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**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
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** accordance with the commercial license agreement provided with the
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** use the contact form at http://qt.digia.com/contact-us.
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
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#include "syssocket.h" // this should be the first header included

#include "servicebrowser.h"
#include "servicebrowser_p.h"

#include <QCoreApplication>
#include <QDebug>
#include <QLibrary>
#include <QString>
#include <QStringList>

#include <errno.h>

#ifndef NO_DNS_SD_LIB

#ifdef Q_OS_MACX
#define ZCONF_MDNS_STATIC_LINKING
#endif

#ifdef ZCONF_MDNS_STATIC_LINKING
extern "C" {
#include "dns_sd_funct.h"
}
#endif

#ifdef Q_OS_UNIX
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#endif

namespace ZeroConf {
namespace Internal {

extern "C" {
typedef void (DNSSD_API *RefDeallocatePtr)(DNSServiceRef sdRef);
typedef DNSServiceErrorType (DNSSD_API *ResolvePtr)(DNSServiceRef *sdRef, DNSServiceFlags flags,
                                                    uint32_t interfaceIndex, const char *name,
                                                    const char *regtype, const char *domain,
                                                    DNSServiceResolveReply callBack, void *context);
typedef DNSServiceErrorType (DNSSD_API *QueryRecordPtr)(DNSServiceRef *sdRef, DNSServiceFlags flags,
                                                        uint32_t interfaceIndex, const char *fullname,
                                                        uint16_t rrtype, uint16_t rrclass,
                                                        DNSServiceQueryRecordReply callBack, void *context);
typedef DNSServiceErrorType (DNSSD_API *GetAddrInfoPtr)(DNSServiceRef *sdRef, DNSServiceFlags flags,
                                                        uint32_t interfaceIndex, DNSServiceProtocol protocol,
                                                        const char *hostname, DNSServiceGetAddrInfoReply callBack,
                                                        void *context);
typedef DNSServiceErrorType (DNSSD_API *ReconfirmRecordPtr)(DNSServiceFlags flags, uint32_t interfaceIndex,
                                                            const char *fullname, uint16_t rrtype,
                                                            uint16_t rrclass, uint16_t rdlen, const void *rdata);
typedef DNSServiceErrorType (DNSSD_API *BrowsePtr)(DNSServiceRef *sdRef, DNSServiceFlags flags,
                                                   uint32_t interfaceIndex, const char *regtype, const char *domain,
                                                   DNSServiceBrowseReply callBack, void *context);
typedef DNSServiceErrorType (DNSSD_API *GetPropertyPtr)(const char *property, void *result, uint32_t *size);
typedef DNSServiceErrorType (DNSSD_API *ProcessResultPtr)(DNSServiceRef sdRef);
typedef DNSServiceErrorType (DNSSD_API *CreateConnectionPtr)(DNSServiceRef *sdRef);
typedef int (DNSSD_API *RefSockFDPtr)(DNSServiceRef sdRef);
}

// represents a zero conf library exposing the dns-sd interface
class DnsSdZConfLib : public ZConfLib {
    Q_DECLARE_TR_FUNCTIONS(ZeroConf)
private:
    RefDeallocatePtr m_refDeallocate;
    ResolvePtr m_resolve;
    QueryRecordPtr m_queryRecord;
    GetAddrInfoPtr m_getAddrInfo;
    ReconfirmRecordPtr m_reconfirmRecord;
    BrowsePtr m_browse;
    GetPropertyPtr m_getProperty;
    ProcessResultPtr m_processResult;
    CreateConnectionPtr m_createConnection;
    RefSockFDPtr m_refSockFD;
    QLibrary dnsSdLib;
public:

