<?xml version="1.0" encoding="UTF-8"?>
<!--
/**
 * Structure definition of validation.xml Validation files
 *
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:annotation>
        <xs:documentation xml:lang="en">
            Magento Validation Configuration File
        </xs:documentation>
    </xs:annotation>

    <xs:element name="validation">
        <xs:annotation>
            <xs:documentation xml:lang="en">
                Validation group uses reference to validation rules
            </xs:documentation>
        </xs:annotation>
        <xs:complexType>
            <xs:sequence>
                <xs:element name="entity" type="entity" maxOccurs="unbounded">
                    <xs:keyref name="ruleNameReference" refer="ruleNameKey">
                        <xs:selector xpath="groups/group/uses/use"/>
                        <xs:field xpath="@rule"/>
                    </xs:keyref>
                    <xs:key name="ruleNameKey">
                        <xs:selector xpath="rules/rule"/>
                        <xs:field xpath="@name"/>
                    </xs:key>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:complexType name="entity">
        <xs:sequence>
            <xs:element name="rules" type="rules" maxOccurs="1" minOccurs="0"/>
            <xs:element name="groups" type="groups" maxOccurs="1" minOccurs="0"/>
        </xs:sequence>
        <xs:attribute name="name" type="xs:string" use="required"/>
    </xs:complexType>

    <xs:complexType name="rules">
        <xs:sequence>
            <xs:element name="rule" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element name="property_constraints" maxOccurs="unbounded" minOccurs="0">
                            <xs:complexType>
                                <xs:sequence>
                                    <xs:element name="property" maxOccurs="unbounded" minOccurs="1">
                                        <xs:complexType>
                                            <xs:sequence>
                                                <xs:element name="constraint" type="constraint"  maxOccurs="unbounded" minOccurs="1"/>
                                            </xs:sequence>
                                            <xs:attribute name="name" type="xs:string" use="required"/>
                                        </xs:complexType>
                                    </xs:element>
                                </xs:sequence>
                            </xs:complexType>
                        </xs:element>
                        <xs:element name="entity_constraints" maxOccurs="unbounded" minOccurs="0">
                            <xs:complexType>
                                <xs:sequence>
                                    <xs:element name="constraint" type="constraint"  maxOccurs="unbounded" minOccurs="1"/>
                                </xs:sequence>
                            </xs:complexType>
                        </xs:element>
                    </xs:sequence>
                    <xs:attribute name="name" type="xs:string" use="required"/>
                </xs:complexType>
            </xs:element>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="constraint">
        <xs:sequence minOccurs="0" maxOccurs="unbounded">
            <xs:choice>
                <xs:element name="argument" type="argument" />
                <xs:element name="method">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="argument" type="argument" maxOccurs="unbounded" minOccurs="0" />
                        </xs:sequence>
                        <xs:attribute name="name" type="xs:string" use="required"/>
                    </xs:complexType>
                </xs:element>
                <xs:element name="callback" type="callback" />
            </xs:choice>
        </xs:sequence>
        <xs:attribute name="class" type="xs:string" use="required"/>
        <xs:attribute name="alias" type="xs:string"/>
    </xs:complexType>

    <xs:complexType name="argument" mixed="true">
        <xs:choice>
            <xs:sequence>
                <xs:element name="option" maxOccurs="unbounded" minOccurs="0">
                    <xs:complexType>
                        <xs:simpleContent>
                            <xs:extension base="xs:string">
                                <xs:attribute name="name" type="xs:string"/>
                            </xs:extension>
                        </xs:simpleContent>
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
            <xs:element name="callback" type="callback" />
        </xs:choice>
    </xs:complexType>

    <xs:complexType name="callback">
        <xs:attribute name="class" type="xs:string" use="required"/>
        <xs:attribute name="method" type="xs:string" use="required"/>
    </xs:complexType>

    <xs:complexType name="groups">
        <xs:sequence>
            <xs:element name="group" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:sequence>
                        <xs:element name="uses" type="uses"/>
                    </xs:sequence>
                    <xs:attribute name="name" type="xs:string" use="required"/>
                    <xs:attribute name="builder" type="xs:string"/>
                </xs:complexType>
                <xs:unique name="groupUse">
                    <xs:selector xpath="uses/use"/>
                    <xs:field xpath="@rule"/>
                </xs:unique>
            </xs:element>
        </xs:sequence>
    </xs:complexType>
    <xs:complexType name="uses">
        <xs:annotation>
            <xs:documentation xml:lang="en">
                All validation rules used by current group are listed in this element
                "rule" attribute of "use" element must point to one of entity's rules
            </xs:documentation>
        </xs:annotation>
        <xs:sequence>
            <xs:element name="use" maxOccurs="unbounded">
                <xs:complexType>
                    <xs:attribute name="rule" type="xs:string"/>
                </xs:complexType>
            </xs:element>
        </xs:sequence>
    </xs:complexType>
</xs:schema>