/**
 * The XEditor class is used for manipulating and tracing XAspect Objects
 * (file extension *.XA). The majority of String processing is done here.
 * 
 * @author JSeifried
 * @version 0.9.0
 */
package jseifried.xaspecteditor;

import java.util.Vector;
import jseifried.xaspecteditor.dj.XAspectLanguage;
import jseifried.xaspecteditor.view.XView;
import org.eclipse.jface.text.IDocument;
import org.eclipse.ui.editors.text.TextEditor;

public class XEditor extends TextEditor {

 /** Flag denoting wether or not the trace is active */
 private boolean traceActive; 
 
 /** The XView object associated with the trace process */
 private XView xview;

 public XEditor() {
  super();
  setSourceViewerConfiguration(new XSourceViewerConfig());
  traceActive = false;
 }
 
 /** 
  * Wrapper method for setting the XView variable 
  * 
  * @param XView the view to be used for trace output 
  * @see jseifred.xaspecteditor.view.XView
  */
 public void setXView(XView view) {
  xview = view;
 }

 /** 
  * Wrapper method for setting the trace flag  
  */ 
 public void activateTrace() {
  traceActive = true;
 }
 
 /**
  * Captures current cursor position if trace is active, and passes control
  * to identifyLine()
  * 
  * @see identifyLine()
  */
 public void handleCursorPositionChanged() {
  super.handleCursorPositionChanged();
  try {
   xview.refresh("", 0, 0, 0);
   if(isDirty()) {
    traceActive = false;
   } 
   if(traceActive) {
    xview.refresh("Selector tracing active...", 0, 0, 200);
    int line = (new Integer(getCursorPosition().substring(
      0,getCursorPosition().indexOf(":")).trim())).intValue()-1;
    int column = (new Integer(getCursorPosition().substring(
      getCursorPosition().indexOf(":")+ 2).trim())).intValue()-1;
    identifyLine(line, column); 
   }
  } 
  //used to catch multi-line selects
  catch (Exception e) {} 
 }
 
 /** 
  * Gets the String representation of the line corresponding to int line 
  * 
  * @param int the line number of the desired string
  * @return String representing the line at int line 
  */
 String getLine(int line) {
  IDocument doc = getDocumentProvider().getDocument(getEditorInput());
  try {
   return doc.get(doc.getLineOffset(line),doc.getLineLength(line));
  } 
  //catch references to lines that do not exist
  catch (Exception e) {return null;} 
 }

 /** 
  * Identifies the type of line being selected and, if trace is active,
  * takes appropiate action to diplay the trace information 
  * 
  * @param int the line number of the cursor position
  *        column the column number of the cursor position
  */  
 void identifyLine(int line, int column) {
  String string = getLine(line).trim();
  if(!string.startsWith("declare")) return;
  String substring = string.substring(0,string.indexOf(":"));
  if(substring.endsWith("set")) {
   String cd = getClassDictionaryName(line);
   showTrace(traceNodeSet(line, cd));
  } 
  if(substring.endsWith("strategy")) { 
   String cd = getClassDictionaryName(line);
   showTrace(traceStrategy(line, cd));
  }  
 }

 /** 
  * Gathers trace information for a Strategy. Triggers getName(), 
  * getStrategy(), and the traceStrategy method of XAspectLanguage.
  * 
  * @param int the line number of the declare statement
  *        cd String containing the name of the Class Dictionary used by the
  *           Strategy being traced
  * 
  * @return Vector containing the Nodes touched, active Class Dictionary, and 
  *         name of the Strategy. 
  * 
  * @see jseifried.xaspecteditor.dj.XAspectLanguage
  */
 Vector traceStrategy(int line, String cd) {
  String contents = getDocumentProvider().getDocument(getEditorInput()).get();
  String name = "Tracing Strategy "+ getName(line) + ":";
  String strategy = getStrategy(line);
  Vector returnVal = XAspectLanguage.traceStrategy(contents, cd ,strategy);
  returnVal.add(name); 
  return returnVal;
 }
 
