osrm-backend/Descriptors/JSONDescriptor.h

/*
    open source routing machine
    Copyright (C) Dennis Luxen, others 2010

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU AFFERO General Public License as published by
the Free Software Foundation; either version 3 of the License, or
any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
or see http://www.gnu.org/licenses/agpl.txt.
 */

#ifndef JSON_DESCRIPTOR_H_
#define JSON_DESCRIPTOR_H_

#include "BaseDescriptor.h"
#include "DescriptionFactory.h"
#include "../Algorithms/ObjectToBase64.h"
#include "../DataStructures/SegmentInformation.h"
#include "../DataStructures/TurnInstructions.h"
#include "../Util/Azimuth.h"
#include "../Util/StringUtil.h"

#include <boost/bind.hpp>
#include <boost/lambda/lambda.hpp>

#include <algorithm>

template<class DataFacadeT>
class JSONDescriptor : public BaseDescriptor<DataFacadeT> {
private:
    DescriptorConfig config;
    DescriptionFactory description_factory;
    DescriptionFactory alternateDescriptionFactory;
    FixedPointCoordinate current;
    unsigned entered_restricted_area_count;
    struct RoundAbout{
        RoundAbout() :
            start_index(INT_MAX),
            name_id(INT_MAX),
            leave_at_exit(INT_MAX)
        {}
        int start_index;
        int name_id;
        int leave_at_exit;
    } roundAbout;

    struct Segment {
        Segment() : name_id(-1), length(-1), position(-1) {}
        Segment(int n, int l, int p) : name_id(n), length(l), position(p) {}
        int name_id;
        int length;
        int position;
    };
    std::vector<Segment> shortest_path_segments, alternative_path_segments;

    struct RouteNames {
        std::string shortestPathName1;
        std::string shortestPathName2;
        std::string alternativePathName1;
        std::string alternativePathName2;
    };

public:
    JSONDescriptor() : entered_restricted_area_count(0) {}
    void SetConfig(const DescriptorConfig & c) { config = c; }

    //TODO: reorder parameters
    void Run(
        http::Reply & reply,
        const RawRouteData & raw_route_information,
        PhantomNodes & phantom_nodes,
        const DataFacadeT * facade
    ) {

        WriteHeaderToOutput(reply.content);

        if(raw_route_information.lengthOfShortestPath != INT_MAX) {
            description_factory.SetStartSegment(phantom_nodes.startPhantom);
            reply.content += "0,"
                    "\"status_message\": \"Found route between points\",";

            //Get all the coordinates for the computed route
            BOOST_FOREACH(const _PathData & path_data, raw_route_information.computedShortestPath) {
                current = facade->GetCoordinateOfNode(path_data.node);
                description_factory.AppendSegment(current, path_data );
            }
            description_factory.SetEndSegment(phantom_nodes.targetPhantom);
        } else {
            //We do not need to do much, if there is no route ;-)
            reply.content += "207,"
                    "\"status_message\": \"Cannot find route between points\",";
        }

        description_factory.Run(facade, config.zoom_level);
        reply.content += "\"route_geometry\": ";
        if(config.geometry) {
            description_factory.AppendEncodedPolylineString(
                reply.content,
                config.encode_geometry
            );
        } else {
            reply.content += "[]";
        }

        reply.content += ","
                "\"route_instructions\": [";
        entered_restricted_area_count = 0;
        if(config.instructions) {
            BuildTextualDescription(
                description_factory,
                reply,
                raw_route_information.lengthOfShortestPath,
                facade,
                shortest_path_segments
            );
        } else {
            BOOST_FOREACH(
                const SegmentInformation & segment,
                description_factory.pathDescription
            ) {
                TurnInstruction current_instruction = segment.turnInstruction & TurnInstructions.InverseAccessRestrictionFlag;
                entered_restricted_area_count += (current_instruction != segment.turnInstruction);
            }
        }
        reply.content += "],";
        description_factory.BuildRouteSummary(
            description_factory.entireLength,
            raw_route_information.lengthOfShortestPath - ( entered_restricted_area_count*TurnInstructions.AccessRestrictionPenalty)
        );

        reply.content += "\"route_summary\":";
        reply.content += "{";
        reply.content += "\"total_distance\":";
        reply.content += description_factory.summary.lengthString;
        reply.content += ","
                "\"total_time\":";
        reply.content += description_factory.summary.durationString;
        reply.content += ","
                "\"start_point\":\"";
        reply.content += facade->GetEscapedNameForNameID(
            description_factory.summary.startName
        );
        reply.content += "\","
                "\"end_point\":\"";
        reply.content += facade->GetEscapedNameForNameID(
            description_factory.summary.destName
        );
        reply.content += "\"";
        reply.content += "}";
        reply.content +=",";

