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

 * Project:  OGR_SCHEMA open options handling

 * Purpose:  Class for representing a layer schema override.

 * Author:   Alessandro Pasotti, elpaso@itopen.it

 *

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

 * Copyright (c) 2024, Alessandro Pasotti <elpaso at itopen dot it>

 *

 * SPDX-License-Identifier: MIT

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

#ifndef OGR_SCHEMA_OVERRIDE_H_INCLUDED

#define OGR_SCHEMA_OVERRIDE_H_INCLUDED

//! @cond Doxygen_Suppress

#include <functional>

#include <string>

#include <map>

#include <optional>

#include <ogr_api.h>

#include <ogr_feature.h>

#include <cpl_vsi.h>

#include <cpl_json.h>

/** Class that holds the schema override options for a single field */

class CPL_DLL OGRFieldDefnOverride

{

  public:

    OGRFieldDefnOverride() = default;

    void SetFieldName(const std::string &osName)

    {

        m_osName = osName;

    }

    void SetSrcFieldType(OGRFieldType eType)

    {

        m_eSrcType = eType;

    }

    void SetSrcFieldSubType(OGRFieldSubType eSubType)

    {

        m_eSrcSubType = eSubType;

    }

    void SetFieldType(OGRFieldType eType)

    {

        m_eType = eType;

    }

    void SetFieldSubType(OGRFieldSubType eSubType)

    {

        m_eSubType = eSubType;

    }

    void SetFieldWidth(int nWidth)

    {

        m_nWidth = nWidth;

    }

    void SetFieldPrecision(int nPrecision)

    {

        m_nPrecision = nPrecision;

    }

    void SetNullable(bool bNullable)

    {

        m_bNullable = bNullable;

    }

    void SetUnique(bool bUnique)

    {

        m_bUnique = bUnique;

    }

    void SetComment(const std::string &osComment)

    {

        m_osComment = osComment;

    }

    void SetAlias(const std::string &osAlias)

    {

        m_osAlias = osAlias;

    }

    void SetTimezone(const std::string &osTimezone)

    {

        m_osTimezone = osTimezone;

    }

    void SetDomainName(const std::string &osDomainName)

    {

        m_osDomainName = osDomainName;

    }

    void SetDefaultValue(const std::string &osDefaultValue)

    {

        m_osDefaultValue = osDefaultValue;

    }

    std::optional<std::string> GetFieldName() const

    {

        return m_osName;

    }

    std::optional<OGRFieldType> GetSrcFieldType() const

    {

        return m_eSrcType;

    }

    std::optional<OGRFieldSubType> GetSrcFieldSubType() const

    {

        return m_eSrcSubType;

    }

    std::optional<OGRFieldType> GetFieldType() const

    {

        return m_eType;

    }

    std::optional<OGRFieldSubType> GetFieldSubType() const

    {

        return m_eSubType;

    }

    std::optional<int> GetFieldWidth() const

    {

        return m_nWidth;

    }

    std::optional<int> GetFieldPrecision() const

    {

        return m_nPrecision;

    }

    std::optional<int> GetNullable() const

    {

        return m_bNullable;

    }

    std::optional<int> GetUnique() const

    {

        return m_bUnique;

    }

    std::optional<std::string> GetComment() const

    {

        return m_osComment;

    }

    std::optional<std::string> GetAlias() const

    {

        return m_osAlias;

    }

    std::optional<std::string> GetTimezone() const

    {

        return m_osTimezone;

    }

    std::optional<std::string> GetDomainName() const

    {

        return m_osDomainName;

    }

    // Considered valid if it carries any change information, otherwise it's considered a no-op

    bool IsValid() const;

    /**

     *  Build an OGRFieldDefn based on the override information.

     *  \a osDefaultName is used as field name if the override doesn't specify one.

     */

    OGRFieldDefn ToFieldDefn(const std::string &osDefaultName) const;

  private:

    std::optional<std::string> m_osName{};

    std::optional<OGRFieldType> m_eSrcType{};

    std::optional<OGRFieldSubType> m_eSrcSubType{};

    std::optional<OGRFieldType> m_eType{};

    std::optional<OGRFieldSubType> m_eSubType{};

    std::optional<int> m_nWidth{};

    std::optional<int> m_nPrecision{};

    std::optional<bool> m_bUnique{};

    std::optional<bool> m_bNullable{};

    std::optional<std::string> m_osComment{};

    std::optional<std::string> m_osAlias{};

    std::optional<std::string> m_osTimezone{};

    std::optional<std::string> m_osDomainName{};

    std::optional<std::string> m_osDefaultValue{};

};

