/*
 * Copyright (C) 2014 Pavel Kirienko <pavel.kirienko@gmail.com>
 */

#pragma once

#include <uavcan/node/subscriber.hpp>
#include <uavcan/util/method_binder.hpp>
#include <uavcan/protocol/GlobalTimeSync.hpp>

namespace uavcan
{
/**
 * Ref. M. Gergeleit, H. Streich - "Implementing a Distributed High-Resolution Real-Time Clock using the CAN-Bus"
 * http://modecs.cs.uni-salzburg.at/results/related_documents/CAN_clock.pdf
 */
class UAVCAN_EXPORT GlobalTimeSyncSlave : Noncopyable
{
    typedef MethodBinder<GlobalTimeSyncSlave*,
                         void (GlobalTimeSyncSlave::*)(const ReceivedDataStructure<protocol::GlobalTimeSync>&)>
        GlobalTimeSyncCallback;

    // Static buffers are explicitly disabled because time should never be unicasted.
    Subscriber<protocol::GlobalTimeSync, GlobalTimeSyncCallback, 2, 0> sub_;

    UtcTime prev_ts_utc_;
    MonotonicTime prev_ts_mono_;
    MonotonicTime last_adjustment_ts_;
    enum State { Update, Adjust } state_;
    NodeID master_nid_;
    TransferID prev_tid_;
    uint8_t prev_iface_index_;
    bool suppressed_;

    ISystemClock& getSystemClock() const { return sub_.getNode().getSystemClock(); }

    void adjustFromMsg(const ReceivedDataStructure<protocol::GlobalTimeSync>& msg);

    void updateFromMsg(const ReceivedDataStructure<protocol::GlobalTimeSync>& msg);

    void processMsg(const ReceivedDataStructure<protocol::GlobalTimeSync>& msg);

    void handleGlobalTimeSync(const ReceivedDataStructure<protocol::GlobalTimeSync>& msg);

public:
    explicit GlobalTimeSyncSlave(INode& node)
        : sub_(node)
        , state_(Update)
        , prev_iface_index_(0xFF)
        , suppressed_(false)
    { }

    int start();

    void suppress(bool suppressed) { suppressed_ = suppressed; }
    bool isSuppressed() const { return suppressed_; }

    bool isActive() const;

    NodeID getMasterNodeID() const;

    MonotonicTime getLastAdjustmentTime() const { return last_adjustment_ts_; }
};

}