/******************************************************************************

 *

 * Project:  OpenGIS Simple Features Reference Implementation

 * Purpose:  Defines OGRUnionLayer class

 * Author:   Even Rouault, even dot rouault at spatialys.com

 *

 ******************************************************************************

 * Copyright (c) 2012-2014, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

 ****************************************************************************/

#ifndef OGRUNIONLAYER_H_INCLUDED

#define OGRUNIONLAYER_H_INCLUDED

#ifndef DOXYGEN_SKIP

#include "ogrsf_frmts.h"

#include <algorithm>

#include <mutex>

#include <utility>

/************************************************************************/

/*                      OGRUnionLayerGeomFieldDefn                      */

/************************************************************************/

class CPL_DLL OGRUnionLayerGeomFieldDefn final : public OGRGeomFieldDefn

{

  public:

    int bGeomTypeSet = false;

    int bSRSSet = false;

    OGREnvelope sStaticEnvelope{};

    OGRUnionLayerGeomFieldDefn(const char *pszName, OGRwkbGeometryType eType);

    explicit OGRUnionLayerGeomFieldDefn(const OGRGeomFieldDefn *poSrc);

    explicit OGRUnionLayerGeomFieldDefn(

        const OGRUnionLayerGeomFieldDefn *poSrc);

    ~OGRUnionLayerGeomFieldDefn() override;

};

/************************************************************************/

/*                         OGRUnionLayer                                */

/************************************************************************/

typedef enum

{

    FIELD_FROM_FIRST_LAYER,

    FIELD_UNION_ALL_LAYERS,

    FIELD_INTERSECTION_ALL_LAYERS,

    FIELD_SPECIFIED,

} FieldUnionStrategy;

class CPL_DLL OGRUnionLayer final : public OGRLayer

{

  private:

    CPL_DISALLOW_COPY_ASSIGN(OGRUnionLayer)

    struct Layer

    {

        std::unique_ptr<OGRLayer> poLayerKeeper{};

        OGRLayer *poLayer = nullptr;

        bool bModified = false;

        bool bCheckIfAutoWrap = false;

        CPL_DISALLOW_COPY_ASSIGN(Layer)

        Layer(OGRLayer *poLayerIn, bool bOwnedIn)

            : poLayerKeeper(bOwnedIn ? poLayerIn : nullptr),

              poLayer(bOwnedIn ? poLayerKeeper.get() : poLayerIn)

        {

        }

        Layer(Layer &&) = default;

        Layer &operator=(Layer &&) = default;

        OGRLayer *operator->()

        {

            return poLayer;

        }

        const OGRLayer *operator->() const

        {

            return poLayer;

        }

        std::pair<OGRLayer *, bool> release()

        {

            const bool bOwnedBackup = poLayerKeeper != nullptr;

            OGRLayer *poLayerBackup =

                poLayerKeeper ? poLayerKeeper.release() : poLayer;

            poLayerKeeper.reset();

            return std::make_pair(poLayerBackup, bOwnedBackup);

        }

        void reset(std::unique_ptr<OGRLayer> poLayerIn)

        {

            poLayerKeeper = std::move(poLayerIn);

            poLayer = poLayerKeeper.get();

        }

    };

    CPLString osName{};

    std::vector<Layer> m_apoSrcLayers{};

    mutable OGRFeatureDefn *poFeatureDefn = nullptr;

    int nFields = 0;

    OGRFieldDefn **papoFields = nullptr;

    int nGeomFields = 0;

    OGRUnionLayerGeomFieldDefn **papoGeomFields = nullptr;

    FieldUnionStrategy eFieldStrategy = FIELD_UNION_ALL_LAYERS;

    CPLString osSourceLayerFieldName{};

    int bPreserveSrcFID = false;

    GIntBig nFeatureCount = -1;

    int iCurLayer = -1;

    bool m_bHasAlreadyIteratedOverFeatures = false;

    char *pszAttributeFilter = nullptr;

    int nNextFID = 0;

    int *panMap = nullptr;

    CPLStringList m_aosIgnoredFields{};

    mutable int bAttrFilterPassThroughValue = -1;

    mutable const OGRSpatialReference *poGlobalSRS = nullptr;

    std::mutex m_oMutex{};

    /* Map from target FID to (source layer, source FID) */

    struct FIDRange

    {

        GIntBig nDstFIDStart = 0;

        GIntBig nFIDCount = 0;

        GIntBig nSrcFIDStart = 0;

        int nLayerIdx = 0;

    };

    std::vector<FIDRange> m_fidRanges{};

    bool m_fidRangesInvalid = false;

    bool m_fidRangesComplete = false;

    void AutoWarpLayerIfNecessary(int iSubLayer);

    std::unique_ptr<OGRFeature> TranslateFromSrcLayer(OGRFeature *poSrcFeature,

                                                      GIntBig nFID);

    void ApplyAttributeFilterToSrcLayer(int iSubLayer);

    int GetAttrFilterPassThroughValue() const;

    void ConfigureActiveLayer();

    void SetSpatialFilterToSourceLayer(OGRLayer *poSrcLayer);

  public:

    OGRUnionLayer(

        const char *pszName, int nSrcLayers, /* must be >= 1 */

        OGRLayer *

            *papoSrcLayers, /* array itself ownership always transferred, layer

                               ownership depending on bTakeLayerOwnership */

        int bTakeLayerOwnership);

    ~OGRUnionLayer() override;

    /* All the following non virtual methods must be called just after the

     * constructor */

    /* and before any virtual method */

    void SetFields(

        FieldUnionStrategy eFieldStrategy, int nFields,

        OGRFieldDefn **papoFields, /* duplicated by the method */

        int nGeomFields, /* maybe -1 to explicitly disable geometry fields */

        OGRUnionLayerGeomFieldDefn *

            *papoGeomFields /* duplicated by the method */);

    void SetSourceLayerFieldName(const char *pszSourceLayerFieldName);

    void SetPreserveSrcFID(int bPreserveSrcFID);

    void SetFeatureCount(int nFeatureCount);

    const char *GetName() const override

    {

        return osName.c_str();

    }

    OGRwkbGeometryType GetGeomType() const override;

    void ResetReading() override;

    OGRFeature *GetNextFeature() override;

    OGRFeature *GetFeature(GIntBig nFeatureId) override;

    OGRErr ICreateFeature(OGRFeature *poFeature) override;

    OGRErr ISetFeature(OGRFeature *poFeature) override;

    OGRErr IUpsertFeature(OGRFeature *poFeature) override;

    OGRErr IUpdateFeature(OGRFeature *poFeature, int nUpdatedFieldsCount,

                          const int *panUpdatedFieldsIdx,

                          int nUpdatedGeomFieldsCount,

                          const int *panUpdatedGeomFieldsIdx,

                          bool bUpdateStyleString) override;

    const OGRFeatureDefn *GetLayerDefn() const override;

    const OGRSpatialReference *GetSpatialRef() const override;

    GIntBig GetFeatureCount(int) override;

    OGRErr SetAttributeFilter(const char *) override;

    int TestCapability(const char *) const override;

    OGRErr IGetExtent(int iGeomField, OGREnvelope *psExtent,

                      bool bForce) override;

    virtual OGRErr ISetSpatialFilter(int iGeomField,

                                     const OGRGeometry *) override;

    OGRErr SetIgnoredFields(CSLConstList papszFields) override;

    OGRErr SyncToDisk() override;

};

#endif /* #ifndef DOXYGEN_SKIP */

#endif  // OGRUNIONLAYER_H_INCLUDED