/*
	SPDX-FileCopyrightText: © 2025 Hornwitser <code@hornwitser.no>
	SPDX-License-Identifier: AGPL-3.0-or-later
*/
import { ClientMap } from "~/utils/client-map";
import { ClientEntity } from "~/utils/client-entity";
import { ClientUser } from "~/utils/client-user";
import { describe, expect, test } from "vitest";
import { DateTime, FixedOffsetZone } from "~/shared/utils/luxon";
import type { ApiTombstone, ApiUser } from "~/shared/types/api";

const locale = "en-GB";
const now = DateTime.now().setLocale(locale);
const earlier = now.minus({ minutes: 2 });
const later = now.plus({ minutes: 2 });
const zone = now.zone;
const earlierIso = earlier.setZone(FixedOffsetZone.utcInstance).toISO();
const nowIso = now.setZone(FixedOffsetZone.utcInstance).toISO();
const laterIso = later.setZone(FixedOffsetZone.utcInstance).toISO();

function fixtureClientMap() {
	const userA = new ClientUser(1, now, false, "A", "regular");
	const userB = new ClientUser(2, now, false, "B", "regular");

	return new ClientMap(
		ClientUser,
		new Map([
			[userA.id, userA],
			[userB.id, userB],
		]),
		new Map([[5, now.toMillis()]]),
	);
}

function fixtureApiMap(): (ApiUser | ApiTombstone)[] {
	return [
		{
			id: 1,
			updatedAt: nowIso,
			name: "A",
			type: "regular",
		},
		{
			id: 2,
			updatedAt: nowIso,
			name: "B",
			type: "regular",
		},
		{
			id: 5,
			updatedAt: nowIso,
			deleted: true,
		},
	];
}

describe("class ClientMap", () => {
	test("load from api", () => {
		const map = ClientMap.fromApi(ClientUser, fixtureApiMap(), { zone, locale })
		expect(map).toStrictEqual(fixtureClientMap());
	});

	test("save to api", () => {
		const map = fixtureClientMap();
		expect(map.toApi(false)).toEqual(fixtureApiMap())
	});

	// State: - = not deleted, x = deleted
	// Timestamp: n = new, - = now, l = later,


	function userFromPattern(pattern: string, laterIsNow: boolean) {
		const [
			serverState,
			serverTs,
			serverName,
			clientState,
			clientTs,
			clientName,
		] = pattern;
		if (serverName === "-" && clientName === "-")
			return undefined;

		const timestamps: Record<string, DateTime> = {
			"-": now,
			"l": laterIsNow ? now : later,
			"n": DateTime.fromMillis(ClientEntity.newEntityMillis),
		};
		const user = new ClientUser(1, now, false, "", "regular");
		user.serverUpdatedAt = timestamps[serverTs];
		user.serverDeleted = serverState === "x";
		user.serverName = serverName.toUpperCase();
		user.updatedAt = timestamps[clientTs];
		user.deleted = clientState === "x";
		user.name = clientName.toUpperCase();
		return user;
	}

	const updatePatterns = [
		// User pattern:
		// --a--a
		// |||||\- Client name: a, b, or - for no entity
		// ||||\- Client timestamp: n for new, - for now, and l for later
		// |||\- Client state: - not deleted, x marked as deleted or if no entity a tombstone
		// ||\- Server name: a, b, or - for no entity
		// |\- Server timestamp: n for new, - for now, and l for later
		// \- Server state: - not deleted, x marked as deleted or if no entity a tombstone

		// inital-user action expected-user
		// Update with entity
		"--a--a A -la-la",
		"--b--a A -la-la",
		"x-a--a A -la-la",
		"x-b--a A -la-la",
		"-na-na A -la-la",
		"-nb-na A -la-la",
		"--ax-a A -lax-a",
		"--bx-a A -lax-a",
		"x-ax-a A -lax-a",
		"x-bx-a A -lax-a",
		"-naxna A -laxna",
		"-nbxna A -laxna",

		"--a--b A -la--b",
		"--b--b A -la-la",
		"x-a--b A -la--b",
		"x-b--b A -la--b",
		"-na-nb A -la-nb",
		"-nb-nb A -la-nb",
		"--ax-b A -lax-b",
		"--bx-b A -lax-b",
		"x-ax-b A -lax-b",
		"x-bx-b A -lax-b",
		"-naxnb A -laxnb",
		"-nbxnb A -laxnb",

		"x----- A -la-la",
		"------ A -la-la",

		// Update with Tombstone
		"--a--a T xl----",
		"--b--a T xlb--a",
		"x-a--a T xla--a",
		"x-b--a T xlb--a",
		"-na-na T xla-na",
		"-nb-na T xlb-na",
		"--ax-a T xl----",
		"--bx-a T xl----",
		"x-ax-a T xl----",
		"x-bx-a T xl----",
		"-naxna T xl----",
		"-nbxna T xl----",

