/*
Copyright 2023 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import { Bot } from "../../pages/bot";
import type { Locator, Page } from "@playwright/test";
import type { ElementAppPage } from "../../pages/ElementAppPage";
import { test, expect } from "../../element-web-test";

test.describe("Lazy Loading", () => {
    const charlies: Bot[] = [];

    test.use({
        displayName: "Alice",
        botCreateOpts: { displayName: "Bob" },
    });

    test.beforeEach(async ({ page }) => {
        await page.addInitScript(() => {
            window.localStorage.setItem("mx_lhs_size", "0"); // Collapse left panel for these tests
        });
    });

    test.beforeEach(async ({ page, homeserver, user, bot }) => {
        for (let i = 1; i <= 10; i++) {
            const displayName = `Charly #${i}`;
            const bot = new Bot(page, homeserver, { displayName, startClient: false, autoAcceptInvites: false });
            charlies.push(bot);
        }
    });

    const name = "Lazy Loading Test";
    const alias = "#lltest:localhost";
    const charlyMsg1 = "hi bob!";
    const charlyMsg2 = "how's it going??";
    let roomId: string;

    async function setupRoomWithBobAliceAndCharlies(page: Page, app: ElementAppPage, bob: Bot, charlies: Bot[]) {
        const visibility = await page.evaluate(() => (window as any).matrixcs.Visibility.Public);
        roomId = await bob.createRoom({
            name,
            room_alias_name: "lltest",
            visibility,
        });

        await Promise.all(charlies.map((bot) => bot.joinRoom(alias)));
        for (const charly of charlies) {
            await charly.sendMessage(roomId, charlyMsg1);
        }
        for (const charly of charlies) {
            await charly.sendMessage(roomId, charlyMsg2);
        }

        for (let i = 20; i >= 1; --i) {
            await bob.sendMessage(roomId, `I will only say this ${i} time(s)!`);
        }
        await app.client.joinRoom(alias);
        await app.viewRoomByName(name);
    }

    async function checkPaginatedDisplayNames(app: ElementAppPage, charlies: Bot[]) {
        await app.timeline.scrollToTop();
        for (const charly of charlies) {
            await expect(await app.timeline.findEventTile(charly.credentials.displayName, charlyMsg1)).toBeAttached();
            await expect(await app.timeline.findEventTile(charly.credentials.displayName, charlyMsg2)).toBeAttached();
        }
    }

    async function openMemberlist(page: Page): Promise<void> {
        await page.locator(".mx_LegacyRoomHeader").getByRole("button", { name: "Room info" }).click();
        await page.locator(".mx_RightPanelTabs").getByText("People").click();
    }

    function getMemberInMemberlist(page: Page, name: string): Locator {
        return page.locator(".mx_MemberList .mx_EntityTile_name").filter({ hasText: name });
    }

    async function checkMemberList(page: Page, charlies: Bot[]) {
        await expect(getMemberInMemberlist(page, "Alice")).toBeAttached();
        await expect(getMemberInMemberlist(page, "Bob")).toBeAttached();
        for (const charly of charlies) {
            await expect(getMemberInMemberlist(page, charly.credentials.displayName)).toBeAttached();
        }
    }

    async function checkMemberListLacksCharlies(page: Page, charlies: Bot[]) {
        for (const charly of charlies) {
            await expect(getMemberInMemberlist(page, charly.credentials.displayName)).not.toBeAttached();
        }
    }

    async function joinCharliesWhileAliceIsOffline(page: Page, app: ElementAppPage, charlies: Bot[]) {
        await app.client.network.goOffline();
        for (const charly of charlies) {
            await charly.joinRoom(alias);
        }
        for (let i = 20; i >= 1; --i) {
            await charlies[0].sendMessage(roomId, "where is charly?");
        }
        await app.client.network.goOnline();
        await app.client.waitForNextSync();
    }

    test("should handle lazy loading properly even when offline", async ({ page, app, bot }) => {
        test.slow();
        const charly1to5 = charlies.slice(0, 5);
        const charly6to10 = charlies.slice(5);

        // Set up room with alice, bob & charlies 1-5
        await setupRoomWithBobAliceAndCharlies(page, app, bot, charly1to5);
        // Alice should see 2 messages from every charly with the correct display name
        await checkPaginatedDisplayNames(app, charly1to5);

        await openMemberlist(page);
        await checkMemberList(page, charly1to5);
        await joinCharliesWhileAliceIsOffline(page, app, charly6to10);
        await checkMemberList(page, charly6to10);

        for (const charly of charlies) {
            await charly.evaluate((client, roomId) => client.leave(roomId), roomId);
        }

        await checkMemberListLacksCharlies(page, charlies);
    });
});
