// Copyright (c) 2012 by István Váradi

// This file is part of libxplcommon, a common utility library for
// development related to X-Plane

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.

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

#include <xplcommon/Thread.h>
#include <xplcommon/Waiter.h>
#include <xplcommon/LocalServerSocket.h>
#include <xplcommon/LocalAcceptor.h>
#include <xplcommon/LocalSocket.h>
#include <xplcommon/LocalClientSocket.h>
#include <xplcommon/LocalConnector.h>
#include <xplcommon/ReadingBuffer.h>
#include <xplcommon/WritingBuffer.h>
#include <xplcommon/WaitableEvent.h>
#include <xplcommon/PseudoRandom.h>

#include <cstdlib>
#include <cstdio>
#include <cassert>

#include <signal.h>

#include <sys/time.h>

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

using xplcommon::Thread;
using xplcommon::Waiter;
using xplcommon::LocalServerSocket;
using xplcommon::LocalAcceptor;
using xplcommon::LocalSocket;
using xplcommon::LocalClientSocket;
using xplcommon::LocalConnector;
using xplcommon::ReadingBuffer;
using xplcommon::WritingBuffer;
using xplcommon::WaitableEvent;
using xplcommon::PseudoRandom;

using std::min;

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

void communicate(ReadingBuffer* readingBuffer, WritingBuffer* writingBuffer,
                 Waiter& waiter, unsigned seed, const char* prefix,
                 WaitableEvent* quitEvent = 0)
{
    static const size_t minToWrite = 2076;
    static const size_t maxToWrite = 1345670;

    static const size_t reportingInterval = 10000;

    static const int sleepThreshold = static_cast<int>(PseudoRandom::MAX * 0.99);
    static const int sleepRemainder = PseudoRandom::MAX - sleepThreshold;
    static const unsigned minSleep = 10;
    static const unsigned maxSleep = 250;
    static const unsigned sleepRange = maxSleep - minSleep;

    size_t numBytesRead = 0;
    size_t nextReportRead = reportingInterval;
    size_t numWriteBlocked = 0;
    size_t numBytesWritten = 0;
    size_t nextReportWritten = reportingInterval;
    size_t numReadBlocked = 0;
    size_t numMillisSlept = 0;

    bool toQuit = false;

    PseudoRandom random(seed);
    while(!toQuit) {
        size_t toWrite = random.nextUnsigned(maxToWrite, minToWrite);

        size_t lastWriteLength = 0;
        if (writingBuffer!=0) {
            lastWriteLength = min(writingBuffer->getCapacity(), toWrite);
            writingBuffer->reset();
            writingBuffer->addLength(lastWriteLength);
        }

        while(toWrite>0) {
            if (quitEvent!=0 && quitEvent->check()) {
                toQuit = true;
                break;
            }

            bool hasPending = false;

            if (writingBuffer!=0) {
                size_t loopCount = 0;
                while(toWrite>0) {
                    ++loopCount;
                    if (writingBuffer->write()) {
                        numBytesWritten += lastWriteLength;
                        toWrite -= lastWriteLength;

                        if (numBytesWritten>=nextReportWritten) {
                            printf("%s: written %lu bytes with %lu blocking and %lu ms sleeping\n",
                                   prefix,
                                   static_cast<unsigned long>(numBytesWritten),
                                   static_cast<unsigned long>(numWriteBlocked),
                                   static_cast<unsigned long>(numMillisSlept));
                            nextReportWritten += reportingInterval;
                        }

                        if (toWrite>0) {
                            if (quitEvent!=0 && quitEvent->check()) {
                                toQuit = true;
                                break;
                            } else {
                                lastWriteLength = min(writingBuffer->getCapacity(), toWrite);
                                writingBuffer->addLength(lastWriteLength);
                                if (loopCount>10) {
                                    break;
                                }
                            }
                        }
                    } else if (writingBuffer->failed()) {
                        printf("%s: writing failed with error: %lu\n",
                               prefix,
                               static_cast<unsigned long>(writingBuffer->getErrorCode()));
                        toQuit = true;
                        break;
                    } else {
                        ++numWriteBlocked;
                        hasPending = true;
                        break;
                    }
                }
                if (toQuit) break;
            }

            if (readingBuffer!=0) {
                size_t loopCount = 0;
                while(true) {
                    ++loopCount;
                    if (readingBuffer->read()) {
                        size_t l = readingBuffer->getLength();
                        if (l==0) {
                            printf("%s: reading encountered end of file\n", prefix);
                            toQuit = true;
                            break;
                        }
                        numBytesRead += l;
                        if (numBytesRead>=nextReportRead) {
                            printf("%s: read %lu bytes with %lu blocking and %lu ms sleeping\n",
                                   prefix,
                                   static_cast<unsigned long>(numBytesRead),
                                   static_cast<unsigned long>(numReadBlocked),
                                   static_cast<unsigned long>(numMillisSlept));
                            nextReportRead += reportingInterval;
                        }
                        readingBuffer->reset();
                        if (quitEvent!=0 && quitEvent->check()) {
                            toQuit = true;
                            break;
                        } else if (loopCount>10) {
                            break;
                        }
                    } else if (readingBuffer->failed()) {
                        printf("%s: reading failed with error: %lu\n",
                               prefix,
                               static_cast<unsigned long>(readingBuffer->getErrorCode()));
                        toQuit = true;
                        break;
                    } else {
                        ++numReadBlocked;
                        hasPending = true;
                        break;
                    }
                }
                if (toQuit) break;
            }

