/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2000 Sun
 * Microsystems, Inc. All Rights Reserved.
 */


package org.netbeans.editor.ext.html;


import java.util.*;

import javax.swing.text.*;

import org.netbeans.editor.ext.*;

/** SyntaxElement is class internal to HTML Completion engine, it is used
 * during the analysis of the HTML code.
 *
 * It is an element of the dynamically created chain of other SyntaxElements.
 * The access to it is done through the HTMLSyntaxSupport, which also takes
 * care of dynamically extending it when needed.
 *
 * @author  Petr Nejedly
 * @version 1.0
 */
class SyntaxElement {
    
    public static final int TYPE_COMMENT = 0;
    public static final int TYPE_DECLARATION = 1;
    public static final int TYPE_ERROR = 2;
    public static final int TYPE_TEXT = 3;
    public static final int TYPE_TAG = 4;
    public static final int TYPE_ENDTAG = 5;
      
    private HTMLSyntaxSupport support;
    private SyntaxElement previous;
    private SyntaxElement next;

    int offset;
    int length;
    int type;

    /** Creates new SyntaxElement */
    public SyntaxElement( HTMLSyntaxSupport support, int from, int to, int type ) {
        this.support = support;
        this.offset = from;
        this.length = to-from;
        this.type = type;
    }

    public int getElementOffset() {
        return offset;
    }

    public int getElementLength() {
        return length;
    }
    
    public int getType() {
        return type;
    }
    
    
    public String getText() {
        try {
            return support.getDocument().getText( offset, length );
        } catch( BadLocationException exc ) {
            // this could happen only when in inconsistent state
           throw new ConcurrentModificationException( "SyntaxElement in inconsistent state" ); // NOI18N
        }
    }

    public SyntaxElement getPrevious() throws BadLocationException {
        if( previous == null ) {
            previous = support.getPreviousElement( offset );
            if( previous != null ) previous.next = this;
        }
        return previous;
    }

    public SyntaxElement getNext() throws BadLocationException {
        if( next == null ) {
            next = support.getNextElement( offset+length );
            if( next != null ) next.previous = this;
        }
        return next;
    }

    public String toString() {
        return "Element(" +type+")[" + offset + "," + (offset+length-1) + "]"; // NOI18N
    }

    
    
    
    /**
     * Declaration models SGML declaration with emphasis on <!DOCTYPE
     * declaration, as other declarations are not allowed inside HTML.
     * It represents unknown/broken declaration or either public or system
     * DOCTYPE declaration.
     */
    static class Declaration extends SyntaxElement {
        private String root;
        private String publicID;
        private String file;
        
        
        /**
         * Creates a model of SGML declaration with some properties of
         * DOCTYPE declaration.
         * @param doctypeRootElement the name of the root element for a DOCTYPE.
         *  Can be null to express that the declaration is not DOCTYPE
         *  declaration or is broken.
         * @param doctypePI public identifier for this DOCTYPE, if available.
         *  null for system doctype or other/broken declaration.
         * @param doctypeFile system identifier for this DOCTYPE, if available.
         *  null otherwise.
         */
        public Declaration( HTMLSyntaxSupport support, int from, int to,
                    String doctypeRootElement,
                    String doctypePI, String doctypeFile
        ) {
            super( support, from, to, TYPE_DECLARATION );
            root = doctypeRootElement;
            publicID = doctypePI;
            file = doctypeFile;
        }
        
        /**
         * @return the name of the root element for a DOCTYPE declaration
         * or null if the declatarion is not DOCTYPE or is broken.
         */
        public String getRootElement() {
            return root;
        }

        /**
         * @return a public identifier of the PUBLIC DOCTYPE declaration
         * or null for SYSTEM DOCTYPE and broken or other declaration.
         */
        public String getPublicIdentifier() {
            return publicID;
        }
        
        /**
         * @return a system identifier of both PUBLIC and SYSTEM DOCTYPE
         * declaration or null for PUBLIC declaration with system identifier
         * not specified and broken or other declaration.
         */
        public String getDoctypeFile() {
            return file;
        }
        
    }

    static class Named extends SyntaxElement {
        String name;

        public Named( HTMLSyntaxSupport support, int from, int to, int type, String name ) {
            super( support, from, to, type );
            this.name = name;
        }

        public String getName() {
            return name;
        }
        public String toString() {
            return super.toString() + " - \"" + name + '"'; // NOI18N
        }
    }


    static class Tag extends SyntaxElement.Named {
        Collection attribs;

        public Tag( HTMLSyntaxSupport support, int from, int to, String name, Collection attribs ) {
            super( support, from, to, TYPE_TAG, name );
            this.attribs = attribs;
        }

        public Collection getAttributes() {
            return attribs;
        }

        public String toString() {
            StringBuffer ret = new StringBuffer( super.toString() );
            ret.append( " - {" );   // NOI18N

            for( Iterator i = attribs.iterator(); i.hasNext(); ) {
                ret.append( i.next() );
                ret.append( ", "  );    // NOI18N
            }

            ret.append( "}" );      //NOI18N
            return ret.toString();
        }
    }

}