// Copyright (C) 2012-2020 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <exceptions/exceptions.h>

// include this first to check the header is self-contained.
#include <dns/rrcollator.h>

#include <dns/name.h>
#include <dns/rdataclass.h>
#include <dns/rrclass.h>
#include <dns/rrtype.h>
#include <dns/rrttl.h>
#include <dns/rdata.h>
#include <dns/rrset.h>

#include <algorithm>
#include <functional>

using namespace isc::dns::rdata;
namespace ph = std::placeholders;

namespace isc {
namespace dns {

class RRCollator::Impl {
public:
    Impl(const AddRRsetCallback& callback) : callback_(callback) {}

    void addRR(const Name& name, const RRClass& rrclass,
               const RRType& rrtype, const RRTTL& rrttl,
               const RdataPtr& rdata);

    RRsetPtr current_rrset_;
    const AddRRsetCallback callback_;
};

namespace {
inline bool
isSameType(RRType type1, const ConstRdataPtr& rdata1,
           const ConstRRsetPtr& rrset)
{
    if (type1 != rrset->getType()) {
        return (false);
    }
    if (type1 == RRType::RRSIG()) {
        RdataIteratorPtr rit = rrset->getRdataIterator();
        return (dynamic_cast<const generic::RRSIG&>(*rdata1).typeCovered()
                == dynamic_cast<const generic::RRSIG&>(
                    rit->getCurrent()).typeCovered());
    }
    return (true);
}
}

void
RRCollator::Impl::addRR(const Name& name, const RRClass& rrclass,
                        const RRType& rrtype, const RRTTL& rrttl,
                        const RdataPtr& rdata)
{
    if (current_rrset_ && (!isSameType(rrtype, rdata, current_rrset_) ||
                           current_rrset_->getClass() != rrclass ||
                           current_rrset_->getName() != name)) {
        callback_(current_rrset_);
        current_rrset_.reset();
    }

    if (!current_rrset_) {
        current_rrset_ = RRsetPtr(new RRset(name, rrclass, rrtype, rrttl));
    } else if (current_rrset_->getTTL() != rrttl) {
        // RRs with different TTLs are given.  Smaller TTL should win.
        current_rrset_->setTTL(std::min(current_rrset_->getTTL(), rrttl));
    }
    current_rrset_->addRdata(rdata);
}

RRCollator::RRCollator(const AddRRsetCallback& callback) :
    impl_(new Impl(callback))
{}

RRCollator::~RRCollator() {
    delete impl_;
}

AddRRCallback
RRCollator::getCallback() {
    return (std::bind(&RRCollator::Impl::addRR, this->impl_,
                      ph::_1, ph::_2, ph::_3, ph::_4, ph::_5));
}

void
RRCollator::flush() {
    if (impl_->current_rrset_) {
        impl_->callback_(impl_->current_rrset_);
        impl_->current_rrset_.reset();
    }
}

} // end namespace dns
} // end namespace isc