            int r = random.next();
            if (r>=sleepThreshold) {
                unsigned toSleep = minSleep +
                    static_cast<unsigned>(static_cast<double>(r - sleepThreshold) *
                                          sleepRange / sleepRemainder);
                assert(toSleep>=minSleep);
                assert(toSleep<maxSleep);
                Thread::sleep(toSleep);
                numMillisSlept += toSleep;
            }

            if (toWrite>0 && hasPending) {
                waiter.wait();
                if (waiter.failed()) {
                    printf("%s: waiting failed with error: %lu\n",
                           prefix,
                           static_cast<unsigned long>(waiter.getErrorCode()));
                    toQuit = true;
                    break;
                }
            }
        }
    }

    printf("%s: written %lu bytes with %lu blocking\n",
           prefix,
           static_cast<unsigned long>(numBytesWritten),
           static_cast<unsigned long>(numWriteBlocked));
    printf("%s: read %lu bytes with %lu blocking\n",
           prefix,
           static_cast<unsigned long>(numBytesRead),
           static_cast<unsigned long>(numReadBlocked));
    printf("%s: slept %lu ms\n", prefix,
           static_cast<unsigned long>(numMillisSlept));
}

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

class ServerThread : public Thread
{
private:
    Waiter waiter;

    WaitableEvent event;

public:
    ServerThread();

    void signal();

    virtual void run();
};

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

ServerThread::ServerThread() :
    event(&waiter)
{
}

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

void ServerThread::signal()
{
    event.fire();
}

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

void ServerThread::run()
{
    unsigned seed = static_cast<unsigned>(time(0)*1.2);
    printf("ServerThread::run: seed=%u\n", seed);

    LocalServerSocket serverSocket("test", &waiter);
    LocalAcceptor& acceptor = serverSocket.getAcceptor();

    bool eventFired = false;
    while(!acceptor.accept()) {
        eventFired = event.check();
        if (eventFired) break;
        if (acceptor.failed()) {
            printf("ServerThread::run: acceptor failed...: %lu\n",
                   (unsigned long)acceptor.getErrorCode());
            return;
        }
        printf("ServerThread::run: waiting...\n");
        waiter.wait();
    }

    if (eventFired) {
        printf("ServerThread::run: waiting done, quitting\n");
        return;
    }

    printf("ServerThread::run: waiting done, received connection\n");
    LocalSocket* socket = acceptor.getSocket();

    communicate(&socket->getReadingBuffer(), &socket->getWritingBuffer(),
                waiter, seed, "ServerThread", &event);


    delete socket;
}

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

class ClientThread : public Thread
{
private:
    Waiter waiter;

    WaitableEvent event;

public:
    ClientThread();

    void signal();

    virtual void run();
};

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

ClientThread::ClientThread() :
    event(&waiter)
{
}

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

void ClientThread::signal()
{
    event.fire();
}

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

void ClientThread::run()
{
    unsigned seed = static_cast<unsigned>(time(0)*1.8);
    printf("ClientThread::run: seed=%u\n", seed);

    printf("ClientThread::run: sleeping\n");
    sleep(500);
    printf("ClientThread::run: connecting\n");

    LocalClientSocket socket("test", &waiter);

    LocalConnector& connector = socket.getConnector();

    while(!connector.connect()) {
        if (connector.failed()) {
            printf("ClientThread::run: connector failed...\n");
            return;
        }
        printf("ClientThread::run: waiting...\n");
        waiter.wait();
    }

    printf("ClientThread::run: connected\n");

    communicate(&socket.getReadingBuffer(), &socket.getWritingBuffer(),
                waiter, seed, "ClientThread", &event);
}

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

int main()
{
#if TARGET_API_POSIX
    signal(SIGPIPE, SIG_IGN);
#endif

    ServerThread serverThread;
    ClientThread clientThread;

    printf("Starting threads\n");
    serverThread.start();
    clientThread.start();

    Thread::sleep(60000);
    //Thread::sleep(5000);
    printf("Signalling the server thread\n");
    //serverThread.signal();
    clientThread.signal();
    printf("Signalled the server thread\n");

    printf("Waiting for the client thread\n");
    clientThread.join();
    printf("Waiting for the server thread\n");
    serverThread.join();
    printf("Both threads returned\n");

    return 0;
}

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

// Local Variables:
// mode: C++
// c-basic-offset: 4
// indent-tabs-mode: nil
// End: