[SP04] Add TestableNetworkStatsProvider

/*

 * Copyright (C) 2020 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.testutils

import android.net.netstats.provider.INetworkStatsProvider

import kotlin.test.assertEquals

import kotlin.test.fail

private const val DEFAULT_TIMEOUT_MS = 200L

open class TestableNetworkStatsProvider : INetworkStatsProvider.Stub() {

    sealed class CallbackType {

        data class RequestUpdate(val token: Int) : CallbackType()

        data class SetLimit(val iface: String?, val quotaBytes: Long) : CallbackType()

        data class SetAlert(val quotaBytes: Long) : CallbackType()

    }

    private val history = ArrayTrackRecord<CallbackType>().ReadHead()

    override fun requestStatsUpdate(token: Int) {

        history.add(CallbackType.RequestUpdate(token))

    }

    override fun setLimit(iface: String?, quotaBytes: Long) {

        history.add(CallbackType.SetLimit(iface, quotaBytes))

    }

    override fun setAlert(quotaBytes: Long) {

        history.add(CallbackType.SetAlert(quotaBytes))

    }

    fun expectStatsUpdate(token: Int) {

        assertEquals(CallbackType.RequestUpdate(token), history.poll(DEFAULT_TIMEOUT_MS))

    }

    fun expectSetLimit(iface: String?, quotaBytes: Long) {

        assertEquals(CallbackType.SetLimit(iface, quotaBytes), history.poll(DEFAULT_TIMEOUT_MS))

    }

    fun expectSetAlert(quotaBytes: Long) {

        assertEquals(CallbackType.SetAlert(quotaBytes), history.poll(DEFAULT_TIMEOUT_MS))

    }

    @JvmOverloads

    fun assertNoCallback(timeout: Long = DEFAULT_TIMEOUT_MS) {

        val cb = history.poll(timeout)

        cb?.let { fail("Expected no callback but got $cb") }

    }

}