// Copyright (C) 2010  Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include <iostream>
#include <string>
#include <sstream>
#include <vector>

#include <boost/lexical_cast.hpp>

#include <util/buffer.h>
#include <util/hex.h>

#include <dns/messagerenderer.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>

#include <stdio.h>
#include <time.h>

using namespace std;
using namespace isc::util;

// BEGIN_ISC_NAMESPACE
// BEGIN_RDATA_NAMESPACE

struct DSImpl {
    // straightforward representation of DS RDATA fields
    DSImpl(uint16_t tag, uint8_t algorithm, uint8_t digest_type,
           const vector<uint8_t>& digest) :
        tag_(tag), algorithm_(algorithm), digest_type_(digest_type),
        digest_(digest)
    {}

    uint16_t tag_;
    uint8_t algorithm_;
    uint8_t digest_type_;
    const vector<uint8_t> digest_;
};

DS::DS(const string& ds_str) :
    impl_(NULL)
{
    istringstream iss(ds_str);
    unsigned int tag, algorithm, digest_type;
    stringbuf digestbuf;

    iss >> tag >> algorithm >> digest_type >> &digestbuf;
    if (iss.bad() || iss.fail()) {
        isc_throw(InvalidRdataText, "Invalid DS text");
    }
    if (tag > 0xffff) {
        isc_throw(InvalidRdataText, "DS tag out of range");
    }
    if (algorithm > 0xff) {
        isc_throw(InvalidRdataText, "DS algorithm out of range");
    }
    if (digest_type > 0xff) {
        isc_throw(InvalidRdataText, "DS digest type out of range");
    }

    vector<uint8_t> digest;
    decodeHex(digestbuf.str(), digest);

    impl_ = new DSImpl(tag, algorithm, digest_type, digest);
}

DS::DS(InputBuffer& buffer, size_t rdata_len) {
    if (rdata_len < 4) {
        isc_throw(InvalidRdataLength, "DS too short");
    }

    uint16_t tag = buffer.readUint16();
    uint16_t algorithm = buffer.readUint8();
    uint16_t digest_type = buffer.readUint8();

    rdata_len -= 4;
    vector<uint8_t> digest(rdata_len);
    buffer.readData(&digest[0], rdata_len);

    impl_ = new DSImpl(tag, algorithm, digest_type, digest);
}

DS::DS(const DS& source) :
    Rdata(), impl_(new DSImpl(*source.impl_))
{}

DS&
DS::operator=(const DS& source) {
    if (impl_ == source.impl_) {
        return (*this);
    }

    DSImpl* newimpl = new DSImpl(*source.impl_);
    delete impl_;
    impl_ = newimpl;

    return (*this);
}

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

string
DS::toText() const {
    using namespace boost;
    return (lexical_cast<string>(static_cast<int>(impl_->tag_)) +
        " " + lexical_cast<string>(static_cast<int>(impl_->algorithm_)) +
        " " + lexical_cast<string>(static_cast<int>(impl_->digest_type_)) +
        " " + encodeHex(impl_->digest_));
}

void
DS::toWire(OutputBuffer& buffer) const {
    buffer.writeUint16(impl_->tag_);
    buffer.writeUint8(impl_->algorithm_);
    buffer.writeUint8(impl_->digest_type_);
    buffer.writeData(&impl_->digest_[0], impl_->digest_.size());
}

void
DS::toWire(MessageRenderer& renderer) const {
    renderer.writeUint16(impl_->tag_);
    renderer.writeUint8(impl_->algorithm_);
    renderer.writeUint8(impl_->digest_type_);
    renderer.writeData(&impl_->digest_[0], impl_->digest_.size());
}

int
DS::compare(const Rdata& other) const {
    const DS& other_ds = dynamic_cast<const DS&>(other);

    if (impl_->tag_ != other_ds.impl_->tag_) {
        return (impl_->tag_ < other_ds.impl_->tag_ ? -1 : 1);
    }
    if (impl_->algorithm_ != other_ds.impl_->algorithm_) {
        return (impl_->algorithm_ < other_ds.impl_->algorithm_ ? -1 : 1);
    }
    if (impl_->digest_type_ != other_ds.impl_->digest_type_) {
        return (impl_->digest_type_ < other_ds.impl_->digest_type_ ? -1 : 1);
    }

    size_t this_len = impl_->digest_.size();
    size_t other_len = other_ds.impl_->digest_.size();
    size_t cmplen = min(this_len, other_len);
    int cmp = memcmp(&impl_->digest_[0], &other_ds.impl_->digest_[0], cmplen);
    if (cmp != 0) {
        return (cmp);
    } else {
        return ((this_len == other_len) ? 0 : (this_len < other_len) ? -1 : 1);
    }
}

uint16_t
DS::getTag() const {
    return (impl_->tag_);
}

// END_RDATA_NAMESPACE
// END_ISC_NAMESPACE