<?xml version="1.0"?>
<sch:schema xmlns:sch="http://purl.oclc.org/dsdl/schematron"
            xmlns:xs="http://www.w3.org/2001/XMLSchema"
            queryBinding="xslt2">

   <sch:let name="document-classification"
            value="/Document/@classification" />

   <sch:pattern id="SecurityClassificationPolicy">

      <sch:p>A Para's classification value cannot be more sensitive 
             than the Document's classification value.</sch:p> 

      <sch:rule context="Para[@classification='top-secret']">

         <sch:assert test="$document-classification='top-secret'"
                     see="Data Requirement 2.1">
             If there is a Para labeled "top-secret" then the Document  
             must be labeled top-secret
         </sch:assert>

      </sch:rule>

      <sch:rule context="Para[@classification='secret']">

         <sch:assert test="($document-classification='top-secret') or
                           ($document-classification='secret')"
                     see="Data Requirement 2.1">
             If there is a Para labeled "secret" then the Document  
             must be labeled either secret or top-secret
         </sch:assert>

      </sch:rule>

      <sch:rule context="Para[@classification='confidential']">

         <sch:assert test="($document-classification='top-secret') or
                           ($document-classification='secret') or 
                           ($document-classification='confidential')"
                     see="Data Requirement 2.1">
             If there is a Para labeled "confidential" then the Document  
             must be labeled either confidential, secret or top-secret
         </sch:assert>

      </sch:rule>

   </sch:pattern>

   <sch:pattern id="ReservedWordFilter">

      <sch:p>These reserved words are not allowed anywhere in the
             document: SCRIPT, FUNCTION.</sch:p> 

      <sch:rule context="Document">

         <sch:assert test="count(//node()[contains(.,'SCRIPT')]) = 0
                           and
                           count(//node()[contains(.,'FUNCTION')]) = 0"
                     see="Data Requirement 3.1">
             The document must not contain the words SCRIPT or FUNCTION
         </sch:assert>

      </sch:rule>

   </sch:pattern>

   <sch:pattern id="DataIntegrityChecks">

      <sch:p>The count value in the NumParas element must match 
             a count of the actual number of Para elements.
             And the hash value must match the value obtained
             by recomputing the hash on the current document.</sch:p> 

      <sch:rule context="NumParas">

         <sch:assert test=". = ../count(Para)"
                     see="Data Requirement 4.1">
             The count value in this element must match 
             a count of the actual number of Para elements
         </sch:assert>

      </sch:rule>

      <sch:rule context="Hash">

         <sch:assert test=". = sum(for $i in //*[not(*) and not(self::Hash)] return 
                                       for $j in string-length($i) return $j)"
                     see="Data Requirement 4.2">
             The value of Hash must match the value that is obtained
             by recomputing the hash algorithm on the current document
         </sch:assert>

      </sch:rule>

   </sch:pattern>

   <sch:pattern id="Grammar">

      <sch:rule context="/*">

         <sch:assert test="name() = 'Document'"
                     see="Data Requirement 8.1">
             The root element must be Document
         </sch:assert>

         <sch:assert test="(count(@*) = 1) and 
                           (name(@*) = 'classification') and
                           (($document-classification='top-secret') or
                           ($document-classification='secret') or 
                           ($document-classification='confidential') or
                           ($document-classification='unclassified'))"
                     see="Data Requirement 8.2">
             Document has one attribute, classification, whose value can 
             be one of top-secret, secret, confidential, or unclassified.
         </sch:assert>

      </sch:rule>

      <sch:rule context="/Document">

         <sch:assert test="(count(NumParas) = 1) and
                           (count(Para) &gt;= 1) and
                           (count(Hash) = 1) and
                           (count(*[name() !='NumParas' and 
                                    name() != 'Paras' and 
                                    name() != 'Hash']) = 0)"
                     see="Data Requirement 8.3 and 8.3.1">
             Document is comprised of one NumParas, one or more Para, and 
             one Hash. These child elements may occur in any order.
         </sch:assert>

      </sch:rule>

      <sch:rule context="Para">

         <sch:assert test="(count(@*) = 1) and 
                           (name(@*) = 'classification') and
                           (($document-classification='top-secret') or
                           ($document-classification='secret') or 
                           ($document-classification='confidential') or
                           ($document-classification='unclassified'))"
                     see="Data Requirement 8.4">
             Para has one attribute, classification, whose value can be 
             one of top-secret, secret, confidential, or unclassified.
         </sch:assert>

         <sch:assert test="(. castable as xs:string) and
                           (string-length() &lt;= 200) and
                           (matches(.,'[\sa-zA-Z0-9,;:\.]*'))"
                     see="Data Requirement 8.5">
             The value of a Para is a string, constrained to a maximum of 
             200 characters, comprised of only these characters: a-z, A-Z, 
             0-9, comma, period, colon, semi-colon.
         </sch:assert>

      </sch:rule>

      <sch:rule context="NumParas">

         <sch:assert test=". castable as xs:nonNegativeInteger"
                     see="Data Requirement 8.6">
             The value of NumParas is a nonNegativeInteger.
         </sch:assert>

      </sch:rule>

      <sch:rule context="Hash">

         <sch:assert test=". castable as xs:long"
                     see="Data Requirement 8.7">
             The value of Hash is a long.
         </sch:assert>

      </sch:rule>

   </sch:pattern>

</sch:schema>