# $Id: RDFTriple.xotcl,v 1.2 2005/09/09 21:07:23 neumann Exp $
package provide xotcl::rdf::triple 1.0

package require XOTcl
package require xotcl::rdf::parser

namespace eval ::xotcl::rdf::triple {
  namespace import ::xotcl::*

  Class RDFTriple -parameter {
    predicate
    subject
    object
  }

  RDFTriple instproc dump {} {
    #set o [my object]; if {[info command $o] != ""} { $o showVars  }
    #return "P: [my predicate] S: [my subject] O: [my object]\n"
    return "[my subject] -[my predicate]-> '[my object]'\n"
  }

  Class NodeInfo -parameter {
    lastCurrentNode
    {aboutEach 0}
    {aboutEachPrefix 0}
    topID
    {statements ""}
  }

  Class DescriptionInfo -superclass NodeInfo -parameter {
    {bagID 0}
  }

  Class PropertyInfo -superclass NodeInfo -parameter {
    {reify 0}
    generatedParentID
  }

  Class AboutEachMgr

  AboutEachMgr instproc init args {
    my array set entries {}
    next
  }

  AboutEachMgr instproc reset {} {
    foreach c [my info children] {$c destroy}
    my init
  }

  AboutEachMgr instproc addEntry {name} {
    my set entries($name) ""
  }

  AboutEachMgr instproc isEntry {name} {
    my exists entries($name)
  }

  AboutEachMgr instproc addTriple {name p s o} {
    if {[my exists entries($name)]} {
      set r [RDFTriple create [self]::[my autoname name%08d]]
      $r set predicate $p
      $r set subject $s
      $r set object $o
      my lappend entries($name) $r
      return $r
    }
    return ""
  }

  AboutEachMgr instproc getTriples {name} {
    if {[my exists entries($name)]} {
      my set entries($name)
    } else {return ""}
  }

  Class RDFTripleDB
  RDFTripleDB instproc add {p s o} {
    #my showCall
    set r [RDFTriple create [self]::[my autoname triple%08d]]
    $r set predicate $p
    $r set subject $s
    $r set object $o
    return $r
  }
  RDFTripleDB instproc dump {} {
    #my showCall
    set r ""
    foreach fact [my info children] {append r [$fact dump]}
    return $r
  }
  RDFTripleDB instproc getTriples {} {
    # for the time being: return only children of type RDFTriple
    set ch {}
    foreach c [my info children] {if {[$c istype "RDFTriple"]} {lappend ch $c}}
    return $ch
    #my info children
  }
  RDFTripleDB instproc reset {} {
    #my showCall
    foreach c [my info children] {$c destroy}
    my autoname -reset triple
    #my showMsg "children after reset: <[my info children]>'"
  }
  # return all triples that match the subject
  RDFTripleDB instproc querySubject {s} {
    #my showCall
    set r ""
    foreach t [my info children] {
      if {[string match $s [$t subject]]} {
	lappend r $t
      }
    }
    return $r
  }

  RDFTripleDB instproc queryPredicate {p} {
    #my showCall
    set r ""
    foreach t [my info children] {
      if {[string match $p [$t predicate]]} {
	lappend r $t
      }
    }
    return $r
  }

  RDFTripleDB instproc queryPredicateOnSubject {p s} {
    #my showCall
    foreach t [my querySubject $s] {
      if {[string match $p [$t predicate]]} {
	# there may be only one matching P on a S
	# return the triple
	return $t
      }
    }
    return ""
  }
  RDFTripleDB instproc prettyTriples {} {
    my instvar result
    if {[my exists table]} {my unset table}
    if {[my exists subjectPrinted]} {my unset subjectPrinted}
    set result ""

    foreach triple [lsort [my getTriples]] {
      set subject [$triple set subject]
      set predicate [$triple set predicate]
      set object [$triple set object]

      regexp {^http.*w3[.]org.*(\#.*)$} $predicate _ predicate
      regexp {^http.*w3[.]org.*(\#.*)$} $object _ object
      my lappend table($subject) $predicate $object
    }
    foreach subject [lsort [my array names table]] {
      if {![regexp {^rdfdoc\#} $subject]} { my prettyStatements "" $subject }
    }
    set r $result; set result ""
    foreach subject [lsort [my array names table]] {
      if {![my exists subjectPrinted($subject)]} { 
	my prettyStatements "" $subject 
      }
    }
    if {$result != ""} {
      append r "\n=================== unreferenced:\n$result"
      
