import { register } from 'prom-client';
import EventEmitter from 'events';
import { IEventStore } from './types/stores/event-store';
import { createTestConfig } from '../test/config/test-config';
import { DB_TIME, REQUEST_TIME } from './metric-events';
import {
    CLIENT_METRICS,
    CLIENT_REGISTER,
    FEATURE_ENVIRONMENT_ENABLED,
    FEATURE_UPDATED,
} from './types/events';
import { createMetricsMonitor } from './metrics';
import createStores from '../test/fixtures/store';
import { InstanceStatsService } from './features/instance-stats/instance-stats-service';
import VersionService from './services/version-service';
import { createFakeGetActiveUsers } from './features/instance-stats/getActiveUsers';
import { createFakeGetProductionChanges } from './features/instance-stats/getProductionChanges';
import { IEnvironmentStore, IUnleashStores } from './types';
import FakeEnvironmentStore from './features/project-environments/fake-environment-store';

const monitor = createMetricsMonitor();
const eventBus = new EventEmitter();
const prometheusRegister = register;
let eventStore: IEventStore;
let environmentStore: IEnvironmentStore;
let statsService: InstanceStatsService;
let stores: IUnleashStores;
beforeAll(() => {
    const config = createTestConfig({
        server: {
            serverMetrics: true,
        },
    });
    stores = createStores();
    eventStore = stores.eventStore;
    environmentStore = new FakeEnvironmentStore();
    stores.environmentStore = environmentStore;
    const versionService = new VersionService(
        stores,
        config,
        createFakeGetActiveUsers(),
        createFakeGetProductionChanges(),
    );
    statsService = new InstanceStatsService(
        stores,
        config,
        versionService,
        createFakeGetActiveUsers(),
        createFakeGetProductionChanges(),
    );

    const db = {
        client: {
            pool: {
                min: 0,
                max: 4,
                numUsed: () => 2,
                numFree: () => 2,
                numPendingAcquires: () => 0,
                numPendingCreates: () => 1,
            },
        },
    };
    // @ts-ignore - We don't want a full knex implementation for our tests, it's enough that it actually yields the numbers we want.
    monitor.startMonitoring(
        config,
        stores,
        '4.0.0',
        eventBus,
        statsService,
        //@ts-ignore
        db,
    );
});
afterAll(() => {
    monitor.stopMonitoring();
});

test('should collect metrics for requests', async () => {
    eventBus.emit(REQUEST_TIME, {
        path: 'somePath',
        method: 'GET',
        statusCode: 200,
        time: 1337,
    });

    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(
        /http_request_duration_milliseconds\{quantile="0\.99",path="somePath",method="GET",status="200",appName="undefined"\}.*1337/,
    );
});

test('should collect metrics for updated toggles', async () => {
    stores.eventStore.emit(FEATURE_UPDATED, {
        featureName: 'TestToggle',
        project: 'default',
        data: { name: 'TestToggle' },
    });

    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(
        /feature_toggle_update_total\{toggle="TestToggle",project="default",environment="default",environmentType="production"\} 1/,
    );
});

test('should set environmentType when toggle is flipped', async () => {
    await environmentStore.create({
        name: 'testEnvironment',
        enabled: true,
        type: 'testType',
        sortOrder: 1,
    });
    stores.eventStore.emit(FEATURE_ENVIRONMENT_ENABLED, {
        featureName: 'TestToggle',
        project: 'default',
        environment: 'testEnvironment',
        data: { name: 'TestToggle' },
    });

    // Wait for event to be processed, not nice, but it works.
    await new Promise((done) => {
        setTimeout(done, 1);
    });
    const metrics = await prometheusRegister.metrics();

    expect(metrics).toMatch(
        /feature_toggle_update_total\{toggle="TestToggle",project="default",environment="testEnvironment",environmentType="testType"\} 1/,
    );
});

test('should collect metrics for client metric reports', async () => {
    eventBus.emit(CLIENT_METRICS, {
        bucket: {
            toggles: {
                TestToggle: {
                    yes: 10,
                    no: 5,
                },
            },
        },
    });

    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(
        /feature_toggle_usage_total\{toggle="TestToggle",active="true",appName="undefined"\} 10\nfeature_toggle_usage_total\{toggle="TestToggle",active="false",appName="undefined"\} 5/,
    );
});

test('should collect metrics for db query timings', async () => {
    eventBus.emit(DB_TIME, {
        store: 'foo',
        action: 'bar',
        time: 0.1337,
    });

    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(
        /db_query_duration_seconds\{quantile="0\.99",store="foo",action="bar"\} 0.1337/,
    );
});

test('should collect metrics for feature toggle size', async () => {
    await new Promise((done) => {
        setTimeout(done, 10);
    });
    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(/feature_toggles_total\{version="(.*)"\} 0/);
});

test('should collect metrics for total client apps', async () => {
    await new Promise((done) => {
        setTimeout(done, 10);
    });
    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(/client_apps_total\{range="(.*)"\} 0/);
});

test('Should collect metrics for database', async () => {
    const metrics = await prometheusRegister.metrics();
    expect(metrics).toMatch(/db_pool_max/);
    expect(metrics).toMatch(/db_pool_min/);
    expect(metrics).toMatch(/db_pool_used/);
    expect(metrics).toMatch(/db_pool_free/);
    expect(metrics).toMatch(/db_pool_pending_creates/);
    expect(metrics).toMatch(/db_pool_pending_acquires/);
});

test('Should collect metrics for client sdk versions', async () => {
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-node:3.2.5',
    });
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-node:3.2.5',
    });
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-node:3.2.5',
    });
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-java:5.0.0',
    });
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-java:5.0.0',
    });
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-java:5.0.0',
    });
    const metrics = await prometheusRegister.getSingleMetricAsString(
        'client_sdk_versions',
    );
    expect(metrics).toMatch(
        /client_sdk_versions\{sdk_name="unleash-client-node",sdk_version="3\.2\.5"\} 3/,
    );
    expect(metrics).toMatch(
        /client_sdk_versions\{sdk_name="unleash-client-java",sdk_version="5\.0\.0"\} 3/,
    );
    eventStore.emit(CLIENT_REGISTER, {
        sdkVersion: 'unleash-client-node:3.2.5',
    });
    const newmetrics = await prometheusRegister.getSingleMetricAsString(
        'client_sdk_versions',
    );
    expect(newmetrics).toMatch(
        /client_sdk_versions\{sdk_name="unleash-client-node",sdk_version="3\.2\.5"\} 4/,
    );
});

test('Should not collect client sdk version if sdkVersion is of wrong format or non-existent', async () => {
    eventStore.emit(CLIENT_REGISTER, { sdkVersion: 'unleash-client-rust' });
    eventStore.emit(CLIENT_REGISTER, {});
    const metrics = await prometheusRegister.getSingleMetricAsString(
        'client_sdk_versions',
    );
    expect(metrics).not.toMatch(/unleash-client-rust/);
});