#ifndef OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP
#define OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP

/*

This file is part of Osmium (http://osmcode.org/libosmium).

Copyright 2013-2015 Jochen Topf <jochen@topf.org> and others (see README).

Boost Software License - Version 1.0 - August 17th, 2003

Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:

The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

*/

/*

About the .osm.pbf file format
This is an excerpt of <http://wiki.openstreetmap.org/wiki/PBF_Format>

The .osm.pbf format and it's derived formats (.osh.pbf and .osc.pbf) are encoded
using googles protobuf library for the low-level storage. They are constructed
by nesting data on two levels:

On the lower level the file is constructed using BlobHeaders and Blobs. A .osm.pbf
file contains multiple sequences of
 1. a 4-byte header size, stored in network-byte-order
 2. a BlobHeader of exactly this size
 3. a Blob

The BlobHeader tells the reader about the type and size of the following Blob. The
Blob can contain data in raw or zlib-compressed form. After uncompressing the blob
it is treated differently depending on the type specified in the BlobHeader.

The contents of the Blob belongs to the higher level. It contains either an HeaderBlock
(type="OSMHeader") or an PrimitiveBlock (type="OSMData"). The file needs to have
at least one HeaderBlock before the first PrimitiveBlock.

The HeaderBlock contains meta-information like the writing program or a bbox. It may
also contain multiple "required features" that describe what kinds of input a
reading program needs to handle in order to fully understand the files' contents.

The PrimitiveBlock can store multiple types of objects (i.e. 5 nodes, 2 ways and
1 relation). It contains one or more PrimitiveGroup which in turn contain multiple
nodes, ways or relations. A PrimitiveGroup should only contain one kind of object.

There's a special kind of "object type" called dense-nodes. It is used to store nodes
in a very dense format, avoiding message overheads and using delta-encoding for nearly
all ids.

All Strings are stored as indexes to rows in a StringTable. The StringTable contains
one row for each used string, so strings that are used multiple times need to be
stored only once. The StringTable is sorted by usage-count, so the most often used
string is stored at index 1.

A simple outline of a .osm.pbf file could look like this:

  4-bytes header size
  BlobHeader
  Blob
    HeaderBlock
  4-bytes header size
  BlobHeader
  Blob
    PrimitiveBlock
      StringTable
      PrimitiveGroup
        5 nodes
      PrimitiveGroup
        2 ways
      PrimitiveGroup
        1 relation

More complete outlines of real .osm.pbf files can be created using the osmpbf-outline tool:
 <https://github.com/MaZderMind/OSM-binary/tree/osmpbf-outline>
*/

#include <algorithm>
#include <chrono>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <future>
#include <iostream>
#include <memory>
#include <ratio>
#include <string>
#include <thread>
#include <time.h>
#include <utility>

#include <osmium/handler.hpp>
#include <osmium/io/detail/output_format.hpp>
#include <osmium/io/detail/pbf.hpp> // IWYU pragma: export
#include <osmium/io/detail/pbf_stringtable.hpp>
#include <osmium/io/detail/zlib.hpp>
#include <osmium/io/file.hpp>
#include <osmium/io/file_format.hpp>
#include <osmium/io/header.hpp>
#include <osmium/memory/buffer.hpp>
#include <osmium/memory/collection.hpp>
#include <osmium/osm/box.hpp>
#include <osmium/osm/item_type.hpp>
#include <osmium/osm/location.hpp>
#include <osmium/osm/node.hpp>
#include <osmium/osm/object.hpp>
#include <osmium/osm/relation.hpp>
#include <osmium/osm/tag.hpp>
#include <osmium/osm/timestamp.hpp>
#include <osmium/osm/way.hpp>
#include <osmium/util/cast.hpp>
#include <osmium/visitor.hpp>

namespace osmium {

    namespace io {

        namespace detail {

            namespace {

                /**
                 * Serialize a protobuf message into a Blob, optionally apply compression
                 * and return it together with a BlobHeader ready to be written to a file.
                 *
                 * @param type Type-string used in the BlobHeader.
                 * @param msg Protobuf-message.
                 * @param use_compression Should the output be compressed using zlib?
                 */
                std::string serialize_blob(const std::string& type, const google::protobuf::MessageLite& msg, bool use_compression) {
                    OSMPBF::Blob pbf_blob;

                    {
                        std::string content;
                        msg.SerializeToString(&content);

                        pbf_blob.set_raw_size(static_cast_with_assert<::google::protobuf::int32>(content.size()));

                        if (use_compression) {
                            pbf_blob.set_zlib_data(osmium::io::detail::zlib_compress(content));
                        } else {
                            pbf_blob.set_raw(content);
                        }
                    }

                    std::string blob_data;
                    pbf_blob.SerializeToString(&blob_data);

                    OSMPBF::BlobHeader pbf_blob_header;
                    pbf_blob_header.set_type(type);
                    pbf_blob_header.set_datasize(static_cast_with_assert<::google::protobuf::int32>(blob_data.size()));

                    std::string blob_header_data;
                    pbf_blob_header.SerializeToString(&blob_header_data);

                    uint32_t sz = htonl(static_cast_with_assert<uint32_t>(blob_header_data.size()));

                    // write to output: the 4-byte BlobHeader-Size followed by the BlobHeader followed by the Blob
                    std::string output;
                    output.reserve(sizeof(sz) + blob_header_data.size() + blob_data.size());
                    output.append(reinterpret_cast<const char*>(&sz), sizeof(sz));
                    output.append(blob_header_data);
                    output.append(blob_data);

                    return output;
                }

            } // anonymous namespace

            class PBFOutputFormat : public osmium::io::detail::OutputFormat, public osmium::handler::Handler {

                /**
                 * This class models a variable that keeps track of the value
                 * it was last set to and returns the delta between old and
                 * new value from the update() call.
                 */
                template <typename T>
                class Delta {

                    T m_value;

                public:

                    Delta() :
                        m_value(0) {
                    }

                    void clear() {
                        m_value = 0;
                    }

                    T update(T new_value) {
                        using std::swap;
                        swap(m_value, new_value);
                        return m_value - new_value;
                    }

                }; // class Delta

                /**
                 * Maximum number of items in a primitive block.
                 *
                 * The uncompressed length of a Blob *should* be less
                 * than 16 megabytes and *must* be less than 32 megabytes.
                 *
                 * A block may contain any number of entities, as long as
                 * the size limits for the surrounding blob are obeyed.
                 * However, for simplicity, the current Osmosis (0.38)
                 * as well as Osmium implementation always
                 * uses at most 8k entities in a block.
                 */
                static constexpr uint32_t max_block_contents = 8000;

                /**
                 * The output buffer (block) will be filled to about
                 * 95% and then written to disk. This leaves more than
                 * enough space for the string table (which typically
                 * needs about 0.1 to 0.3% of the block size).
                 */
                static constexpr int64_t buffer_fill_percent = 95;

                /**
                 * protobuf-struct of a HeaderBlock
                 */
                OSMPBF::HeaderBlock pbf_header_block;

                /**
                 * protobuf-struct of a PrimitiveBlock
                 */
                OSMPBF::PrimitiveBlock pbf_primitive_block;

                /**
                 * pointer to PrimitiveGroups inside the current PrimitiveBlock,
                 * used for writing nodes, ways or relations
                 */
                OSMPBF::PrimitiveGroup* pbf_nodes;
                OSMPBF::PrimitiveGroup* pbf_ways;
                OSMPBF::PrimitiveGroup* pbf_relations;

                /**
                 * To flexibly handle multiple resolutions, the granularity, or
                 * resolution used for representing locations is adjustable in
                 * multiples of 1 nanodegree. The default scaling factor is 100
                 * nanodegrees, corresponding to about ~1cm at the equator.
                 * This is the current resolution of the OSM database.
                 */
                int m_location_granularity;

                /**
                 * The granularity used for representing timestamps is also adjustable in
                 * multiples of 1 millisecond. The default scaling factor is 1000
                 * milliseconds, which is the current resolution of the OSM database.
                 */
                int m_date_granularity;

                /**
                 * should nodes be serialized into the dense format?
                 *
                 * nodes can be encoded one of two ways, as a Node
                 * (m_use_dense_nodes = false) and a special dense format.
                 * In the dense format, all information is stored 'column wise',
                 * as an array of ID's, array of latitudes, and array of
                 * longitudes. Each column is delta-encoded. This reduces
                 * header overheads and allows delta-coding to work very effectively.
                 */
                bool m_use_dense_nodes {true};

                /**
                 * should the PBF blobs contain zlib compressed data?
                 *
                 * the zlib compression is optional, it's possible to store the
                 * blobs in raw format. Disabling the compression can improve the
                 * writing speed a little but the output will be 2x to 3x bigger.
                 */
                bool m_use_compression {true};

                /**
                 * Should the string tables in the data blocks be sorted?
                 *
                 * Not sorting the string tables makes writing PBF files
                 * slightly faster.
                 */
                bool m_sort_stringtables { true };

                /**
                 * While the .osm.pbf-format is able to carry all meta information, it is
                 * also able to omit this information to reduce size.
                 */
                bool m_should_add_metadata {true};

                /**
                 * Should the visible flag be added on objects?
                 */
                bool m_add_visible;

                /**
                 * counter used to quickly check the number of objects stored inside
                 * the current PrimitiveBlock. When the counter reaches max_block_contents
                 * the PrimitiveBlock is serialized into a Blob and flushed to the file.
                 *
                 * this check is performed in check_block_contents_counter() which is
                 * called once for each object.
                 */
                uint16_t primitive_block_contents;
                int primitive_block_size;

                // StringTable management
                StringTable string_table;

                /**
                 * These variables are used to calculate the
                 * delta-encoding while storing dense-nodes. It holds the last seen values
                 * from which the difference is stored into the protobuf.
                 */
                Delta<int64_t> m_delta_id;
                Delta<int64_t> m_delta_lat;
                Delta<int64_t> m_delta_lon;
                Delta<int64_t> m_delta_timestamp;
                Delta<int64_t> m_delta_changeset;
                Delta<int64_t> m_delta_uid;
                Delta<::google::protobuf::int32> m_delta_user_sid;

                bool debug;

                bool has_debug_level(int) {
                    return false;
                }

                ///// Blob writing /////

                void delta_encode_string_ids() {
                    if (pbf_nodes && pbf_nodes->has_dense()) {
                        OSMPBF::DenseNodes* dense = pbf_nodes->mutable_dense();

                        if (dense->has_denseinfo()) {
                            OSMPBF::DenseInfo* denseinfo = dense->mutable_denseinfo();

                            for (int i = 0, l=denseinfo->user_sid_size(); i<l; ++i) {
                                auto user_sid = denseinfo->user_sid(i);
                                denseinfo->set_user_sid(i, m_delta_user_sid.update(user_sid));
                            }
                        }
                    }
                }

                /**
                 * Before a PrimitiveBlock gets serialized, all interim StringTable-ids needs to be
                 * mapped to the associated real StringTable ids. This is done in this function.
                 *
                 * This function needs to know about the concrete structure of all item types to find
                 * all occurrences of string-ids.
                 */
                void map_string_ids() {
                    // test, if the node-block has been allocated
                    if (pbf_nodes) {
                        // iterate over all nodes, passing them to the map_common_string_ids function
                        for (int i = 0, l=pbf_nodes->nodes_size(); i<l; ++i) {
                            map_common_string_ids(pbf_nodes->mutable_nodes(i));
                        }

                        // test, if the node-block has a densenodes structure
                        if (pbf_nodes->has_dense()) {
                            // get a pointer to the densenodes structure
                            OSMPBF::DenseNodes* dense = pbf_nodes->mutable_dense();

                            // in the densenodes structure keys and vals are encoded in an intermixed
                            // array, individual nodes are seperated by a value of 0 (0 in the StringTable
                            // is always unused). String-ids of 0 are thus kept alone.
                            for (int i = 0, l=dense->keys_vals_size(); i<l; ++i) {
                                // map interim string-ids > 0 to real string ids
                                auto sid = dense->keys_vals(i);
                                if (sid > 0) {
                                    dense->set_keys_vals(i, string_table.map_string_id(sid));
                                }
                            }

