/*
 * Copyright 2022 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.android.fhir.sync

import com.google.android.fhir.LocalChange
import com.google.android.fhir.db.impl.dao.LocalChangeToken
import kotlinx.coroutines.flow.Flow
import org.hl7.fhir.r4.model.Bundle

/** Module for uploading local changes to a [DataSource]. */
internal interface Uploader {

  /**
   * Uploads the local changes to the [DataSource]. Particular implementations should take care of
   * transforming the [SquashedLocalChange]s to particular network operations.
   */
  suspend fun upload(
    localChanges: List<LocalChange>,
  ): Flow<UploadResult>
}

internal sealed class UploadResult {
  data class Success(val localChangeToken: LocalChangeToken, val resource: Bundle) : UploadResult()
  data class Failure(val syncError: ResourceSyncException) : UploadResult()
}
