/**********************************************************************
 Copyright (c) 2002  Widespace, OU  and others.
 All rights reserved.   This program and the accompanying materials
 are made available under the terms of the Common Public License v1.0
 which accompanies this distribution, and is available at
 http://solareclipse.sourceforge.net/legal/cpl-v10.html

 Contributors:
 Igor Malinin - initial contribution

 $Id: PHPPartitionScanner.java,v 1.26 2005-05-05 14:06:38 axelcl Exp $
 **********************************************************************/
package net.sourceforge.phpeclipse.phpeditor.php;

import java.util.HashMap;
import java.util.Map;

import net.sourceforge.phpeclipse.ui.text.rules.AbstractPartitioner;

import org.eclipse.core.internal.indexing.AbstractPagePolicy;
import org.eclipse.jface.text.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IPartitionTokenScanner;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.Token;

/**
 * 
 * 
 * @author Igor Malinin
 */
public class PHPPartitionScanner implements IPartitionTokenScanner {
  //	public static final String JSP_DIRECTIVE = "__jsp_directive";
  //	public static final String JSP_COMMENT = "__jsp_comment";
  //// public static final String JSP_TAG = "__jsp_tag";
  //	public static final String JSP_DECLARATION = "__jsp_declaration";
  public static final String PHP_SCRIPTING_AREA = "__php_scripting_area ";

  //	public static final String JSP_EXPRESSION = "__jsp_expression";

  public static final int STATE_DEFAULT = 0;

  //	public static final int STATE_TAG = 1;
  //	public static final int STATE_SCRIPT = 2;

  private IDocument document;

  private int begin;

  private int end;

  private int offset;

  private int length;

  private int position;

  private int state;

  private Map tokens = new HashMap();

  public PHPPartitionScanner() {
  }

  /*
   * @see org.eclipse.jface.text.rules.ITokenScanner#nextToken()
   */
  public IToken nextToken() {
    offset += length;

    /*
     * switch (state) { case STATE_TAG: return nextTagToken(); }
     */

    switch (read()) {
    case ICharacterScanner.EOF:
      state = STATE_DEFAULT;
      return getToken(null);

    case '<':
      switch (read()) {
      case ICharacterScanner.EOF:
        state = STATE_DEFAULT;
        return getToken(null);

      case '?': // <%SCRIPLET <%@DIRECTIVE <%!DECLARATION <%=EXPRESSION <%--COMMENT
        int ch = read();
        //						 if (Character.isWhitespace((char)ch)) {
        //						   return nextJSPToken(PHP_SCRIPTING_AREA);
        //						 }
        switch (ch) {
        case ICharacterScanner.EOF:
          state = STATE_DEFAULT;
          return getToken(PHP_SCRIPTING_AREA);

        //							case '-': // <%- <%--COMMENT
        //								switch (read()) {
        //									case ICharacterScanner.EOF:
        //									case '-': // <%--
        //										return nextCommentToken();
        //								}
        //
        //								break;
        }

        return scanUntilPHPEndToken(PHP_SCRIPTING_AREA);
      }

      unread();
    }

    loop: while (true) {
      switch (read()) {
      case ICharacterScanner.EOF:
        state = STATE_DEFAULT;
        return getToken(null);

      case '<':
        switch (read()) {
        case ICharacterScanner.EOF:
          state = STATE_DEFAULT;
          return getToken(null);

        case '?':
          unread();
          break;

        case '<':
          unread();

        default:
          continue loop;
        }

        unread();

        state = STATE_DEFAULT;
        return getToken(null);
      }
    }
  }

  private IToken scanUntilPHPEndToken(String token) {
    int ch = read();
    while (true) {
      switch (ch) {
      case ICharacterScanner.EOF:
        state = STATE_DEFAULT;
        return getToken(token);
      case '"': // double quoted string
        // read until end of double quoted string
        if (!readUntilEscapedDQ()) {
          state = STATE_DEFAULT;
          return getToken(token);
        }
        break;
      case '\'': // single quoted string
        // read until end of single quoted string
        if (!readUntilEscapedSQ()) {
          state = STATE_DEFAULT;
          return getToken(token);
        }
        break;
      case '/': // comment start?
        ch = read();
        switch (ch) {
        case ICharacterScanner.EOF:
          break;
        case '/':
          // read until end of line
          readSingleLine();
          break;
        case '*':
          // read until end of comment
          readMultiLineComment();
          break;
        default:
          continue;
        }
        break;
      case '#': // line comment
        // read until end of line
        readSingleLine();
        break;
      case '?':
        ch = read();
        switch (ch) {
        case ICharacterScanner.EOF:
        case '>':
          state = STATE_DEFAULT;
          return getToken(token);

