/*
 * Copyright (C) 2015 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.settingslib.wifi;

import static android.net.NetworkCapabilities.NET_CAPABILITY_CAPTIVE_PORTAL;
import static android.net.NetworkCapabilities.NET_CAPABILITY_PARTIAL_CONNECTIVITY;
import static android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED;

import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkInfo;
import android.net.NetworkKey;
import android.net.NetworkRequest;
import android.net.NetworkScoreManager;
import android.net.ScoredNetwork;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiNetworkScoreCache;
import android.net.wifi.WifiSsid;
import android.os.Handler;
import android.os.Looper;

import com.android.settingslib.R;

import java.util.List;

public class WifiStatusTracker extends ConnectivityManager.NetworkCallback {
    private final Context mContext;
    private final WifiNetworkScoreCache mWifiNetworkScoreCache;
    private final WifiManager mWifiManager;
    private final NetworkScoreManager mNetworkScoreManager;
    private final ConnectivityManager mConnectivityManager;
    private final Handler mHandler = new Handler(Looper.getMainLooper());
    private final WifiNetworkScoreCache.CacheListener mCacheListener =
            new WifiNetworkScoreCache.CacheListener(mHandler) {
                @Override
                public void networkCacheUpdated(List<ScoredNetwork> updatedNetworks) {
                    updateStatusLabel();
                    mCallback.run();
                }
            };
    private final NetworkRequest mNetworkRequest = new NetworkRequest.Builder()
            .clearCapabilities()
            .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
            .addTransportType(NetworkCapabilities.TRANSPORT_WIFI).build();
    private final ConnectivityManager.NetworkCallback mNetworkCallback = new ConnectivityManager
            .NetworkCallback() {
        @Override
        public void onCapabilitiesChanged(
                Network network, NetworkCapabilities networkCapabilities) {
            updateStatusLabel();
            mCallback.run();
        }
    };
    private final Runnable mCallback;

    private WifiInfo mWifiInfo;
    public boolean enabled;
    public int state;
    public boolean connected;
    public String ssid;
    public int rssi;
    public int level;
    public String statusLabel;

    public WifiStatusTracker(Context context, WifiManager wifiManager,
            NetworkScoreManager networkScoreManager, ConnectivityManager connectivityManager,
            Runnable callback) {
        mContext = context;
        mWifiManager = wifiManager;
        mWifiNetworkScoreCache = new WifiNetworkScoreCache(context);
        mNetworkScoreManager = networkScoreManager;
        mConnectivityManager = connectivityManager;
        mCallback = callback;
    }

    public void setListening(boolean listening) {
        if (listening) {
            mNetworkScoreManager.registerNetworkScoreCache(NetworkKey.TYPE_WIFI,
                    mWifiNetworkScoreCache, NetworkScoreManager.CACHE_FILTER_CURRENT_NETWORK);
            mWifiNetworkScoreCache.registerListener(mCacheListener);
            mConnectivityManager.registerNetworkCallback(
                    mNetworkRequest, mNetworkCallback, mHandler);
        } else {
            mNetworkScoreManager.unregisterNetworkScoreCache(NetworkKey.TYPE_WIFI,
                    mWifiNetworkScoreCache);
            mWifiNetworkScoreCache.unregisterListener();
            mConnectivityManager.unregisterNetworkCallback(mNetworkCallback);
        }
    }

    public void handleBroadcast(Intent intent) {
        String action = intent.getAction();
        if (action.equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) {
            updateWifiState();
        } else if (action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)) {
            updateWifiState();
            final NetworkInfo networkInfo =
                    intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
            connected = networkInfo != null && networkInfo.isConnected();
            mWifiInfo = null;
            ssid = null;
            if (connected) {
                mWifiInfo = mWifiManager.getConnectionInfo();
                if (mWifiInfo != null) {
                    ssid = getValidSsid(mWifiInfo);
                    updateRssi(mWifiInfo.getRssi());
                    maybeRequestNetworkScore();
                }
            }
            updateStatusLabel();
        } else if (action.equals(WifiManager.RSSI_CHANGED_ACTION)) {
            // Default to -200 as its below WifiManager.MIN_RSSI.
            updateRssi(intent.getIntExtra(WifiManager.EXTRA_NEW_RSSI, -200));
            updateStatusLabel();
        }
    }

    private void updateWifiState() {
        state = mWifiManager.getWifiState();
        enabled = state == WifiManager.WIFI_STATE_ENABLED;
    }

    private void updateRssi(int newRssi) {
        rssi = newRssi;
        level = WifiManager.calculateSignalLevel(rssi, WifiManager.RSSI_LEVELS);
    }

    private void maybeRequestNetworkScore() {
        NetworkKey networkKey = NetworkKey.createFromWifiInfo(mWifiInfo);
        if (mWifiNetworkScoreCache.getScoredNetwork(networkKey) == null) {
            mNetworkScoreManager.requestScores(new NetworkKey[]{ networkKey });
        }
    }

    private void updateStatusLabel() {
        final NetworkCapabilities networkCapabilities
                = mConnectivityManager.getNetworkCapabilities(mWifiManager.getCurrentNetwork());
        if (networkCapabilities != null) {
            if (networkCapabilities.hasCapability(NET_CAPABILITY_CAPTIVE_PORTAL)) {
                statusLabel = mContext.getString(R.string.wifi_status_sign_in_required);
                return;
            } else if (networkCapabilities.hasCapability(NET_CAPABILITY_PARTIAL_CONNECTIVITY)) {
                statusLabel = mContext.getString(R.string.wifi_limited_connection);
                return;
            } else if (!networkCapabilities.hasCapability(NET_CAPABILITY_VALIDATED)) {
                statusLabel = mContext.getString(R.string.wifi_status_no_internet);
                return;
            }
        }

        ScoredNetwork scoredNetwork =
                mWifiNetworkScoreCache.getScoredNetwork(NetworkKey.createFromWifiInfo(mWifiInfo));
        statusLabel = scoredNetwork == null
                ? null : AccessPoint.getSpeedLabel(mContext, scoredNetwork, rssi);
    }

    private String getValidSsid(WifiInfo info) {
        String ssid = info.getSSID();
        if (ssid != null && !WifiSsid.NONE.equals(ssid)) {
            return ssid;
        }
        // OK, it's not in the connectionInfo; we have to go hunting for it
        List<WifiConfiguration> networks = mWifiManager.getConfiguredNetworks();
        int length = networks.size();
        for (int i = 0; i < length; i++) {
            if (networks.get(i).networkId == info.getNetworkId()) {
                return networks.get(i).SSID;
            }
        }
        return null;
    }
}