/******************************************************************************
 *
 * Project:  GDAL/OGR Geography Network support (Geographic Network Model)
 * Purpose:  GNM general public declarations.
 * Authors:  Mikhail Gusev (gusevmihs at gmail dot com)
 *           Dmitry Baryshnikov, polimax@mail.ru
 *
 ******************************************************************************
 * Copyright (c) 2014, Mikhail Gusev
 * Copyright (c) 2014-2015, NextGIS <info@nextgis.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * 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 AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/

#ifndef GNM
#define GNM

#if defined(__cplusplus) && !defined(CPL_SUPRESS_CPLUSPLUS)
#include "ogrsf_frmts.h"
#endif
#include "gnmgraph.h"

// Direction of an edge.
typedef int GNMDirection;  // We use int values in order to save them to the
                           // network data.

// Network's metadata parameters names.
#define GNM_MD_NAME "net_name"
#define GNM_MD_DESCR "net_description"
#define GNM_MD_SRS "net_srs"
#define GNM_MD_VERSION "net_version"
#define GNM_MD_RULE "net_rule"
#define GNM_MD_FORMAT "FORMAT"
#define GNM_MD_FETCHEDGES "fetch_edge"
#define GNM_MD_FETCHVERTEX "fetch_vertex"
#define GNM_MD_NUM_PATHS "num_paths"
#define GNM_MD_EMITTER "emitter"

// TODO: Constants for capabilities.
// #define GNMCanChangeConnections "CanChangeConnections"

typedef enum
{
    /** Dijkstra shortest path */ GATDijkstraShortestPath = 1,
    /** KShortest Paths        */ GATKShortestPath,
    /** Recursive Breadth-first search */ GATConnectedComponents
} GNMGraphAlgorithmType;

#if defined(__cplusplus) && !defined(CPL_SUPRESS_CPLUSPLUS)

/**
 * General GNM class which represents a geography network of common format.
 *
 * @since GDAL 2.1
 */

class CPL_DLL GNMNetwork : public GDALDataset
{
  public:
    GNMNetwork();
    ~GNMNetwork() override;

    // GDALDataset Interface
    const OGRSpatialReference *GetSpatialRef() const override;
    char **GetFileList(void) override;

    // GNMNetwork Interface

    /**
     * @brief Create network system layers
     *
     * Creates the connectivity (the "network path" of data) over the dataset
     * and returns the resulting network.
     * NOTE: This method does not create any connections among features
     * but creates the necessary set of fields, layers, etc.
     * NOTE: After the successful creation the passed dataset must not be
     * modified outside (but can be read as usual).
     * NOTE: For the common network format the creation is forbidden if the
     * passed dataset already has network system layers and OVERWRITE creation
     * option is FALSE.
     *
     * @param pszFilename - A path there the network folder (schema, etc.) will
     *                      be created. The folder (schema, etc.) name get
     *                      options.
     * @param papszOptions - create network options. The create options
     *                       specific for gnm driver.
     * @return CE_None on success
     */
    virtual CPLErr Create(const char *pszFilename, char **papszOptions) = 0;

    /**
     * @brief Open a network
     * @param poOpenInfo GDALOpenInfo pointer
     * @return CE_None on success
     */
    virtual CPLErr Open(GDALOpenInfo *poOpenInfo) = 0;

    /**
     * @brief Delete network. Delete all dependent layers
     * @return CE_None on success
     */
    virtual CPLErr Delete() = 0;

    /**
     * @brief GetName - a network name. The value provided to create function
     *        in GNM_MD_NAME key. While creation this value used to create the
     *        folder or db schema name. But can be changed after creation.
     * @return Network name string
     */
    virtual const char *GetName() const;

    /**
     * @brief GetVersion return the network version if applicable
     * @return version value
     */
    virtual int GetVersion() const
    {
        return 0;
    }

