<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://clish.sourceforge.net/XMLSchema" targetNamespace="http://clish.sourceforge.net/XMLSchema">
    <!--
***********************************************************
* Forward declare the main element identifiers
***********************************************************
-->
    <xs:element name="CLISH_MODULE" type="clish_module_t"/>
    <xs:element name="VIEW" type="view_t"/>
    <xs:element name="COMMAND" type="command_t"/>
    <xs:element name="STARTUP" type="startup_t"/>
    <xs:element name="ACTION" type="action_t"/>
    <xs:element name="OVERVIEW" type="overview_t"/>
    <xs:element name="DETAIL" type="detail_t"/>
    <xs:element name="PTYPE" type="ptype_t"/>
    <xs:element name="PARAM" type="param_t"/>
    <xs:element name="NAMESPACE" type="namespace_t"/>
    <xs:element name="CONFIG" type="config_t"/>


    <!--
*********************************************************** 
* The common simple types
*********************************************************** 
-->
    <xs:simpleType name="bool_t">
        <xs:restriction base="xs:string">
            <xs:enumeration value="true"/>
            <xs:enumeration value="false"/>
        </xs:restriction>
    </xs:simpleType>

    <!--
*********************************************************** 
* <CLISH_MODULE> is the top level container.
* Any commands which are defined within this tag are global in scope 
* i.e. they are visible from all views.
*********************************************************** 
-->
    <xs:complexType name="clish_module_t">
        <xs:sequence>
            <xs:element ref="OVERVIEW" minOccurs="0"/>
            <xs:element ref="STARTUP" minOccurs="0"/>
            <xs:element ref="PTYPE" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element ref="COMMAND" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element ref="VIEW" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element ref="NAMESPACE" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>
    <!--
***********************************************************
* Identify some attribute groups
***********************************************************
-->
    <xs:attributeGroup name="menu_item_g">
        <xs:attribute name="name" type="xs:string" use="required"/>
        <xs:attribute name="help" type="xs:string" use="required"/>
    </xs:attributeGroup>
    <!--
*******************************************************
* <PTYPE> is used to define the syntax for a parameter type.
*
* name    - a textual name for this type. This name can be used to
*         reference this type within a <PARAM? ptype attribute. 
*
* help    - a textual string which describes the syntax of this type.
*         When a parameter is filled out incorrectly on the CLI, this
*         text will be used to prompt the user to fill out the value 
*         correctly.
*
* pattern     - A regular expression which defines the syntax of the type.
*
* method      - The means by which the pattern is interpreted.
*
*               "regexp" [default] - A POSIX regular expression.
*
*               "integer"          - A numeric definition "min..max"
*
*               "select"           - A list of possible values. 
*               The syntax of the string is of the form: 
*                 "valueOne(ONE) valueTwo(TWO) valueThree(THREE)"
*               where the text before the parethesis defines the syntax 
*               that the user must use, and the value within the parenthesis 
*               is the result expanded as a parameter value. 
*
* preprocess  - An optional directive to process the value entered before
*               validating it. This can greatly simplify the regular expressions
*               needed to match case insensitive values.
*
*               "none" [default] - do nothing
*
*               "toupper"        - before validation convert to uppercase.
*
*               "tolower"        - before validation convert to lowercase.
*
********************************************************
-->
    <xs:simpleType name="ptype_method_e">
        <xs:restriction base="xs:string">
            <xs:enumeration value="regexp"/>
            <xs:enumeration value="integer"/>
            <xs:enumeration value="select"/>
            <xs:enumeration value="choice"/>
            <xs:enumeration value="subcommand"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="ptype_preprocess_e">
        <xs:restriction base="xs:string">
            <xs:enumeration value="none"/>
            <xs:enumeration value="toupper"/>
            <xs:enumeration value="tolower"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="ptype_t">
        <xs:attributeGroup ref="menu_item_g"/>
        <xs:attribute name="pattern"     type="xs:string"/>
        <xs:attribute name="method"      type="ptype_method_e"      use="optional" default="regexp"/>
        <xs:attribute name="preprocess" type="ptype_preprocess_e" use="optional" default="none"/>
    </xs:complexType>
    <!--
*******************************************************
* <VIEW> defines the contents of a specific CLI view.
*
* name      - a textual name for the view
*
* prompt    - a textual definition of the prompt to be
*           used whilst in this view.
*           NB. The prompt may contain environment
*           or dynamic variables which are expanded
*           before display.
*
* [depth]   - a depth of nested view (uses for config).
*
* [restore] - restore the depth or view of commands
*           contained by this view
********************************************************
-->

