/*
 * Copyright (C) 2014 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;

import android.annotation.NonNull;
import android.net.NetworkCapabilities.NetCapability;
import android.net.NetworkCapabilities.Transport;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.Process;
import android.text.TextUtils;
import android.util.proto.ProtoOutputStream;

import java.util.Objects;
import java.util.Set;

Defines a request for a network, made through Builder and used to request a network via ConnectivityManager.requestNetwork or listen for changes via ConnectivityManager.registerNetworkCallback. /**
 * Defines a request for a network, made through {@link NetworkRequest.Builder} and used
 * to request a network via {@link ConnectivityManager#requestNetwork} or listen for changes
 * via {@link ConnectivityManager#registerNetworkCallback}.
 */
public class NetworkRequest implements Parcelable {
    
The NetworkCapabilities that define this request. 
@hide
/**
     * The {@link NetworkCapabilities} that define this request.
     * @hide
     */
    public final @NonNull NetworkCapabilities networkCapabilities;

    
Identifies the request.  NetworkRequests should only be constructed by
the Framework and given out to applications as tokens to be used to identify
the request.
@hide
/**
     * Identifies the request.  NetworkRequests should only be constructed by
     * the Framework and given out to applications as tokens to be used to identify
     * the request.
     * @hide
     */
    public final int requestId;

    
Set for legacy requests and the default.  Set to TYPE_NONE for none.
Causes CONNECTIVITY_ACTION broadcasts to be sent.
@hide
/**
     * Set for legacy requests and the default.  Set to TYPE_NONE for none.
     * Causes CONNECTIVITY_ACTION broadcasts to be sent.
     * @hide
     */
    public final int legacyType;

    
A NetworkRequest as used by the system can be one of the following types:
    - LISTEN, for which the framework will issue callbacks about any
      and all networks that match the specified NetworkCapabilities,
    - REQUEST, capable of causing a specific network to be created
      first (e.g. a telephony DUN request), the framework will issue
      callbacks about the single, highest scoring current network
      (if any) that matches the specified NetworkCapabilities, or
    - TRACK_DEFAULT, a hybrid of the two designed such that the
      framework will issue callbacks for the single, highest scoring
      current network (if any) that matches the capabilities of the
      default Internet request (mDefaultRequest), but which cannot cause
      the framework to either create or retain the existence of any
      specific network. Note that from the point of view of the request
      matching code, TRACK_DEFAULT is identical to REQUEST: its special
      behaviour is not due to different semantics, but to the fact that
      the system will only ever create a TRACK_DEFAULT with capabilities
      that are identical to the default request's capabilities, thus
      causing it to share fate in every way with the default request.
    - BACKGROUND_REQUEST, like REQUEST but does not cause any networks
      to retain the NET_CAPABILITY_FOREGROUND capability. A network with
      no foreground requests is in the background. A network that has
      one or more background requests and loses its last foreground
      request to a higher-scoring network will not go into the
      background immediately, but will linger and go into the background
      after the linger timeout.
    - The value NONE is used only by applications. When an application
      creates a NetworkRequest, it does not have a type; the type is set
      by the system depending on the method used to file the request
      (requestNetwork, registerNetworkCallback, etc.).
@hide
/**
     * A NetworkRequest as used by the system can be one of the following types:
     *
     *     - LISTEN, for which the framework will issue callbacks about any
     *       and all networks that match the specified NetworkCapabilities,
     *
     *     - REQUEST, capable of causing a specific network to be created
     *       first (e.g. a telephony DUN request), the framework will issue
     *       callbacks about the single, highest scoring current network
     *       (if any) that matches the specified NetworkCapabilities, or
     *
     *     - TRACK_DEFAULT, a hybrid of the two designed such that the
     *       framework will issue callbacks for the single, highest scoring
     *       current network (if any) that matches the capabilities of the
     *       default Internet request (mDefaultRequest), but which cannot cause
     *       the framework to either create or retain the existence of any
     *       specific network. Note that from the point of view of the request
     *       matching code, TRACK_DEFAULT is identical to REQUEST: its special
     *       behaviour is not due to different semantics, but to the fact that
     *       the system will only ever create a TRACK_DEFAULT with capabilities
     *       that are identical to the default request's capabilities, thus
     *       causing it to share fate in every way with the default request.
     *
     *     - BACKGROUND_REQUEST, like REQUEST but does not cause any networks
     *       to retain the NET_CAPABILITY_FOREGROUND capability. A network with
     *       no foreground requests is in the background. A network that has
     *       one or more background requests and loses its last foreground
     *       request to a higher-scoring network will not go into the
     *       background immediately, but will linger and go into the background
     *       after the linger timeout.
     *
     *     - The value NONE is used only by applications. When an application
     *       creates a NetworkRequest, it does not have a type; the type is set
     *       by the system depending on the method used to file the request
     *       (requestNetwork, registerNetworkCallback, etc.).
     *
     * @hide
     */
    public static enum Type {
        NONE,
        LISTEN,
        TRACK_DEFAULT,
        REQUEST,
        BACKGROUND_REQUEST,
    };