		"--a--b T xla--b",
		"--b--b T xl----",
		"x-a--b T xla--b",
		"x-b--b T xlb--b",
		"-na-nb T xla-nb",
		"-nb-nb T xlb-nb",
		"--ax-b T xl----",
		"--bx-b T xl----",
		"x-ax-b T xl----",
		"x-bx-b T xl----",
		"-naxnb T xl----",
		"-nbxnb T xl----",

		"x----- T xl----",
		"------ T xl----",
	];
	function tombFromPattern(pattern: string, laterIsNow: boolean) {
		if (pattern[0] === "x") {
			if (pattern[1] === "-")
				return now.toMillis();
			if (pattern[1] === "l")
				return (laterIsNow ? now : later).toMillis();
		}
	}
	for (const pattern of updatePatterns) {
		test(`apply diff pattern ${pattern}`, () => {
			for (const useSameTimestamp of [false, true]) {
				const map = new ClientMap(ClientUser, new Map(), new Map());
				const [startPattern, action, expectedPattern] = pattern.split(" ");
				const user = userFromPattern(startPattern, useSameTimestamp);
				const tomb = tombFromPattern(startPattern, useSameTimestamp);
				if (user)
					map.add(user);
				if (tomb)
					map.tombstones.set(1, tomb);
				// Update
				let update: ApiUser | ApiTombstone;
				if (action === "A") {
					update = {
						id: 1,
						updatedAt: useSameTimestamp ? nowIso : laterIso,
						name: "A",
						type: "regular",
					}
				} else if (action === "T") {
					update = {
						id: 1,
						updatedAt: useSameTimestamp ? nowIso : laterIso,
						deleted: true,
					}
				} else {
					throw new Error(`Unknown action pattern ${action}`)
				}
				map.apiUpdate([update], { zone, locale });
				// Check
				const expectedUser = userFromPattern(expectedPattern, useSameTimestamp);
				const expectedTomb = tombFromPattern(expectedPattern, useSameTimestamp);
				expect(map.get(1)).toEqual(expectedUser);
				expect(map.tombstones.get(1)).toEqual(expectedTomb);
			}
		});
	}

	for (const pattern of updatePatterns) {
		if (pattern[1] === "n" || pattern[2] === "-")
			continue; // Skip tests involving new or missing entities
		test(`ignore diff pattern ${pattern.slice(0, 8)}`, () => {
			for (const useSameTimestamp of [false, true]) {
				const map = new ClientMap(ClientUser, new Map(), new Map());
				const [startPattern, action] = pattern.split(" ");
				const user = userFromPattern(startPattern, useSameTimestamp);
				const tomb = tombFromPattern(startPattern, useSameTimestamp);
				if (user)
					map.add(user);
				if (tomb)
					map.tombstones.set(1, tomb);
				// Update
				let update: ApiUser | ApiTombstone;
				if (action === "A") {
					update = {
						id: 1,
						updatedAt: earlierIso,
						name: "A",
						type: "regular",
					}
				} else if (action === "T") {
					update = {
						id: 1,
						updatedAt: earlierIso,
						deleted: true,
					}
				} else {
					throw new Error(`Unknown action pattern ${action}`)
				}
				map.apiUpdate([update], { zone, locale });
				// Check
				const expectedUser = userFromPattern(startPattern, useSameTimestamp);
				const expectedTomb = tombFromPattern(startPattern, useSameTimestamp);
				expect(map.get(1)).toEqual(expectedUser);
				expect(map.tombstones.get(1)).toEqual(expectedTomb);
			}
		});
	}

	test("create", () => {
		const map = fixtureClientMap();
		const entity = ClientUser.create(3, "New user", "regular", { zone, locale });
		expect(map.isModified()).toBe(false);
		// Create
		map.add(entity);
		// Check
		expect(map.isModified()).toBe(true);
		expect(map.get(entity.id)!.isModified()).toBe(true);
	});
	test("edit", () => {
		const map = fixtureClientMap();
		expect(map.isModified()).toBe(false);
		expect(map.get(1)!.isModified()).toBe(false);
		// Edit
		map.get(1)!.name = "Modified User";
		// Check
		expect(map.isModified()).toBe(true);
		expect(map.get(1)!.isModified()).toBe(true);
	});
	test("delete", () => {
		const map = fixtureClientMap();
		expect(map.isModified()).toBe(false);
		expect(map.get(1)!.isModified()).toBe(false);
		// Delete
		map.get(1)!.deleted = true;
		// Check
		expect(map.isModified()).toBe(true);
		expect(map.get(1)!.isModified()).toBe(true);
	});
});