    }
    return $r
  }
  RDFTripleDB instproc prettyStatement {space subject predicate object} {
    my append result "$space   [format %-35s $subject] [format %-25s $predicate] $object\n"
  }
  RDFTripleDB instproc prettyStatements {space subject} {
    if {![my exists table($subject)]} {
      my append result "$space NO VALUE FOR $subject\n"
    } else {
      if {![my exists subjectPrinted($subject)]} {
	my set subjectPrinted($subject) 1
	foreach {predicate object} [my set table($subject)] {
	  my prettyStatement $space $subject $predicate $object
	  if {[regexp {^rdfdoc\#} $object]} {
	    my prettyStatements "$space  " $object
	  }
	}
      }
    }
  }


  Class TripleVisitor -superclass NodeTreeVisitor -parameter {
    {descriptionAsBag 0}
    {currentNode ""}
    parser
    rdfNS
  }

  TripleVisitor instproc getInfo {} {
    my set openNode([my set currentNode])
  }

  TripleVisitor instproc getLastInfo {info} {
    my set openNode([$info set lastCurrentNode])
  }

  TripleVisitor instproc popInfo {objName} {
    set i [my getInfo]
    my set currentNode [$i set lastCurrentNode]
    my unset openNode($objName)
    return $i
  }

  TripleVisitor instproc pushInfo {objName ei} {
    set lce [$ei set lastCurrentNode [my set currentNode]]
    if {$lce != ""} {
      set lastInfo [my set openNode($lce)]
      $ei aboutEach [$lastInfo aboutEach]
      $ei aboutEachPrefix [$lastInfo aboutEachPrefix]
    }
    my set openNode($objName) $ei
    my set currentNode $objName
  }

  TripleVisitor instproc qualify {obj var} {
    [$obj resolveNS] getFullName $var
  }

  TripleVisitor instproc init args {
    my array set openNode {{} {}}
    RDFTripleDB create [self]::db
    AboutEachMgr create [self]::aboutEach
    AboutEachMgr create [self]::aboutEachPrefix
    next
  }

  TripleVisitor instproc resetWithoutDB args {
    [self]::aboutEach reset
    [self]::aboutEachPrefix reset
    next
  }

  TripleVisitor instproc reset args {
    [self]::db reset
    my resetWithoutDB
    next
  }

  TripleVisitor instproc addDB {p s o} {
    #puts "ADDDB: P<$p> S<$s> O<$o>"
    set info [my getInfo]
    if {$info != ""} {
      set topID [$info set topID]
      if {[$info aboutEach]} {
	return [[self]::aboutEach addTriple $topID $p $s $o]
      } elseif {[$info aboutEachPrefix]} {
	return [[self]::aboutEachPrefix addTriple $topID $p $s $o]
      }
    }
    return [[self]::db add $p $s $o]
  }

  TripleVisitor instproc checkReification {triple node} {
    # for statements that nest inside a description/property, we remember
    # the statement to be able to reify them
    # (e.g., bag created for description)
    if {$triple != "" && $node != ""} {
      set info [my set openNode($node)]
      if {[my isobject $info] && [$info istype NodeInfo]} {
	${info} lappend statements $triple
      }
    }
  }

  TripleVisitor instproc qualifyWithBaseURL v {
    if {[string match "\#*" $v]} {
      return [[my set parser] baseURL]$v
    }
    return $v
  }

  TripleVisitor instproc RDFTag {objName} {
    set ns [$objName resolveNS]
    set rdfNS [$ns searchNamespaceByPrefix rdf]
    if {$rdfNS == ""} {
      set rdfNS [$ns searchNamespaceByPrefix xmlns]
    }
    my set rdfNS $rdfNS
  }
  TripleVisitor instproc DescriptionNode objName {
    set di [DescriptionInfo create [self]::[my autoname di]]
    $di topID [my qualifyWithBaseURL [$objName getSubject]]
    my pushInfo $objName $di
    #
    # if a description nests inside a Member, we need a triple
    # for the member index (connected to the Description topId)
    #
    if {[namespace tail [[set member [$objName info parent]] info class]] \
	    == "RDFMember"} {
      set bag_ID [[$member info parent] set ID]
      my addDB [my qualify $objName [$member set memberIndex]] \
	  $bag_ID [$di set topID] 
    }
  }