    
The type of the request. This is only used by the system and is always NONE elsewhere.
@hide
/**
     * The type of the request. This is only used by the system and is always NONE elsewhere.
     *
     * @hide
     */
    public final Type type;

    
@hide
/**
     * @hide
     */
    public NetworkRequest(NetworkCapabilities nc, int legacyType, int rId, Type type) {
        if (nc == null) {
            throw new NullPointerException();
        }
        requestId = rId;
        networkCapabilities = nc;
        this.legacyType = legacyType;
        this.type = type;
    }

    
@hide
/**
     * @hide
     */
    public NetworkRequest(NetworkRequest that) {
        networkCapabilities = new NetworkCapabilities(that.networkCapabilities);
        requestId = that.requestId;
        this.legacyType = that.legacyType;
        this.type = that.type;
    }

    
Builder used to create NetworkRequest objects. Specify the Network features needed in terms of NetworkCapabilities features /**
     * Builder used to create {@link NetworkRequest} objects.  Specify the Network features
     * needed in terms of {@link NetworkCapabilities} features
     */
    public static class Builder {
        private final NetworkCapabilities mNetworkCapabilities;

        
Default constructor for Builder.
/**
         * Default constructor for Builder.
         */
        public Builder() {
            // By default, restrict this request to networks available to this app.
            // Apps can rescind this restriction, but ConnectivityService will enforce
            // it for apps that do not have the NETWORK_SETTINGS permission.
            mNetworkCapabilities = new NetworkCapabilities();
            mNetworkCapabilities.setSingleUid(Process.myUid());
        }

        
Build NetworkRequest give the current set of capabilities. /**
         * Build {@link NetworkRequest} give the current set of capabilities.
         */
        public NetworkRequest build() {
            // Make a copy of mNetworkCapabilities so we don't inadvertently remove NOT_RESTRICTED
            // when later an unrestricted capability could be added to mNetworkCapabilities, in
            // which case NOT_RESTRICTED should be returned to mNetworkCapabilities, which
            // maybeMarkCapabilitiesRestricted() doesn't add back.
            final NetworkCapabilities nc = new NetworkCapabilities(mNetworkCapabilities);
            nc.maybeMarkCapabilitiesRestricted();
            return new NetworkRequest(nc, ConnectivityManager.TYPE_NONE,
                    ConnectivityManager.REQUEST_ID_UNSET, Type.NONE);
        }

        
Add the given capability requirement to this builder.  These represent
the requested network's required capabilities.  Note that when searching
for a network to satisfy a request, all capabilities requested must be
satisfied.
Params:
capability – The capability to add.
Returns:
The builder to facilitate chaining builder.addCapability(...).addCapability();./**
         * Add the given capability requirement to this builder.  These represent
         * the requested network's required capabilities.  Note that when searching
         * for a network to satisfy a request, all capabilities requested must be
         * satisfied.
         *
         * @param capability The capability to add.
         * @return The builder to facilitate chaining
         *         {@code builder.addCapability(...).addCapability();}.
         */
        public Builder addCapability(@NetworkCapabilities.NetCapability int capability) {
            mNetworkCapabilities.addCapability(capability);
            return this;
        }

        
Removes (if found) the given capability from this builder instance.
Params:
capability – The capability to remove.
Returns:
The builder to facilitate chaining./**
         * Removes (if found) the given capability from this builder instance.
         *
         * @param capability The capability to remove.
         * @return The builder to facilitate chaining.
         */
        public Builder removeCapability(@NetworkCapabilities.NetCapability int capability) {
            mNetworkCapabilities.removeCapability(capability);
            return this;
        }

        
Set the NetworkCapabilities for this builder instance, overriding any capabilities that had been previously set. 
Params:
nc – The superseding NetworkCapabilities instance.
Returns:
The builder to facilitate chaining.
@hide
/**
         * Set the {@code NetworkCapabilities} for this builder instance,
         * overriding any capabilities that had been previously set.
         *
         * @param nc The superseding {@code NetworkCapabilities} instance.
         * @return The builder to facilitate chaining.
         * @hide
         */
        public Builder setCapabilities(NetworkCapabilities nc) {
            mNetworkCapabilities.set(nc);
            return this;
        }

