/*
Copyright 2024 New Vector Ltd.
Copyright 2019-2022 The Matrix.org Foundation C.I.C.
Copyright 2018 New Vector Ltd

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import { EventEmitter } from "events";
import { Room, RoomMember, EventType, MatrixEvent } from "matrix-js-sdk/src/matrix";
import { KnownMembership } from "matrix-js-sdk/src/types";

import { MatrixClientPeg } from "../../../../src/MatrixClientPeg";
import { PermalinkParts } from "../../../../src/utils/permalinks/PermalinkConstructor";
import {
    makeRoomPermalink,
    makeUserPermalink,
    parsePermalink,
    RoomPermalinkCreator,
} from "../../../../src/utils/permalinks/Permalinks";
import { IConfigOptions } from "../../../../src/IConfigOptions";
import SdkConfig from "../../../../src/SdkConfig";
import { getMockClientWithEventEmitter } from "../../../test-utils";

describe("Permalinks", function () {
    const userId = "@test:example.com";
    const mockClient = getMockClientWithEventEmitter({
        getUserId: jest.fn().mockReturnValue(userId),
        getRoom: jest.fn(),
    });
    mockClient.credentials = { userId };

    const makeMemberWithPL = (roomId: Room["roomId"], userId: string, powerLevel: number): RoomMember => {
        const member = new RoomMember(roomId, userId);
        member.powerLevel = powerLevel;
        return member;
    };

    function mockRoom(
        roomId: Room["roomId"],
        members: RoomMember[],
        serverACLContent?: { deny?: string[]; allow?: string[] },
    ): Room {
        members.forEach((m) => (m.membership = KnownMembership.Join));
        const powerLevelsUsers = members.reduce<Record<string, number>>((pl, member) => {
            if (Number.isFinite(member.powerLevel)) {
                pl[member.userId] = member.powerLevel;
            }
            return pl;
        }, {});

        const room = new Room(roomId, mockClient, userId);

        const powerLevels = new MatrixEvent({
            type: EventType.RoomPowerLevels,
            room_id: roomId,
            state_key: "",
            content: {
                users: powerLevelsUsers,
                users_default: 0,
            },
        });
        const serverACL = serverACLContent
            ? new MatrixEvent({
                  type: EventType.RoomServerAcl,
                  room_id: roomId,
                  state_key: "",
                  content: serverACLContent,
              })
            : undefined;
        const stateEvents = serverACL ? [powerLevels, serverACL] : [powerLevels];
        room.currentState.setStateEvents(stateEvents);

        jest.spyOn(room, "getCanonicalAlias").mockReturnValue(null);
        jest.spyOn(room, "getJoinedMembers").mockReturnValue(members);
        jest.spyOn(room, "getMember").mockImplementation((userId) => members.find((m) => m.userId === userId) || null);

        return room;
    }
    beforeEach(function () {
        jest.clearAllMocks();
    });

    afterAll(() => {
        jest.spyOn(MatrixClientPeg, "get").mockRestore();
    });

    it("should not clean up listeners even if start was called multiple times", () => {
        const room = mockRoom("!fake:example.org", []);
        const getListenerCount = (emitter: EventEmitter) =>
            emitter
                .eventNames()
                .map((e) => emitter.listenerCount(e))
                .reduce((a, b) => a + b, 0);
        const listenerCountBefore = getListenerCount(room.currentState);

        const creator = new RoomPermalinkCreator(room);
        creator.start();
        creator.start();
        creator.start();
        creator.start();
        expect(getListenerCount(room.currentState)).toBeGreaterThan(listenerCountBefore);

        creator.stop();
        expect(getListenerCount(room.currentState)).toBe(listenerCountBefore);
    });

    it("should pick no candidate servers when the room has no members", function () {
        const room = mockRoom("!fake:example.org", []);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should gracefully handle invalid MXIDs", () => {
        const roomId = "!fake:example.org";
        const alice50 = makeMemberWithPL(roomId, "@alice:pl_50:org", 50);
        const room = mockRoom(roomId, [alice50]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
    });

    it("should pick a candidate server for the highest power level user in the room", function () {
        const roomId = "!fake:example.org";
        const alice50 = makeMemberWithPL(roomId, "@alice:pl_50", 50);
        const alice75 = makeMemberWithPL(roomId, "@alice:pl_75", 75);
        const alice95 = makeMemberWithPL(roomId, "@alice:pl_95", 95);
        const room = mockRoom("!fake:example.org", [alice50, alice75, alice95]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(3);
        expect(creator.serverCandidates![0]).toBe("pl_95");
        // we don't check the 2nd and 3rd servers because that is done by the next test
    });

    it("should change candidate server when highest power level user leaves the room", function () {
        const roomId = "!fake:example.org";
        const member95 = makeMemberWithPL(roomId, "@alice:pl_95", 95);

