/*
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 { mocked } from "jest-mock";
import { MatrixClient, Room } from "matrix-js-sdk/src/matrix";
import { act } from "react-dom/test-utils";

import { createTestClient, flushPromises, setupAsyncStoreWithClient } from "../test-utils";
import SettingsStore from "../../src/settings/SettingsStore";
import { BreadcrumbsStore } from "../../src/stores/BreadcrumbsStore";
import { Action } from "../../src/dispatcher/actions";
import { defaultDispatcher } from "../../src/dispatcher/dispatcher";

describe("BreadcrumbsStore", () => {
    let store: BreadcrumbsStore;
    const client: MatrixClient = createTestClient();

    beforeEach(() => {
        jest.resetAllMocks();
        store = BreadcrumbsStore.instance;
        setupAsyncStoreWithClient(store, client);
        jest.spyOn(SettingsStore, "setValue").mockImplementation(() => Promise.resolve());
    });

    describe("If the feature_breadcrumbs_v2 feature is not enabled", () => {
        beforeEach(() => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue(false);
        });

        it("does not meet room requirements if there are not enough rooms", () => {
            // We don't have enough rooms, so we don't meet requirements
            mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(2));
            expect(store.meetsRoomRequirement).toBe(false);
        });

        it("meets room requirements if there are enough rooms", () => {
            // We do have enough rooms to show breadcrumbs
            mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(25));
            expect(store.meetsRoomRequirement).toBe(true);
        });

        describe("And the feature_dynamic_room_predecessors is enabled", () => {
            beforeEach(() => {
                // Turn on feature_dynamic_room_predecessors setting
                jest.spyOn(SettingsStore, "getValue").mockImplementation(
                    (settingName) => settingName === "feature_dynamic_room_predecessors",
                );
            });

            it("passes through the dynamic room precessors flag", () => {
                mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(25));
                store.meetsRoomRequirement;
                expect(client.getVisibleRooms).toHaveBeenCalledWith(true);
            });
        });

        describe("And the feature_dynamic_room_predecessors is not enabled", () => {
            it("passes through the dynamic room precessors flag", () => {
                mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(25));
                store.meetsRoomRequirement;
                expect(client.getVisibleRooms).toHaveBeenCalledWith(false);
            });
        });
    });

    describe("If the feature_breadcrumbs_v2 feature is enabled", () => {
        beforeEach(() => {
            // Turn on feature_breadcrumbs_v2 setting
            jest.spyOn(SettingsStore, "getValue").mockImplementation(
                (settingName) => settingName === "feature_breadcrumbs_v2",
            );
        });

        it("always meets room requirements", () => {
            // With enough rooms, we meet requirements
            mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(25));
            expect(store.meetsRoomRequirement).toBe(true);

            // And even with not enough we do, because the feature is enabled.
            mocked(client.getVisibleRooms).mockReturnValue(fakeRooms(2));
            expect(store.meetsRoomRequirement).toBe(true);
        });
    });

    describe("If the feature_dynamic_room_predecessors is not enabled", () => {
        beforeEach(() => {
            jest.spyOn(SettingsStore, "getValue").mockReturnValue(false);
        });

        it("Appends a room when you join", async () => {
            // Sanity: no rooms initially
            expect(store.rooms).toEqual([]);

            // Given a room
            const room = fakeRoom();
            mocked(client.getRoom).mockReturnValue(room);
            mocked(client.getRoomUpgradeHistory).mockReturnValue([]);

            // When we hear that we have joined it
            await dispatchJoinRoom(room.roomId);

            // It is stored in the store's room list
            expect(store.rooms.map((r) => r.roomId)).toEqual([room.roomId]);
        });

        it("Replaces the old room when a newer one joins", async () => {
            // Given an old room and a new room
            const oldRoom = fakeRoom();
            const newRoom = fakeRoom();
            mocked(client.getRoom).mockImplementation((roomId) => {
                if (roomId === oldRoom.roomId) return oldRoom;
                return newRoom;
            });
            // Where the new one is a predecessor of the old one
            mocked(client.getRoomUpgradeHistory).mockReturnValue([oldRoom, newRoom]);

            // When we hear that we joined the old room, then the new one
            await dispatchJoinRoom(oldRoom.roomId);
            await dispatchJoinRoom(newRoom.roomId);

            // The store only has the new one
            expect(store.rooms.map((r) => r.roomId)).toEqual([newRoom.roomId]);
        });

        it("Passes through the dynamic predecessor setting", async () => {
            // Given a room
            const room = fakeRoom();
            mocked(client.getRoom).mockReturnValue(room);
            mocked(client.getRoomUpgradeHistory).mockReturnValue([]);

            // When we signal that we have joined
            await dispatchJoinRoom(room.roomId);

            // We pass the value of the dynamic predecessor setting through
            expect(client.getRoomUpgradeHistory).toHaveBeenCalledWith(room.roomId, false, false);
        });
    });

    describe("If the feature_dynamic_room_predecessors is enabled", () => {
        beforeEach(() => {
            // Turn on feature_dynamic_room_predecessors setting
            jest.spyOn(SettingsStore, "getValue").mockImplementation(
                (settingName) => settingName === "feature_dynamic_room_predecessors",
            );
        });

        it("Passes through the dynamic predecessor setting", async () => {
            // Given a room
            const room = fakeRoom();
            mocked(client.getRoom).mockReturnValue(room);
            mocked(client.getRoomUpgradeHistory).mockReturnValue([]);

            // When we signal that we have joined
            await dispatchJoinRoom(room.roomId);

            // We pass the value of the dynamic predecessor setting through
            expect(client.getRoomUpgradeHistory).toHaveBeenCalledWith(room.roomId, false, true);
        });
    });

    /**
     * Send a JoinRoom event via the dispatcher, and wait for it to process.
     */
    async function dispatchJoinRoom(roomId: string) {
        defaultDispatcher.dispatch(
            {
                action: Action.JoinRoom,
                roomId,
                metricsTrigger: null,
            },
            true, // synchronous dispatch
        );

        // Wait for event dispatch to happen
        await act(async () => {
            await flushPromises();
        });
    }

    /**
     * Create as many fake rooms in an array as you ask for.
     */
    function fakeRooms(howMany: number): Array<Room> {
        const ret = [];
        for (let i = 0; i < howMany; i++) {
            ret.push(fakeRoom());
        }
        return ret;
    }

    let roomIdx = 0;

    function fakeRoom(): Room {
        roomIdx++;
        return new Room(`room${roomIdx}`, client, "@user:example.com");
    }
});