/*
Copyright 2021 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 { PostHog } from "posthog-js";
import { MatrixClient } from "matrix-js-sdk/src/matrix";
import { CryptoApi } from "matrix-js-sdk/src/crypto-api";

import { Anonymity, getRedactedCurrentLocation, IPosthogEvent, PosthogAnalytics } from "../src/PosthogAnalytics";
import SdkConfig from "../src/SdkConfig";
import { getMockClientWithEventEmitter } from "./test-utils";
import SettingsStore from "../src/settings/SettingsStore";
import { Layout } from "../src/settings/enums/Layout";
import defaultDispatcher from "../src/dispatcher/dispatcher";
import { Action } from "../src/dispatcher/actions";
import { SettingLevel } from "../src/settings/SettingLevel";

const getFakePosthog = (): PostHog =>
    ({
        capture: jest.fn(),
        init: jest.fn(),
        identify: jest.fn(),
        reset: jest.fn(),
        register: jest.fn(),
        get_distinct_id: jest.fn(),
        persistence: {
            get_property: jest.fn(),
        },
        identifyUser: jest.fn(),
    }) as unknown as PostHog;

interface ITestEvent extends IPosthogEvent {
    eventName: "JestTestEvents";
    foo?: string;
}

describe("PosthogAnalytics", () => {
    let fakePosthog: PostHog;
    const shaHashes: Record<string, string> = {
        "42": "73475cb40a568e8da8a045ced110137e159f890ac4da883b6b17dc651b3a8049",
        "some": "a6b46dd0d1ae5e86cbc8f37e75ceeb6760230c1ca4ffbcb0c97b96dd7d9c464b",
        "pii": "bd75b3e080945674c0351f75e0db33d1e90986fa07b318ea7edf776f5eef38d4",
        "foo": "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae",
    };

    beforeEach(() => {
        fakePosthog = getFakePosthog();

        Object.defineProperty(window, "crypto", {
            value: {
                subtle: {
                    digest: async (_: AlgorithmIdentifier, encodedMessage: BufferSource) => {
                        const message = new TextDecoder().decode(encodedMessage);
                        const hexHash = shaHashes[message];
                        const bytes: number[] = [];
                        for (let c = 0; c < hexHash.length; c += 2) {
                            bytes.push(parseInt(hexHash.slice(c, c + 2), 16));
                        }
                        return bytes;
                    },
                },
            },
        });
    });

    afterEach(() => {
        Object.defineProperty(window, "crypto", {
            value: null,
        });
        SdkConfig.reset(); // we touch the config, so clean up
    });

    describe("Initialisation", () => {
        it("Should not be enabled without config being set", () => {
            // force empty/invalid state for posthog options
            SdkConfig.put({ brand: "Testing" });
            const analytics = new PosthogAnalytics(fakePosthog);
            expect(analytics.isEnabled()).toBe(false);
        });

        it("Should be enabled if config is set", () => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });
            const analytics = new PosthogAnalytics(fakePosthog);
            analytics.setAnonymity(Anonymity.Pseudonymous);
            expect(analytics.isEnabled()).toBe(true);
        });
    });

    describe("Tracking", () => {
        let analytics: PosthogAnalytics;

        beforeEach(() => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });

            analytics = new PosthogAnalytics(fakePosthog);
        });

        it("Should pass event to posthog", () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][0]).toBe("JestTestEvents");
            expect(mocked(fakePosthog).capture.mock.calls[0][1]!["foo"]).toEqual("bar");
        });

        it("Should not track events if anonymous", async () => {
            analytics.setAnonymity(Anonymity.Anonymous);
            await analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(fakePosthog.capture).not.toHaveBeenCalled();
        });

        it("Should not track any events if disabled", async () => {
            analytics.setAnonymity(Anonymity.Disabled);
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
                foo: "bar",
            });
            expect(fakePosthog.capture).not.toHaveBeenCalled();
        });

        it("Should anonymise location of a known screen", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "#/register/some/pii", "/");
            expect(location).toBe("https://foo.bar/#/register/<redacted>");
        });

        it("Should anonymise location of an unknown screen", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "#/not_a_screen_name/some/pii", "/");
            expect(location).toBe("https://foo.bar/#/<redacted_screen_name>/<redacted>");
        });

        it("Should handle an empty hash", async () => {
            const location = getRedactedCurrentLocation("https://foo.bar", "", "/");
            expect(location).toBe("https://foo.bar/");
        });

        it("Should identify the user to posthog if pseudonymous", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);
            const client = getMockClientWithEventEmitter({
                getAccountDataFromServer: jest.fn().mockResolvedValue(null),
                setAccountData: jest.fn().mockResolvedValue({}),
            });
            await analytics.identifyUser(client, () => "analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls[0][0]).toBe("analytics_id");
        });

        it("Should not identify the user to posthog if anonymous", async () => {
            analytics.setAnonymity(Anonymity.Anonymous);
            const client = getMockClientWithEventEmitter({});
            await analytics.identifyUser(client, () => "analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls.length).toBe(0);
        });

        it("Should identify using the server's analytics id if present", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);