    /**
     * @brief DisconnectAll method clears the network graph
     * @return CE_None on success
     */
    virtual CPLErr DisconnectAll() = 0;

    /**
     * @brief GetFeatureByGlobalFID search all network layers for given feature
     *        identificator.
     * @param nGFID feature identificator.
     * @return OGRFeature pointer or NULL. The pointer should be freed via
     *         OGRFeature::DestroyFeature().
     */
    virtual OGRFeature *GetFeatureByGlobalFID(GNMGFID nGFID) = 0;

    /**
     * @brief Create path between start and end GFIDs.
     * @param nStartFID - start identificator
     * @param nEndFID - end identificator
     * @param eAlgorithm - The algorithm to get path
     * @param papszOptions - algorithm specific options
     * @return In memory OGRLayer pointer with features constituting
     *         the shortest path (or paths). The caller have to free
     *         the pointer via @see ReleaseResultSet().
     */
    virtual OGRLayer *GetPath(GNMGFID nStartFID, GNMGFID nEndFID,
                              GNMGraphAlgorithmType eAlgorithm,
                              char **papszOptions) = 0;

    /** Casts a handle to a pointer */
    static inline GNMNetwork *FromHandle(GNMGenericNetworkH hNet)
    {
        return static_cast<GNMNetwork *>(hNet);
    }

    /** Casts a pointer to a handle */
    static inline GNMGenericNetworkH ToHandle(GNMNetwork *poNetwork)
    {
        return static_cast<GNMGenericNetworkH>(poNetwork);
    }

  protected:
    /**
     * @brief Check if network already exist
     * @param pszFilename - path to network (folder or database
     * @param papszOptions - create options
     * @return TRUE if exist and not overwrite or FALSE
     */
    virtual int CheckNetworkExist(const char *pszFilename,
                                  char **papszOptions) = 0;

  protected:
    //! @cond Doxygen_Suppress
    CPLString m_soName{};
    OGRSpatialReference m_oSRS{};
    //! @endcond
};

class GNMRule;
class OGRGNMWrappedResultLayer;

/**
 * GNM class which represents a geography network of generic format.
 *
 * @since GDAL 2.1
 */

class CPL_DLL GNMGenericNetwork : public GNMNetwork
{
  public:
    GNMGenericNetwork();
    ~GNMGenericNetwork() override;

    // GDALDataset Interface

    int GetLayerCount() const override;
    OGRLayer *GetLayer(int) const override;
    OGRErr DeleteLayer(int) override;

    int TestCapability(const char *) const override;

    virtual OGRLayer *CopyLayer(OGRLayer *poSrcLayer, const char *pszNewName,
                                char **papszOptions = nullptr) override;

    int CloseDependentDatasets() override;
    CPLErr FlushCache(bool bAtClosing) override;

    // GNMNetwork Interface

    virtual CPLErr Create(const char *pszFilename,
                          char **papszOptions) override = 0;
    CPLErr Delete() override;

    int GetVersion() const override;
    /**
     * @brief GetNewGlobalFID increase the global ID counter.
     * @return New global feature ID.
     */
    virtual GNMGFID GetNewGlobalFID();

    /**
     * @brief Get the algorithm name
     * @param eAlgorithm GNM algorithm type
     * @param bShortName Indicator which name to return - short or long
     * @return String with algorithm name
     */
    virtual CPLString GetAlgorithmName(GNMDirection eAlgorithm,
                                       bool bShortName);

    /**
     * @brief AddFeatureGlobalFID add the FID <-> Layer name link to fast access
     *        features by global FID.
     * @param nFID - global FID
     * @param pszLayerName - layer name
     * @return CE_None on success
     */
    virtual CPLErr AddFeatureGlobalFID(GNMGFID nFID, const char *pszLayerName);

