/*
 * Copyright (C) 2025 The Android Open Source Project
 *
 * 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.android.privatespace.filetransfer

import android.content.Context
import androidx.datastore.preferences.core.booleanPreferencesKey
import androidx.datastore.preferences.core.edit
import androidx.datastore.preferences.preferencesDataStore
import kotlinx.coroutines.flow.first
import kotlinx.coroutines.flow.map

/** Interface for managing the writes and reads of the state of file transfer. */
interface IFileTransferStateRepository {
    /** Saves the state of the file transfer. */
    suspend fun saveState(context: Context, keepOriginal: Boolean, transferInProgress: Boolean)

    /** Returns the current state of the file transfer. */
    suspend fun getTransferState(context: Context): TransferState
}

/** Manages the writes and reads of the state of file transfer */
object FileTransferStateRepository : IFileTransferStateRepository {
    private val Context.dataStore by preferencesDataStore(name = FILE_TRANSFER_PREFS_KEY)

    private const val FILE_TRANSFER_PREFS_KEY = "file_transfer_prefs"
    private val KEEP_ORIGINAL_KEY = booleanPreferencesKey("keep_original")
    private val TRANSFER_IN_PROGRESS_KEY = booleanPreferencesKey("transfer_in_progress")

    override suspend fun saveState(
        context: Context,
        keepOriginal: Boolean,
        transferInProgress: Boolean,
    ) {
        context.dataStore.edit { prefs ->
            prefs[KEEP_ORIGINAL_KEY] = keepOriginal
            prefs[TRANSFER_IN_PROGRESS_KEY] = transferInProgress
        }
    }

    /**
     * Returns the current {@link TransferState}.
     *
     * If there is no state saved, it means that no file transfer is in progress. The default value
     * for keepOriginal file is true, while the default for transferInProgress is false
     */
    override suspend fun getTransferState(context: Context): TransferState {
        return context.dataStore.data
            .map { prefs ->
                val keepOriginal = prefs[KEEP_ORIGINAL_KEY] ?: true
                val transferInProgress = prefs[TRANSFER_IN_PROGRESS_KEY] ?: false
                TransferState(keepOriginal, transferInProgress)
            }
            .first()
    }
}