followers.js

async function followGrant(knex, grantId, userId) {
    return knex.transaction(async (trx) => {
        try {
            await trx('grant_followers').insert({ grant_id: grantId, user_id: userId });
        } catch (err) {
            if (err.code === '23505') { // unique constraint violation
                await trx.rollback();
            } else {
                throw err;
            }
        }
    });
}

async function unfollowGrant(knex, grantId, userId) {
    await knex('grant_followers')
        .where({ grant_id: grantId, user_id: userId })
        .del();
}

async function getFollowerForGrant(knex, grantId, userId) {
    const [grantFollower] = await knex('grant_followers')
        .select(
            'grant_followers.id',
            'grant_followers.grant_id',
            'grant_followers.user_id',
            'grant_followers.created_at',
        )
        .where({ grant_id: grantId, user_id: userId });

    if (!grantFollower) {
        return null;
    }

    return {
        id: grantFollower.id,
        grant: {
            id: grantFollower.grant_id,
        },
        user: {
            id: grantFollower.user_id,
        },
        createdAt: grantFollower.created_at,
    };
}

async function getFollowersForGrant(knex, grantId, organizationId, {
    cursor, limit = 50,
} = {}) {
    const query = knex('grant_followers')
        .select(
            'grant_followers.id',
            'grant_followers.grant_id',
            'grant_followers.user_id',
            'grant_followers.created_at',
            'users.name as user_name',
            'users.email as user_email',
            'users.avatar_color as user_avatar_color',
            'tenants.id as organization_id',
            'tenants.display_name as organization_name',
            'agencies.id as team_id',
            'agencies.name as team_name',
        )
        .join('users', 'users.id', 'grant_followers.user_id')
        .join('agencies', 'agencies.id', 'users.agency_id')
        .join('tenants', 'tenants.id', 'users.tenant_id')
        .where('grant_followers.grant_id', grantId)
        .andWhere('tenants.id', organizationId)
        .orderBy('created_at', 'desc')
        .limit(limit + 1);

    if (cursor) {
        query.andWhere('grant_followers.id', '<', cursor);
    }

    const followersWithLead = await query;
    const hasMore = followersWithLead.length > limit;

    // remove forward looking lead
    const grantFollowers = hasMore
        ? followersWithLead.slice(0, -1)
        : followersWithLead;

    return {
        followers: grantFollowers
            .map((grantFollower) => ({
                id: grantFollower.id,
                createdAt: grantFollower.created_at,
                grant: {
                    id: grantFollower.grant_id,
                },
                user: {
                    id: grantFollower.user_id,
                    name: grantFollower.user_name,
                    email: grantFollower.user_email,
                    avatarColor: grantFollower.user_avatar_color,
                    team: {
                        id: grantFollower.team_id,
                        name: grantFollower.team_name,
                    },
                    organization: {
                        id: grantFollower.organization_id,
                        name: grantFollower.organizationName,
                    },
                },
            })),
        pagination: {
            next: hasMore ? grantFollowers[grantFollowers.length - 1].id : null,
        },
    };
}

module.exports = {
    followGrant, unfollowGrant, getFollowerForGrant, getFollowersForGrant,
};