    /**
     * @brief Connects two features via third feature (may be virtual, so the
     *        identificator should be -1). The features may be at the same layer
     *        or different layers.
     * @param nSrcFID - source feature identificator
     * @param nTgtFID - target feature identificator
     * @param nConFID - connection feature identificator (-1 for virtual
     * connection)
     * @param dfCost - cost moving from source to target (default 1)
     * @param dfInvCost - cost moving from target to source (default 1)
     * @param eDir - direction, may be source to target, target to source or
     * both. (default - both)
     * @return CE_None on success
     */
    virtual CPLErr ConnectFeatures(GNMGFID nSrcFID, GNMGFID nTgtFID,
                                   GNMGFID nConFID = -1, double dfCost = 1,
                                   double dfInvCost = 1,
                                   GNMDirection eDir = GNM_EDGE_DIR_BOTH);

    /**
     * @brief Remove features connection
     * @param nSrcFID - source feature identificator
     * @param nTgtFID - target feature identificator
     * @param nConFID - connection feature identificator
     * @return CE_None on success
     */
    virtual CPLErr DisconnectFeatures(GNMGFID nSrcFID, GNMGFID nTgtFID,
                                      GNMGFID nConFID);

    /**
     * @brief Find the corresponding identificator in graph (source, target,
     *        connector) and remove such connections.
     * @param nFID - identificator to find.
     * @return CE_None on success
     */
    virtual CPLErr DisconnectFeaturesWithId(GNMGFID nFID);

    /**
     * @brief Change connection attributes. Search the connection by source
     *        feature identificator, target feature identificator and connection
     *        identificator.
     * @param nSrcFID - source feature identificator
     * @param nTgtFID - target feature identificator
     * @param nConFID - connection feature identificator
     * @param dfCost - new cost moving from source to target
     * @param dfInvCost - new cost moving from target to source
     * @param eDir - new direction
     * @return CE_None on success
     */
    virtual CPLErr ReconnectFeatures(GNMGFID nSrcFID, GNMGFID nTgtFID,
                                     GNMGFID nConFID, double dfCost = 1,
                                     double dfInvCost = 1,
                                     GNMDirection eDir = GNM_EDGE_DIR_BOTH);

    CPLErr DisconnectAll() override;

    OGRFeature *GetFeatureByGlobalFID(GNMGFID nFID) override;

    /**
     * @brief Create network rule
     *
     * Creates the rule in the network according to the special syntax. These
     * rules are declarative and make an effect for the network when they exist.
     * Each rule for layer can be created only if the corresponding layer
     * existed and removed when the layer is being deleted.
     *
     * Rules syntax for the common network format in GNM contains the key words
     * (words in capital letters or signs) and the modifiers which refers to the
     * network objects. All the following combinations are available:
     *
     *  Notation:
     *  layer1, layer2, layer3 - a layer names (the corresponding layers must be
     *                           exist;
     *  field1 - a field name (field must be exist);
     *  constant1 - any double constant;
     *  string1 - any string;
     *
     *  Rules describing which layer can be connected or not connected with each
     *  other, and (optional) which layer must serve as a connector. By default
     *  all connections are forbidden. But while network creation process the
     *  rule to allow any connection added. During the connection process each
     *  rule tested if this connection can be created.
     *
     *    "ALLOW CONNECTS ANY"
     *    "DENY CONNECTS ANY"
     *    "DENY CONNECTS layer1 WITH layer2"
     *    "ALLOW CONNECTS layer1 WITH layer2 VIA layer3"
     *
     * @param pszRuleStr Rule string which will parsed. If the parsing was
     *        successful, the rule will start having effect immediately.
     * @return CE_None on success.
     */
    virtual CPLErr CreateRule(const char *pszRuleStr);

    /**
     * @brief Delete all rules from network
     * @return CE_None on success.
     */
    virtual CPLErr DeleteAllRules();

    /**
     * @brief Delete the specified rule
     * @param pszRuleStr - the rule to delete
     * @return CE_None on success.
     */
    virtual CPLErr DeleteRule(const char *pszRuleStr);

