"use strict";

const assureArray = require("assure-array");
const isPlainObj = require("is-plain-obj");
const defaultValue = require("default-value");
const flat = require("array.prototype.flat");

const matchSpecial = require("@validatem/match-special");
const isPlainObjectValidator = require("@validatem/is-plain-object");
const hasShape = require("@validatem/has-shape");

// FIXME: Write an example.js

module.exports = function normalizeRules(rules, options) {
	let normalizeObjects = defaultValue(options.normalizeObjects, false);

	// TODO: Switch to `Array#flat` once it is available
	let flattened = flat(assureArray(rules));
	let actualRules = flattened.filter((rule) => rule != null);

	if (normalizeObjects) {
		return actualRules.flatMap((rule) => {
			if (isPlainObj(rule) && !matchSpecial(rule)) {
				return [
					isPlainObjectValidator,
					hasShape(rule)
				];
			} else {
				return rule;
			}
		});
	} else {
		return actualRules;
	}
};