package net.i2p.router.transport.udp;

import java.util.ArrayList;
import java.net.InetAddress;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import net.i2p.data.DataHelper;
import net.i2p.data.Hash;
import net.i2p.data.SessionKey;

/**
 *  Track the state of a peer test.
 *  Used only by PeerTestManager.
 */
class PeerTestState {
    private final long _testNonce;
    private final Role _ourRole;
    private final boolean _isIPv6;
    private PeerState2 _alice;
    private InetAddress _aliceIP;
    private int _alicePort;
    private final PeerState _bob;
    private InetAddress _charlieIP;
    private int _charliePort;
    private InetAddress _aliceIPFromCharlie;
    private int _alicePortFromCharlie;
    private SessionKey _aliceIntroKey;
    private SessionKey _aliceCipherKey;
    private SessionKey _aliceMACKey;
    private SessionKey _charlieIntroKey;
    // SSU2 only
    private Hash _aliceHash;
    // SSU2 only
    private Hash _charlieHash;
    // SSU2 BOB only
    private byte[] _testData;
    // SSU2 BOB only
    private final List<Hash> _previousCharlies;
    private final long _beginTime;
    private long _lastSendTime;
    private long _receiveAliceTime;
    private long _receiveBobTime;
    private long _receiveCharlieTime;
    private long _sendAliceTime;
    private long _sendCharlieTime;
    private int _status;
    private final AtomicInteger _packetsRelayed = new AtomicInteger();
    
    public enum Role {ALICE, BOB, CHARLIE};
    
    /**
     * @param bob null if role is BOB
     */
    public PeerTestState(Role role, PeerState bob, boolean isIPv6, long nonce, long now) {
        _ourRole = role;
        _bob = bob;
        _isIPv6 = isIPv6;
        _testNonce = nonce;
        _beginTime = now;
        _previousCharlies = role == Role.BOB ? new ArrayList<Hash>(8) : null;
    }

    public long getNonce() { return _testNonce; }

    /** Are we Alice, bob, or Charlie. */
    public Role getOurRole() { return _ourRole; }

    /**
     * @return null if we are bob
     * @since 0.9.54
     */
    public PeerState getBob() { return _bob; }

    /**
     * Is this an IPv6 test?
     * @since 0.9.27
     */
    public boolean isIPv6() { return _isIPv6; }

    /**
     * If we are Alice, this will contain the IP that Bob says we
     * can be reached at - the IP Charlie says we can be reached 
     * at is _aliceIPFromCharlie
     *
     */
    public InetAddress getAliceIP() { return _aliceIP; }
    /**
     * SSU2 only
     * @since 0.9.54
     */
    public PeerState2 getAlice() { return _alice; }
    /**
     * SSU2 only
     * @since 0.9.54
     */
    public void setAlice(PeerState2 alice) {
        _alice = alice;
    }
    /**
     * @param hash SSU2 only, null for SSU1
     * @since 0.9.54
     */
    public void setAlice(InetAddress ip, int port, Hash hash) {
        _aliceIP = ip;
        _alicePort = port;
        _aliceHash = hash;
    }
    public InetAddress getBobIP() { return _bob.getRemoteIPAddress(); }
    public InetAddress getCharlieIP() { return _charlieIP; }

    /**
     * SSU2 only, null for SSU1.
     * @since 0.9.57
     */
    public Hash getCharlieHash() { return _charlieHash; }

    /**
     * @param hash SSU2 only, null for SSU1
     * @since 0.9.54
     */
    public void setCharlie(InetAddress ip, int port, Hash hash) {
        _charlieIP = ip;
        _charliePort = port;
        if (_charlieHash != null && _previousCharlies != null && !_charlieHash.equals(hash))
            _previousCharlies.add(_charlieHash);
        _charlieHash = hash;
    }

    /**
     * SSU2 only, BOB only, else returns null.
     * Does not include current charlie.
     * @since 0.9.57
     */
    public List<Hash> getPreviousCharlies() { return _previousCharlies; }

    public InetAddress getAliceIPFromCharlie() { return _aliceIPFromCharlie; }
    public void setAliceIPFromCharlie(InetAddress ip) { _aliceIPFromCharlie = ip; }
    /**
     * If we are Alice, this will contain the port that Bob says we
     * can be reached at - the port Charlie says we can be reached
     * at is _alicePortFromCharlie
     *
     */
    public int getAlicePort() { return _alicePort; }
    public int getBobPort() { return _bob.getRemotePort(); }
    public int getCharliePort() { return _charliePort; }
    public void setCharliePort(int charliePort) { _charliePort = charliePort; }
    
    public int getAlicePortFromCharlie() { return _alicePortFromCharlie; }
    public void setAlicePortFromCharlie(int alicePortFromCharlie) { _alicePortFromCharlie = alicePortFromCharlie; }
    
    public SessionKey getAliceIntroKey() { return _aliceIntroKey; }
    public void setAliceIntroKey(SessionKey key) { _aliceIntroKey = key; }

    /**
     *  @since 0.9.52
     */
    public SessionKey getAliceCipherKey() { return _aliceCipherKey; }

    /**
     *  @since 0.9.52
     */
    public SessionKey getAliceMACKey() { return _aliceMACKey; }