    /**
     * @brief Get the rule list
     * @return list of rule strings. The caller have to free the lis via
     * CPLDestroy.
     */
    virtual char **GetRules() const;

    /**
     * @brief Attempts to build the network topology automatically
     *
     * The method simply gets point and line or multiline layers from the
     * papszLayerList and searches for each line which connects two points:
     * start and end, so it can be not so effective in performance when it is
     * called on huge networks. Note, when passing your tolerance value: this
     * value will depend of spatial reference system of the network, and
     * especially of its 0,0 position because dfTolerance is just divided by 2
     * and added/subtracted to/from both sides of each line-feature end point
     * forming thus the square area around it. The first point-feature occurred
     * inside this area will be given as a start/end point for the current
     * connection. So it is also desirable that at least two layers are passed
     * in papszLayerList (one point and one line), and they are already
     * connected "visually" ("geometrically").
     *
     * @param papszLayerList A list of layers to connect. The list should be
     *                       freed via CSLDestroy.
     * @param dfTolerance Snapping tolerance.
     * @param dfCost Direct cost.
     * @param dfInvCost Inverse cost.
     * @param eDir Direction.
     * @return CE_None on success
     */
    virtual CPLErr ConnectPointsByLines(char **papszLayerList,
                                        double dfTolerance, double dfCost,
                                        double dfInvCost, GNMDirection eDir);

    /**
     * @brief Change the block state of edge or vertex
     * @param nFID Identificator
     * @param bIsBlock Block or unblock
     * @return CE_None on success
     */
    virtual CPLErr ChangeBlockState(GNMGFID nFID, bool bIsBlock);

    /**
     * @brief Change all vertices and edges block state.
     *
     * This is mainly use for unblock all vertices and edges.
     *
     * @param bIsBlock Block or unblock
     * @return CE_None on success
     */
    virtual CPLErr ChangeAllBlockState(bool bIsBlock = false);

    virtual OGRLayer *GetPath(GNMGFID nStartFID, GNMGFID nEndFID,
                              GNMGraphAlgorithmType eAlgorithm,
                              char **papszOptions) override;

    /** Casts a handle to a pointer */
    static inline GNMGenericNetwork *FromHandle(GNMGenericNetworkH hNet)
    {
        return static_cast<GNMGenericNetwork *>(hNet);
    }

    /** Casts a pointer to a handle */
    static inline GNMGenericNetworkH ToHandle(GNMGenericNetwork *poNetwork)
    {
        return static_cast<GNMGenericNetworkH>(poNetwork);
    }

  protected:
    /**
     * @brief Check or create layer OGR driver
     * @param pszDefaultDriverName - default driver name
     * @param papszOptions - create options
     * @return CE_None if driver is exist or CE_Failure
     */
    virtual CPLErr CheckLayerDriver(const char *pszDefaultDriverName,
                                    char **papszOptions);
    /**
     * @brief Check if provided OGR driver accepted as storage for network data
     * @param pszDriverName The driver name
     * @return true if supported, else false
     */
    virtual bool CheckStorageDriverSupport(const char *pszDriverName) = 0;

