/*
 * Copyright (C) 2008 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.wifi;

import android.os.Parcel;
import android.os.Parcelable;

/**
 * From <code>defs.h</code> in <code>wpa_supplicant</code>.
 * <p/>
 * These enumeration values are used to indicate the current wpa_supplicant
 * state. This is more fine-grained than most users will be interested in.
 * In general, it is better to use
 * {@link android.net.NetworkInfo.State NetworkInfo.State}.
 * <p/>
 * Note, the order of these enum constants must match the numerical values of the
 * state constants in <code>defs.h</code> in <code>wpa_supplicant</code>.
 */
public enum SupplicantState implements Parcelable {
    /**
     * This state indicates that client is not associated, but is likely to
     * start looking for an access point. This state is entered when a
     * connection is lost.
     */
    DISCONNECTED,

    /**
     * Interface is disabled
     * <p/>
     * This state is entered if the network interface is disabled.
     * wpa_supplicant refuses any new operations that would
     * use the radio until the interface has been enabled.
     */
    INTERFACE_DISABLED,

    /**
     * Inactive state (wpa_supplicant disabled).
     * <p/>
     * This state is entered if there are no enabled networks in the
     * configuration. wpa_supplicant is not trying to associate with a new
     * network and external interaction (e.g., ctrl_iface call to add or
     * enable a network) is needed to start association.
     */
    INACTIVE,

    /**
     * Scanning for a network.
     * <p/>
     * This state is entered when wpa_supplicant starts scanning for a
     * network.
     */
    SCANNING,

    /**
     * Trying to authenticate with a BSS/SSID
     * <p/>
     * This state is entered when wpa_supplicant has found a suitable BSS
     * to authenticate with and the driver is configured to try to
     * authenticate with this BSS.
     */
    AUTHENTICATING,

    /**
     * Trying to associate with a BSS/SSID.
     * <p/>
     * This state is entered when wpa_supplicant has found a suitable BSS
     * to associate with and the driver is configured to try to associate
     * with this BSS in ap_scan=1 mode. When using ap_scan=2 mode, this
     * state is entered when the driver is configured to try to associate
     * with a network using the configured SSID and security policy.
     */
    ASSOCIATING,

    /**
     * Association completed.
     * <p/>
     * This state is entered when the driver reports that association has
     * been successfully completed with an AP. If IEEE 802.1X is used
     * (with or without WPA/WPA2), wpa_supplicant remains in this state
     * until the IEEE 802.1X/EAPOL authentication has been completed.
     */
    ASSOCIATED,

    /**
     * WPA 4-Way Key Handshake in progress.
     * <p/>
     * This state is entered when WPA/WPA2 4-Way Handshake is started. In
     * case of WPA-PSK, this happens when receiving the first EAPOL-Key
     * frame after association. In case of WPA-EAP, this state is entered
     * when the IEEE 802.1X/EAPOL authentication has been completed.
     */
    FOUR_WAY_HANDSHAKE,

    /**
     * WPA Group Key Handshake in progress.
     * <p/>
     * This state is entered when 4-Way Key Handshake has been completed
     * (i.e., when the supplicant sends out message 4/4) and when Group
     * Key rekeying is started by the AP (i.e., when supplicant receives
     * message 1/2).
     */
    GROUP_HANDSHAKE,

    /**
     * All authentication completed.
     * <p/>
     * This state is entered when the full authentication process is
     * completed. In case of WPA2, this happens when the 4-Way Handshake is
     * successfully completed. With WPA, this state is entered after the
     * Group Key Handshake; with IEEE 802.1X (non-WPA) connection is
     * completed after dynamic keys are received (or if not used, after
     * the EAP authentication has been completed). With static WEP keys and
     * plaintext connections, this state is entered when an association
     * has been completed.
     * <p/>
     * This state indicates that the supplicant has completed its
     * processing for the association phase and that data connection is
     * fully configured. Note, however, that there may not be any IP
     * address associated with the connection yet. Typically, a DHCP
     * request needs to be sent at this point to obtain an address.
     */
    COMPLETED,

    /**
     * An Android-added state that is reported when a client issues an
     * explicit DISCONNECT command. In such a case, the supplicant is
     * not only dissociated from the current access point (as for the
     * DISCONNECTED state above), but it also does not attempt to connect
     * to any access point until a RECONNECT or REASSOCIATE command
     * is issued by the client.
     */
    DORMANT,

    /**
     * No connection to wpa_supplicant.
     * <p/>
     * This is an additional pseudo-state to handle the case where
     * wpa_supplicant is not running and/or we have not been able
     * to establish a connection to it.
     */
    UNINITIALIZED,

    /**
     * A pseudo-state that should normally never be seen.
     */
    INVALID;

    /**
     * Returns {@code true} if the supplicant state is valid and {@code false}
     * otherwise.
     * @param state The supplicant state
     * @return {@code true} if the supplicant state is valid and {@code false}
     * otherwise.
     */
    public static boolean isValidState(SupplicantState state) {
        return state != UNINITIALIZED && state != INVALID;
    }


    /** Supplicant associating or authenticating is considered a handshake state {@hide} */
    public static boolean isHandshakeState(SupplicantState state) {
        switch(state) {
            case AUTHENTICATING:
            case ASSOCIATING:
            case ASSOCIATED:
            case FOUR_WAY_HANDSHAKE:
            case GROUP_HANDSHAKE:
                return true;
            case COMPLETED:
            case DISCONNECTED:
            case INTERFACE_DISABLED:
            case INACTIVE:
            case SCANNING:
            case DORMANT:
            case UNINITIALIZED:
            case INVALID:
                return false;
            default:
                throw new IllegalArgumentException("Unknown supplicant state");
        }
    }

    static boolean isConnecting(SupplicantState state) {
        switch(state) {
            case AUTHENTICATING:
            case ASSOCIATING:
            case ASSOCIATED:
            case FOUR_WAY_HANDSHAKE:
            case GROUP_HANDSHAKE:
            case COMPLETED:
                return true;
            case DISCONNECTED:
            case INTERFACE_DISABLED:
            case INACTIVE:
            case SCANNING:
            case DORMANT:
            case UNINITIALIZED:
            case INVALID:
                return false;
            default:
                throw new IllegalArgumentException("Unknown supplicant state");
        }
    }

    static boolean isDriverActive(SupplicantState state) {
        switch(state) {
            case DISCONNECTED:
            case DORMANT:
            case INACTIVE:
            case AUTHENTICATING:
            case ASSOCIATING:
            case ASSOCIATED:
            case SCANNING:
            case FOUR_WAY_HANDSHAKE:
            case GROUP_HANDSHAKE:
            case COMPLETED:
                return true;
            case INTERFACE_DISABLED:
            case UNINITIALIZED:
            case INVALID:
                return false;
            default:
                throw new IllegalArgumentException("Unknown supplicant state");
        }
    }

    /** Implement the Parcelable interface {@hide} */
    public int describeContents() {
        return 0;
    }

    /** Implement the Parcelable interface {@hide} */
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name());
    }

    /** Implement the Parcelable interface {@hide} */
    public static final Creator<SupplicantState> CREATOR =
        new Creator<SupplicantState>() {
            public SupplicantState createFromParcel(Parcel in) {
                return SupplicantState.valueOf(in.readString());
            }

            public SupplicantState[] newArray(int size) {
                return new SupplicantState[size];
            }
        };

}