    DnsSdZConfLib(QString libName = QLatin1String("dns_sd"), ZConfLib::Ptr fallBack = ZConfLib::Ptr(0)) : ZConfLib(fallBack), dnsSdLib(libName)
    {
#ifndef ZCONF_MDNS_STATIC_LINKING
        // dynamic linking
        if (!dnsSdLib.load()) {
            m_isOk = false;
            m_errorMsg = tr("could not load native library");
        }
        m_refDeallocate = reinterpret_cast<RefDeallocatePtr>(dnsSdLib.resolve("DNSServiceRefDeallocate"));
        m_resolve = reinterpret_cast<ResolvePtr>(dnsSdLib.resolve("DNSServiceResolve"));
        m_queryRecord = reinterpret_cast<QueryRecordPtr>(dnsSdLib.resolve("DNSServiceQueryRecord"));
        m_getAddrInfo = reinterpret_cast<GetAddrInfoPtr>(dnsSdLib.resolve("DNSServiceGetAddrInfo"));
        m_reconfirmRecord = reinterpret_cast<ReconfirmRecordPtr>(dnsSdLib.resolve("DNSServiceReconfirmRecord"));
        m_browse = reinterpret_cast<BrowsePtr>(dnsSdLib.resolve("DNSServiceBrowse"));
        m_getProperty = reinterpret_cast<GetPropertyPtr>(dnsSdLib.resolve("DNSServiceGetProperty"));
        m_processResult = reinterpret_cast<ProcessResultPtr>(dnsSdLib.resolve("DNSServiceProcessResult")) ;
        m_createConnection = reinterpret_cast<CreateConnectionPtr>(dnsSdLib.resolve("DNSServiceCreateConnection"));
        m_refSockFD = reinterpret_cast<RefSockFDPtr>(dnsSdLib.resolve("DNSServiceRefSockFD"));
#else
        // static linking
        m_refDeallocate = reinterpret_cast<RefDeallocatePtr>(&DNSServiceRefDeallocate);
        m_resolve = reinterpret_cast<ResolvePtr>(&DNSServiceResolve);
        m_queryRecord = reinterpret_cast<QueryRecordPtr>(DNSServiceQueryRecord);
        m_getAddrInfo = reinterpret_cast<GetAddrInfoPtr>(&DNSServiceGetAddrInfo);
        m_reconfirmRecord = reinterpret_cast<ReconfirmRecordPtr>(&DNSServiceReconfirmRecord);
        m_browse = reinterpret_cast<BrowsePtr>(&DNSServiceBrowse);
        m_getProperty = reinterpret_cast<GetPropertyPtr>(&DNSServiceGetProperty);
        m_processResult = reinterpret_cast<ProcessResultPtr>(&DNSServiceProcessResult) ;
        m_createConnection = reinterpret_cast<CreateConnectionPtr>(&DNSServiceCreateConnection);
        m_refSockFD = reinterpret_cast<RefSockFDPtr>(&DNSServiceRefSockFD);
#endif
        if (m_isOk && m_getAddrInfo == 0) {
            m_isOk = false;
#ifdef Q_OS_LINUX
            m_errorMsg = tr("skipping over avahi compatibility lib (or obsolete mdnsd)");
#else
            m_errorMsg = tr("*WARNING* detected an obsolete version of Apple Bonjour, either disable/uninstall it or upgrade it, otherwise zeroconf will fail");
#endif
        }
        if (DEBUG_ZEROCONF){
            if (m_refDeallocate == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_refDeallocate == 0");
            if (m_resolve == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_resolve == 0");
            if (m_queryRecord == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_queryRecord == 0");
            if (m_getAddrInfo == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_getAddrInfo == 0");
            if (m_reconfirmRecord == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_reconfirmRecord == 0");
            if (m_browse == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_browse == 0");
            if (m_getProperty == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_getProperty == 0");
            if (m_processResult == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_processResult == 0");
            if (m_createConnection == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_createConnection == 0");
            if (m_refSockFD == 0) qDebug() << QLatin1String("DnsSdZConfLib.m_refSockFD == 0");
        }
    }

    ~DnsSdZConfLib() {
    }

    QString name(){
        return QString::fromLatin1("Dns_sd (Apple Bonjour) Library");
    }

    // bool tryStartDaemon();
    void refDeallocate(DNSServiceRef sdRef) {
        if (m_refDeallocate == 0) return;
        m_refDeallocate(sdRef);
    }

    void browserDeallocate(BrowserRef *bRef) {
        if (m_refDeallocate == 0) return;
        if (bRef) {
            m_refDeallocate(*reinterpret_cast<DNSServiceRef *>(bRef));
            *bRef = 0;
        }
    }

    void stopConnection(ConnectionRef cRef)
    {
        int sock = refSockFD(cRef);
        if (sock>0)
            shutdown(sock, SHUT_RDWR);
    }

    void destroyConnection(ConnectionRef *sdRef) {
        if (m_refDeallocate == 0) return;
        if (sdRef) {
            m_refDeallocate(*reinterpret_cast<DNSServiceRef *>(sdRef));
            *sdRef = 0;
        }
    }

    DNSServiceErrorType resolve(ConnectionRef cRef, DNSServiceRef *sdRef,
                                uint32_t interfaceIndex, ZK_IP_Protocol /* protocol */, const char *name,
                                const char *regtype, const char *domain,
                                ServiceGatherer *gatherer)
    {
        if (m_resolve == 0) return kDNSServiceErr_Unsupported;
        *sdRef = reinterpret_cast<DNSServiceRef>(cRef);
        return m_resolve(sdRef, kDNSServiceFlagsShareConnection /* | kDNSServiceFlagsSuppressUnusable*/ | kDNSServiceFlagsTimeout,
                         interfaceIndex, name, regtype, domain, &cServiceResolveReply, gatherer
                         );
    }

    DNSServiceErrorType queryRecord(ConnectionRef cRef, DNSServiceRef *sdRef,
                                    uint32_t interfaceIndex, const char *fullname,
                                    ServiceGatherer *gatherer)
    {
        if (m_queryRecord == 0) return kDNSServiceErr_Unsupported;
        *sdRef = reinterpret_cast<DNSServiceRef>(cRef);
        return m_queryRecord(sdRef, kDNSServiceFlagsShareConnection
                             /* | kDNSServiceFlagsSuppressUnusable*/ | kDNSServiceFlagsTimeout,
                             interfaceIndex, fullname,
                             kDNSServiceType_TXT, kDNSServiceClass_IN, &cTxtRecordReply, gatherer);
    }