  protected:
    //! @cond Doxygen_Suppress
    virtual CPLErr CreateMetadataLayer(GDALDataset *const pDS, int nVersion,
                                       size_t nFieldSize = 1024);
    virtual CPLErr StoreNetworkSrs();
    virtual CPLErr LoadNetworkSrs();
    virtual CPLErr CreateGraphLayer(GDALDataset *const pDS);
    virtual CPLErr CreateFeaturesLayer(GDALDataset *const pDS);
    virtual CPLErr LoadMetadataLayer(GDALDataset *const pDS);
    virtual CPLErr LoadGraphLayer(GDALDataset *const pDS);
    virtual CPLErr LoadGraph();
    virtual CPLErr LoadFeaturesLayer(GDALDataset *const pDS);
    virtual CPLErr DeleteMetadataLayer() = 0;
    virtual CPLErr DeleteGraphLayer() = 0;
    virtual CPLErr DeleteFeaturesLayer() = 0;
    virtual CPLErr LoadNetworkLayer(const char *pszLayername) = 0;
    virtual CPLErr DeleteNetworkLayers() = 0;
    virtual void ConnectPointsByMultiline(
        GIntBig nFID, const OGRMultiLineString *poMultiLineString,
        const std::vector<OGRLayer *> &paPointLayers, double dfTolerance,
        double dfCost, double dfInvCost, GNMDirection eDir);
    virtual void
    ConnectPointsByLine(GIntBig nFID, const OGRLineString *poLineString,
                        const std::vector<OGRLayer *> &paPointLayers,
                        double dfTolerance, double dfCost, double dfInvCost,
                        GNMDirection eDir);
    virtual GNMGFID
    FindNearestPoint(const OGRPoint *poPoint,
                     const std::vector<OGRLayer *> &paPointLayers,
                     double dfTolerance);
    virtual OGRFeature *FindConnection(GNMGFID nSrcFID, GNMGFID nTgtFID,
                                       GNMGFID nConFID);
    virtual bool SaveRules();
    virtual GNMGFID GetNewVirtualFID();
    virtual void FillResultLayer(OGRGNMWrappedResultLayer *poResLayer,
                                 const GNMPATH &path, int nNoOfPath,
                                 bool bReturnVertices, bool bReturnEdges);
    //! @endcond
  protected:
    //! @cond Doxygen_Suppress
    int m_nVersion = 0;
    GNMGFID m_nGID = 0;
    GNMGFID m_nVirtualConnectionGID = -1;
    OGRLayer *m_poMetadataLayer = nullptr;
    OGRLayer *m_poGraphLayer = nullptr;
    OGRLayer *m_poFeaturesLayer = nullptr;

    GDALDriver *m_poLayerDriver = nullptr;

    std::map<GNMGFID, CPLString> m_moFeatureFIDMap{};
    std::vector<OGRLayer *> m_apoLayers{};
    std::vector<GNMRule> m_asRules;
    bool m_bIsRulesChanged = false;

    GNMGraph m_oGraph{};
    bool m_bIsGraphLoaded = false;
    //! @endcond
  private:
    CPL_DISALLOW_COPY_ASSIGN(GNMGenericNetwork)
};

/**
 * GNM layer which represents a geography network layer of generic format.
 * The class override some OGRLayer methods to fulfill the network requirements.
 *
 * @since GDAL 2.1
 */

class GNMGenericLayer final : public OGRLayer
{
  public:
    GNMGenericLayer(OGRLayer *poLayer, GNMGenericNetwork *poNetwork);
    ~GNMGenericLayer() override;

    // OGRLayer Interface

    OGRGeometry *GetSpatialFilter() override;

    virtual OGRErr ISetSpatialFilter(int iGeomField,
                                     const OGRGeometry *) override;

    OGRErr SetAttributeFilter(const char *) override;

    void ResetReading() override;
    OGRFeature *GetNextFeature() override;
    OGRErr SetNextByIndex(GIntBig nIndex) override;

    OGRErr DeleteFeature(GIntBig nFID) override;

    const char *GetName() const override;
    OGRwkbGeometryType GetGeomType() const override;
    const OGRFeatureDefn *GetLayerDefn() const override;
    virtual int FindFieldIndex(const char *pszFieldName,
                               int bExactMatch) override;

    const OGRSpatialReference *GetSpatialRef() const override;