        const room = mockRoom(roomId, [
            makeMemberWithPL(roomId, "@alice:pl_50", 50),
            makeMemberWithPL(roomId, "@alice:pl_75", 75),
            member95,
        ]);
        const creator = new RoomPermalinkCreator(room, null);
        creator.load();
        expect(creator.serverCandidates![0]).toBe("pl_95");
        member95.membership = KnownMembership.Leave;
        // @ts-ignore illegal private property
        creator.onRoomStateUpdate();
        expect(creator.serverCandidates![0]).toBe("pl_75");
        member95.membership = KnownMembership.Join;
        // @ts-ignore illegal private property
        creator.onRoomStateUpdate();
        expect(creator.serverCandidates![0]).toBe("pl_95");
    });

    it("should pick candidate servers based on user population", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [
            makeMemberWithPL(roomId, "@alice:first", 0),
            makeMemberWithPL(roomId, "@bob:first", 0),
            makeMemberWithPL(roomId, "@charlie:first", 0),
            makeMemberWithPL(roomId, "@alice:second", 0),
            makeMemberWithPL(roomId, "@bob:second", 0),
            makeMemberWithPL(roomId, "@charlie:third", 0),
        ]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(3);
        expect(creator.serverCandidates![0]).toBe("first");
        expect(creator.serverCandidates![1]).toBe("second");
        expect(creator.serverCandidates![2]).toBe("third");
    });

    it("should pick prefer candidate servers with higher power levels", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [
            makeMemberWithPL(roomId, "@alice:first", 100),
            makeMemberWithPL(roomId, "@alice:second", 0),
            makeMemberWithPL(roomId, "@bob:second", 0),
            makeMemberWithPL(roomId, "@charlie:third", 0),
        ]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates!.length).toBe(3);
        expect(creator.serverCandidates![0]).toBe("first");
        expect(creator.serverCandidates![1]).toBe("second");
        expect(creator.serverCandidates![2]).toBe("third");
    });

    it("should pick a maximum of 3 candidate servers", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [
            makeMemberWithPL(roomId, "@alice:alpha", 100),
            makeMemberWithPL(roomId, "@alice:bravo", 0),
            makeMemberWithPL(roomId, "@alice:charlie", 0),
            makeMemberWithPL(roomId, "@alice:delta", 0),
            makeMemberWithPL(roomId, "@alice:echo", 0),
        ]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(3);
    });

    it("should not consider IPv4 hosts", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [makeMemberWithPL(roomId, "@alice:127.0.0.1", 100)]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should not consider IPv6 hosts", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [makeMemberWithPL(roomId, "@alice:[::1]", 100)]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should not consider IPv4 hostnames with ports", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [makeMemberWithPL(roomId, "@alice:127.0.0.1:8448", 100)]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should not consider IPv6 hostnames with ports", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [makeMemberWithPL(roomId, "@alice:[::1]:8448", 100)]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should work with hostnames with ports", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(roomId, [makeMemberWithPL(roomId, "@alice:example.org:8448", 100)]);

        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(1);
        expect(creator.serverCandidates![0]).toBe("example.org:8448");
    });

    it("should not consider servers explicitly denied by ACLs", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(
            roomId,
            [
                makeMemberWithPL(roomId, "@alice:evilcorp.com", 100),
                makeMemberWithPL(roomId, "@bob:chat.evilcorp.com", 0),
            ],
            {
                deny: ["evilcorp.com", "*.evilcorp.com"],
                allow: ["*"],
            },
        );
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should not consider servers not allowed by ACLs", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(
            roomId,
            [
                makeMemberWithPL(roomId, "@alice:evilcorp.com", 100),
                makeMemberWithPL(roomId, "@bob:chat.evilcorp.com", 0),
            ],
            {
                deny: [],
                allow: [], // implies "ban everyone"
            },
        );
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(0);
    });

    it("should consider servers not explicitly banned by ACLs", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(
            roomId,
            [
                makeMemberWithPL(roomId, "@alice:evilcorp.com", 100),
                makeMemberWithPL(roomId, "@bob:chat.evilcorp.com", 0),
            ],
            {
                deny: ["*.evilcorp.com"], // evilcorp.com is still good though
                allow: ["*"],
            },
        );
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(1);
        expect(creator.serverCandidates![0]).toEqual("evilcorp.com");
    });

    it("should consider servers not disallowed by ACLs", function () {
        const roomId = "!fake:example.org";
        const room = mockRoom(
            "!fake:example.org",
            [
                makeMemberWithPL(roomId, "@alice:evilcorp.com", 100),
                makeMemberWithPL(roomId, "@bob:chat.evilcorp.com", 0),
            ],
            {
                deny: [],
                allow: ["evilcorp.com"], // implies "ban everyone else"
            },
        );
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        expect(creator.serverCandidates).toBeTruthy();
        expect(creator.serverCandidates!.length).toBe(1);
        expect(creator.serverCandidates![0]).toEqual("evilcorp.com");
    });

