/*
 * (C) Copyright 1996- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

/// @author Baudouin Raoult
/// @author Tiago Quintino
/// @date   Jun 2011

#ifndef eckit_net_Connector_h
#define eckit_net_Connector_h

#include "eckit/io/BufferCache.h"
#include "eckit/io/Length.h"
#include "eckit/io/cluster/NodeInfo.h"
#include "eckit/net/TCPSocket.h"
#include "eckit/serialisation/Stream.h"


namespace eckit {
namespace net {

//----------------------------------------------------------------------------------------------------------------------

class ConnectorException : public Exception {
    virtual bool retryOnServer() const { return true; }
    virtual bool retryOnClient() const { return true; }

public:
    ConnectorException(const std::string& what) : Exception(what) {}
};

//----------------------------------------------------------------------------------------------------------------------

class Connector : public Stream {
public:
    Connector(const std::string& name, const std::string& node);

    ~Connector();

    // -- Methods

    void lock();
    void unlock();
    void reset();
    void check();

    bool locked() const { return locked_; }

    const std::string& host() const { return host_; }
    const std::string& node() const { return node_; }

    void autoclose(bool on) { autoclose_ = on; }

    void memoize(bool on, unsigned long time);

    static Connector& service(const std::string& name, const std::string& node);
    static Connector& service(const std::string& name, const std::map<std::string, Length>& cost,
                              const std::set<std::string>& attributes={});

    static NodeInfo nodeInfo(const std::string& name, const std::string& node);

protected:
    // -- Members
    // None
    Connector(const std::string&, int, const std::string&);

    // -- Methods

    void print(std::ostream&) const override;

    // -- Class members
    // None
    static Connector& get(const std::string& host, int port, const std::string&);


    // -- Class methods
    // None

private:
    // -- Members

    std::string host_;
    std::string node_;

    int port_;
    TCPSocket socket_;
    bool locked_;


    // Memoisation
    bool memoize_;
    bool sent_;
    unsigned long life_;

    BufferCache out_;
    BufferCache in_;
    bool autoclose_;

    std::map<BufferCache, BufferCache> cache_;

    struct {
        const char* buffer_;
        size_t pos_;
        size_t size_;
    } cached_;

    // -- Methods
    // None

    TCPSocket& socket();
    template <class T, class F>
    long socketIo(F proc, T buf, long len, const char*);

    // -- Overridden methods
    // None

    // From Stream
    virtual long write(const void* buf, long len) override;
    virtual long read(void* buf, long len) override;
    virtual std::string name() const override;

    // -- Friends

    friend std::ostream& operator<<(std::ostream& s, const Connector& p) {
        p.print(s);
        return s;
    }

    friend class ConnectorCache;
};


//----------------------------------------------------------------------------------------------------------------------


class AutoMemoize {
    Connector& c_;
    unsigned long t_;

public:
    AutoMemoize(Connector& c, unsigned long t) : c_(c), t_(t) { c_.memoize(true, t_); }
    ~AutoMemoize() { c_.memoize(false, t_); }
};


//----------------------------------------------------------------------------------------------------------------------

}  // namespace net
}  // namespace eckit

#endif