                            // test if the densenodes block has meta infos
                            if (dense->has_denseinfo()) {
                                // get a pointer to the denseinfo structure
                                OSMPBF::DenseInfo* denseinfo = dense->mutable_denseinfo();

                                // iterate over all username string-ids
                                for (int i = 0, l=denseinfo->user_sid_size(); i<l; ++i) {
                                    // map interim string-ids > 0 to real string ids
                                    auto user_sid = string_table.map_string_id(denseinfo->user_sid(i));

                                    // delta encode the string-id
                                    denseinfo->set_user_sid(i, m_delta_user_sid.update(user_sid));
                                }
                            }
                        }
                    }

                    // test, if the ways-block has been allocated
                    if (pbf_ways) {
                        // iterate over all ways, passing them to the map_common_string_ids function
                        for (int i = 0, l=pbf_ways->ways_size(); i<l; ++i) {
                            map_common_string_ids(pbf_ways->mutable_ways(i));
                        }
                    }

                    // test, if the relations-block has been allocated
                    if (pbf_relations) {
                        // iterate over all relations
                        for (int i = 0, l=pbf_relations->relations_size(); i<l; ++i) {
                            // get a pointer to the relation
                            OSMPBF::Relation* relation = pbf_relations->mutable_relations(i);

                            // pass them to the map_common_string_ids function
                            map_common_string_ids(relation);

                            // iterate over all relation members, mapping the interim string-ids
                            // of the role to real string ids
                            for (int mi = 0; mi < relation->roles_sid_size(); ++mi) {
                                relation->set_roles_sid(mi, string_table.map_string_id(relation->roles_sid(mi)));
                            }
                        }
                    }
                }

                /**
                * a helper function used in map_string_ids to map common interim string-ids of the
                * user name and all tags to real string ids.
                *
                * TPBFObject is either OSMPBF::Node, OSMPBF::Way or OSMPBF::Relation.
                */
                template <class TPBFObject>
                void map_common_string_ids(TPBFObject* in) {
                    // if the object has meta-info attached
                    if (in->has_info()) {
                        // map the interim-id of the user name to a real id
                        OSMPBF::Info* info = in->mutable_info();
                        info->set_user_sid(string_table.map_string_id(info->user_sid()));
                    }

                    // iterate over all tags and map the interim-ids of the key and the value to real ids
                    for (int i = 0, l=in->keys_size(); i<l; ++i) {
                        in->set_keys(i, string_table.map_string_id(in->keys(i)));
                        in->set_vals(i, string_table.map_string_id(in->vals(i)));
                    }
                }


                ///// MetaData helper /////

                /**
                 * convert a double lat or lon value to an int, respecting the current blocks granularity
                 */
                int64_t lonlat2int(double lonlat) {
                    return static_cast<int64_t>(std::round(lonlat * OSMPBF::lonlat_resolution / location_granularity()));
                }

                /**
                 * convert a timestamp to an int, respecting the current blocks granularity
                 */
                int64_t timestamp2int(time_t timestamp) {
                    return static_cast<int64_t>(std::round(timestamp * (1000.0 / date_granularity())));
                }

                /**
                 * helper function used in the write()-calls to apply common information from an osmium-object
                 * onto a pbf-object.
                 *
                 * TPBFObject is either OSMPBF::Node, OSMPBF::Way or OSMPBF::Relation.
                 */
                template <class TPBFObject>
                void apply_common_info(const osmium::OSMObject& in, TPBFObject* out) {
                    // set the object-id
                    out->set_id(in.id());

                    // iterate over all tags and set the keys and vals, recording the strings in the
                    // interim StringTable and storing the interim ids
                    for (const auto& tag : in.tags()) {
                        out->add_keys(string_table.record_string(tag.key()));
                        out->add_vals(string_table.record_string(tag.value()));
                    }

                    if (m_should_add_metadata) {
                        // add an info-section to the pbf object and set the meta-info on it
                        OSMPBF::Info* out_info = out->mutable_info();
                        if (m_add_visible) {
                            out_info->set_visible(in.visible());
                        }
                        out_info->set_version(static_cast<::google::protobuf::int32>(in.version()));
                        out_info->set_timestamp(timestamp2int(in.timestamp()));
                        out_info->set_changeset(in.changeset());
                        out_info->set_uid(static_cast<::google::protobuf::int32>(in.uid()));
                        out_info->set_user_sid(string_table.record_string(in.user()));
                    }
                }