  TripleVisitor instproc handlePCData {objName pcdata} {
    set info [my getInfo]

    if {[set lcn [$info set lastCurrentNode]] == ""} {
      #puts stderr "cannot determine lastCurrentNode from $info"
      #$info showVars
      set selector ""
    } else {
      set selector [namespace tail [$lcn info class]]
    }
    
    switch -exact $selector {
      RDFDescription {
	set triple [my addDB \
			[my qualify $objName [$objName set content]] \
			[$info set topID] $pcdata]
	my checkReification $triple $lcn
      }
      RDFProperty {
	if {[set rAttr [$lcn getRDFAttribute resource]] != ""} {
	  set triple [my addDB \
			  [my qualify $objName [$objName set content]] \
			  [$lcn set $rAttr] $pcdata]
	  #$lcn showVars
	} else {
	  set lastInfo [my getLastInfo $info]
	  if {[$lastInfo exists generatedParentID]} {
	    set parentID [$lastInfo set generatedParentID]
	  } else {
	    set parentID [[$objName info parent] set ID]
	  }
	  #set parentID [$lastInfo set generatedParentID]
	  set triple [my addDB \
			  [my qualify $objName [$objName set content]] \
			  $parentID $pcdata]
	}
      }
      default {
	#puts stderr "create a generatedParentID for reification"
	$info set generatedParentID [[my set parser] makeID]
	set triple [my addDB \
			[my qualify $objName [$objName set content]] \
			[$info set generatedParentID] $pcdata]
	my checkReification $triple [my set currentNode]
      }
    }
    $info set tripleWritten 1
  }

  TripleVisitor instproc Property objName {
    set info [PropertyInfo create [self]::[my autoname pi]]
    ## if we find no subject and are in Container ->
    ## reifiy over generatedParentID
    set propSubject [$objName getSubject]

    $info topID [my qualifyWithBaseURL $propSubject]
    my pushInfo $objName $info
    
    if {[$objName exists pcdata]} {
      my handlePCData $objName [$objName getFirstPCData]
    } 
  }

  TripleVisitor instproc ContainerNode objName {
    set ID [my qualifyWithBaseURL [$objName set ID]]
    foreach t [$objName array names rdfTypes] {
      my addDB [my qualify $objName \
		    [$objName qualifyWithRdfNsPrefix type]] $ID $t
    }
  }

  TripleVisitor instproc Member objName {
    set container [$objName info parent]
    set resource [$objName qualifyWithRdfNsPrefix resource]
    set parseType [$objName qualifyWithRdfNsPrefix parseType]
    if {[$objName exists pcdata]} {
      set co [$objName getFirstPCData]
    } elseif {[$objName exists attributes(resource)]} {
      set co [$objName set attributes(resource)]
    } elseif {[$objName exists attributes($resource)]} {
      set co [$objName set attributes($resource)]
    }
    #puts stderr "CONTAINER = [info exists co]"
    if {[info exists co]} {
      my addDB \
	  [my qualify $container [$objName set memberIndex]] \
	  [$container set ID] $co
    } else {
      #$objName showVars
    }
  }

  TripleVisitor instproc visit objName {
    set cl [namespace tail [$objName info class]]
    $objName instvar attributes
    set triple ""

    #puts "********Visit $objName -- $cl"

    switch -exact $cl {
      RDFTag 		{my RDFTag $objName}
      RDFDescription 	{my DescriptionNode $objName}
      RDFProperty 	{my Property $objName}
      RDFBag - RDFSeq - RDFAlt {my ContainerNode $objName}
      RDFMember 	{my Member $objName}
    }

    foreach a [array names attributes] {
      regexp "^([$objName set rdfNSPrefix]:|)(.*)" $a _ __ an
      switch -exact $an {
	bagID {
	  set info [my getInfo]
	  $info set bagID 1
	}
	aboutEach {
	  set info [my getInfo]
	  if {[DescriptionInfo info instances $info] == ""} {
	    error "AboutEach not in description"
	  }
	  $info aboutEach 1
	  [self]::aboutEach addEntry [my qualifyWithBaseURL [$objName getSubject]]
	}
	aboutEachPrefix {
	  set info [my getInfo]
	  if {[DescriptionInfo info instances $info] == ""} {
	    error "AboutEachPrefix not in description"
	  }
	  $info aboutEachPrefix 1
	  [self]::aboutEachPrefix addEntry [my qualifyWithBaseURL [$objName getSubject]]
	}
	resource {
	  if {$cl eq "RDFProperty"} {
	    my handlePCData $objName [set attributes($a)]
	  }
	}
      }
    }
  }

