// ***************************************************************************
// TcpSocketEngine_p.cpp (c) 2011 Derek Barnett
// Marth Lab, Department of Biology, Boston College
// ---------------------------------------------------------------------------
// Last modified: 8 December 2011 (DB)
// ---------------------------------------------------------------------------
// Provides low-level implementation of TCP I/O
// ***************************************************************************

// N.B. - this file contains the top-level, platform-independent logic. "Native" methods
//        are called as needed from the TcpSocketEngine_<X>.cpp files. Selection of the proper
//        native method file should have been handled at build-time by CMake.

#include "api/internal/io/HostInfo_p.h"
#include "api/internal/io/TcpSocketEngine_p.h"

using namespace BamTools;
using namespace BamTools::Internal;

TcpSocketEngine::TcpSocketEngine(void)
    : m_socketDescriptor(-1)
//    , m_localPort(0)
    , m_remotePort(0)
    , m_socketError(TcpSocket::UnknownSocketError)
    , m_socketState(TcpSocket::UnconnectedState)
{ }

TcpSocketEngine::TcpSocketEngine(const TcpSocketEngine& other)
    : m_socketDescriptor(other.m_socketDescriptor)
//    , m_localAddress(other.m_localAddress)
    , m_remoteAddress(other.m_remoteAddress)
//    , m_localPort(other.m_localPort)
    , m_remotePort(other.m_remotePort)
    , m_socketError(other.m_socketError)
    , m_socketState(other.m_socketState)
    , m_errorString(other.m_errorString)
{ }

TcpSocketEngine::~TcpSocketEngine(void) {
    Close();
}

void TcpSocketEngine::Close(void) {

    // close socket if we have valid FD
    if ( m_socketDescriptor != -1 ) {
        nativeClose();
        m_socketDescriptor = -1;
    }

    // reset state
    m_socketState = TcpSocket::UnconnectedState;
//    m_localAddress.Clear();
    m_remoteAddress.Clear();
//    m_localPort = 0;
    m_remotePort = 0;
}

bool TcpSocketEngine::Connect(const HostAddress& address, const uint16_t port) {

    // return failure if invalid FD or already connected
    if ( !IsValid() || (m_socketState == TcpSocket::ConnectedState) ) {
        // TODO: set error string
        return false;
    }

    // attempt to connect to host address on requested port
    if ( !nativeConnect(address, port) ) {
        // TODO: set error string
        return false;
    }

    // if successful, store remote host address port & return success
    // TODO: (later) fetch proxied remote & local host/port  here
    m_remoteAddress = address;
    m_remotePort    = port;
    return true;
}

std::string TcpSocketEngine::GetErrorString(void) const {
    return m_errorString;
}

//HostAddress TcpSocketEngine::GetLocalAddress(void) const {
//    return m_localAddress;
//}

//uint16_t TcpSocketEngine::GetLocalPort(void) const {
//    return m_localPort;
//}

HostAddress TcpSocketEngine::GetRemoteAddress(void) const {
    return m_remoteAddress;
}

uint16_t TcpSocketEngine::GetRemotePort(void) const {
    return m_remotePort;
}

int TcpSocketEngine::GetSocketDescriptor(void) const {
    return m_socketDescriptor;
}

TcpSocket::SocketError TcpSocketEngine::GetSocketError(void) {
    return m_socketError;
}

TcpSocket::SocketState TcpSocketEngine::GetSocketState(void) {
    return m_socketState;
}

bool TcpSocketEngine::Initialize(HostAddress::NetworkProtocol protocol) {

    // close current socket if we have one open
    if ( IsValid() )
        Close();

    // attempt to create new socket
    return nativeCreateSocket(protocol);
}

bool TcpSocketEngine::IsValid(void) const {
    return (m_socketDescriptor != -1);
}

int64_t TcpSocketEngine::NumBytesAvailable(void) const {

    // return 0 if socket FD is invalid
    if ( !IsValid() ) {
        // TODO: set error string
        return -1;
    }

    // otherwise check socket to see how much is ready
    return nativeNumBytesAvailable();
}

int64_t TcpSocketEngine::Read(char* dest, size_t max) {

    // return failure if can't read
    if ( !IsValid() || (m_socketState != TcpSocket::ConnectedState) )
        return -1;

    // otherwise return number of bytes read
    return nativeRead(dest, max);
}

bool TcpSocketEngine::WaitForRead(int msec, bool* timedOut) {

    // reset timedOut flag
    *timedOut = false;

    // need to wait for our socket to be ready to read
    const int ret = nativeSelect(msec, true);

    // if timed out
    if ( ret == 0 ) {
        *timedOut = true;
        m_socketError = TcpSocket::SocketTimeoutError;
        m_errorString = "socket timed out";
    }

    // return if any sockets available for reading
    return ( ret > 0 );
}

bool TcpSocketEngine::WaitForWrite(int msec, bool* timedOut) {

    // reset timedOut flag
    *timedOut = false;

    // need to wait for our socket to be ready to write
    const int ret = nativeSelect(msec, false);

    // if timed out
    if ( ret == 0 ) {
        *timedOut = true;
        m_socketError = TcpSocket::SocketTimeoutError;
        m_errorString = "socket timed out";
    }

    // return if any sockets available for reading
    return ( ret > 0 );
}

int64_t TcpSocketEngine::Write(const char* data, size_t length) {

    // return failure if can't write
    if ( !IsValid() || (m_socketState != TcpSocket::ConnectedState) ) {
        // TODO: set error string
        return -1;
    }

    // otherwise return number of bytes written
    return nativeWrite(data, length);
}