    GIntBig GetFeatureCount(int bForce = TRUE) override;

    virtual OGRErr IGetExtent(int iGeomField, OGREnvelope *psExtent,
                              bool bForce = true) override;

    int TestCapability(const char *) const override;

    virtual OGRErr CreateField(const OGRFieldDefn *poField,
                               int bApproxOK = TRUE) override;
    OGRErr DeleteField(int iField) override;
    OGRErr ReorderFields(int *panMap) override;
    virtual OGRErr AlterFieldDefn(int iField, OGRFieldDefn *poNewFieldDefn,
                                  int nFlagsIn) override;

    virtual OGRErr CreateGeomField(const OGRGeomFieldDefn *poField,
                                   int bApproxOK = TRUE) override;

    OGRErr SyncToDisk() override;

    OGRStyleTable *GetStyleTable() override;
    void SetStyleTableDirectly(OGRStyleTable *poStyleTable) override;

    void SetStyleTable(OGRStyleTable *poStyleTable) override;

    OGRErr StartTransaction() override;
    OGRErr CommitTransaction() override;
    OGRErr RollbackTransaction() override;

    const char *GetFIDColumn() const override;
    const char *GetGeometryColumn() const override;

    OGRErr SetIgnoredFields(CSLConstList papszFields) override;

    /** Intersection */
    OGRErr Intersection(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                        char **papszOptions = nullptr,
                        GDALProgressFunc pfnProgress = nullptr,
                        void *pProgressArg = nullptr);
    /** Union */
    OGRErr Union(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                 char **papszOptions = nullptr,
                 GDALProgressFunc pfnProgress = nullptr,
                 void *pProgressArg = nullptr);
    /** SymDifference */
    OGRErr SymDifference(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                         char **papszOptions, GDALProgressFunc pfnProgress,
                         void *pProgressArg);
    /** Identity */
    OGRErr Identity(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                    char **papszOptions = nullptr,
                    GDALProgressFunc pfnProgress = nullptr,
                    void *pProgressArg = nullptr);
    /** Update */
    OGRErr Update(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                  char **papszOptions = nullptr,
                  GDALProgressFunc pfnProgress = nullptr,
                  void *pProgressArg = nullptr);
    /** Clip */
    OGRErr Clip(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                char **papszOptions = nullptr,
                GDALProgressFunc pfnProgress = nullptr,
                void *pProgressArg = nullptr);
    /** Erase */
    OGRErr Erase(OGRLayer *pLayerMethod, OGRLayer *pLayerResult,
                 char **papszOptions = nullptr,
                 GDALProgressFunc pfnProgress = nullptr,
                 void *pProgressArg = nullptr);

    /** GetFeaturesRead */
    GIntBig GetFeaturesRead();

    /** AttributeFilterEvaluationNeedsGeometry */
    int AttributeFilterEvaluationNeedsGeometry();

    //! @cond Doxygen_Suppress
    /* consider these private */
    OGRErr InitializeIndexSupport(const char *);
    OGRLayerAttrIndex *GetIndex();
    //! @endcond

  protected:
    //! @cond Doxygen_Suppress
    OGRErr ISetFeature(OGRFeature *poFeature) override;
    OGRErr ICreateFeature(OGRFeature *poFeature) override;

  protected:
    CPLString m_soLayerName{};
    OGRLayer *m_poLayer = nullptr;
    GNMGenericNetwork *m_poNetwork = nullptr;
    std::map<GNMGFID, GIntBig> m_mnFIDMap{};
    //! @endcond

  private:
    CPL_DISALLOW_COPY_ASSIGN(GNMGenericLayer)
};

typedef enum
{
    /** Rule for connect features */ GRTConnection = 0
} GNMRuleType;

/**
 * @brief The simple class for rules
 *
 * By now we have only connect rules, so the one class is enough. Maybe in
 * future the set of classes for different rule types will be needed.
 *
 * @since GDAL 2.1
 */

class CPL_DLL GNMRule /* non final */
{
  public:
    /** Constructor */
    GNMRule();
    /** Constructor */
    explicit GNMRule(const std::string &oRule);
    /** Constructor */
    explicit GNMRule(const char *pszRule);