/**

 *  Class that holds the schema override options for a single geometry field

 */

class CPL_DLL OGRGeomFieldDefnOverride

{

  public:

    OGRGeomFieldDefnOverride() = default;

    void SetFieldName(const std::string &osName)

    {

        m_osName = osName;

    }

    void SetGeometryType(OGRwkbGeometryType eType)

    {

        m_eType = eType;

    }

    void SetSRS(const OGRSpatialReference &oSRS)

    {

        m_oSRS = oSRS;

    }

    void SetNullable(bool bNullable)

    {

        m_bNullable = bNullable;

    }

    std::optional<std::string> GetFieldName() const

    {

        return m_osName;

    }

    std::optional<OGRwkbGeometryType> GetGeometryType() const

    {

        return m_eType;

    }

    std::optional<OGRSpatialReference> GetSRS() const

    {

        return m_oSRS;

    }

    std::optional<bool> GetNullable() const

    {

        return m_bNullable;

    }

    /**

     *  Build an OGRGeometryFieldDefn based on the override information.

     *  \a osDefaultName is used as field name if the override doesn't specify one.

     *  If the override doesn't specify a type, wkbUnknown is used as default type.

     */

    OGRGeomFieldDefn

    ToGeometryFieldDefn(const std::string &osDefaultName) const;

  private:

    std::optional<bool> m_bNullable{};

    std::optional<std::string> m_osName{};

    std::optional<OGRwkbGeometryType> m_eType{};

    std::optional<OGRSpatialReference> m_oSRS{};

};

/** Class that holds the schema override options for a single layer */

class CPL_DLL OGRLayerSchemaOverride

{

  public:

    OGRLayerSchemaOverride() = default;

    void SetLayerName(const std::string &osLayerName);

    void AddNamedFieldOverride(const std::string &osFieldName,

                               const OGRFieldDefnOverride &oFieldOverride);

    void AddUnnamedFieldOverride(const OGRFieldDefnOverride &oFieldOverride);

    const std::string &GetLayerName() const;

    const std::map<std::string, OGRFieldDefnOverride> &

    GetNamedFieldOverrides() const;

    const std::vector<OGRFieldDefnOverride> &GetUnnamedFieldOverrides() const;

    void AddGeometryFieldOverride(

        const OGRGeomFieldDefnOverride &oGeomFieldOverride);

    const std::vector<OGRGeomFieldDefnOverride> &

    GetGeometryFieldOverrides() const;

    std::vector<OGRFieldDefn> GetFieldDefinitions() const;

    std::vector<OGRGeomFieldDefn> GetGeomFieldDefinitions() const;

    bool IsFullOverride() const;

    void SetFullOverride(bool bIsFullOverride);

    bool IsValid() const;

    bool empty() const;

  private:

    std::string m_osLayerName{};

    std::map<std::string, OGRFieldDefnOverride> m_oNamedFieldOverrides{};

    std::vector<OGRFieldDefnOverride> m_aoUnnamedFieldOverrides{};

    std::vector<OGRGeomFieldDefnOverride> m_aoGeomFieldOverrides{};

    bool m_bIsFullOverride = false;

};

class GDALDataset;

/** Class that holds the schema override options for a datasource */

class CPL_DLL OGRSchemaOverride

{

  public:

    OGRSchemaOverride() = default;

    void AddLayerOverride(const OGRLayerSchemaOverride &oLayerOverride);

    /**

     * Load an override schema from JSON string that follows OGR_SCHEMA specification.

     * @param osJSON JSON string

     * @param bAllowGeometryFields Whether to allow a geometry fields in the JSON (normally not overridable but allowed if the schema is applied to a dataset that doesn't have any geometry field, so that it can be used to create a geometry field in that case)

     * @return TRUE if the JSON was successfully parsed and the schema override is valid, FALSE otherwise

     */

    bool LoadFromJSON(const std::string &osJSON,

                      bool bAllowGeometryFields = false);

    const std::vector<OGRLayerSchemaOverride> &GetLayerOverrides() const;

    bool IsValid() const;

    /**

     *  Default implementation to apply the overrides to a dataset

     *  \note geometry fields are ignored (not overridable)

     */

    bool DefaultApply(

        GDALDataset *poDS, const char *pszDebugKey,

        std::function<void(OGRLayer *, int)> callbackWhenRemovingField =

            [](OGRLayer *, int) {}) const;

    const OGRLayerSchemaOverride &

    GetLayerOverride(const std::string &osLayerName) const;

  private:

    std::vector<OGRLayerSchemaOverride> m_aoLayerOverrides{};

};

//! @endcond

#endif /* ndef OGR_FEATURE_H_INCLUDED */