        case '?':
          continue;
        }
      }

      ch = read();
    }
  }

  //	private IToken nextCommentToken() {
  //		int ch = read();
  //		loop: while (true) {
  //			switch (ch) {
  //				case ICharacterScanner.EOF:
  //					break loop;
  //
  //				case '-': // - --%>
  //					ch = read();
  //					switch (ch) {
  //						case ICharacterScanner.EOF:
  //							break loop;
  //
  //						case '-': // -- --%>
  //							ch = read();
  //							switch (ch) {
  //								case ICharacterScanner.EOF:
  //									break loop;
  //
  //								case '%': // --% --%>
  //									ch = read();
  //									switch (ch) {
  //										case ICharacterScanner.EOF:
  //										case '>':
  //											break loop;
  //									}
  //
  //									continue loop;
  //
  //								case '-': // --- ---%>
  //									unread();
  //									continue loop;
  //							}
  //
  //							ch = read();
  //							continue loop;
  //					}
  //			}
  //
  //			ch = read();
  //		}
  //
  //		return getToken(JSP_COMMENT);
  //	}

  private IToken getToken(String type) {
    length = position - offset;

    if (length == 0) {
      return Token.EOF;
    }

    if (type == null) {
      return Token.UNDEFINED;
    }

    IToken token = (IToken) tokens.get(type);
    if (token == null) {
      token = new Token(type);
      tokens.put(type, token);
    }

    return token;
  }

  private int read() {
    if (position >= end) {
      return ICharacterScanner.EOF;
    }

    try {
      return document.getChar(position++);
    } catch (BadLocationException e) {
      --position;
      return ICharacterScanner.EOF;
    }
  }

  private boolean readUntilEscapedDQ() {
    // search last double quoted character
    if (position >= end) {
      return false;
    }
    try {
      char ch;
      while (true) {
        ch = document.getChar(position++);
        if (ch == '\\') {
          ch = document.getChar(position++); // ignore escaped character
        } else if (ch == '"') {
          return true;
        }
      }
    } catch (BadLocationException e) {
      --position;
    }
    return false;
  }
  
  private boolean readUntilEscapedSQ() {
    // search last single quoted character
    if (position >= end) {
      return false;
    }
    try {  
      char ch;
      while (true) {
        ch = document.getChar(position++); 
        if (ch == '\\') {
          ch = document.getChar(position++); // ignore escaped character
        } else if (ch == '\'') {
          return true;
        }
      }
    } catch (BadLocationException e) {
      --position;
    }
    return false;
  }

  private void readSingleLine() {
    if (position >= end) {
      return;
    }
    try {
      while (document.getChar(position++) != '\n') {

      }
    } catch (BadLocationException e) {
      --position;
      return;
    }
  }

  private void readMultiLineComment() {
    if (position >= end) {
      return;
    }
    try {
      char ch;
      while (true) {
        ch = document.getChar(position++);
        if (ch == '*') {
          if (document.getChar(position) == '/') {
            position++;
            break;
          }
        }
      }
    } catch (BadLocationException e) {
      --position;
      return;
    }
  }

  private void unread() {
    --position;
  }

  /*
   * @see org.eclipse.jface.text.rules.ITokenScanner#getTokenOffset()
   */
  public int getTokenOffset() {
    if (AbstractPartitioner.DEBUG) {
      Assert.isTrue(offset >= 0, Integer.toString(offset));
    }
    return offset;
  }

  /*
   * @see org.eclipse.jface.text.rules.ITokenScanner#getTokenLength()
   */
  public int getTokenLength() {
    return length;
  }

  /*
   * @see org.eclipse.jface.text.rules.ITokenScanner#setRange(IDocument, int, int)
   */
  public void setRange(IDocument document, int offset, int length) {
    this.document = document;
    this.begin = offset;
    this.end = offset + length;

    this.offset = offset;
    this.position = offset;
    this.length = 0;
  }

  /*
   * @see org.eclipse.jface.text.rules.IPartitionTokenScanner
   */
  public void setPartialRange(IDocument document, int offset, int length, String contentType, int partitionOffset) {
    state = STATE_DEFAULT;
    //    if (partitionOffset > -1) {
    //		int delta= offset - partitionOffset;
    //		if (delta > 0) {
    //			this.setRange(document, partitionOffset, length + delta);
    //			return;
    //		}
    //	}
    setRange(document, partitionOffset, length);
  }

  //	private boolean isContinuationPartition(IDocument document, int offset) {
  //		try {
  //			String type = document.getContentType(offset - 1);
  //
  //			if (type != IDocument.DEFAULT_CONTENT_TYPE) {
  //				return true;
  //			}
  //		} catch (BadLocationException e) {}
  //
  //		return false;
  //	}
}