import {} from '../../index.client'
import { maxDate, sdk, verifyId } from '../../../index.client'
import { EntityBase, EntityStorage, EntitySyncMap, SyncMap } from './EntityBase'

/**
 * @param API one of the storage table interfaces.
 * @param DE the corresponding entity class
 */
export class MergeEntity<API extends sdk.EntityTimeStamp, DE extends EntityBase<API>> {
  idMap: Record<number, number>

  constructor(
    public stateArray: API[] | undefined,
    public find: (
      storage: EntityStorage,
      userId: number,
      ei: API,
      syncMap: SyncMap,
      trx?: sdk.TrxToken
    ) => Promise<{ found: boolean; eo: DE; eiId: number }>,
    /** id map for primary id of API and DE object. */
    public esm: EntitySyncMap
  ) {
    this.idMap = esm.idMap
  }

  updateSyncMap(map: Record<number, number>, inId: number, outId: number) {
    const i = verifyId(inId)
    const o = verifyId(outId)
    if (map[i] === undefined) {
      map[i] = o
    } else if (map[i] !== o)
      throw new sdk.WERR_INTERNAL(`updateSyncMap map[${inId}] can't override ${map[i]} with ${o}`)
  }

  /**
   * @param since date of current sync chunk
   */
  async merge(
    since: Date | undefined,
    storage: EntityStorage,
    userId: number,
    syncMap: SyncMap,
    trx?: sdk.TrxToken
  ): Promise<{ inserts: number; updates: number }> {
    let inserts = 0,
      updates = 0
    if (!this.stateArray) return { inserts, updates }
    for (const ei of this.stateArray) {
      this.esm.maxUpdated_at = maxDate(this.esm.maxUpdated_at, ei.updated_at)
      /**
       * TODO:
       * Switch to using syncMap. If the ei id is in the map its an existing merge, else its a new merge.
       */
      try {
        const { found, eo, eiId } = await this.find(storage, userId, ei, syncMap, trx)
        if (found) {
          if (await eo.mergeExisting(storage, since, ei, syncMap, trx)) {
            updates++
          }
        } else {
          await eo.mergeNew(storage, userId, syncMap, trx)
          inserts++
        }
        if (eiId > -1) this.updateSyncMap(this.idMap, eiId, eo.id)
      } catch (eu: unknown) {
        throw eu
      }
    }
    return { inserts, updates }
  }
}