        
Set the watched UIDs for this request. This will be reset and wiped out unless
the calling app holds the CHANGE_NETWORK_STATE permission.
Params:
uids – The watched UIDs as a set of UidRanges, or null for everything.
Returns:
The builder to facilitate chaining.
@hide
/**
         * Set the watched UIDs for this request. This will be reset and wiped out unless
         * the calling app holds the CHANGE_NETWORK_STATE permission.
         *
         * @param uids The watched UIDs as a set of UidRanges, or null for everything.
         * @return The builder to facilitate chaining.
         * @hide
         */
        public Builder setUids(Set<UidRange> uids) {
            mNetworkCapabilities.setUids(uids);
            return this;
        }

        
Add a capability that must not exist in the requested network.
 If the capability was previously added to the list of required capabilities (for example, it was there by default or added using addCapability(int) method), then it will be removed from the list of required capabilities as well. 
Params:
capability – The capability to add to unwanted capability list.
See Also:
addCapability(int)
Returns:
The builder to facilitate chaining.
@hide
/**
         * Add a capability that must not exist in the requested network.
         * <p>
         * If the capability was previously added to the list of required capabilities (for
         * example, it was there by default or added using {@link #addCapability(int)} method), then
         * it will be removed from the list of required capabilities as well.
         *
         * @see #addCapability(int)
         *
         * @param capability The capability to add to unwanted capability list.
         * @return The builder to facilitate chaining.
         *
         * @hide
         */
        public Builder addUnwantedCapability(@NetworkCapabilities.NetCapability int capability) {
            mNetworkCapabilities.addUnwantedCapability(capability);
            return this;
        }

        
Completely clears all the NetworkCapabilities from this builder instance, removing even the capabilities that are set by default when the object is constructed. 
Returns:
The builder to facilitate chaining.
@hide
/**
         * Completely clears all the {@code NetworkCapabilities} from this builder instance,
         * removing even the capabilities that are set by default when the object is constructed.
         *
         * @return The builder to facilitate chaining.
         * @hide
         */
        public Builder clearCapabilities() {
            mNetworkCapabilities.clearAll();
            return this;
        }

        
Adds the given transport requirement to this builder.  These represent
the set of allowed transports for the request.  Only networks using one
of these transports will satisfy the request.  If no particular transports
are required, none should be specified here.
Params:
transportType – The transport type to add.
Returns:
The builder to facilitate chaining./**
         * Adds the given transport requirement to this builder.  These represent
         * the set of allowed transports for the request.  Only networks using one
         * of these transports will satisfy the request.  If no particular transports
         * are required, none should be specified here.
         *
         * @param transportType The transport type to add.
         * @return The builder to facilitate chaining.
         */
        public Builder addTransportType(@NetworkCapabilities.Transport int transportType) {
            mNetworkCapabilities.addTransportType(transportType);
            return this;
        }

        
Removes (if found) the given transport from this builder instance.
Params:
transportType – The transport type to remove.
Returns:
The builder to facilitate chaining./**
         * Removes (if found) the given transport from this builder instance.
         *
         * @param transportType The transport type to remove.
         * @return The builder to facilitate chaining.
         */
        public Builder removeTransportType(@NetworkCapabilities.Transport int transportType) {
            mNetworkCapabilities.removeTransportType(transportType);
            return this;
        }

        
@hide
/**
         * @hide
         */
        public Builder setLinkUpstreamBandwidthKbps(int upKbps) {
            mNetworkCapabilities.setLinkUpstreamBandwidthKbps(upKbps);
            return this;
        }
        
@hide
/**
         * @hide
         */
        public Builder setLinkDownstreamBandwidthKbps(int downKbps) {
            mNetworkCapabilities.setLinkDownstreamBandwidthKbps(downKbps);
            return this;
        }