    <xs:simpleType name="restore_t">
        <xs:restriction base="xs:string">
            <xs:enumeration value="none"/>
            <xs:enumeration value="depth"/>
            <xs:enumeration value="view"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="view_t">
        <xs:sequence>
            <xs:element ref="NAMESPACE" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element ref="COMMAND" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attribute name="name" type="xs:string" use="required"/>
        <xs:attribute name="prompt" type="xs:string" use="optional"/>
        <xs:attribute name="depth" type="xs:string" use="optional" default="0"/>
        <xs:attribute name="restore" type="restore_t" use="optional" default="none"/>
    </xs:complexType>
    <!--
*******************************************************
* <STARTUP> is used to define what happens when the CLI
* is started. Any text held in a <DETAIL> sub-element will
* be used as banner text, then any defined <ACTION> will be 
* executed. This action may provide Message Of The Day (MOTD)
* type behaviour.
*
* view   - defines the view which will be transitioned to, on 
*          successful execution of any <ACTION> tag.
*
* [viewid] - defined the new value of the ${VIEWID} variable to
*          be used if a transition to a new view occurs.
*
* [default_shebang] - The default shebang for all commands.
********************************************************
-->
    <xs:complexType name="startup_t">
        <xs:sequence>
            <xs:element ref="DETAIL" minOccurs="0"/>
            <xs:element ref="ACTION" minOccurs="0"/>
        </xs:sequence>
        <xs:attribute name="view" type="xs:string" use="required"/>
        <xs:attribute name="viewid" type="xs:string" use="optional"/>
        <xs:attribute name="default_shebang" type="xs:string" use="optional"/>
    </xs:complexType>
    <!--
*******************************************************
* <COMMAND> is used to define a command within the CLI.
*
* name           - a textual name for this command. (This may contain
*                spaces e.g. "display acl")
*
* help           - a textual string which describes the purpose of the
*                command.
*
* [view]         - defines the view which will be transitioned to, on 
*                successful execution of any <ACTION> tag. By default the
*                current view stays in scope.
*
* [viewid]       - defined the new value of the ${VIEWID} variable to
*                be used if a transition to a new view occurs. By default
*                the viewid will retain it's current value.
* 
* [access]       - defines the user group/level to which execution of this 
*                command is restricted. By default there is no restriction.
*                The exact interpretation of this field is dependant on the
*                client of libclish but for example the clish and tclish 
*                applications map this to the UNIX user groups.
*
* [escape_chars] - defines the characters which will be escaped (e.g. \$) before
*                being expanded as a variable. By default the following
*                characters will be escaped `|$<>&()#
*
* [args]         - defines a parameter name to be used to gather the rest of the
*                command line after the formally defined parameters 
*                (PARAM elements). The formatting of this parameter is a raw
*                string containing as many words as there are on the rest of the
*                command line.
*
* [args_help]    - a textual string which describes the purpose of the 'args' 
*                parameter. If the "args" attribute is given then this MUST be
*                given also.
*
* [lock]         - the boolean field that specify to lock lockfile while
*                command execution or not. Default is true.
*
********************************************************
-->
    <xs:complexType name="command_t">
        <xs:sequence>
            <xs:element ref="DETAIL" minOccurs="0"/>
            <xs:element ref="PARAM" minOccurs="0" maxOccurs="unbounded"/>
            <xs:element ref="CONFIG" minOccurs="0"/>
            <xs:element ref="ACTION" minOccurs="0"/>
        </xs:sequence>
        <xs:attributeGroup ref="menu_item_g"/>
        <xs:attribute name="view" type="xs:string" use="optional"/>
        <xs:attribute name="viewid" type="xs:string" use="optional"/>
        <xs:attribute name="access" type="xs:string" use="optional"/>
        <xs:attribute name="args" type="xs:string" use="optional"/>
        <xs:attribute name="args_help" type="xs:string" use="optional"/>
        <xs:attribute name="escape_chars" type="xs:string" use="optional"/>
        <xs:attribute name="lock" type="bool_t" use="optional" default="true"/>
    </xs:complexType>
    <!--
*******************************************************
* <PARAM> This tag is used to define a parameter for a command.
*
* name      - a textual name for this parameter. 
*
* help      - a textual string which describes the purpose of the
*           parameter.
*
* ptype     - Reference to a PTYPE name. This parameter will be 
*           validated against the syntax specified for that type.
*           The special value of "" indicates the parameter is a boolean flag.
*           The verbatim presence of the texual name on the command line
*           simply controls the conditional variable expansion for this 
*           parameter.
*
* [mode]    - Parameter mode. It can be "common", "switch" or
*           "subcommand".
*
* [prefix]  - defines the prefix for an optional parameter. A prefix
*           with this value on the command line will signify the presence
*           of an additional argument which will be validated as the
*           value of this parameter.
*
* [optional]- Specify whether parameter is optional. The allowed values
*           is "true" or "false". It false by default.
* 
* [default] - defines a default value for a parameter. Any parameters
*           at the end of command line which have default values need 
*           not explicitly be entered.
*
* [value]   - defines the user's value for subcommand. If this option
*           is defined the entered parameter will be compared to this
*           value instead the "name" field. If this field is defined
*           the mode of PARAM will be forced to "subcommand". The
*           feature is implemented to support subcommands with the
*           same names.
*
* [hidden]  - define the visibility of the parameter while ${__line}
*           and ${__params} auto variables expanding. The allowed values
*           is "true" and "false".
*
* [test]    - define the condition (see the description of 'test'
*           utility) to process this parameter.
********************************************************
    -->