                ///// High-Level Block writing /////

                /**
                 * store the current pbf_header_block into a Blob and clear this struct afterwards.
                 */
                void store_header_block() {
                    if (debug && has_debug_level(1)) {
                        std::cerr << "storing header block" << std::endl;
                    }

                    std::promise<std::string> promise;
                    m_output_queue.push(promise.get_future());
                    promise.set_value(serialize_blob("OSMHeader", pbf_header_block, m_use_compression));

                    pbf_header_block.Clear();
                }

                /**
                 * store the interim StringTable to the current pbf_primitive_block, map all interim string ids
                 * to real StringTable ids and then store the current pbf_primitive_block into a Blob and clear
                 * this struct and all related pointers and maps afterwards.
                 */
                void store_primitive_block() {
                    if (debug && has_debug_level(1)) {
                        std::cerr << "storing primitive block with " << primitive_block_contents << " items" << std::endl;
                    }

                    // set the granularity
                    pbf_primitive_block.set_granularity(location_granularity());
                    pbf_primitive_block.set_date_granularity(date_granularity());

                    string_table.store_stringtable(pbf_primitive_block.mutable_stringtable(), m_sort_stringtables);

                    if (m_sort_stringtables) {
                        map_string_ids();
                    } else {
                        delta_encode_string_ids();
                    }

                    std::promise<std::string> promise;
                    m_output_queue.push(promise.get_future());
                    promise.set_value(serialize_blob("OSMData", pbf_primitive_block, m_use_compression));

                    // clear the PrimitiveBlock struct
                    pbf_primitive_block.Clear();

                    // clear the interim StringTable and its id map
                    string_table.clear();

                    // reset the delta variables
                    m_delta_id.clear();
                    m_delta_lat.clear();
                    m_delta_lon.clear();
                    m_delta_timestamp.clear();
                    m_delta_changeset.clear();
                    m_delta_uid.clear();
                    m_delta_user_sid.clear();

                    // reset the contents-counter to zero
                    primitive_block_contents = 0;
                    primitive_block_size = 0;

                    // reset the node/way/relation pointers to nullptr
                    pbf_nodes = nullptr;
                    pbf_ways = nullptr;
                    pbf_relations = nullptr;
                }

                /**
                 * this little function checks primitive_block_contents counter against its maximum and calls
                 * store_primitive_block to flush the block to the disk when it's reached. It's also responsible
                 * for increasing this counter.
                 *
                 * this function also checks the estimated size of the current block and calls store_primitive_block
                 * when the estimated size reaches buffer_fill_percent of the maximum uncompressed blob size.
                 */
                void check_block_contents_counter() {
                    if (primitive_block_contents >= max_block_contents) {
                        store_primitive_block();
                    } else if (primitive_block_size > OSMPBF::max_uncompressed_blob_size * buffer_fill_percent / 100) {
                        if (debug && has_debug_level(1)) {
                            std::cerr << "storing primitive_block with only " << primitive_block_contents << " items, because its ByteSize (" << primitive_block_size << ") reached " <<
                                      (static_cast<float>(primitive_block_size) / static_cast<float>(OSMPBF::max_uncompressed_blob_size) * 100.0) << "% of the maximum blob-size" << std::endl;
                        }

                        store_primitive_block();
                    }

                    ++primitive_block_contents;
                }


                ///// Block content writing /////

                /**
                 * Add a node to the block.
                 *
                 * @param node The node to add.
                 */
                void write_node(const osmium::Node& node) {
                    // add a way to the group
                    OSMPBF::Node* pbf_node = pbf_nodes->add_nodes();

                    // copy the common meta-info from the osmium-object to the pbf-object
                    apply_common_info(node, pbf_node);