        
Sets the optional bearer specific network specifier.
This has no meaning if a single transport is also not specified, so calling
this without a single transport set will generate an exception, as will
subsequently adding or removing transports after this is set.
 The interpretation of this String is bearer specific and bearers that use it should document their particulars. For example, Bluetooth may use some sort of device id while WiFi could used ssid and/or bssid. Cellular may use carrier spn. 
Params:
networkSpecifier – An String of opaque format used to specify the bearer specific network specifier where the bearer has a choice of networks./**
         * Sets the optional bearer specific network specifier.
         * This has no meaning if a single transport is also not specified, so calling
         * this without a single transport set will generate an exception, as will
         * subsequently adding or removing transports after this is set.
         * </p>
         * The interpretation of this {@code String} is bearer specific and bearers that use
         * it should document their particulars.  For example, Bluetooth may use some sort of
         * device id while WiFi could used ssid and/or bssid.  Cellular may use carrier spn.
         *
         * @param networkSpecifier An {@code String} of opaque format used to specify the bearer
         *                         specific network specifier where the bearer has a choice of
         *                         networks.
         */
        public Builder setNetworkSpecifier(String networkSpecifier) {
            /*
             * A StringNetworkSpecifier does not accept null or empty ("") strings. When network
             * specifiers were strings a null string and an empty string were considered equivalent.
             * Hence no meaning is attached to a null or empty ("") string.
             */
            return setNetworkSpecifier(TextUtils.isEmpty(networkSpecifier) ? null
                    : new StringNetworkSpecifier(networkSpecifier));
        }

        
Sets the optional bearer specific network specifier.
This has no meaning if a single transport is also not specified, so calling
this without a single transport set will generate an exception, as will
subsequently adding or removing transports after this is set.

Params:
networkSpecifier – A concrete, parcelable framework class that extends
                        NetworkSpecifier./**
         * Sets the optional bearer specific network specifier.
         * This has no meaning if a single transport is also not specified, so calling
         * this without a single transport set will generate an exception, as will
         * subsequently adding or removing transports after this is set.
         * </p>
         *
         * @param networkSpecifier A concrete, parcelable framework class that extends
         *                         NetworkSpecifier.
         */
        public Builder setNetworkSpecifier(NetworkSpecifier networkSpecifier) {
            MatchAllNetworkSpecifier.checkNotMatchAllNetworkSpecifier(networkSpecifier);
            mNetworkCapabilities.setNetworkSpecifier(networkSpecifier);
            return this;
        }

        
Sets the signal strength. This is a signed integer, with higher values indicating a
stronger signal. The exact units are bearer-dependent. For example, Wi-Fi uses the same
RSSI units reported by WifiManager.
 Note that when used to register a network callback, this specifies the minimum acceptable signal strength. When received as the state of an existing network it specifies the current value. A value of SIGNAL_STRENGTH_UNSPECIFIED means no value when received and has no effect when requesting a callback. 
Params:
signalStrength – the bearer-specific signal strength.
@hide
/**
         * Sets the signal strength. This is a signed integer, with higher values indicating a
         * stronger signal. The exact units are bearer-dependent. For example, Wi-Fi uses the same
         * RSSI units reported by WifiManager.
         * <p>
         * Note that when used to register a network callback, this specifies the minimum acceptable
         * signal strength. When received as the state of an existing network it specifies the
         * current value. A value of {@code SIGNAL_STRENGTH_UNSPECIFIED} means no value when
         * received and has no effect when requesting a callback.
         *
         * @param signalStrength the bearer-specific signal strength.
         * @hide
         */
        public Builder setSignalStrength(int signalStrength) {
            mNetworkCapabilities.setSignalStrength(signalStrength);
            return this;
        }
    }

    // implement the Parcelable interface
    public int describeContents() {
        return 0;
    }
    public void writeToParcel(Parcel dest, int flags) {
        networkCapabilities.writeToParcel(dest, flags);
        dest.writeInt(legacyType);
        dest.writeInt(requestId);
        dest.writeString(type.name());
    }
    public static final Creator<NetworkRequest> CREATOR =
        new Creator<NetworkRequest>() {
            public NetworkRequest createFromParcel(Parcel in) {
                NetworkCapabilities nc = NetworkCapabilities.CREATOR.createFromParcel(in);
                int legacyType = in.readInt();
                int requestId = in.readInt();
                Type type = Type.valueOf(in.readString());  // IllegalArgumentException if invalid.
                NetworkRequest result = new NetworkRequest(nc, legacyType, requestId, type);
                return result;
            }
            public NetworkRequest[] newArray(int size) {
                return new NetworkRequest[size];
            }
        };

    
Returns true iff. this NetworkRequest is of type LISTEN.
@hide
/**
     * Returns true iff. this NetworkRequest is of type LISTEN.
     *
     * @hide
     */
    public boolean isListen() {
        return type == Type.LISTEN;
    }

