unleash.unleash/src/lib/features/onboarding/onboarding-read-model.ts

import type { Db } from '../../db/db';
import type {
    IOnboardingReadModel,
    InstanceOnboarding,
} from './onboarding-read-model-type';
import { millisecondsToMinutes } from 'date-fns';

interface IOnboardingUser {
    first_login: string;
}
const parseStringToNumber = (value: string): number | null => {
    return Number.isNaN(Number(value)) ? null : Number(value);
};

const calculateTimeDifferenceInMinutes = (date1?: Date, date2?: Date) => {
    if (date1 && date2) {
        const diffInMilliseconds = date2.getTime() - date1.getTime();
        return millisecondsToMinutes(diffInMilliseconds);
    }
    return null;
};

export class OnboardingReadModel implements IOnboardingReadModel {
    private db: Db;

    constructor(db: Db) {
        this.db = db;
    }

    async getInstanceOnboardingMetrics(): Promise<InstanceOnboarding> {
        const firstUserCreatedResult = await this.db('users')
            .select('created_at')
            .orderBy('created_at')
            .first();
        const firstLoginResult = await this.db('users')
            .select('first_seen_at')
            .orderBy('first_seen_at')
            .limit(2);

        const firstInitialResult = await this.db('feature_lifecycles')
            .select('created_at')
            .where('stage', 'initial')
            .orderBy('created_at')
            .first();
        const firstPreLiveResult = await this.db('feature_lifecycles')
            .select('created_at')
            .where('stage', 'pre-live')
            .orderBy('created_at')
            .first();
        const firstLiveResult = await this.db('feature_lifecycles')
            .select('created_at')
            .where('stage', 'live')
            .orderBy('created_at')
            .first();

        const createdAt = firstUserCreatedResult?.created_at;
        const firstLogin = firstLoginResult[0]?.first_seen_at;
        const secondLogin = firstLoginResult[1]?.first_seen_at;
        const firstInitial = firstInitialResult?.created_at;
        const firstPreLive = firstPreLiveResult?.created_at;
        const firstLive = firstLiveResult?.created_at;

        const firstLoginDiff = calculateTimeDifferenceInMinutes(
            createdAt,
            firstLogin,
        );
        const secondLoginDiff = calculateTimeDifferenceInMinutes(
            createdAt,
            secondLogin,
        );
        const firstFlagDiff = calculateTimeDifferenceInMinutes(
            createdAt,
            firstInitial,
        );
        const firstPreLiveDiff = calculateTimeDifferenceInMinutes(
            createdAt,
            firstPreLive,
        );
        const firstLiveDiff = calculateTimeDifferenceInMinutes(
            createdAt,
            firstLive,
        );

        return {
            firstLogin: firstLoginDiff,
            secondLogin: secondLoginDiff,
            firstFeatureFlag: firstFlagDiff,
            firstPreLive: firstPreLiveDiff,
            firstLive: firstLiveDiff,
        };
    }
}