTrigger;
exports.validateAATriggerObject = validateAATriggerObject;
exports.dryRunPrimaryAATrigger = dryRunPrimaryAATrigger;
exports.estimatePrimaryAATrigger = estimatePrimaryAATrigger;