    
Returns true iff. the contained NetworkRequest is one that:
    - should be associated with at most one satisfying network
      at a time;
    - should cause a network to be kept up, but not necessarily in
      the foreground, if it is the best network which can satisfy the
      NetworkRequest.
For full detail of how isRequest() is used for pairing Networks with
NetworkRequests read rematchNetworkAndRequests().
@hide
/**
     * Returns true iff. the contained NetworkRequest is one that:
     *
     *     - should be associated with at most one satisfying network
     *       at a time;
     *
     *     - should cause a network to be kept up, but not necessarily in
     *       the foreground, if it is the best network which can satisfy the
     *       NetworkRequest.
     *
     * For full detail of how isRequest() is used for pairing Networks with
     * NetworkRequests read rematchNetworkAndRequests().
     *
     * @hide
     */
    public boolean isRequest() {
        return isForegroundRequest() || isBackgroundRequest();
    }

    
Returns true iff. the contained NetworkRequest is one that:
    - should be associated with at most one satisfying network
      at a time;
    - should cause a network to be kept up and in the foreground if
      it is the best network which can satisfy the NetworkRequest.
For full detail of how isRequest() is used for pairing Networks with
NetworkRequests read rematchNetworkAndRequests().
@hide
/**
     * Returns true iff. the contained NetworkRequest is one that:
     *
     *     - should be associated with at most one satisfying network
     *       at a time;
     *
     *     - should cause a network to be kept up and in the foreground if
     *       it is the best network which can satisfy the NetworkRequest.
     *
     * For full detail of how isRequest() is used for pairing Networks with
     * NetworkRequests read rematchNetworkAndRequests().
     *
     * @hide
     */
    public boolean isForegroundRequest() {
        return type == Type.TRACK_DEFAULT || type == Type.REQUEST;
    }

    
Returns true iff. this NetworkRequest is of type BACKGROUND_REQUEST.
@hide
/**
     * Returns true iff. this NetworkRequest is of type BACKGROUND_REQUEST.
     *
     * @hide
     */
    public boolean isBackgroundRequest() {
        return type == Type.BACKGROUND_REQUEST;
    }

    
See Also:
addCapability.addCapability(int)/**
     * @see Builder#addCapability(int)
     */
    public boolean hasCapability(@NetCapability int capability) {
        return networkCapabilities.hasCapability(capability);
    }

    
See Also:
addUnwantedCapability.addUnwantedCapability(int)
@hide
/**
     * @see Builder#addUnwantedCapability(int)
     *
     * @hide
     */
    public boolean hasUnwantedCapability(@NetCapability int capability) {
        return networkCapabilities.hasUnwantedCapability(capability);
    }

    
See Also:
addTransportType.addTransportType(int)/**
     * @see Builder#addTransportType(int)
     */
    public boolean hasTransport(@Transport int transportType) {
        return networkCapabilities.hasTransport(transportType);
    }

    public String toString() {
        return "NetworkRequest [ " + type + " id=" + requestId +
                (legacyType != ConnectivityManager.TYPE_NONE ? ", legacyType=" + legacyType : "") +
                ", " + networkCapabilities.toString() + " ]";
    }

    private int typeToProtoEnum(Type t) {
        switch (t) {
            case NONE:
                return NetworkRequestProto.TYPE_NONE;
            case LISTEN:
                return NetworkRequestProto.TYPE_LISTEN;
            case TRACK_DEFAULT:
                return NetworkRequestProto.TYPE_TRACK_DEFAULT;
            case REQUEST:
                return NetworkRequestProto.TYPE_REQUEST;
            case BACKGROUND_REQUEST:
                return NetworkRequestProto.TYPE_BACKGROUND_REQUEST;
            default:
                return NetworkRequestProto.TYPE_UNKNOWN;
        }
    }

    
@hide
/** @hide */
    public void writeToProto(ProtoOutputStream proto, long fieldId) {
        final long token = proto.start(fieldId);

        proto.write(NetworkRequestProto.TYPE, typeToProtoEnum(type));
        proto.write(NetworkRequestProto.REQUEST_ID, requestId);
        proto.write(NetworkRequestProto.LEGACY_TYPE, legacyType);
        networkCapabilities.writeToProto(proto, NetworkRequestProto.NETWORK_CAPABILITIES);

        proto.end(token);
    }

    public boolean equals(Object obj) {
        if (obj instanceof NetworkRequest == false) return false;
        NetworkRequest that = (NetworkRequest)obj;
        return (that.legacyType == this.legacyType &&
                that.requestId == this.requestId &&
                that.type == this.type &&
                Objects.equals(that.networkCapabilities, this.networkCapabilities));
    }

    public int hashCode() {
        return Objects.hash(requestId, legacyType, networkCapabilities, type);
    }
}