'use strict';
const { getBooleanOption, cppdb } = require('../util');

module.exports = function defineFunction(name, options, fn) {
	// Apply defaults
	if (options == null) options = {};
	if (typeof options === 'function') { fn = options; options = {}; }

	// Validate arguments
	if (typeof name !== 'string') throw new TypeError('Expected first argument to be a string');
	if (typeof fn !== 'function') throw new TypeError('Expected last argument to be a function');
	if (typeof options !== 'object') throw new TypeError('Expected second argument to be an options object');
	if (!name) throw new TypeError('User-defined function name cannot be an empty string');

	// Interpret options
	const safeIntegers = 'safeIntegers' in options ? +getBooleanOption(options, 'safeIntegers') : 2;
	const deterministic = getBooleanOption(options, 'deterministic');
	const directOnly = getBooleanOption(options, 'directOnly');
	const varargs = getBooleanOption(options, 'varargs');
	let argCount = -1;

	// Determine argument count
	if (!varargs) {
		argCount = fn.length;
		if (!Number.isInteger(argCount) || argCount < 0) throw new TypeError('Expected function.length to be a positive integer');
		if (argCount > 100) throw new RangeError('User-defined functions cannot have more than 100 arguments');
	}

	this[cppdb].function(fn, name, argCount, safeIntegers, deterministic, directOnly);
	return this;
};