<?xml version="1.0" encoding="UTF-8"?>
<!--
/******************************************************************************
 * $Id$
 *
 * Project:  GDAL/OGR
 * Purpose:  XML Schema for GDAL GTI files.
 * Author:   Even Rouault, <even dot rouault at spatialys dot com>
 *
 **********************************************************************
 * Copyright (c) 2023, Even Rouault
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" version="1.0">
    <xs:element name="GDALTileIndexDataset">
        <xs:complexType>
            <xs:sequence>
                <xs:choice minOccurs="0" maxOccurs="unbounded">
                    <!-- IndexDataset is required for a standalone XML GTI -->
                    <!-- It is ignored if the XML document is embedded in the xml:GTI metadata domain of a vector layer -->
                    <xs:element name="IndexDataset" type="xs:string"/>

                    <xs:element name="IndexLayer" type="xs:string"/>
                    <xs:element name="Filter" type="xs:string"/>

                    <xs:element name="LocationField" type="xs:string" default="location"/>
                    <xs:element name="SortField" type="xs:string"/>
                    <xs:element name="SortFieldAsc" type="OGRBooleanType" default="true"/>

                    <xs:element name="SRS" type="SRSType"/>

                    <xs:element name="Resampling" type="xs:string"/>

                    <xs:element name="BlockXSize" type="nonNegativeInteger32" default="256"/>
                    <xs:element name="BlockYSize" type="nonNegativeInteger32" default="256"/>

                    <xs:element name="GeoTransform" type="xs:string"/>
                    <xs:element name="XSize" type="nonNegativeInteger32"/>
                    <xs:element name="YSize" type="nonNegativeInteger32"/>

                    <!-- None or both of the 2 following elements should be specified -->
                    <xs:element name="ResX" type="xs:double"/>
                    <xs:element name="ResY" type="xs:double"/>

                    <!-- None or all of the 4 following elements should be specified -->
                    <xs:element name="MinX" type="xs:double"/>
                    <xs:element name="MinY" type="xs:double"/>
                    <xs:element name="MaxX" type="xs:double"/>
                    <xs:element name="MaxY" type="xs:double"/>

                    <xs:element name="Metadata" type="MetadataType"/> <!-- may be repeated -->

                    <!-- BandCount is generally only defined if no Band elements are defined -->
                    <xs:element name="BandCount" type="xs:nonNegativeInteger"/>
                    <xs:element name="DataType" type="DataTypeType"/>  <!-- single value that applies to all bands -->
                    <xs:element name="NoDataValue" type="DoubleOrNanType"/>  <!-- single value that applies to all bands -->

                    <xs:element name="MaskBand" type="OGRBooleanType"/>

                    <xs:element name="Band" type="BandType"/> <!-- may be repeated -->
                    <xs:element name="Overview" type="OverviewType"/>  <!-- may be repeated -->
                </xs:choice>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:complexType name="BandType">
        <xs:sequence>
            <xs:choice minOccurs="0" maxOccurs="unbounded">
                <xs:element name="Description" type="xs:string"/>
                <xs:element name="ColorInterp" type="ColorInterpType"/>
                <xs:element name="NoDataValue" type="DoubleOrNanType"/>
                <xs:element name="Offset" type="xs:double"/>
                <xs:element name="Scale" type="xs:double"/>
                <xs:element name="UnitType" type="xs:string"/>
                <xs:element name="Metadata" type="MetadataType"/>
                <xs:element name="CategoryNames" type="CategoryNamesType"/>
                <xs:element name="ColorTable" type="ColorTableType"/>
                <xs:element name="GDALRasterAttributeTable" type="GDALRasterAttributeTableType"/>
            </xs:choice>
        </xs:sequence>
        <xs:attribute name="dataType" type="DataTypeType"/>
        <xs:attribute name="band" type="xs:unsignedInt"/>
    </xs:complexType>

    <xs:complexType name="OverviewType">
        <xs:sequence>
            <xs:choice minOccurs="0" maxOccurs="unbounded">
                <xs:element name="Dataset" type="xs:string"/>
                <xs:element name="Layer" type="xs:string"/>
                <xs:element name="Factor" type="xs:double"/>
                <xs:element name="OpenOptions" type="OpenOptionsType"/>
            </xs:choice>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="OpenOptionsType">
        <xs:sequence>
            <xs:element name="OOI" type="OOIType" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="OOIType">
        <xs:simpleContent>
            <xs:extension base="xs:string">
                <xs:attribute name="key" type="xs:string" use="required"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:complexType name="MetadataType">
        <xs:sequence>
            <!--<xs:choice>-->
                <!--<xs:element name="MDI" type="MDIType" minOccurs="0" maxOccurs="unbounded"/>-->
                <xs:any processContents="skip" minOccurs="0" maxOccurs="unbounded"/>
            <!--</xs:choice>-->
        </xs:sequence>
        <xs:attribute name="domain" type="xs:string"/>
        <xs:attribute name="format" type="xs:string"/>
    </xs:complexType>

