//%LICENSE////////////////////////////////////////////////////////////////
//
// Licensed to The Open Group (TOG) under one or more contributor license
// agreements.  Refer to the OpenPegasusNOTICE.txt file distributed with
// this work for additional information regarding copyright ownership.
// Each contributor licenses this file to you under the OpenPegasus Open
// Source License; you may not use this file except in compliance with the
// License.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
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//////////////////////////////////////////////////////////////////////////
//
//%/////////////////////////////////////////////////////////////////////////////

#include "DynamicConsumer.h"
#include "DynamicConsumerFacade.h"

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/Time.h>
#include <Pegasus/Common/System.h>
#include <Pegasus/Common/Tracer.h>
#include <Pegasus/Common/XmlWriter.h>
#include <Pegasus/Common/XmlReader.h>
#include <Pegasus/Common/XmlParser.h>
#include <Pegasus/Common/FileSystem.h>

PEGASUS_NAMESPACE_BEGIN
PEGASUS_USING_STD;


DynamicConsumer::DynamicConsumer(): Base(0)
{
}

DynamicConsumer::DynamicConsumer(const String& name):
Base(0),
_module(0),
_eventqueue(),
_name(name),
_initialized(false),
_dieNow(0),
_no_unload(0)
{
    _check_queue = new Semaphore(0);
    _shutdownSemaphore = new Semaphore(0);
    _listeningSemaphore = new Semaphore(0);
}

//ATTN: For migration from old listener -- do we want to support it?
DynamicConsumer::DynamicConsumer(const String & name,
                                 ConsumerModule* consumerModule,
                                 CIMIndicationConsumerProvider* consumerRef) :
Base(consumerRef),
_module(consumerModule),
_eventqueue(),
_name(name),
_initialized(false),
_dieNow(0),
_no_unload(0)
{
    _check_queue = new Semaphore(0);
    _shutdownSemaphore = new Semaphore(0);
    _listeningSemaphore = new Semaphore(0);
}

DynamicConsumer::~DynamicConsumer(void)
{
    //delete any outstanding events
    IndicationDispatchEvent* event;
    while (_eventqueue.size())
    {
        event = _eventqueue.remove_front();
        delete event;
    }

    //delete semaphores
    delete _check_queue;

    delete _shutdownSemaphore;

    delete _listeningSemaphore;
}

CIMIndicationConsumerProvider* DynamicConsumer::getConsumer()
{
    return(_consumer);
}

ConsumerModule* DynamicConsumer::getModule(void) const
{
    return(_module);
}

String DynamicConsumer::getName(void) const
{
    return(_name);
}

Boolean DynamicConsumer::isLoaded(void) const
{
    return(_module == 0 ? false : true);
}

Boolean DynamicConsumer::isInitialized(void) const
{
    return(_initialized);
}

/** Initializes the consumer.
 *  Caller assumes responsibility for catching exceptions thrown by this method.
 */
void DynamicConsumer::initialize()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::initialize");

    if (!_initialized)
    {
        try
        {
            //there is no cimom handle in the listener, so pass null
            CIMOMHandle* handle = 0;
            DynamicConsumerFacade::initialize(*(handle));

            updateIdleTimer();
            _initialized = true;

            PEG_TRACE_CSTRING(
                TRC_LISTENER,
                Tracer::LEVEL3,
                "Successfully initialized consumer.");

        } catch (...)
        {
            PEG_TRACE((TRC_LISTENER,Tracer::LEVEL1,
                "Exception caught in DynamicConsumerFacade::initialize for %s",
                (const char*)_name.getCString()));
            throw;
        }
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::setShutdownSemaphore(Semaphore* shutdownSemaphore)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::setShutdownSemaphore");

    _shutdownSemaphore = shutdownSemaphore;

    PEG_METHOD_EXIT();
}

Semaphore* DynamicConsumer::getShutdownSemaphore()
{
    return _shutdownSemaphore;
}

void DynamicConsumer::sendShutdownSignal()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::sendShutdownSignal");

    _dieNow = true;
    _check_queue->signal();

    PEG_METHOD_EXIT();
}

void DynamicConsumer::terminate(void)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::terminate");

    if (_initialized)
    {
        //terminate consumer
        try
        {
            DynamicConsumerFacade::terminate();

        } catch (...)
        {
            PEG_TRACE((TRC_LISTENER,Tracer::LEVEL1,
                "Exception caught in DynamicConsumerFacade::Terminate for %s",
                (const char*)_name.getCString()));
            throw;
        }

        //update status
        _initialized = false;
        _dieNow = false;
    }

    PEG_METHOD_EXIT();
}

/** This method should be called after the physical consumer
 *  is loaded and before initialization.
 */
void DynamicConsumer::set(ConsumerModule* consumerModule,
                          CIMIndicationConsumerProvider* consumerRef)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::set");

    if (_initialized)
    {
        throw Exception(
                  MessageLoaderParms(
                      "DynListener.DynamicConsumer.CONSUMER_INVALID_STATE",
                      "Error: The consumer is not in the correct state"
                          " to perform the operation."));
    }

    _module = consumerModule;
    _consumer = consumerRef;

    PEG_METHOD_EXIT();
}

/** This method should be called after the consumer is terminated and the
 * module is unloaded.  Note that we cannot test for a loaded condition,
 * since the _module reference here may still exist (if more than one
 * consumer is using the module).
 * Simply test whether the consumer is initialized.
 * If it was terminated properly, initialized will be false and the _module
 * ref count will be decremented.
 */
void DynamicConsumer::reset()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::reset");

    if (_initialized)
    {
        throw Exception(
                 MessageLoaderParms(
                     "DynListener.DynamicConsumer.CONSUMER_INVALID_STATE",
                     "Error: The consumer is not in the correct state to "
                         "perform the operation."));
    }

    // do not delete it, that is taken care of in ConsumerModule itself
    _module = 0;
    // ATTN: attempting to delete this causes an exception -- why??
    _consumer = 0;

    PEG_TRACE((TRC_LISTENER,Tracer::LEVEL4,
                  "Deleting %d outstanding requests for %s",
                  _eventqueue.size(),
                  (const char*)_name.getCString()));

    //delete outstanding requests
    IndicationDispatchEvent* event = 0;
    for (Uint32 i = 0; i < _eventqueue.size(); i++)
    {
        event = _eventqueue.remove_front();
        delete event;
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::enqueueEvent(IndicationDispatchEvent* event)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::enqueueEvent");

    if (!isLoaded())
    {
        PEG_TRACE_CSTRING(
            TRC_LISTENER,
            Tracer::LEVEL1,
            "Error: The consumer is not loaded and "
                "therefore cannot handle events.");
        return;
    }

    try
    {
        PEG_TRACE((TRC_LISTENER,Tracer::LEVEL4,
            "enqueueEvent before %s",(const char*)_name.getCString()));

        // Our event queue is first in first out.
        _eventqueue.insert_back(event);
        _check_queue->signal();

        PEG_TRACE((TRC_LISTENER,Tracer::LEVEL4,
            "enqueueEvent after %s",(const char*)_name.getCString()));

    } catch (Exception& ex)
    {
        //ATTN: Log missed indication
        PEG_TRACE((TRC_LISTENER,Tracer::LEVEL1,
            "Exception at enqueueingEvent: %s",
            (const char*)ex.getMessage().getCString()));

    } catch (...)
    {
        //ATTN: Log missed indication
        PEG_TRACE_CSTRING(TRC_LISTENER,Tracer::LEVEL1,
            "Unknow exception at enqueueingEvent!");
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::getIdleTimer(struct timeval *tv)
{
    if (tv == 0)
    {
        return;
    }

    try
    {
        AutoMutex lock(_idleTimeMutex);
        memcpy(tv, &_idleTime, sizeof(struct timeval));
    } catch (...)
    {
        Time::gettimeofday(tv);
    }
}

void DynamicConsumer::updateIdleTimer()
{
    try
    {
        AutoMutex lock(_idleTimeMutex);
        Time::gettimeofday(&_idleTime);

    } catch (...)
    {
    }
}

Uint32 DynamicConsumer::getPendingIndications()
{
    return _eventqueue.size();
}

String DynamicConsumer::toString()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::toString");

    String buffer;
    if (_initialized)
    {
        buffer.append("Consumer " + _name + " is initialized.\n");
        buffer.append("Module name " + _module->getFileName() + "\n");
    }

    PEG_METHOD_EXIT();
    return buffer;
}

/** Returns true if the consumer has been inactive for
 *  longer than the idle period.
 */
Boolean DynamicConsumer::isIdle()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::isIdle");

    if (!isLoaded())
    {
        PEG_TRACE_CSTRING(
            TRC_LISTENER,
            Tracer::LEVEL2,
            "Consumer is not loaded.");
        return false;
    }

    struct timeval now;
    Time::gettimeofday(&now);

    struct timeval timeout = {0,0};
    getIdleTimer(&timeout);

    // if no consumer is currently being served and there's no consumer that
    // has pending indications, we are idle
    if (!_current_operations.get() && !getPendingIndications())
    {
        PEG_METHOD_EXIT();
        return true;
    }

    PEG_METHOD_EXIT();
    return false;
}

/** This method waits until the event thread is ready to accept incoming
 *  indications.  Otherwise, there is a miniscule chance that
 *  the first event will be enqueued before the consumer is waiting for it
 *  and the first indication after loading the consumer will be lost.
 */
void DynamicConsumer::waitForEventThread()
{
    _listeningSemaphore->wait();
}

/** This method is called when the consumer is initialized for the first time.
 *  It reads the outstanding requests from the dat file and enqueues them.
 *
 * ATTN: This method will only get called when a consumer is initialized.
 * Therefore, when the listener starts, the outstanding indications for this
 * consumer will not get sent UNTIL a new indication comes in.  This is not
 * really an acceptable scenario.  Maybe the consumer manager needs to check
 * the .dat files upon startup and load if they are not empty.
 */
void DynamicConsumer::_loadOutstandingIndications(
         Array<IndicationDispatchEvent> indications)
{
    PEG_METHOD_ENTER(
        TRC_LISTENER,
        "DynamicConsumer::_loadOutstandingIndications");

    //create dispatch events from the instances
    IndicationDispatchEvent* event = 0;
    for (Uint32 i=0; i < indications.size(); i++)
    {

        event = new IndicationDispatchEvent(
                        OperationContext(),  //ATTN: Do we need to store this?
                        indications[i].getURL(),
                        indications[i].getIndicationInstance());

        _eventqueue.insert_back(event);
    }

    //signal the worker thread so it falls into the queue processing code
    if (_eventqueue.size())
    {
        _check_queue->signal();
    }

    PEG_METHOD_EXIT();
}

/** This method serializes the remaining indications in the queue.
 *  It should be called when the consumer is shutting down.  Each time the
 *  consumer is loaded, these indications will be reloaded into the queue.
 *  Therefore, the file should be overwritten each time to eliminate
 *  duplicating outstanding indications.
 *
 * ATTN: Should we let another method delete the instances?
 */
Array<IndicationDispatchEvent>
    DynamicConsumer::_retrieveOutstandingIndications()
{
    PEG_METHOD_ENTER(
        TRC_LISTENER,
        "DynamicConsumer::_retrieveOutstandingIndications");

    Array<IndicationDispatchEvent> indications;
    IndicationDispatchEvent* temp = 0;

    try
    {
        if (_eventqueue.try_lock())
        {
            temp = _eventqueue.front();
            while (temp)
            {
                PEG_TRACE_CSTRING(TRC_LISTENER, Tracer::LEVEL4, "retrieving");
                indications.append(*temp);
                temp = _eventqueue.next_of(temp);
            }
            _eventqueue.unlock();
        }
        else
        {
            PEG_TRACE_CSTRING(TRC_LISTENER, Tracer::LEVEL3,
                "Failed to lock _eventqueue");
        }
    }
    catch (...)
    {
        PEG_TRACE_CSTRING(TRC_LISTENER, Tracer::LEVEL4, "Unknown Exception");
    }

    PEG_METHOD_EXIT();
    return indications;
}


////////////////////////////////
// IndicationDispatchEvent
////////////////////////////////

IndicationDispatchEvent::IndicationDispatchEvent()
{
}

IndicationDispatchEvent::IndicationDispatchEvent(OperationContext context,
                                                 String url,
                                                 CIMInstance instance) :
_context(context),
_url(url),
_instance(instance),
_retries(0),
_lastAttemptTime(CIMDateTime())
{
}

IndicationDispatchEvent::IndicationDispatchEvent(
    const IndicationDispatchEvent &event) : Linkable(event)
{
    _context = event._context;
    _url = event._url;
    _instance = event._instance;
    _retries = event._retries.get();
    _lastAttemptTime = event._lastAttemptTime;
}

IndicationDispatchEvent::~IndicationDispatchEvent()
{
}

OperationContext IndicationDispatchEvent::getContext() const
{
    return _context;
}

String IndicationDispatchEvent::getURL() const
{
    return _url;
}

CIMInstance IndicationDispatchEvent::getIndicationInstance() const
{
    return _instance;
}

Uint32 IndicationDispatchEvent::getRetries()
{
    return _retries.get();
}

void IndicationDispatchEvent::increaseRetries()
{
    PEG_TRACE_CSTRING(TRC_LISTENER, Tracer::LEVEL4, "Increasing retries\n");
    _retries++;
    _lastAttemptTime = CIMDateTime::getCurrentDateTime();
    PEG_TRACE((TRC_LISTENER,Tracer::LEVEL4,"Last attempt time %s",
        (const char*)_lastAttemptTime.toString().getCString()));
}

CIMDateTime IndicationDispatchEvent::getLastAttemptTime()
{
    return _lastAttemptTime;
}


IndicationDispatchEvent&
    IndicationDispatchEvent::operator=(const IndicationDispatchEvent &event)
{
    _context = event._context;
    _url = event._url;
    _instance = event._instance;
    _retries = event._retries.get();
    _lastAttemptTime = event._lastAttemptTime;

    return *this;
}

Boolean IndicationDispatchEvent::operator==
            (const IndicationDispatchEvent& event) const
{
    if (String::equal(this->_url, event._url) &&
        (this->_instance.identical(event._instance)))
    {
        return true;
    }
    return false;
}

PEGASUS_NAMESPACE_END