    <xs:simpleType name="param_mode_t">
        <xs:restriction base="xs:string">
            <xs:enumeration value="common"/>
            <xs:enumeration value="switch"/>
            <xs:enumeration value="subcommand"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="param_t">
        <xs:sequence>
            <xs:element ref="PARAM" minOccurs="0" maxOccurs="unbounded"/>
        </xs:sequence>
        <xs:attributeGroup ref="menu_item_g"/>
        <xs:attribute name="ptype" type="xs:string" use="required"/>
        <xs:attribute name="default" type="xs:string" use="optional"/>
        <xs:attribute name="prefix" type="xs:string" use="optional"/>
        <xs:attribute name="mode" type="param_mode_t" use="optional" default="common"/>
        <xs:attribute name="optional" type="bool_t" use="optional" default="false"/>
        <xs:attribute name="value" type="xs:string" use="optional"/>
        <xs:attribute name="hidden" type="bool_t" use="optional" default="false"/>
        <xs:attribute name="test" type="xs:string" use="optional"/>
    </xs:complexType>
    <!--
********************************************************
* <ACTION> specifies the action to be taken for
* a command. 
* 
* The textual contents of the tag are variable expanded
* (environment, dynamic and parameter) the the resulting
* text is interpreted by the client's script interpreter.
*
* In addition the optional 'builtin' attribute can specify
* the name of an internal command which will be invoked
* instead of the client's script handler.
*
* NB. for security reasons any special shell characters 
* (e.g. $|<>`) are escaped before evaluation.
*
* [builtin] - specify the name of an internally registered
*           function. The content of the ACTION tag is
*           taken as the arguments to this builtin function.
*
* [shebang] - specify the programm to execute the action
*           script.
********************************************************
-->
    <xs:complexType name="action_t">
        <xs:simpleContent>
            <xs:extension base="xs:string">
                <xs:attribute name="builtin" type="xs:string" use="optional"/>
                <xs:attribute name="shebang" type="xs:string" use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>
    <!--
********************************************************
* <OVERVIEW> specifies a textual description of the shell.
* 
* This should provide instructions about key bindings and
* escape sequences which can be used in the CLI.
*
********************************************************
-->
    <xs:simpleType name="overview_t">
        <xs:restriction base="xs:string">
            <xs:whiteSpace value="preserve"/>
        </xs:restriction>
    </xs:simpleType>
    <!--
********************************************************
* <DETAIL> specifies a textual description.
* 
* This may be used within the scope of a <COMMAND> 
* element, in which case it would typically contain 
* detailed usage instructions including examples.
*
* This may also be used within the scope of a <STARTUP>
* element, in which case the text is used as the banner
* details which are displayed on shell startup. This is
* shown before any specified <ACTION> is executed.
*
* This text may also be used in the production of user manuals.
********************************************************
-->
    <xs:simpleType name="detail_t">
        <xs:restriction base="xs:string">
            <xs:whiteSpace value="preserve"/>
        </xs:restriction>
    </xs:simpleType>
    <!--
*******************************************************
* <NAMESPACE> import commands from specific view to current view.
*
* ref            - the view to import commands from
*
* [prefix]       - the prefix for imported commands
*
* [prefix_help]  - the help for namespace prefix
*
* [help]         - a boolean flag to use imported
*                commands while help
*
* [completion]   - a boolean flag to use imported
*                commands while completion
*
* [context_help] - a boolean flag to use imported
*                commands while context help
*
* [inherit]      - a boolean flag to inherit nested
*                namespace commands recursively
********************************************************
-->

    <xs:complexType name="namespace_t">
        <xs:attribute name="ref" type="xs:string" use="required"/>
        <xs:attribute name="prefix" type="xs:string" use="optional"/>
        <xs:attribute name="prefix_help" type="xs:string" use="optional"/>
        <xs:attribute name="help" type="bool_t" use="optional" default="false"/>
        <xs:attribute name="completion" type="bool_t" use="optional" default="true"/>
        <xs:attribute name="context_help" type="bool_t" use="optional" default="false"/>
        <xs:attribute name="inherit" type="bool_t" use="optional" default="true"/>
    </xs:complexType>

<!--
*******************************************************
* <CONFIG> Specify the config operation.
*
* operation - config operation to perform
*
********************************************************
-->
    <xs:simpleType name="operation_t">
        <xs:restriction base="xs:string">
            <xs:enumeration value="none"/>
            <xs:enumeration value="set"/>
            <xs:enumeration value="unset"/>
            <xs:enumeration value="dump"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="config_t">
        <xs:attribute name="operation" type="operation_t" use="optional" default="set"/>
        <xs:attribute name="priority" type="xs:string" use="optional" default="0x7f00"/>
        <xs:attribute name="pattern" type="xs:string" use="optional" default="^${__cmd}"/>
        <xs:attribute name="file" type="xs:string" use="optional" default="startup-config"/>
        <xs:attribute name="splitter" type="bool_t" use="optional" default="true"/>
        <xs:attribute name="sequence" type="xs:string" use="optional" default="0"/>
        <xs:attribute name="unique" type="bool_t" use="optional" default="true"/>
        <xs:attribute name="depth" type="xs:string" use="optional"/>
    </xs:complexType>

</xs:schema>