  TripleVisitor instproc reificate {objName p s o} {
    set memberID [[my set parser] makeID]
    my addDB [my qualify $objName \
		  [$objName qualifyWithRdfNsPrefix predicate]] $memberID $p
    my addDB [my qualify $objName \
		  [$objName qualifyWithRdfNsPrefix subject]] $memberID $s
    my addDB [my qualify $objName \
		  [$objName qualifyWithRdfNsPrefix object]] $memberID $o
    my addDB [my qualify $objName \
		  [$objName qualifyWithRdfNsPrefix type]] $memberID \
	[my qualify $objName [$objName qualifyWithRdfNsPrefix Statement]]
    return $memberID
  }

  TripleVisitor instproc visitEnd objName {
    switch -exact [namespace tail [$objName info class]] {
      RDFDescription {
	set di [my popInfo $objName]
	if {[my descriptionAsBag] || [$di set bagID]} {
	  set bagID [$objName set bagID]
	  my addDB [my qualify $objName [$objName qualifyWithRdfNsPrefix type]] \
	      $bagID [my qualify $objName [$objName qualifyWithRdfNsPrefix Bag]]
	  
	  set bagCount 0
	  
	  foreach s [$di set statements] {
	    set memberID [my reificate $objName \
			      [$s set predicate] [$s set subject] [$s set object]]
	    my addDB [my qualify $objName \
			  [$objName qualifyWithRdfNsPrefix _[incr bagCount]]] \
		$bagID $memberID
	  }
	}
	foreach t [$objName array names rdfTypes] {
	  my addDB [my qualify $objName [$objName qualifyWithRdfNsPrefix "type"]] \
	      [$objName getSubject] $t
	}
	$di destroy
      }
      RDFProperty {
	set info [my popInfo $objName]
	if {![$info exists tripleWritten]} {
	  set triple ""
	  foreach fc [$objName info children] {
	    switch -exact [namespace tail [$fc info class]] {
	      RDFDescription {
		set triple [my addDB \
				[my qualify $objName [$objName set content]] \
				[my qualifyWithBaseURL [$objName getSubject]] [$fc getSubject]]
		break
	      }
	      RDFBag - RDFSeq - RDFAlt {
		set triple [my addDB \
				[my qualify $objName [$objName set content]] \
				[my qualifyWithBaseURL [$objName getSubject]] [$fc set ID]]
		break
	      }
	    }
	  }
	  if {$triple != ""} {
	    my checkReification $triple [my set currentNode]
	  }
	}
	$info destroy
      }
    }
  }

  TripleVisitor instproc evaluateAboutEach {} {
    set triplesWritten ""
    set rdfNSFullName [[my rdfNS] searchPrefix rdf]

    foreach entry [[self]::aboutEach array names entries] {
      # matching entry triples should be bag types and their
      # members -> duplication of aboutEach statements for the
      # members
      foreach entryTriple [lsort [[self]::db querySubject $entry]] {
	if {[regexp "^${rdfNSFullName}_\[0-9\]*$" [$entryTriple predicate]]} {
	  foreach t [[self]::aboutEach getTriples $entry] {
	    set subject [$t subject]
	    # if this is a toplevel elt of an about each tree -> its
	    # subject is the object of the container member
	    if {$subject eq $entry} {
	      [self]::db add [$t predicate] [$entryTriple object] [$t object]
	    } elseif {[lsearch $triplesWritten $t] == -1} {
	      [self]::db add [$t predicate] $subject [$t object]
	      lappend triplesWritten $t
	    }
	  }
	}
      }
    }
  }

  TripleVisitor instproc interpretNodeTree {node} {
    my set parser [$node set parser]
    $node accept [self]
    my evaluateAboutEach
  }

  namespace export RDFTriple NodeInfo DescriptionInfo PropertyInfo \
      AboutEachMgr RDFTripleDB TripleVisitor
}
namespace import ::xotcl::rdf::triple::*