"use strict";

const expect = require("chai").expect;

const dm = require("../src");

/* FIXME: setOf/mapOf? */
/* FIXME: Type aliases? Both producing and consuming */

describe("registry", () => {
	let registry = dm.createRegistry();

	describe("registry API", () => {
		it("should not expose registry-specific methods on the primary module API", () => {
			expect(dm.type).to.equal(undefined);
			expect(dm.trait).to.equal(undefined);
		});

		it("should expose the createRegistry method on the primary module API", () => {
			expect(dm.createRegistry).to.be.a("function");
		});

		it("should expose registry-specific methods on the registry API", () => {
			expect(registry.type).to.be.a("function");
			expect(registry.trait).to.be.a("function");
		});

		it("should not expose the createRegistry method on the registry API", () => {
			expect(registry.createRegistry).to.equal(undefined);
		});
	});

	describe("registry usage", () => {
		it("should work correctly for types", () => {
			let SimplePerson = registry.createType("SimplePerson", {
				name: dm.string(),
				favouriteGift: registry.type("SimpleGift").optional()
			});

			let SimpleGift = registry.createType("SimpleGift", {
				description: dm.string(),
				from: registry.type("SimplePerson"),
				to: registry.type("SimplePerson")
			});

			let joe = SimplePerson({
				name: "Joe"
			});

			let jane = SimplePerson({
				name: "Jane"
			});

			let flowers = SimpleGift({
				description: "Flowers",
				from: jane,
				to: joe
			});

			joe.favouriteGift = flowers;

			expect(joe.favouriteGift).to.equal(flowers);
			expect(flowers.to).to.equal(joe);
			expect(flowers.from).to.equal(jane);

			expect(() => {
				jane.favouriteGift = "not a gift";
			}).to.throw("Expected an instance of SimpleGift, got a string instead");

			expect(() => {
				flowers.to = "not a person";
			}).to.throw("Expected an instance of SimplePerson, got a string instead");

			expect(() => {
				flowers.to = flowers;
			}).to.throw("Expected an instance of SimplePerson, got an instance of SimpleGift instead");
		});

		it("should work correctly for traits", () => {
			let Givable = registry.createTrait("Givable", {
				from: registry.type("Person"),
				to: registry.type("Person")
			});

			let Person = registry.createType("Person", {
				name: dm.string(),
				favouriteGift: registry.trait("Givable").optional()
			});

			let Gift = registry.createType("Gift", {
				description: dm.string()
			}).implements(Givable, {
				from: dm.slot(),
				to: dm.slot()
			});

			let joe = Person({
				name: "Joe"
			});

			let jane = Person({
				name: "Jane"
			});

			let flowers = Gift({
				description: "Flowers",
				from: jane,
				to: joe
			});

			joe.favouriteGift = flowers;

			expect(joe.favouriteGift).to.equal(flowers);
			expect(flowers.to).to.equal(joe);
			expect(flowers.from).to.equal(jane);

			expect(() => {
				jane.favouriteGift = "not a gift";
			}).to.throw("Expected object of a type with the Givable trait, got a string instead");

			expect(() => {
				flowers.to = "not a person";
			}).to.throw("Expected an instance of Person, got a string instead");

			expect(() => {
				flowers.to = flowers;
			}).to.throw("Expected an instance of Person, got an instance of Gift instead");
		});

		it("should work correctly for type aliases", () => {
			let CheckedString = registry.createType("CheckedString", dm.string({ matches: /^[a-z]+$/ }));

			let SomeType = registry.createType("SomeType", {
				value: registry.type("CheckedString")
			});

			let instance = SomeType({
				value: "foo"
			});

			expect(instance.value).to.equal("foo");

			expect(() => {
				SomeType({
					value: "bar42"
				});
			}).to.throw("Value for property 'value' failed `matches` condition");
		});

		it("should work correctly for guarded maps and sets", () => {
			let SomeNewType = registry.createType("SomeNewType", {
				value: dm.string()
			});

			let SomeOtherType = registry.createType("SomeOtherType", {
				things: dm.setOf(registry.type("SomeNewType")),
				thingsMap: dm.mapOf(dm.string(), registry.type("SomeNewType"))
			});

			let thingOne = SomeNewType({
				value: "one"
			});

			let thingTwo = SomeNewType({
				value: "two"
			});

			let collection = SomeOtherType({
				things: new Set([
					thingOne,
					thingTwo
				]),
				thingsMap: new Map([
					["one", thingOne],
					["two", thingTwo]
				])
			});

			expect(() => {
				SomeOtherType({
					things: new Set([
						"not",
						"things"
					]),
					thingsMap: new Map([
						["one", thingOne],
						["two", thingTwo]
					])
				});
			}).to.throw("Expected an instance of SomeNewType, got a string instead");

			expect(() => {
				SomeOtherType({
					things: new Set([
						thingOne,
						thingTwo
					]),
					thingsMap: new Map([
						["one", "not"],
						["two", "things"]
					])
				});
			}).to.throw("Expected an instance of SomeNewType, got a string instead");
		});

		it("should reject duplicate type registrations", () => {
			registry.createType("DuplicateType", {});

			expect(() => {
				registry.createType("DuplicateType", {});
			}).to.throw("A type named DuplicateType already exists in this registry");
		});

		it("should reject duplicate trait registrations", () => {
			registry.createTrait("DuplicateTrait", {});

			expect(() => {
				registry.createTrait("DuplicateTrait", {});
			}).to.throw("A trait named DuplicateTrait already exists in this registry");
		});

		it("should allow using types from different registries (as well as registry-less types) with one another", () => {
			let registryOne = dm.createRegistry();
			let registryTwo = dm.createRegistry();

			let Item = dm.createType("Item", {
				value: dm.string()
			});

			let ItemOne = registryOne.createType("Item", {
				two: registryTwo.type("Item")
			});

			let ItemTwo = registryTwo.createType("Item", {
				item: Item
			});

			let zero = Item({
				value: "foo"
			});

			let two = ItemTwo({
				item: zero
			});

			let one = ItemOne({
				two: two
			});

			expect(one.two.item.value).to.equal("foo");

			expect(() => {
				ItemOne({
					two: ItemOne({
						two: ItemTwo({
							item: Item({
								value: "bar"
							})
						})
					})
				});
			}).to.throw("Expected an instance of Item, got an instance of Item instead");
			/* TODO: Clarify the error message when the display name of two types is the same. */
		});
	});
});