            const client = getMockClientWithEventEmitter({
                getAccountDataFromServer: jest.fn().mockResolvedValue({ id: "existing_analytics_id" }),
                setAccountData: jest.fn().mockResolvedValue({}),
            });
            await analytics.identifyUser(client, () => "new_analytics_id");
            expect(mocked(fakePosthog).identify.mock.calls[0][0]).toBe("existing_analytics_id");
        });
    });

    describe("WebLayout", () => {
        let analytics: PosthogAnalytics;

        beforeEach(() => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });

            analytics = new PosthogAnalytics(fakePosthog);
            analytics.setAnonymity(Anonymity.Pseudonymous);
        });

        it("should send layout IRC correctly", async () => {
            await SettingsStore.setValue("layout", null, SettingLevel.DEVICE, Layout.IRC);
            defaultDispatcher.dispatch(
                {
                    action: Action.SettingUpdated,
                    settingName: "layout",
                },
                true,
            );
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][1]!["$set"]).toStrictEqual({
                WebLayout: "IRC",
            });
        });

        it("should send layout Bubble correctly", async () => {
            await SettingsStore.setValue("layout", null, SettingLevel.DEVICE, Layout.Bubble);
            defaultDispatcher.dispatch(
                {
                    action: Action.SettingUpdated,
                    settingName: "layout",
                },
                true,
            );
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][1]!["$set"]).toStrictEqual({
                WebLayout: "Bubble",
            });
        });

        it("should send layout Group correctly", async () => {
            await SettingsStore.setValue("layout", null, SettingLevel.DEVICE, Layout.Group);
            defaultDispatcher.dispatch(
                {
                    action: Action.SettingUpdated,
                    settingName: "layout",
                },
                true,
            );
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][1]!["$set"]).toStrictEqual({
                WebLayout: "Group",
            });
        });

        it("should send layout Compact correctly", async () => {
            await SettingsStore.setValue("layout", null, SettingLevel.DEVICE, Layout.Group);
            await SettingsStore.setValue("useCompactLayout", null, SettingLevel.DEVICE, true);
            defaultDispatcher.dispatch(
                {
                    action: Action.SettingUpdated,
                    settingName: "useCompactLayout",
                },
                true,
            );
            analytics.trackEvent<ITestEvent>({
                eventName: "JestTestEvents",
            });
            expect(mocked(fakePosthog).capture.mock.calls[0][1]!["$set"]).toStrictEqual({
                WebLayout: "Compact",
            });
        });
    });

    describe("CryptoSdk", () => {
        let analytics: PosthogAnalytics;
        const getFakeClient = (): MatrixClient =>
            ({
                getCrypto: jest.fn(),
                setAccountData: jest.fn(),
                // just fake return an `im.vector.analytics` content
                getAccountDataFromServer: jest.fn().mockReturnValue({
                    id: "0000000",
                    pseudonymousAnalyticsOptIn: true,
                }),
            }) as unknown as MatrixClient;

        beforeEach(async () => {
            SdkConfig.put({
                brand: "Testing",
                posthog: {
                    project_api_key: "foo",
                    api_host: "bar",
                },
            });

            analytics = new PosthogAnalytics(fakePosthog);
        });

        // `updateAnonymityFromSettings` is called On page load / login / account data change.
        // We manually call it so we can test the behaviour.
        async function simulateLogin(rustBackend: boolean, pseudonymous = true) {
            // To simulate a switch we call updateAnonymityFromSettings.
            // As per documentation this function is called On login.
            const mockClient = getFakeClient();
            mocked(mockClient.getCrypto).mockReturnValue({
                getVersion: () => {
                    return rustBackend ? "Rust SDK 0.6.0 (9c6b550), Vodozemac 0.5.0" : "Olm 3.2.0";
                },
            } as unknown as CryptoApi);
            await analytics.updateAnonymityFromSettings(mockClient, pseudonymous);
        }

        it("should send rust cryptoSDK superProperty correctly", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);

            await simulateLogin(false);

            expect(mocked(fakePosthog).register.mock.lastCall![0]["cryptoSDK"]).toStrictEqual("Legacy");
        });

        it("should send Legacy cryptoSDK superProperty correctly", async () => {
            analytics.setAnonymity(Anonymity.Pseudonymous);

            await simulateLogin(false);

            // Super Properties are properties associated with events that are set once and then sent with every capture call.
            // They are set using posthog.register
            expect(mocked(fakePosthog).register.mock.lastCall![0]["cryptoSDK"]).toStrictEqual("Legacy");
        });

        it("should send cryptoSDK superProperty when enabling analytics", async () => {
            analytics.setAnonymity(Anonymity.Disabled);

            await simulateLogin(true, false);

            // This initial call is due to the call to register platformSuperProperties
            // The important thing is that the cryptoSDK superProperty is not set.
            expect(mocked(fakePosthog).register.mock.lastCall![0]).toStrictEqual({});

            // switching to pseudonymous should ensure that the cryptoSDK superProperty is set correctly
            analytics.setAnonymity(Anonymity.Pseudonymous);
            // Super Properties are properties associated with events that are set once and then sent with every capture call.
            // They are set using posthog.register
            expect(mocked(fakePosthog).register.mock.lastCall![0]["cryptoSDK"]).toStrictEqual("Rust");
        });
    });
});