                    // modify lat & lon to integers, respecting the block's granularity and copy
                    // the ints to the pbf-object
                    pbf_node->set_lon(lonlat2int(node.location().lon_without_check()));
                    pbf_node->set_lat(lonlat2int(node.location().lat_without_check()));
                }

                /**
                 * Add a node to the block using DenseNodes.
                 *
                 * @param node The node to add.
                 */
                void write_dense_node(const osmium::Node& node) {
                    // add a DenseNodes-Section to the PrimitiveGroup
                    OSMPBF::DenseNodes* dense = pbf_nodes->mutable_dense();

                    // copy the id, delta encoded
                    dense->add_id(m_delta_id.update(node.id()));

                    // copy the longitude, delta encoded
                    dense->add_lon(m_delta_lon.update(lonlat2int(node.location().lon_without_check())));

                    // copy the latitude, delta encoded
                    dense->add_lat(m_delta_lat.update(lonlat2int(node.location().lat_without_check())));

                    // in the densenodes structure keys and vals are encoded in an intermixed
                    // array, individual nodes are seperated by a value of 0 (0 in the StringTable
                    // is always unused)
                    // so for three nodes the keys_vals array may look like this: 3 5 2 1 0 0 8 5
                    // the first node has two tags (3=>5 and 2=>1), the second node does not
                    // have any tags and the third node has a single tag (8=>5)
                    for (const auto& tag : node.tags()) {
                        dense->add_keys_vals(string_table.record_string(tag.key()));
                        dense->add_keys_vals(string_table.record_string(tag.value()));
                    }
                    dense->add_keys_vals(0);

                    if (m_should_add_metadata) {
                        // add a DenseInfo-Section to the PrimitiveGroup
                        OSMPBF::DenseInfo* denseinfo = dense->mutable_denseinfo();

                        denseinfo->add_version(static_cast<::google::protobuf::int32>(node.version()));

                        if (m_add_visible) {
                            denseinfo->add_visible(node.visible());
                        }

                        // copy the timestamp, delta encoded
                        denseinfo->add_timestamp(m_delta_timestamp.update(timestamp2int(node.timestamp())));

                        // copy the changeset, delta encoded
                        denseinfo->add_changeset(m_delta_changeset.update(node.changeset()));

                        // copy the user id, delta encoded
                        denseinfo->add_uid(static_cast<::google::protobuf::int32>(m_delta_uid.update(node.uid())));

                        // record the user-name to the interim stringtable and copy the
                        // interim string-id to the pbf-object
                        denseinfo->add_user_sid(string_table.record_string(node.user()));
                    }
                }

                /**
                 * Add a way to the block.
                 *
                 * @param way The way to add.
                 */
                void write_way(const osmium::Way& way) {
                    // add a way to the group
                    OSMPBF::Way* pbf_way = pbf_ways->add_ways();

                    // copy the common meta-info from the osmium-object to the pbf-object
                    apply_common_info(way, pbf_way);

                    // last way-node-id used for delta-encoding
                    Delta<int64_t> delta_id;

                    for (const auto& node_ref : way.nodes()) {
                        // copy the way-node-id, delta encoded
                        pbf_way->add_refs(delta_id.update(node_ref.ref()));
                    }

                    // count up blob size by the size of the Way
                    primitive_block_size += pbf_way->ByteSize();
                }

                /**
                 * Add a relation to the block.
                 *
                 * @param relation The relation to add.
                 */
                void write_relation(const osmium::Relation& relation) {
                    // add a relation to the group
                    OSMPBF::Relation* pbf_relation = pbf_relations->add_relations();

                    // copy the common meta-info from the osmium-object to the pbf-object
                    apply_common_info(relation, pbf_relation);

                    Delta<int64_t> delta_id;

                    for (const auto& member : relation.members()) {
                        // record the relation-member role to the interim stringtable and copy the
                        // interim string-id to the pbf-object
                        pbf_relation->add_roles_sid(string_table.record_string(member.role()));

                        // copy the relation-member-id, delta encoded
                        pbf_relation->add_memids(delta_id.update(member.ref()));

                        // copy the relation-member-type, mapped to the OSMPBF enum
                        pbf_relation->add_types(item_type_to_osmpbf_membertype(member.type()));
                    }

