/**********************************************************
* This script provides syntax highlighting support for 
* the Ntriples format.
* Ntriples format specification: 
*     http://www.w3.org/TR/rdf-testcases/#ntriples
***********************************************************/

/* 
    The following expression defines the defined ASF grammar transitions.

    pre_subject ->
        {
        ( writing_subject_uri | writing_bnode_uri )
            -> pre_predicate 
                -> writing_predicate_uri 
                    -> pre_object 
                        -> writing_object_uri | writing_object_bnode | 
                          ( 
                            writing_object_literal 
                                -> writing_literal_lang | writing_literal_type
                          )
                            -> post_object
                                -> BEGIN
         } otherwise {
             -> ERROR
         }
*/
CodeMirror.defineMode("ntriples", function() {  

  var Location = {
    PRE_SUBJECT         : 0,
    WRITING_SUB_URI     : 1,
    WRITING_BNODE_URI   : 2,
    PRE_PRED            : 3,
    WRITING_PRED_URI    : 4,
    PRE_OBJ             : 5,
    WRITING_OBJ_URI     : 6,
    WRITING_OBJ_BNODE   : 7,
    WRITING_OBJ_LITERAL : 8,
    WRITING_LIT_LANG    : 9,
    WRITING_LIT_TYPE    : 10,
    POST_OBJ            : 11,
    ERROR               : 12
  };
  function transitState(currState, c) {
    var currLocation = currState.location;
    var ret;
    
    // Opening.
    if     (currLocation == Location.PRE_SUBJECT && c == '<') ret = Location.WRITING_SUB_URI;
    else if(currLocation == Location.PRE_SUBJECT && c == '_') ret = Location.WRITING_BNODE_URI;
    else if(currLocation == Location.PRE_PRED    && c == '<') ret = Location.WRITING_PRED_URI;
    else if(currLocation == Location.PRE_OBJ     && c == '<') ret = Location.WRITING_OBJ_URI;
    else if(currLocation == Location.PRE_OBJ     && c == '_') ret = Location.WRITING_OBJ_BNODE;
    else if(currLocation == Location.PRE_OBJ     && c == '"') ret = Location.WRITING_OBJ_LITERAL;
    
    // Closing.
    else if(currLocation == Location.WRITING_SUB_URI     && c == '>') ret = Location.PRE_PRED;
    else if(currLocation == Location.WRITING_BNODE_URI   && c == ' ') ret = Location.PRE_PRED;
    else if(currLocation == Location.WRITING_PRED_URI    && c == '>') ret = Location.PRE_OBJ;
    else if(currLocation == Location.WRITING_OBJ_URI     && c == '>') ret = Location.POST_OBJ;
    else if(currLocation == Location.WRITING_OBJ_BNODE   && c == ' ') ret = Location.POST_OBJ;
    else if(currLocation == Location.WRITING_OBJ_LITERAL && c == '"') ret = Location.POST_OBJ;
    else if(currLocation == Location.WRITING_LIT_LANG && c == ' ') ret = Location.POST_OBJ;
    else if(currLocation == Location.WRITING_LIT_TYPE && c == '>') ret = Location.POST_OBJ;
    
    // Closing typed and language literal.
    else if(currLocation == Location.WRITING_OBJ_LITERAL && c == '@') ret = Location.WRITING_LIT_LANG;
    else if(currLocation == Location.WRITING_OBJ_LITERAL && c == '^') ret = Location.WRITING_LIT_TYPE;

    // Spaces.
    else if( c == ' ' &&                             
             (
               currLocation == Location.PRE_SUBJECT || 
               currLocation == Location.PRE_PRED    || 
               currLocation == Location.PRE_OBJ     || 
               currLocation == Location.POST_OBJ
             )
           ) ret = currLocation;
    
    // Reset.
    else if(currLocation == Location.POST_OBJ && c == '.') ret = Location.PRE_SUBJECT;    
    
    // Error
    else ret = Location.ERROR;
    
    currState.location=ret;
  }

  return {
    startState: function() {
       return { 
           location : Location.PRE_SUBJECT,
           uris     : [],
           anchors  : [],
           bnodes   : [],
           langs    : [],
           types    : []
       };
    },
    token: function(stream, state) {
      var ch = stream.next();
      if(ch == '<') {
         transitState(state, ch);
         var parsedURI = '';
         stream.eatWhile( function(c) { if( c != '#' && c != '>' ) { parsedURI += c; return true; } return false;} );
         state.uris.push(parsedURI);
         if( stream.match('#', false) ) return 'variable';
         stream.next();
         transitState(state, '>');
         return 'variable';
      }
      if(ch == '#') {
        var parsedAnchor = '';
        stream.eatWhile(function(c) { if(c != '>' && c != ' ') { parsedAnchor+= c; return true; } return false;});
        state.anchors.push(parsedAnchor);
        return 'variable-2';
      }
      if(ch == '>') {
          transitState(state, '>');
          return 'variable';
      }
      if(ch == '_') {
          transitState(state, ch);
          var parsedBNode = '';
          stream.eatWhile(function(c) { if( c != ' ' ) { parsedBNode += c; return true; } return false;});
          state.bnodes.push(parsedBNode);
          stream.next();
          transitState(state, ' ');
          return 'builtin';
      }
      if(ch == '"') {
          transitState(state, ch);
          stream.eatWhile( function(c) { return c != '"'; } );
          stream.next();
          if( stream.peek() != '@' && stream.peek() != '^' ) {
              transitState(state, '"');
          }
          return 'string';
      }
      if( ch == '@' ) {
          transitState(state, '@');
          var parsedLang = '';
          stream.eatWhile(function(c) { if( c != ' ' ) { parsedLang += c; return true; } return false;});
          state.langs.push(parsedLang);
          stream.next();
          transitState(state, ' ');
          return 'string-2';
      }
      if( ch == '^' ) {
          stream.next();
          transitState(state, '^');
          var parsedType = '';
          stream.eatWhile(function(c) { if( c != '>' ) { parsedType += c; return true; } return false;} );
          state.types.push(parsedType);
          stream.next();
          transitState(state, '>');
          return 'variable';
      }
      if( ch == ' ' ) {
          transitState(state, ch);
      }
      if( ch == '.' ) {
          transitState(state, ch);
      }
    }
  };
});

CodeMirror.defineMIME("text/n-triples", "ntriples");
