/*
 * Copyright (C) 2019 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 android.net.util

import android.content.Context
import android.content.res.Resources
import android.net.ConnectivityResources
import android.net.NetworkCapabilities
import android.net.NetworkCapabilities.MAX_TRANSPORT
import android.net.NetworkCapabilities.TRANSPORT_CELLULAR
import android.net.NetworkCapabilities.TRANSPORT_ETHERNET
import android.net.NetworkCapabilities.TRANSPORT_VPN
import android.net.NetworkCapabilities.TRANSPORT_WIFI
import android.os.Build
import androidx.test.filters.SmallTest
import com.android.internal.R
import com.android.testutils.DevSdkIgnoreRule
import com.android.testutils.DevSdkIgnoreRunner
import org.junit.After
import org.junit.Assert.assertArrayEquals
import org.junit.Assert.assertEquals
import org.junit.Assert.fail
import org.junit.Test
import org.junit.runner.RunWith
import org.mockito.ArgumentMatchers.eq
import org.mockito.Mockito.any
import org.mockito.Mockito.doReturn
import org.mockito.Mockito.mock

/**
 * Tests for [KeepaliveUtils].
 *
 * Build, install and run with:
 * atest android.net.util.KeepaliveUtilsTest
 */
@RunWith(DevSdkIgnoreRunner::class)
@SmallTest
@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.R)
class KeepaliveUtilsTest {

    // Prepare mocked context with given resource strings.
    private fun getMockedContextWithStringArrayRes(
        id: Int,
        name: String,
        res: Array<out String?>?
    ): Context {
        val mockRes = mock(Resources::class.java)
        doReturn(res).`when`(mockRes).getStringArray(eq(id))
        doReturn(id).`when`(mockRes).getIdentifier(eq(name), any(), any())

        return mock(Context::class.java).apply {
            doReturn(mockRes).`when`(this).getResources()
            ConnectivityResources.setResourcesContextForTest(this)
        }
    }

    @After
    fun tearDown() {
        ConnectivityResources.setResourcesContextForTest(null)
    }

    @Test
    fun testGetSupportedKeepalives() {
        fun assertRunWithException(res: Array<out String?>?) {
            try {
                val mockContext = getMockedContextWithStringArrayRes(
                        R.array.config_networkSupportedKeepaliveCount,
                        "config_networkSupportedKeepaliveCount", res)
                KeepaliveUtils.getSupportedKeepalives(mockContext)
                fail("Expected KeepaliveDeviceConfigurationException")
            } catch (expected: KeepaliveUtils.KeepaliveDeviceConfigurationException) {
            }
        }

        // Check resource with various invalid format.
        assertRunWithException(null)
        assertRunWithException(arrayOf<String?>(null))
        assertRunWithException(arrayOfNulls<String?>(10))
        assertRunWithException(arrayOf(""))
        assertRunWithException(arrayOf("3,ABC"))
        assertRunWithException(arrayOf("6,3,3"))
        assertRunWithException(arrayOf("5"))

        // Check resource with invalid slots value.
        assertRunWithException(arrayOf("3,-1"))

        // Check resource with invalid transport type.
        assertRunWithException(arrayOf("-1,3"))
        assertRunWithException(arrayOf("10,3"))

        // Check valid customization generates expected array.
        val validRes = arrayOf("0,3", "1,0", "4,4")
        val expectedValidRes = intArrayOf(3, 0, 0, 0, 4, 0, 0, 0, 0)

        val mockContext = getMockedContextWithStringArrayRes(
                R.array.config_networkSupportedKeepaliveCount,
                "config_networkSupportedKeepaliveCount", validRes)
        val actual = KeepaliveUtils.getSupportedKeepalives(mockContext)
        assertArrayEquals(expectedValidRes, actual)
    }

    @Test
    fun testGetSupportedKeepalivesForNetworkCapabilities() {
        // Mock customized supported keepalives for each transport type, and assuming:
        //   3 for cellular,
        //   6 for wifi,
        //   0 for others.
        val cust = IntArray(MAX_TRANSPORT + 1).apply {
            this[TRANSPORT_CELLULAR] = 3
            this[TRANSPORT_WIFI] = 6
        }

        val nc = NetworkCapabilities()
        // Check supported keepalives with single transport type.
        nc.transportTypes = intArrayOf(TRANSPORT_CELLULAR)
        assertEquals(3, KeepaliveUtils.getSupportedKeepalivesForNetworkCapabilities(cust, nc))

        // Check supported keepalives with multiple transport types.
        nc.transportTypes = intArrayOf(TRANSPORT_WIFI, TRANSPORT_VPN)
        assertEquals(0, KeepaliveUtils.getSupportedKeepalivesForNetworkCapabilities(cust, nc))

        // Check supported keepalives with non-customized transport type.
        nc.transportTypes = intArrayOf(TRANSPORT_ETHERNET)
        assertEquals(0, KeepaliveUtils.getSupportedKeepalivesForNetworkCapabilities(cust, nc))

        // Check supported keepalives with undefined transport type.
        nc.transportTypes = intArrayOf(MAX_TRANSPORT + 1)
        try {
            KeepaliveUtils.getSupportedKeepalivesForNetworkCapabilities(cust, nc)
            fail("Expected ArrayIndexOutOfBoundsException")
        } catch (expected: ArrayIndexOutOfBoundsException) {
        }
    }
}