                    // count up blob size by the size of the Relation
                    primitive_block_size += pbf_relation->ByteSize();
                }

                // objects of this class can't be copied
                PBFOutputFormat(const PBFOutputFormat&) = delete;
                PBFOutputFormat& operator=(const PBFOutputFormat&) = delete;

            public:

                /**
                 * Create PBFOutputFormat object from File.
                 */
                explicit PBFOutputFormat(const osmium::io::File& file, data_queue_type& output_queue) :
                    OutputFormat(file, output_queue),
                    pbf_header_block(),
                    pbf_primitive_block(),
                    pbf_nodes(nullptr),
                    pbf_ways(nullptr),
                    pbf_relations(nullptr),
                    m_location_granularity(pbf_primitive_block.granularity()),
                    m_date_granularity(pbf_primitive_block.date_granularity()),
                    m_add_visible(file.has_multiple_object_versions()),
                    primitive_block_contents(0),
                    primitive_block_size(0),
                    string_table(),
                    m_delta_id(),
                    m_delta_lat(),
                    m_delta_lon(),
                    m_delta_timestamp(),
                    m_delta_changeset(),
                    m_delta_uid(),
                    m_delta_user_sid(),
                    debug(true) {
                    GOOGLE_PROTOBUF_VERIFY_VERSION;
                    if (file.get("pbf_dense_nodes") == "false") {
                        m_use_dense_nodes = false;
                    }
                    if (file.get("pbf_compression") == "none" || file.get("pbf_compression") == "false") {
                        m_use_compression = false;
                    }
                    if (file.get("pbf_sort_stringtables") == "false") {
                        m_sort_stringtables = false;
                    }
                    if (file.get("pbf_add_metadata") == "false") {
                        m_should_add_metadata = false;
                    }
                }

                void write_buffer(osmium::memory::Buffer&& buffer) override final {
                    osmium::apply(buffer.cbegin(), buffer.cend(), *this);
                }


                /**
                 * getter to access the granularity
                 */
                int location_granularity() const {
                    return m_location_granularity;
                }

                /**
                 * setter to set the granularity
                 */
                PBFOutputFormat& location_granularity(int g) {
                    m_location_granularity = g;
                    return *this;
                }


                /**
                 * getter to access the date_granularity
                 */
                int date_granularity() const {
                    return m_date_granularity;
                }

                /**
                 * Set date granularity.
                 */
                PBFOutputFormat& date_granularity(int g) {
                    m_date_granularity = g;
                    return *this;
                }


                /**
                 * Initialize the writing process.
                 *
                 * This initializes the header-block, sets the required-features and
                 * the writing-program and adds the obligatory StringTable-Index 0.
                 */
                void write_header(const osmium::io::Header& header) override final {
                    // add the schema version as required feature to the HeaderBlock
                    pbf_header_block.add_required_features("OsmSchema-V0.6");

                    // when the densenodes-feature is used, add DenseNodes as required feature
                    if (m_use_dense_nodes) {
                        pbf_header_block.add_required_features("DenseNodes");
                    }

                    // when the resulting file will carry history information, add
                    // HistoricalInformation as required feature
                    if (m_file.has_multiple_object_versions()) {
                        pbf_header_block.add_required_features("HistoricalInformation");
                    }

                    // set the writing program
                    pbf_header_block.set_writingprogram(header.get("generator"));

                    if (!header.boxes().empty()) {
                        OSMPBF::HeaderBBox* pbf_bbox = pbf_header_block.mutable_bbox();
                        osmium::Box box = header.joined_boxes();
                        pbf_bbox->set_left(static_cast<::google::protobuf::int64>(box.bottom_left().lon() * OSMPBF::lonlat_resolution));
                        pbf_bbox->set_bottom(static_cast<::google::protobuf::int64>(box.bottom_left().lat() * OSMPBF::lonlat_resolution));
                        pbf_bbox->set_right(static_cast<::google::protobuf::int64>(box.top_right().lon() * OSMPBF::lonlat_resolution));
                        pbf_bbox->set_top(static_cast<::google::protobuf::int64>(box.top_right().lat() * OSMPBF::lonlat_resolution));
                    }