        //only one alternative route is computed at this time, so this is hardcoded

        if(raw_route_information.lengthOfAlternativePath != INT_MAX) {
            alternateDescriptionFactory.SetStartSegment(phantom_nodes.startPhantom);
            //Get all the coordinates for the computed route
            BOOST_FOREACH(const _PathData & path_data, raw_route_information.computedAlternativePath) {
                current = facade->GetCoordinateOfNode(path_data.node);
                alternateDescriptionFactory.AppendSegment(current, path_data );
            }
            alternateDescriptionFactory.SetEndSegment(phantom_nodes.targetPhantom);
        }
        alternateDescriptionFactory.Run(facade, config.zoom_level);

        //give an array of alternative routes
        reply.content += "\"alternative_geometries\": [";
        if(config.geometry && INT_MAX != raw_route_information.lengthOfAlternativePath) {
            //Generate the linestrings for each alternative
            alternateDescriptionFactory.AppendEncodedPolylineString(
                reply.content,
                config.encode_geometry
            );
        }
        reply.content += "],";
        reply.content += "\"alternative_instructions\":[";
        entered_restricted_area_count = 0;
        if(INT_MAX != raw_route_information.lengthOfAlternativePath) {
            reply.content += "[";
            //Generate instructions for each alternative
            if(config.instructions) {
                BuildTextualDescription(
                    alternateDescriptionFactory,
                    reply,
                    raw_route_information.lengthOfAlternativePath,
                    facade,
                    alternative_path_segments
                );
            } else {
                BOOST_FOREACH(const SegmentInformation & segment, alternateDescriptionFactory.pathDescription) {
                	TurnInstruction current_instruction = segment.turnInstruction & TurnInstructions.InverseAccessRestrictionFlag;
                    entered_restricted_area_count += (current_instruction != segment.turnInstruction);
                }
            }
            reply.content += "]";
        }
        reply.content += "],";
        reply.content += "\"alternative_summaries\":[";
        if(INT_MAX != raw_route_information.lengthOfAlternativePath) {
            //Generate route summary (length, duration) for each alternative
            alternateDescriptionFactory.BuildRouteSummary(alternateDescriptionFactory.entireLength, raw_route_information.lengthOfAlternativePath - ( entered_restricted_area_count*TurnInstructions.AccessRestrictionPenalty));
            reply.content += "{";
            reply.content += "\"total_distance\":";
            reply.content += alternateDescriptionFactory.summary.lengthString;
            reply.content += ","
                    "\"total_time\":";
            reply.content += alternateDescriptionFactory.summary.durationString;
            reply.content += ","
                    "\"start_point\":\"";
            reply.content += facade->GetEscapedNameForNameID(description_factory.summary.startName);
            reply.content += "\","
                    "\"end_point\":\"";
            reply.content += facade->GetEscapedNameForNameID(description_factory.summary.destName);
            reply.content += "\"";
            reply.content += "}";
        }
        reply.content += "],";

        //Get Names for both routes
        RouteNames routeNames;
        GetRouteNames(shortest_path_segments, alternative_path_segments, facade, routeNames);

        reply.content += "\"route_name\":[\"";
        reply.content += routeNames.shortestPathName1;
        reply.content += "\",\"";
        reply.content += routeNames.shortestPathName2;
        reply.content += "\"],"
                "\"alternative_names\":[";
        reply.content += "[\"";
        reply.content += routeNames.alternativePathName1;
        reply.content += "\",\"";
        reply.content += routeNames.alternativePathName2;
        reply.content += "\"]";
        reply.content += "],";
        //list all viapoints so that the client may display it
        reply.content += "\"via_points\":[";
        std::string tmp;
        if(config.geometry && INT_MAX != raw_route_information.lengthOfShortestPath) {
            for(unsigned i = 0; i < raw_route_information.segmentEndCoordinates.size(); ++i) {
                reply.content += "[";
                if(raw_route_information.segmentEndCoordinates[i].startPhantom.location.isSet())
                    convertInternalReversedCoordinateToString(raw_route_information.segmentEndCoordinates[i].startPhantom.location, tmp);
                else
                    convertInternalReversedCoordinateToString(raw_route_information.rawViaNodeCoordinates[i], tmp);