    DNSServiceErrorType getAddrInfo(ConnectionRef cRef, DNSServiceRef *sdRef,
                                    uint32_t interfaceIndex, DNSServiceProtocol protocol,
                                    const char *hostname, ServiceGatherer *gatherer)
    {
        enum { longTTL = 100 };
        if (m_getAddrInfo == 0) {
#ifdef Q_OS_UNIX
            // try to use getaddrinfo (for example on linux with avahi)
            struct addrinfo req, *ans; int err;
            memset(&req, 0, sizeof(req));
            req.ai_flags = 0;
            req.ai_family = AF_UNSPEC;
            req.ai_socktype = SOCK_STREAM;
            req.ai_protocol = 0;
            if ((err = getaddrinfo(hostname, 0, &req, &ans)) != 0) {
                qDebug() << "getaddrinfo for " << hostname << " failed with " << gai_strerror(err);
                return kDNSServiceErr_Unsupported; // use another error here???
            }
            for (struct addrinfo *ansAtt = ans; ansAtt != 0; ansAtt = ansAtt->ai_next){
                gatherer->addrReply(kDNSServiceFlagsAdd, kDNSServiceErr_NoError,
                                    hostname, ansAtt->ai_addr, longTTL);
            }
            freeaddrinfo(ans);
            return kDNSServiceErr_NoError;
#else
            return kDNSServiceErr_Unsupported;
#endif
        }
        *sdRef = reinterpret_cast<DNSServiceRef>(cRef);
        return m_getAddrInfo(sdRef, kDNSServiceFlagsShareConnection
                             /*| kDNSServiceFlagsSuppressUnusable */ | kDNSServiceFlagsTimeout,
                             interfaceIndex, protocol, hostname, &cAddrReply, gatherer);
    }

    DNSServiceErrorType reconfirmRecord(ConnectionRef /*cRef*/, uint32_t /*interfaceIndex*/,
                                        const char * /*name*/, const char * /*type*/,
                                        const char * /*domain*/, const char * /*fullname*/)
    {
        if (m_reconfirmRecord == 0) return kDNSServiceErr_Unsupported;
        // reload and force update with in the callback with
        // m_reconfirmRecord(flags, interfaceIndex, fullname, rrtype,
        //                         rrclass, rdlen, rdata);
        return kDNSServiceErr_Unsupported;
    }

    DNSServiceErrorType browse(ConnectionRef cRef, BrowserRef *bRef,
                               uint32_t interfaceIndex, const char *regtype,
                               const char *domain, ServiceBrowserPrivate *browser)
    {
        if (m_browse == 0) return kDNSServiceErr_Unsupported;
        DNSServiceRef *sdRef = reinterpret_cast<DNSServiceRef *>(bRef);
        *sdRef = reinterpret_cast<DNSServiceRef>(cRef);
        return m_browse(sdRef, kDNSServiceFlagsShareConnection /*| kDNSServiceFlagsSuppressUnusable*/,
                        interfaceIndex, regtype, domain, &cBrowseReply, browser);
    }

    DNSServiceErrorType getProperty(const char *property, void       *result, uint32_t   *size)
    {
        if (m_getProperty == 0)
            return kDNSServiceErr_Unsupported;
        return m_getProperty(property, result, size);
    }

    RunLoopStatus processOneEventBlock(ConnectionRef cRef)
    {
        if (m_processResult == 0)
            return ProcessedFailure;
        if (m_processResult(reinterpret_cast<DNSServiceRef>(cRef)) != kDNSServiceErr_NoError)
            return ProcessedError;
        return ProcessedOk;
    }

    DNSServiceErrorType createConnection(MainConnection *, ConnectionRef *sdRef)
    {
        if (m_createConnection == 0) return kDNSServiceErr_Unsupported;
        return m_createConnection(reinterpret_cast<DNSServiceRef *>(sdRef));
    }

    int refSockFD(ConnectionRef sdRef)
    {
        if (m_refSockFD == 0) return kDNSServiceErr_Unsupported;
        return m_refSockFD(reinterpret_cast<DNSServiceRef>(sdRef));
    }
};

ZConfLib::Ptr ZConfLib::createDnsSdLib(const QString &libName, const ZConfLib::Ptr &fallback) {
    return ZConfLib::Ptr(new DnsSdZConfLib(libName, fallback));
}
} // namespace Internal
} // namespace ZeroConf

#else // NO_DNS_SD_LIB

namespace ZeroConf {
namespace Internal {

ZConfLib::Ptr ZConfLib::createDnsSdLib(const QString &/*extraPaths*/, const ZConfLib::Ptr &fallback) {
    return fallback;
}

} // namespace Internal
} // namespace ZeroConf
#endif