/*
 * (C) Copyright 1996-2017 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.
 */

// File ClusterNodes.cc
// Baudouin Raoult - (c) ECMWF Jul 11


#include "eckit/thread/AutoLock.h"
#include "eckit/io/cluster/ClusterNodes.h"
#include "eckit/parser/JSON.h"
#include "eckit/container/MappedArray.h"
#include "eckit/io/cluster/NodeInfo.h"
#include "eckit/config/Resource.h"

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

namespace eckit {

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

class ClusterNodeEntry {
	bool active_;
	time_t lastSeen_;
	bool offLine_;
	char node_[256];
	char type_[256];
	char host_[256];
	int port_;

public:
	ClusterNodeEntry(const std::string& node, const std::string& type, const std::string& host, int port) :
		active_(true), lastSeen_(::time(0)), offLine_(false), port_(port)
	{
		zero(node_);
		strncpy(node_, node.c_str(), sizeof(node_) - 1);
		zero(type_);
		strncpy(type_, type.c_str(), sizeof(type_) - 1);
		zero(host_);
		strncpy(host_, host.c_str(), sizeof(host_) - 1);
	}

	bool operator<(const ClusterNodeEntry& other) const
	{
		if (strcmp(node_, other.node_) < 0)
			return true;
		if (strcmp(type_, other.type_) < 0)
			return true;
		return false;
	}

	void send(Stream& s) const
	{
		unsigned long long t = lastSeen_;
		s << t;
		s << offLine_;
		s << node_;
		s << type_;
		s << host_;
		s << port_;
	}

	void json(JSON& s) const
	{
        s.startObject();
		s << "lastSeen"  << lastSeen_ ;
		s << "offLine"   << offLine_ ;
		s << "available" << available();
		s << "node"      << node_;
		s << "type"      << type_;
		s << "host"      << host_;
		s << "port"      << port_;
        s.endObject();
	}

	void receive(Stream& s)
	{
		unsigned long long t;
		std::string x;

		s >> t;
		lastSeen_ = t;

		s >> offLine_;

		s >> x;
		zero(node_);
		strncpy(node_, x.c_str(), sizeof(node_) - 1);

		s >> x;
		zero(type_);
		strncpy(type_, x.c_str(), sizeof(type_) - 1);

		s >> x;
		zero(host_);
		strncpy(host_, x.c_str(), sizeof(host_) - 1);

		s >> port_;

		active_ = true;
	}

	bool available() const
	{
        static long maxNodeLastSeen = Resource<long>("maxNodeLastSeen", 60);
		return ((::time(0) - lastSeen_) <= maxNodeLastSeen) && !offLine_;
	}

	void active(bool on)
	{

		active_ = on;
	}
	void offLine(bool on)
	{
		offLine_ = on;
	}

	bool active() const
	{
		return active_;
	}

	bool offLine() const
	{
		return offLine_;
	}

	time_t lastSeen() const
	{
		return lastSeen_;
	}

	void lastSeen(time_t n)
	{
		lastSeen_ = n;
	}

	const char* node() const
	{
		return node_;
	}

	const char* type() const
	{
		return type_;
	}

	const char* host() const
	{
		return host_;
	}

	void host(const std::string& h)
	{
		zero(host_);
		strncpy(host_, h.c_str(), sizeof(host_) - 1);
	}

	void port(int p)
	{
		port_ = p;
	}

	int port() const
	{
		return port_;
	}

	friend std::ostream& operator<<(std::ostream&, const ClusterNodeEntry&);

};
std::ostream& operator<<(std::ostream& s, const ClusterNodeEntry& d)
{
	s << "ClusterNodeEntry[" << d.node_ << "," << d.type_ << "," << d.host_ << ":" << d.port_ << "," << (::time(0) - d.lastSeen_)
        << "," << (d.available() ? "available" : "not-available")
        << "," << (d.offLine_ ? "off" : "on") << "-line" 
        << "]";
	return s;
}

inline unsigned long version(ClusterNodeEntry*)
{
	return 1;
}

typedef MappedArray<ClusterNodeEntry> NodeArray;
static NodeArray* nodeArray = 0;

static pthread_once_t once = PTHREAD_ONCE_INIT;

static void init()
{
	nodeArray = new NodeArray("~/etc/cluster/nodes", 1024);
}

void ClusterNodes::reset()
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
        (*k).offLine(true);
}

void ClusterNodes::cleanup()
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
        if((*k).active() && !(*k).available())
        {
            Log::info() << "Forget " << (*k) << std::endl;
            (*k).active(false);
        }
}


void ClusterNodes::forget(const NodeInfo& info)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if (info.node() == (*k).node())
		{
			(*k).active(false);
		}
	}
}

void ClusterNodes::refresh(const NodeInfo& info)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	time_t now = ::time(0);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
        if((*k).active()) 
        {
		if (info.node() == (*k).node() && info.name() == (*k).type())
		{
			(*k).lastSeen(now);
			(*k).host(info.host());
			(*k).port(info.port());
			(*k).offLine(false);
			return;
		}
        }
	}

	std::sort(nodeArray->begin(), nodeArray->end());
	ClusterNodeEntry c(info.node(), info.name(), info.host(), info.port());
	ASSERT(!(*nodeArray)[0].active());
	(*nodeArray)[0] = c;
	std::sort(nodeArray->begin(), nodeArray->end());
}

NodeInfo ClusterNodes::lookUp(const std::string& type, const std::string& node)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && type == (*k).type() && node == (*k).node())
		{
			NodeInfo info;
			info.name((*k).type());
			info.node((*k).node());
			info.host((*k).host());
			info.port((*k).port());
			info.active(!(*k).offLine());
			return info;
		}
	}

	throw SeriousBug(std::string("Cannot find info for ") + type + "@" + node);
}

NodeInfo ClusterNodes::any(const std::string& type)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && (*k).available() && type == (*k).type())
		{
			NodeInfo info;
			info.name((*k).type());
			info.node((*k).node());
			info.host((*k).host());
			info.port((*k).port());
			info.active(!(*k).offLine());
			return info;
		}
	}

	throw Retry(std::string("Cannot find any node for ") + type);
}

bool ClusterNodes::available(const std::string& type, const std::string& node)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && type == (*k).type() && node == (*k).node())
			return (*k).available();
	}

	return false;
}

void ClusterNodes::offLine(const NodeInfo& info)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	const std::string& node = info.node();
	const std::string& type = info.name();

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && type == (*k).type() && node == (*k).node())
			(*k).offLine(true);
	}
}

void ClusterNodes::offLine(const std::string& host,int port)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && host == (*k).host() && port == (*k).port())
			(*k).offLine(true);
	}
}

void ClusterNodes::onLine(const std::string& host,int port)
{
	pthread_once(&once, init);
	AutoLock<NodeArray> lock(*nodeArray);

	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active() && host == (*k).host() && port == (*k).port())
			(*k).offLine(false);
	}
}

void ClusterNodes::list(std::ostream& out)
{
	pthread_once(&once, init);

	AutoLock<NodeArray> lock(*nodeArray);
	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active())
			out << *k << std::endl;
	}
}

std::vector<NodeInfo> ClusterNodes::all()
{
	pthread_once(&once, init);
    std::vector<NodeInfo> result;

	AutoLock<NodeArray> lock(*nodeArray);
	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active())
        {
			NodeInfo info;
			info.name((*k).type());
			info.node((*k).node());
			info.host((*k).host());
			info.port((*k).port());
			info.active(!(*k).offLine());
            result.push_back(info);
		}
	}

    return result;
}

void ClusterNodes::json(JSON& j)
{
	pthread_once(&once, init);


    j.startList();

	AutoLock<NodeArray> lock(*nodeArray);
	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active())
		{
			(*k).json(j);
		}
	}

    j.endList();

}

void ClusterNodes::send(Stream& s)
{
	pthread_once(&once, init);

	AutoLock<NodeArray> lock(*nodeArray);
	for (NodeArray::const_iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
	{
		if ((*k).active())
		{
			s << bool(true);
			(*k).send(s);
		}
	}

	s << bool(false);
}

void ClusterNodes::receive(Stream& s)
{
	pthread_once(&once, init);

	AutoLock<NodeArray> lock(*nodeArray);
	for (NodeArray::iterator k = nodeArray->begin(); k != nodeArray->end(); ++k)
		(*k).active(false);

	bool more;
	NodeArray::iterator k = nodeArray->begin();

	for (;;)
	{

		s >> more;

		if (!more)
			break;

		ASSERT( k != nodeArray->end() );
		(*k).receive(s);

		++k;
	}

}


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

} // namespace eckit