    it("should generate an event permalink for room IDs with no candidate servers", function () {
        const room = mockRoom("!somewhere:example.org", []);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        const result = creator.forEvent("$something:example.com");
        expect(result).toBe("https://matrix.to/#/!somewhere:example.org/$something:example.com");
    });

    it("should generate an event permalink for room IDs with some candidate servers", function () {
        const roomId = "!somewhere:example.org";
        const room = mockRoom(roomId, [
            makeMemberWithPL(roomId, "@alice:first", 100),
            makeMemberWithPL(roomId, "@bob:second", 0),
        ]);
        const creator = new RoomPermalinkCreator(room);
        creator.load();
        const result = creator.forEvent("$something:example.com");
        expect(result).toBe("https://matrix.to/#/!somewhere:example.org/$something:example.com?via=first&via=second");
    });

    it("should generate a room permalink for room IDs with some candidate servers", function () {
        mockClient.getRoom.mockImplementation((roomId: Room["roomId"]) => {
            return mockRoom(roomId, [
                makeMemberWithPL(roomId, "@alice:first", 100),
                makeMemberWithPL(roomId, "@bob:second", 0),
            ]);
        });
        const result = makeRoomPermalink(mockClient, "!somewhere:example.org");
        expect(result).toBe("https://matrix.to/#/!somewhere:example.org?via=first&via=second");
    });

    it("should generate a room permalink for room aliases with no candidate servers", function () {
        mockClient.getRoom.mockReturnValue(null);
        const result = makeRoomPermalink(mockClient, "#somewhere:example.org");
        expect(result).toBe("https://matrix.to/#/#somewhere:example.org");
    });

    it("should generate a room permalink for room aliases without candidate servers", function () {
        mockClient.getRoom.mockImplementation((roomId: Room["roomId"]) => {
            return mockRoom(roomId, [
                makeMemberWithPL(roomId, "@alice:first", 100),
                makeMemberWithPL(roomId, "@bob:second", 0),
            ]);
        });
        const result = makeRoomPermalink(mockClient, "#somewhere:example.org");
        expect(result).toBe("https://matrix.to/#/#somewhere:example.org");
    });

    it("should generate a user permalink", function () {
        const result = makeUserPermalink("@someone:example.org");
        expect(result).toBe("https://matrix.to/#/@someone:example.org");
    });

    it("should use permalink_prefix for permalinks", function () {
        const sdkConfigGet = SdkConfig.get;
        jest.spyOn(SdkConfig, "get").mockImplementation((key: keyof IConfigOptions, altCaseName?: string) => {
            if (key === "permalink_prefix") {
                return "https://element.fs.tld";
            } else return sdkConfigGet(key, altCaseName);
        });
        const result = makeUserPermalink("@someone:example.org");
        expect(result).toBe("https://element.fs.tld/#/user/@someone:example.org");
    });

    describe("parsePermalink", () => {
        it("should correctly parse room permalinks with a via argument", () => {
            const result = parsePermalink("https://matrix.to/#/!room_id:server?via=some.org");
            expect(result?.roomIdOrAlias).toBe("!room_id:server");
            expect(result?.viaServers).toEqual(["some.org"]);
        });

        it("should correctly parse room permalink via arguments", () => {
            const result = parsePermalink("https://matrix.to/#/!room_id:server?via=foo.bar&via=bar.foo");
            expect(result?.roomIdOrAlias).toBe("!room_id:server");
            expect(result?.viaServers).toEqual(["foo.bar", "bar.foo"]);
        });

        it("should correctly parse event permalink via arguments", () => {
            const result = parsePermalink(
                "https://matrix.to/#/!room_id:server/$event_id/some_thing_here/foobar" + "?via=m1.org&via=m2.org",
            );
            expect(result?.eventId).toBe("$event_id/some_thing_here/foobar");
            expect(result?.roomIdOrAlias).toBe("!room_id:server");
            expect(result?.viaServers).toEqual(["m1.org", "m2.org"]);
        });

        it("should correctly parse permalinks with http protocol", () => {
            expect(parsePermalink("http://matrix.to/#/@user:example.com")).toEqual(
                new PermalinkParts(null, null, "@user:example.com", null),
            );
        });

        it("should correctly parse permalinks without protocol", () => {
            expect(parsePermalink("matrix.to/#/@user:example.com")).toEqual(
                new PermalinkParts(null, null, "@user:example.com", null),
            );
        });
    });
});