    /** Copy constructor */
    GNMRule(const GNMRule &) = default;

    /** Move constructor */
    GNMRule(GNMRule &&) = default;

    /** Assignment operator */
    GNMRule &operator=(const GNMRule &) = default;

    /** Move assignment operator */
    GNMRule &operator=(GNMRule &&) = default;

    /** Destructor */
    virtual ~GNMRule();

    /**
     * @brief  This function indicate if rule string was parsed successfully
     * @return true if rule is valid
     */
    virtual bool IsValid() const;
    /**
     * @brief Indicator of any layer state
     * @return true if accept any layer
     */
    virtual bool IsAcceptAny() const;
    /**
     * @brief This is for future use to indicate the rule type/ Now return only
     * GRTConnection type.
     * @return the rule type
     */
    virtual GNMRuleType GetType() const;
    /**
     * @brief Check if connection can take place.
     * @param soSrcLayerName - the layer name
     * @param soTgtLayerName - the layer name
     * @param soConnLayerName - the layer name
     * @return true if can connect features from soSrcLayerName and
     * soTgtLayerName via soConnLayerName
     */
    virtual bool CanConnect(const CPLString &soSrcLayerName,
                            const CPLString &soTgtLayerName,
                            const CPLString &soConnLayerName = "");
    /** Return source layer name */
    virtual CPLString GetSourceLayerName() const;
    /** Return target layer name */
    virtual CPLString GetTargetLayerName() const;
    /** Return connector layer name */
    virtual CPLString GetConnectorLayerName() const;
    /** Return rule as a string */
    const char *c_str() const;
    /** Return rule as a string */
    operator const char *(void) const;

  protected:
    //! @cond Doxygen_Suppress
    virtual bool ParseRuleString();

  protected:
    CPLString m_soSrcLayerName{};
    CPLString m_soTgtLayerName{};
    CPLString m_soConnLayerName{};
    bool m_bAllow = false;
    bool m_bValid = false;
    bool m_bAny = false;
    CPLString m_soRuleString{};
    //! @endcond
};

/**
 * @brief The OGRGNMWrappedResultLayer class for search paths queries results.
 *
 * @since GDAL 2.1
 */

class OGRGNMWrappedResultLayer final : public OGRLayer
{
  public:
    OGRGNMWrappedResultLayer(GDALDataset *poDS, OGRLayer *poLayer);
    ~OGRGNMWrappedResultLayer() override;

    // OGRLayer
    void ResetReading() override;
    OGRFeature *GetNextFeature() override;
    OGRErr SetNextByIndex(GIntBig nIndex) override;
    OGRFeature *GetFeature(GIntBig nFID) override;
    const OGRFeatureDefn *GetLayerDefn() const override;
    GIntBig GetFeatureCount(int bForce = TRUE) override;
    int TestCapability(const char *pszCap) const override;
    virtual OGRErr CreateField(const OGRFieldDefn *poField,
                               int bApproxOK = TRUE) override;
    virtual OGRErr CreateGeomField(const OGRGeomFieldDefn *poField,
                                   int bApproxOK = TRUE) override;
    const char *GetFIDColumn() const override;
    const char *GetGeometryColumn() const override;
    const OGRSpatialReference *GetSpatialRef() const override;

    // OGRGNMWrappedResultLayer
    OGRErr InsertFeature(OGRFeature *poFeature, const CPLString &soLayerName,
                         int nPathNo, bool bIsEdge);

  protected:
    OGRErr ISetFeature(OGRFeature *poFeature) override;
    OGRErr ICreateFeature(OGRFeature *poFeature) override;

  protected:
    //! @cond Doxygen_Suppress
    GDALDataset *poDS = nullptr;
    OGRLayer *poLayer = nullptr;
    //! @endcond

  private:
    CPL_DISALLOW_COPY_ASSIGN(OGRGNMWrappedResultLayer)
};

#endif  // __cplusplus

#endif  // GNM
