flexor-web/src/utils/normalization.ts

import {
    EntityType,
    EntityStore,
    Entity,
    User,
    Invitation,
    GroupLog,
} from '../types'

import compact from 'lodash/compact'

export interface NormalizeResult {
    keys: string[]
    entities: EntityStore
}

function set(type: EntityType, store: EntityStore, entity?: Entity): string | undefined {
    if (!entity) return

    const collection = store[type] || {}
    const existing = collection[entity.id] || {}

    collection[entity.id] = {
        ...existing,
        ...entity,
    }

    store[type] = collection
    return entity.id
}

function get(type: EntityType, store: EntityStore, id?: string): Entity | undefined {
    if (!id) return

    const collection = store[type] || {}
    return collection[id]
}

export function normalize(entities: Entity[], type: EntityType): NormalizeResult {
    let keys: Array<string | undefined> = []
    const newStore: EntityStore = {}

    switch (type) {
        case EntityType.User:
            keys = entities.map(entity => {
                const user = entity as User

                return set(type, newStore, {
                    ...user,
                    group: set(EntityType.Group, newStore, user.group),
                })
            })

            break
        case EntityType.Group:
            keys = entities.map(entity => set(type, newStore, entity))
            break
        case EntityType.Invitation:
            keys = entities.map(entity => {
                const invitation = entity as Invitation

                return set(type, newStore, {
                    ...invitation,
                    user: set(EntityType.User, newStore, invitation.user),
                })
            })

            break
        case EntityType.Log:
            keys = entities.map(entity => {
                const log = entity as GroupLog

                return set(type, newStore, {
                    ...log,
                    user: set(EntityType.User, newStore, log.user),
                })
            })

            break
    }

    return {
        keys: compact(keys),
        entities: newStore,
    }
}

export function denormalize(keys: string[], type: EntityType, store: EntityStore): Entity[] {
    const entities = keys.map(key => {
        switch (type) {
            case EntityType.User:
                const user = get(type, store, key)
                if (!user) return

                return {
                    ...user,
                    group: get(EntityType.Group, store, user.group),
                }
            case EntityType.Group:
                return get(type, store, key)
            case EntityType.Invitation:
                const invitation = get(type, store, key)
                if (!invitation) return

                return {
                    ...invitation,
                    user: get(EntityType.User, store, invitation.user)
                }
            case EntityType.Log:
                const log = get(type, store, key)
                if (!log) return

                return {
                    ...log,
                    user: get(EntityType.User, store, log.user)
                }
        }
    })

    return compact(entities)
}