using System.Collections;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace Rokojori
{  
  public class XMLLexer:Lexer
  {
    public static readonly string Inside_Start_Tag = "Inside_Start_Tag";

    public static readonly LexerMatcher XMLComment = 
      new LexerMatcher( "XMLComment", @"<!--((?:.|\r|\n)*?)-->" ); 

    public static readonly LexerMatcher XMLCData = 
      new LexerMatcher( "XMLCData", @"<![CDATA[((?:.|\r|\n)*?)]]>" ); 

    public static readonly LexerMatcher XMLInstruction = 
      new LexerMatcher( "XMLInstruction", @"<!((?:.|\r|\n)*?)>" ); 

    public static readonly LexerMatcher XMLProcessingInstruction = 
      new LexerMatcher( "XMLDeclaration", @"<\?((?:.|\r|\n)*?)>" ); 

    public static readonly LexerMatcher XMLStartTag = 
      new LexerMatcher( "XMLStartTag", 
      XMLRegexExtensions.Extend( @"<(?:\xml-name:)?\xml-name" ), 
      Lexer.Default_Mode, XMLLexer.Inside_Start_Tag 
    ); 

    public static readonly LexerMatcher XMLEndTag = 
      new LexerMatcher( "XMLEndTag", 
      XMLRegexExtensions.Extend( @"<\/(?:\xml-name:)?\xml-name>" ) 
    ); 

    public static readonly LexerMatcher XMLEscapedEntity = 
      new LexerMatcher( "XMLEscapedEntity", @"&#?\w+;" );
  

    public static readonly LexerMatcher XMLText = 
      new LexerMatcher( "XMLText", @"([^<].)" );  

    public static readonly LexerMatcher XMLAttributeName = 
      new LexerMatcher( "XMLAttributeName", 
      XMLRegexExtensions.Extend( @"(?:\xml-name:)?\xml-name" ), 
      XMLLexer.Inside_Start_Tag, XMLLexer.Inside_Start_Tag
    );

    public static readonly LexerMatcher XMLStartTagClosing = 
      new LexerMatcher( "XMLStartTagClosing", @"\/?>", XMLLexer.Inside_Start_Tag, Lexer.Default_Mode );

    public static readonly LexerMatcher XMLAttributeAssignment = 
      new LexerMatcher( "XMLAttributeAssignment", @"=", XMLLexer.Inside_Start_Tag, XMLLexer.Inside_Start_Tag );

    public static readonly LexerMatcher InsideStartTag_SingleQuotedStringMatcher = 
      LexerMatcherLibrary.SingleQuotedStringMatcher.WithModes( XMLLexer.Inside_Start_Tag );

    public static readonly LexerMatcher InsideStartTag_DoubleQuotedStringMatcher =
      LexerMatcherLibrary.DoubleQuotedStringMatcher.WithModes( XMLLexer.Inside_Start_Tag );

    public static readonly LexerMatcher InsideStartTag_WhiteSpaceMatcher = 
      LexerMatcherLibrary.WhiteSpaceMatcher.WithModes( XMLLexer.Inside_Start_Tag );

    public static readonly LexerMatcher InsideStartTag_BreakMatcher =
      LexerMatcherLibrary.BreakMatcher.WithModes( XMLLexer.Inside_Start_Tag );
    

    public static List<LexerEvent> Lex( string source )
    {
      var lexer = new XMLLexer();
      var events = lexer.LexToList( source );      

      if ( lexer.hasError )
      {
        return null;
      }

      events.ForEach( ev => { ev.GrabMatch( source ); } );
      return events;
    }

    public XMLLexer()
    {        
      
      /*
      
      default:
      { <!--*-->, COMMENT }
      { <!WORD>, INSTRUCTION }
      { <?*?>, XML DEC }
      { <NS:START_TAG, START_TAG, insideTag }
      { </NS:CLOSE_TAG>, CLOSE_TAG }
      { &*; ESCAPED_TEXT }
      { *, TEXT }
      
      insideStartTag:
      { >, START_TAG_CLOSER, "default" }
      { "\*", STRING }
      { '\*', STRING }
      { NS:\w(-\w), WORD_WITH_HYPHEN }
      { =, ASSIGNMENT }

      */
      
      AddAllMatchers(
        XMLLexer.XMLComment,
        XMLLexer.XMLCData,
        XMLLexer.XMLInstruction,
        XMLLexer.XMLProcessingInstruction,

        XMLLexer.XMLStartTag,
        XMLLexer.XMLEndTag,

        XMLLexer.XMLEscapedEntity,
        LexerMatcherLibrary.WhiteSpaceMatcher,
        LexerMatcherLibrary.BreakMatcher,
        XMLLexer.XMLText,          

        XMLLexer.XMLStartTagClosing,

        XMLLexer.InsideStartTag_SingleQuotedStringMatcher,
        XMLLexer.InsideStartTag_DoubleQuotedStringMatcher,
        XMLLexer.XMLAttributeName,
        XMLLexer.XMLAttributeAssignment,
        XMLLexer.InsideStartTag_WhiteSpaceMatcher,
        XMLLexer.InsideStartTag_BreakMatcher
      );

    }
  }
}