                reply.content += tmp;
                reply.content += "],";
            }
            reply.content += "[";
            if(raw_route_information.segmentEndCoordinates.back().startPhantom.location.isSet())
                convertInternalReversedCoordinateToString(raw_route_information.segmentEndCoordinates.back().targetPhantom.location, tmp);
            else
                convertInternalReversedCoordinateToString(raw_route_information.rawViaNodeCoordinates.back(), tmp);
            reply.content += tmp;
            reply.content += "]";
        }
        reply.content += "],";
        reply.content += "\"hint_data\": {";
        reply.content += "\"checksum\":";
        intToString(raw_route_information.checkSum, tmp);
        reply.content += tmp;
        reply.content += ", \"locations\": [";

        std::string hint;
        for(unsigned i = 0; i < raw_route_information.segmentEndCoordinates.size(); ++i) {
            reply.content += "\"";
            EncodeObjectToBase64(raw_route_information.segmentEndCoordinates[i].startPhantom, hint);
            reply.content += hint;
            reply.content += "\", ";
        }
        EncodeObjectToBase64(raw_route_information.segmentEndCoordinates.back().targetPhantom, hint);
        reply.content += "\"";
        reply.content += hint;
        reply.content += "\"]";
        reply.content += "},";
        reply.content += "\"transactionId\": \"OSRM Routing Engine JSON Descriptor (v0.3)\"";
        reply.content += "}";
    }

    // construct routes names
    void GetRouteNames(
        std::vector<Segment> & shortest_path_segments,
        std::vector<Segment> & alternative_path_segments,
        const DataFacadeT * facade,
        RouteNames & routeNames
    ) {

        Segment shortestSegment1, shortestSegment2;
        Segment alternativeSegment1, alternativeSegment2;

        if(0 < shortest_path_segments.size()) {
            sort(shortest_path_segments.begin(), shortest_path_segments.end(), boost::bind(&Segment::length, _1) > boost::bind(&Segment::length, _2) );
            shortestSegment1 = shortest_path_segments[0];
            if(0 < alternative_path_segments.size()) {
                sort(alternative_path_segments.begin(), alternative_path_segments.end(), boost::bind(&Segment::length, _1) > boost::bind(&Segment::length, _2) );
                alternativeSegment1 = alternative_path_segments[0];
            }
            std::vector<Segment> shortestDifference(shortest_path_segments.size());
            std::vector<Segment> alternativeDifference(alternative_path_segments.size());
            std::set_difference(shortest_path_segments.begin(), shortest_path_segments.end(), alternative_path_segments.begin(), alternative_path_segments.end(), shortestDifference.begin(), boost::bind(&Segment::name_id, _1) < boost::bind(&Segment::name_id, _2) );
            int size_of_difference = shortestDifference.size();
            if(0 < size_of_difference ) {
                int i = 0;
                while( i < size_of_difference && shortestDifference[i].name_id == shortest_path_segments[0].name_id) {
                    ++i;
                }
                if(i < size_of_difference ) {
                    shortestSegment2 = shortestDifference[i];
                }
            }

            std::set_difference(alternative_path_segments.begin(), alternative_path_segments.end(), shortest_path_segments.begin(), shortest_path_segments.end(), alternativeDifference.begin(), boost::bind(&Segment::name_id, _1) < boost::bind(&Segment::name_id, _2) );
            size_of_difference = alternativeDifference.size();
            if(0 < size_of_difference ) {
                int i = 0;
                while( i < size_of_difference && alternativeDifference[i].name_id == alternative_path_segments[0].name_id) {
                    ++i;
                }
                if(i < size_of_difference ) {
                    alternativeSegment2 = alternativeDifference[i];
                }
            }
            if(shortestSegment1.position > shortestSegment2.position)
                std::swap(shortestSegment1, shortestSegment2);

            if(alternativeSegment1.position >  alternativeSegment2.position)
                std::swap(alternativeSegment1, alternativeSegment2);

            routeNames.shortestPathName1 = facade->GetEscapedNameForNameID(
                shortestSegment1.name_id
            );
            routeNames.shortestPathName2 = facade->GetEscapedNameForNameID(
                shortestSegment2.name_id
            );

            routeNames.alternativePathName1 = facade->GetEscapedNameForNameID(
                alternativeSegment1.name_id
            );
            routeNames.alternativePathName2 = facade->GetEscapedNameForNameID(
                alternativeSegment2.name_id
            );
        }
    }

    inline void WriteHeaderToOutput(std::string & output) {
        output += "{"
                "\"version\": 0.3,"
                "\"status\":";
    }