    <xs:simpleType name="nonNegativeInteger32">
        <xs:restriction base="xs:nonNegativeInteger">
            <xs:maxInclusive value="2147483647"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="DataTypeType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="Byte"/>
            <xs:enumeration value="UInt16"/>
            <xs:enumeration value="Int16"/>
            <xs:enumeration value="UInt32"/>
            <xs:enumeration value="Int32"/>
            <xs:enumeration value="UInt64"/>
            <xs:enumeration value="Int64"/>
            <xs:enumeration value="Float32"/>
            <xs:enumeration value="Float64"/>
            <xs:enumeration value="CInt16"/>
            <xs:enumeration value="CInt32"/>
            <xs:enumeration value="CFloat32"/>
            <xs:enumeration value="CFloat64"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="ColorInterpType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="Gray"/>
            <xs:enumeration value="Palette"/>
            <xs:enumeration value="Red"/>
            <xs:enumeration value="Green"/>
            <xs:enumeration value="Blue"/>
            <xs:enumeration value="Alpha"/>
            <xs:enumeration value="Hue"/>
            <xs:enumeration value="Saturation"/>
            <xs:enumeration value="Lightness"/>
            <xs:enumeration value="Cyan"/>
            <xs:enumeration value="Magenta"/>
            <xs:enumeration value="Yellow"/>
            <xs:enumeration value="Black"/>
            <xs:enumeration value="YCbCr_Y"/>
            <xs:enumeration value="YCbCr_Cb"/>
            <xs:enumeration value="YCbCr_Cr"/>
            <xs:enumeration value="Undefined"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="SRSType">
        <xs:simpleContent>
            <xs:extension base="xs:string">
                <xs:attribute name="dataAxisToSRSAxisMapping" type="xs:string"/>
                <xs:attribute name="coordinateEpoch" type="xs:float"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="DoubleOrNanType">
        <xs:union memberTypes="xs:double NANType" />
    </xs:simpleType>

    <xs:simpleType name="NANType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="nan"/>
            <xs:enumeration value="NAN"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="OGRBooleanType">
        <xs:restriction base="xs:string">
            <xs:enumeration value="1"/>
            <xs:enumeration value="0"/>
            <xs:enumeration value="ON"/>
            <xs:enumeration value="OFF"/>
            <xs:enumeration value="on"/>
            <xs:enumeration value="off"/>
            <xs:enumeration value="YES"/>
            <xs:enumeration value="NO"/>
            <xs:enumeration value="yes"/>
            <xs:enumeration value="no"/>
            <xs:enumeration value="TRUE"/>
            <xs:enumeration value="FALSE"/>
            <xs:enumeration value="true"/>
            <xs:enumeration value="false"/>
            <xs:enumeration value="True"/>
            <xs:enumeration value="False"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="CategoryNamesType">
        <xs:sequence minOccurs="0" maxOccurs="unbounded">
            <xs:element name="Category" type="xs:string"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="ColorTableType">
        <xs:sequence minOccurs="0" maxOccurs="unbounded">
            <xs:element name="Entry" type="ColorTableEntryType"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="ColorTableEntryType">
        <xs:attribute name="c1" type="xs:unsignedInt" use="required"/>
        <xs:attribute name="c2" type="xs:unsignedInt" use="required" />
        <xs:attribute name="c3" type="xs:unsignedInt" use="required" />
        <xs:attribute name="c4" type="xs:unsignedInt" />
    </xs:complexType>

    <xs:complexType name="GDALRasterAttributeTableType">
        <xs:sequence>
            <xs:element name="FieldDefn" type="FieldDefnType" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element name="Row" type="RowType" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="FieldDefnType">
        <xs:sequence>
            <xs:element name="Name" type="xs:string"/>
            <xs:element name="Type" type="xs:unsignedInt"/>
            <xs:element name="Usage" type="xs:unsignedInt"/>
        </xs:sequence>
        <xs:attribute name="index" type="xs:unsignedInt" use="required"/>
    </xs:complexType>

    <xs:complexType name="RowType">
        <xs:sequence>
            <xs:element name="F" type="xs:anyType" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attribute name="index" type="xs:unsignedInt" use="required"/>
    </xs:complexType>

</xs:schema>