// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.base;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.os.Build;
import android.os.Process;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;

import androidx.annotation.RequiresApi;

import org.jni_zero.CalledByNative;
import org.jni_zero.JNINamespace;

import org.chromium.base.compat.ApiHelperForM;
import org.chromium.base.compat.ApiHelperForP;

/** Exposes radio related information about the current device. */
@JNINamespace("base::android")
public class RadioUtils {
    // Cached value indicating if app has ACCESS_NETWORK_STATE permission.
    private static Boolean sHaveAccessNetworkState;
    // Cached value indicating if app has ACCESS_WIFI_STATE permission.
    private static Boolean sHaveAccessWifiState;

    private RadioUtils() {}

    /**
     * Return whether the current SDK supports necessary functions and the app
     * has necessary permissions.
     * @return True or false.
     */
    @CalledByNative
    private static boolean isSupported() {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.P
                && haveAccessNetworkState()
                && haveAccessWifiState();
    }

    private static boolean haveAccessNetworkState() {
        // This could be racy if called on multiple threads, but races will
        // end in the same result so it's not a problem.
        if (sHaveAccessNetworkState == null) {
            sHaveAccessNetworkState =
                    ApiCompatibilityUtils.checkPermission(
                                    ContextUtils.getApplicationContext(),
                                    Manifest.permission.ACCESS_NETWORK_STATE,
                                    Process.myPid(),
                                    Process.myUid())
                            == PackageManager.PERMISSION_GRANTED;
        }
        return sHaveAccessNetworkState;
    }

    private static boolean haveAccessWifiState() {
        // This could be racy if called on multiple threads, but races will
        // end in the same result so it's not a problem.
        if (sHaveAccessWifiState == null) {
            sHaveAccessWifiState =
                    ApiCompatibilityUtils.checkPermission(
                                    ContextUtils.getApplicationContext(),
                                    Manifest.permission.ACCESS_WIFI_STATE,
                                    Process.myPid(),
                                    Process.myUid())
                            == PackageManager.PERMISSION_GRANTED;
        }
        return sHaveAccessWifiState;
    }

    /**
     * Return whether the device is currently connected to a wifi network.
     * @return True or false.
     */
    @CalledByNative
    @RequiresApi(Build.VERSION_CODES.P)
    @SuppressWarnings("AssertionSideEffect") // isSupported() caches via sHaveAccessNetworkState.
    private static boolean isWifiConnected() {
        assert isSupported();
        try (TraceEvent te = TraceEvent.scoped("RadioUtils::isWifiConnected")) {
            ConnectivityManager connectivityManager =
                    (ConnectivityManager)
                            ContextUtils.getApplicationContext()
                                    .getSystemService(Context.CONNECTIVITY_SERVICE);
            Network network = ApiHelperForM.getActiveNetwork(connectivityManager);
            if (network == null) {
                return false;
            }
            NetworkCapabilities networkCapabilities =
                    connectivityManager.getNetworkCapabilities(network);
            if (networkCapabilities == null) {
                return false;
            }
            return networkCapabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI);
        }
    }

    /**
     * Return current cell signal level.
     * @return Signal level from 0 (no signal) to 4 (good signal) or -1 in case of error.
     */
    @CalledByNative
    @RequiresApi(Build.VERSION_CODES.P)
    @SuppressWarnings("AssertionSideEffect") // isSupported() caches via sHaveAccessNetworkState.
    private static int getCellSignalLevel() {
        assert isSupported();
        try (TraceEvent te = TraceEvent.scoped("RadioUtils::getCellSignalLevel")) {
            TelephonyManager telephonyManager =
                    (TelephonyManager)
                            ContextUtils.getApplicationContext()
                                    .getSystemService(Context.TELEPHONY_SERVICE);
            int level = -1;
            try {
                SignalStrength signalStrength = ApiHelperForP.getSignalStrength(telephonyManager);
                if (signalStrength != null) {
                    level = signalStrength.getLevel();
                }
            } catch (java.lang.SecurityException e) {
                // Sometimes SignalStrength.getLevel() requires extra permissions
                // that Chrome doesn't have. See crbug.com/1150536.
            }
            return level;
        }
    }

    /**
     * Return current cell data activity.
     * @return 0 - none, 1 - in, 2 - out, 3 - in/out, 4 - dormant, or -1 in case of error.
     */
    @CalledByNative
    @RequiresApi(Build.VERSION_CODES.P)
    @SuppressWarnings("AssertionSideEffect") // isSupported() caches via sHaveAccessNetworkState.
    private static int getCellDataActivity() {
        assert isSupported();
        try (TraceEvent te = TraceEvent.scoped("RadioUtils::getCellDataActivity")) {
            TelephonyManager telephonyManager =
                    (TelephonyManager)
                            ContextUtils.getApplicationContext()
                                    .getSystemService(Context.TELEPHONY_SERVICE);
            try {
                return telephonyManager.getDataActivity();
            } catch (java.lang.SecurityException e) {
                // Just in case getDataActivity() requires extra permissions.
                return -1;
            }
        }
    }
}