    //TODO: reorder parameters
    inline void BuildTextualDescription(
        DescriptionFactory & description_factory,
        http::Reply & reply,
        const int route_length,
        const DataFacadeT * facade,
        std::vector<Segment> & route_segments_list
    ) {
        //Segment information has following format:
        //["instruction","streetname",length,position,time,"length","earth_direction",azimuth]
        //Example: ["Turn left","High Street",200,4,10,"200m","NE",22.5]
        //See also: http://developers.cloudmade.com/wiki/navengine/JSON_format
        unsigned prefixSumOfNecessarySegments = 0;
        roundAbout.leave_at_exit = 0;
        roundAbout.name_id = 0;
        std::string tmpDist, tmpLength, tmpDuration, tmpBearing, tmpInstruction;
        //Fetch data from Factory and generate a string from it.
        BOOST_FOREACH(const SegmentInformation & segment, description_factory.pathDescription) {
        	TurnInstruction current_instruction = segment.turnInstruction & TurnInstructions.InverseAccessRestrictionFlag;
            entered_restricted_area_count += (current_instruction != segment.turnInstruction);
            if(TurnInstructions.TurnIsNecessary( current_instruction) ) {
                if(TurnInstructions.EnterRoundAbout == current_instruction) {
                    roundAbout.name_id = segment.nameID;
                    roundAbout.start_index = prefixSumOfNecessarySegments;
                } else {
                    if(0 != prefixSumOfNecessarySegments){
                        reply.content += ",";
                    }
                    reply.content += "[\"";
                    if(TurnInstructions.LeaveRoundAbout == current_instruction) {
                        intToString(TurnInstructions.EnterRoundAbout, tmpInstruction);
                        reply.content += tmpInstruction;
                        reply.content += "-";
                        intToString(roundAbout.leave_at_exit+1, tmpInstruction);
                        reply.content += tmpInstruction;
                        roundAbout.leave_at_exit = 0;
                    } else {
                        intToString(current_instruction, tmpInstruction);
                        reply.content += tmpInstruction;
                    }

                    reply.content += "\",\"";
                    reply.content += facade->GetEscapedNameForNameID(segment.nameID);
                    reply.content += "\",";
                    intToString(segment.length, tmpDist);
                    reply.content += tmpDist;
                    reply.content += ",";
                    intToString(prefixSumOfNecessarySegments, tmpLength);
                    reply.content += tmpLength;
                    reply.content += ",";
                    intToString(segment.duration/10, tmpDuration);
                    reply.content += tmpDuration;
                    reply.content += ",\"";
                    intToString(segment.length, tmpLength);
                    reply.content += tmpLength;
                    reply.content += "m\",\"";
                    reply.content += Azimuth::Get(segment.bearing);
                    reply.content += "\",";
                    intToString(round(segment.bearing), tmpBearing);
                    reply.content += tmpBearing;
                    reply.content += "]";

                    route_segments_list.push_back(
                        Segment(
                            segment.nameID,
                            segment.length,
                            route_segments_list.size()
                        )
                    );
                }
            } else if(TurnInstructions.StayOnRoundAbout == current_instruction) {
                ++roundAbout.leave_at_exit;
            }
            if(segment.necessary)
                ++prefixSumOfNecessarySegments;
        }
        if(INT_MAX != route_length) {
            reply.content += ",[\"";
            intToString(TurnInstructions.ReachedYourDestination, tmpInstruction);
            reply.content += tmpInstruction;
            reply.content += "\",\"";
            reply.content += "\",";
            reply.content += "0";
            reply.content += ",";
            intToString(prefixSumOfNecessarySegments-1, tmpLength);
            reply.content += tmpLength;
            reply.content += ",";
            reply.content += "0";
            reply.content += ",\"";
            reply.content += "\",\"";
            reply.content += Azimuth::Get(0.0);
            reply.content += "\",";
            reply.content += "0.0";
            reply.content += "]";
        }
    }

};
#endif /* JSON_DESCRIPTOR_H_ */