    /**
     *  @param ck cipher key
     *  @param mk MAC key
     *  @since 0.9.52
     */
    public void setAliceKeys(SessionKey ck, SessionKey mk) {
        _aliceCipherKey = ck;
        _aliceMACKey = mk;
    }

    public SessionKey getCharlieIntroKey() { return _charlieIntroKey; }
    public void setCharlieIntroKey(SessionKey key) { _charlieIntroKey = key; }

    public SessionKey getBobCipherKey() { return _bob.getCurrentCipherKey(); }
    public SessionKey getBobMACKey() { return _bob.getCurrentMACKey(); }

    /** when did this test begin? */
    public long getBeginTime() { return _beginTime; }

    /** when did we last send out a packet? */
    public long getLastSendTime() { return _lastSendTime; }
    public void setLastSendTime(long when) { _lastSendTime = when; }

    /**
     * when did we last hear from alice?
     */
    public long getReceiveAliceTime() { return _receiveAliceTime; }
    public void setReceiveAliceTime(long when) { _receiveAliceTime = when; }

    /** when did we last hear from bob? */
    public long getReceiveBobTime() { return _receiveBobTime; }
    public void setReceiveBobTime(long when) { _receiveBobTime = when; }

    /** when did we last hear from charlie? */
    public long getReceiveCharlieTime() { return _receiveCharlieTime; }
    public void setReceiveCharlieTime(long when) { _receiveCharlieTime = when; }

    /**
     * when did we send to alice, SSU2 Bob only
     * @since 0.9.57
     */
    public long getSendAliceTime() { return _sendAliceTime; }

    /**
     * when did we send to alice, SSU2 Bob only
     * @since 0.9.57
     */
    public void setSendAliceTime(long when) { _sendAliceTime = when; }

    /**
     * when did we send to Charlie, SSU2 Alice only
     * @since 0.9.57
     */
    public long getSendCharlieTime() { return _sendCharlieTime; }

    /**
     * when did we send to Charlie, SSU2 Alice only
     * @since 0.9.57
     */
    public void setSendCharlieTime(long when) { _sendCharlieTime = when; }

    /**
     * what code did we send to alice, SSU2 Bob only
     * @since 0.9.57
     */
    public int getStatus() { return _status; }

    /**
     * what code did we send to alice, SSU2 Bob only
     * @since 0.9.57
     */
    public void setStatus(int status) { _status = status; }

    /**
     *  Get for retransmission.
     *  SSU2 only, we are Alice, Bob or Charlie
     *  @since 0.9.57
     */
    public byte[] getTestData() { return _testData; }

    /**
     *  Save for retransmission.
     *  SSU2 only, we are Alice, Bob or Charlie
     *  @since 0.9.57
     */
    public void setTestData(byte[] data) { _testData = data; }

    /** @return new value */
    public int incrementPacketsRelayed() { return _packetsRelayed.incrementAndGet(); }
    
    @Override
    public String toString() {
        StringBuilder buf = new StringBuilder(256);
        buf.append("PeerTest ").append(_testNonce)
           .append(_isIPv6 ? " IPv6" : " IPv4")
           .append(" started ").append(DataHelper.formatTime(_beginTime))
           .append(" as ").append(_ourRole.toString());
        if (_aliceIP != null) {
            buf.append("; Alice: ");
            if (_ourRole == Role.ALICE)
                buf.append("me ");
            buf.append(_aliceIP).append(':').append(_alicePort);
            if (_aliceHash != null)
                buf.append(' ').append(_aliceHash.toBase64(), 0, 6);
        }
        if (_aliceIPFromCharlie != null)
            buf.append(" (fromCharlie ").append(_aliceIPFromCharlie).append(':').append(_alicePortFromCharlie).append(')');
        if (_bob != null)
            buf.append(" Bob: ").append(_bob.toString());
        else
            buf.append(" Bob: me");
        if (_charlieIP != null) {
            buf.append(" Charlie: ");
            if (_ourRole == Role.CHARLIE) {
                buf.append("me");
            } else {
                buf.append(_charlieIP).append(':').append(_charliePort);
                if (_charlieHash != null)
                    buf.append(' ').append(_charlieHash.toBase64(), 0, 6);
            }
            if (_previousCharlies != null && !_previousCharlies.isEmpty())
                buf.append(" previous: ").append(_previousCharlies);
        }
        if (_lastSendTime > 0)
            buf.append("; last send after ").append(_lastSendTime - _beginTime);
        if (_sendAliceTime > 0)
            buf.append("; last send to Alice ").append(DataHelper.formatTime(_sendAliceTime));
        if (_receiveAliceTime > 0)
            buf.append("; rcvd from Alice after ").append(_receiveAliceTime - _beginTime);
        if (_receiveBobTime > 0)
            buf.append("; rcvd from Bob after ").append(_receiveBobTime - _beginTime);
        if (_sendCharlieTime > 0)
            buf.append("; last send to Charlie ").append(DataHelper.formatTime(_sendCharlieTime));
        if (_receiveCharlieTime > 0)
            buf.append("; rcvd from Charlie after ").append(_receiveCharlieTime - _beginTime);
        buf.append("; pkts relayed: ").append(_packetsRelayed.get());
        return buf.toString();
    }
}