                    std::string osmosis_replication_timestamp = header.get("osmosis_replication_timestamp");
                    if (!osmosis_replication_timestamp.empty()) {
                        osmium::Timestamp ts(osmosis_replication_timestamp.c_str());
                        pbf_header_block.set_osmosis_replication_timestamp(ts);
                    }

                    std::string osmosis_replication_sequence_number = header.get("osmosis_replication_sequence_number");
                    if (!osmosis_replication_sequence_number.empty()) {
                        pbf_header_block.set_osmosis_replication_sequence_number(std::atoll(osmosis_replication_sequence_number.c_str()));
                    }

                    std::string osmosis_replication_base_url = header.get("osmosis_replication_base_url");
                    if (!osmosis_replication_base_url.empty()) {
                        pbf_header_block.set_osmosis_replication_base_url(osmosis_replication_base_url);
                    }

                    store_header_block();
                }

                /**
                 * Add a node to the pbf.
                 *
                 * A call to this method won't write the node to the file directly but
                 * cache it for later bulk-writing. Calling final() ensures that everything
                 * gets written and every file pointer is closed.
                 */
                void node(const osmium::Node& node) {
                    // first of we check the contents-counter which may flush the cached nodes to
                    // disk if the limit is reached. This call also increases the contents-counter
                    check_block_contents_counter();

                    if (debug && has_debug_level(2)) {
                        std::cerr << "node " << node.id() << " v" << node.version() << std::endl;
                    }

                    // if no PrimitiveGroup for nodes has been added, add one and save the pointer
                    if (!pbf_nodes) {
                        pbf_nodes = pbf_primitive_block.add_primitivegroup();
                    }

                    if (m_use_dense_nodes) {
                        write_dense_node(node);
                    } else {
                        write_node(node);
                    }
                }

                /**
                 * Add a way to the pbf.
                 *
                 * A call to this method won't write the way to the file directly but
                 * cache it for later bulk-writing. Calling final() ensures that everything
                 * gets written and every file pointer is closed.
                 */
                void way(const osmium::Way& way) {
                    // first of we check the contents-counter which may flush the cached ways to
                    // disk if the limit is reached. This call also increases the contents-counter
                    check_block_contents_counter();

                    // if no PrimitiveGroup for nodes has been added, add one and save the pointer
                    if (!pbf_ways) {
                        pbf_ways = pbf_primitive_block.add_primitivegroup();
                    }

                    write_way(way);
                }

                /**
                 * Add a relation to the pbf.
                 *
                 * A call to this method won't write the way to the file directly but
                 * cache it for later bulk-writing. Calling final() ensures that everything
                 * gets written and every file pointer is closed.
                 */
                void relation(const osmium::Relation& relation) {
                    // first of we check the contents-counter which may flush the cached relations to
                    // disk if the limit is reached. This call also increases the contents-counter
                    check_block_contents_counter();

                    // if no PrimitiveGroup for relations has been added, add one and save the pointer
                    if (!pbf_relations) {
                        pbf_relations = pbf_primitive_block.add_primitivegroup();
                    }

                    write_relation(relation);
                }

                /**
                 * Finalize the writing process, flush any open primitive blocks to the file and
                 * close the file.
                 */
                void close() override final {
                    if (debug && has_debug_level(1)) {
                        std::cerr << "finishing" << std::endl;
                    }

                    // if the current block contains any elements, flush it to the protobuf
                    if (primitive_block_contents > 0) {
                        store_primitive_block();
                    }

                    std::promise<std::string> promise;
                    m_output_queue.push(promise.get_future());
                    promise.set_value(std::string());
                }

            }; // class PBFOutputFormat

            namespace {

                const bool registered_pbf_output = osmium::io::detail::OutputFormatFactory::instance().register_output_format(osmium::io::file_format::pbf,
                    [](const osmium::io::File& file, data_queue_type& output_queue) {
                        return new osmium::io::detail::PBFOutputFormat(file, output_queue);
                });

            } // anonymous namespace

        } // namespace detail

    } // namespace io

} // namespace osmium

#endif // OSMIUM_IO_DETAIL_PBF_OUTPUT_FORMAT_HPP