require "singleton"

class UriNamespace
  include Singleton
  def initialize
    # Les 1er sont prioritaire pour unalias ??
    @urialiases=Hash.new(nil)
    @urialiases["http:\/\/uml\/2"]="uml"
    #@urialiases["http://schema.omg.org/spec/UML/2.1"]="uml"
    #@urialiases["http:\/\/uml\/1.4"]="uml"
    @urialiases["http:\/\/www.w3.org\/2000\/01\/rdf-schema"]="rdfs"
    @urialiases["http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns"]="rdf"
    @urialiases["http:\/\/protege.stanford.edu\/system"]="sys"
    @urialiases["http:\/\/protege.stanford.edu\/kb"]="kb"
    @urialiases["http:\/\/ft\/uml\/2"]="umlx"
    @urialiases["http:\/\/kb"]="ukb"
    @urialiases["http:\/\/orange-ftgroup.com\/2007\/rd\/xmda\/bpm"]="bpm"
    @urialiases["http:\/\/protege.stanford.edu\/soa"]="soa"
    #enterprise architect
    @urialiases["http:\/\/EA"]="ea"
  end

  # Returns unaliases uri for uri
  # Used by magic draw export plugin
  # NOTE:
  #   raises an error if alias is unknown.
  # Example:
  #   unalias("rdf_XYZ") return @urialises("rdf")+"#"+"XYZ"
  def unalias(uri)
    n=uri.split('_',2)
    @urialiases.each {|k,v|
      next if v!=n[0]
      return k+"#"+n[1]
    }
    # no alias is ok
    return uri
    #raise "unalias failed for #{uri}"
  end

  # Returns the alias associated to ns.
  # NOTE:
  #    uri of the form http://orange-ft.com/[0-9]+/XyZ are aliases xyz
  def getNamespaceAlias(ns)
    _alias=@urialiases[ns]
    return _alias if _alias

    md=/^http:\/\/orange-ft.com\/[0-9]+\/([a-z0-9A-Z]+)$/.match(ns)
    if md.nil?
      _alias="ns_#{@urialiases.length.to_s}"
    else
      # La première lettre doit être minuscule
      _alias=md[1].downcase
    end
    addAliasHelp(_alias,ns)
    addAlias(_alias,ns)
    return _alias

  end

  def addAliasHelp(_alias,ns)
    #return if context[:displayAddAliasHelp,true]
    log.debug <<ENDMSG

**********************************************************
** An unknown rdf namespace has been found and a random
** alias has been generated for it : '#{_alias}'
**
** Using a random alias is OK if you do not need to
** reference a namespace somewhere in your code.
**
** If, for example, you need to declare methods
** for elements of this namespace
** (for generating code for example),
** you will need a fix namespace alias.
**
** Run the following ruby code once in your ruby
** program to declare a new alias:
**
** YourCode.rb
**   require 'ontomde-core'
**   (...)
**   UriNamespace.instance.addAlias('yourAlias',
**       '#{ns.gsub(/\//,'\\\/')}'
**       )
**
** Note: beware of \\/ ruby string escaping)
**********************************************************
ENDMSG
  end

  #adds an alias to the predefined list of aliases.
  def addAlias(_alias,ns)
    log.debug { "Creation d'un alias de namespace xmlns:"+_alias+"=\""+ns+"#\"" }
    @urialiases[ns]=_alias
    return nil
  end

  #compute aliases name for given uri
  #exemple alias('http://foo#bar') --> 'ns1:bar'
  #Note:
  # method added for uml2_kb which stores unaliased uri in kb text field for back reference to uml model.
  def urialias(uri)
    a=uri.split("#",2)
    return uri if a[1].nil?
    ns=getNamespaceAlias(a[0])
    #puts "uri=#{ns}_#{a[1]}"
    return "#{ns}_#{a[1]}"
  end
end

#RDF triplet handling.
class NTriple
  attr_reader :about_uri, :predicat_uri,  :value_uri, :value_litteral
  def valueIsReference?
  end

  # Initialization of internal cache (performance enchancement)
  def initialize
    # Le cache est remis à zéro à chaque fichier.
    # Les essais avec SID.nt montrent un gain de performance
    # de 10% sur la méthode urialias, les fichiers étant largement disjoints.
    #@@cacheUse=1
    #@@cacheMiss=100
    #log.debug "initialize triplet"
    @uriMappingCache=Hash.new(nil)
  end

  # Returns an aliases uri
  # uri is in ntriple format: '<http://foo#bar>'
  # Optimize for ntriple file handling
  def urialias(uri)
    #log.debug "#{uri} ??"
    #return nil if uri == nil
    ret=@uriMappingCache[uri]
    #log.debug "cache miss %=#{1.0*@@cacheMiss/@@cacheUse*100} cacheUse=#{@@cacheUse}"
    #@@cacheUse=@@cacheUse+1
    return ret unless ret.nil?
    #log.debug "cache miss"
    #@@cacheMiss=@@cacheMiss+1
    @uriMappingCache[uri]=ret=compute_urialias(uri)
    #log.debug "#{uri} -> #{ret}"
    return ret
  end

  # Internal use
  def compute_urialias(uri)
    #renvoi une uri apres avoir remplacer le chemin par son alias
    raise Warning.new,"Bad NT URI (#{uri})" if uri.nil? || (uri[0] != 60)
    #uri=uri[1,uri.length-2]
    #log.debug "uri[0,1] -> '#{uri[0,1]}'"
    uri=uri[1,uri.length].split(">",2)[0]
    #log.debug "uri-->#{uri}"
    return ::UriNamespace.instance.urialias(uri)

    #a=uri.split("#",2)
    #return uri if a[1].nil?
    #r=::UriNamespace.instance.getNamespaceAlias(a[0])
    #log.debug "urialias="+r+"_"+a[1]
    #return r+"_"+a[1]
    #return "#{r}_#{a[1]}"
  end

end