 /** 
  * Captures the String representing the Strategy 
  * 
  * @param int the line number of the declare statement
  * @return String representation of the Strategy 
  */
 String getStrategy(int line) {
  IDocument doc = getDocumentProvider().getDocument(getEditorInput());
  int offsetBegin = 0, offsetEnd = 0;
  char current = '0';
  try {
   offsetBegin = doc.getLineOffset(line);
   while(current!='"') {
    offsetBegin++;
    current = doc.getChar(offsetBegin);
   }
   current = '0';
   offsetEnd = offsetBegin + 1;
   while(current!='"') {
    offsetEnd++;
    current = doc.getChar(offsetEnd);
   }
   return doc.get(offsetBegin+1, offsetEnd-offsetBegin-1);
  } 
  //catches out-of-bounds errors with String indicies and line numbers
  catch (Exception e) {return null;}
 }

 /** 
  * Gathers trace information for a Node Set. Triggers getName(), 
  * getStrategy(), and the traceNodeSet method of XAspectLanguage.
  * 
  * @param int the line number of the declare statement
  *        cd String containing the name of the Class Dictionary used by the
  *           Node Set being traced
  * 
  * @return Vector containing the Nodes touched, active Class Dictionary, and 
  *         name of the Node Set. 
  * 
  * @see jseifried.xaspecteditor.dj.XAspectLanguage
  */
 Vector traceNodeSet(int line, String cd) {
  String contents = getDocumentProvider().getDocument(getEditorInput()).get();
  String name = "Tracing Node Set "+ getName(line) + ":";
  String nodeset = getNodeSet(line);
  Vector returnVal = XAspectLanguage.traceStrategy(contents, cd ,"from * to *");
  returnVal.add(name); 
  return returnVal; 
 }

 /** 
  * Captures the String representing the Node Set 
  * 
  * @param int the line number of the declare statement
  * @return String representation of the Node Set 
  */  
 String getNodeSet(int line) {
  IDocument doc = getDocumentProvider().getDocument(getEditorInput());
  int offsetBegin = 0, offsetEnd = 0;
  char current = '0';
  try {
   offsetBegin = doc.getLineOffset(line) + getLine(line).lastIndexOf(":");
   offsetEnd = offsetBegin + 1;
   while(current!=';') {
	offsetEnd++;
	current = doc.getChar(offsetEnd);
   }
   return doc.get(offsetBegin+1, offsetEnd-offsetBegin-1).trim();
  } 
  //catches out-of-bounds errors with String indicies and line numbers
  catch (Exception e) {return null;}
 }
    
 /** 
  * Captures the name of the Selector that is being traced 
  * 
  * @param int the line number of the declare statement
  * @return String representing the name of the Selector 
  */
 String getName(int line) {
  IDocument doc = getDocumentProvider().getDocument(getEditorInput());
  int offsetBegin = 0, offsetEnd = 0;
  char current = '0';
  try {
   offsetBegin = doc.getLineOffset(line);
   while(current!=':') {
	offsetBegin++;
	current = doc.getChar(offsetBegin);
   }
   current = '0';
   offsetEnd = offsetBegin + 1;
   while(current!=':') {
	offsetEnd++;
	current = doc.getChar(offsetEnd);
   }
   return doc.get(offsetBegin+1, offsetEnd-offsetBegin-1).trim();
  } 
  //catches out-of-bounds errors with String indicies and line numbers
  catch (Exception e) {return null;} 
 }

 /** 
  * Captures the name of the Class Dictionary used by the Selector that 
  * is being traced. 
  * 
  * @param int the line number of the declare statement
  * @return String representing the name of the Class Dictionary 
  */
 String getClassDictionaryName(int line) {
  String string = "", returnVal = null;
  int index = 0;
  while((!string.startsWith("declare")) || (!string.endsWith("dictionary"))) {
   line++;
   string = getLine(line).trim();
   index = string.indexOf(":");
   if(index!=-1) string = getLine(line).trim().substring(0,index); 
  }
  returnVal = getLine(line).trim().substring(
    index+1,getLine(line).trim().indexOf(";")).trim();
  return returnVal;
 }

 /** 
  * Displays the results of the trace in the XView. 
  * 
  * @param Vector the resulting data of the trace 
  * @see jseifried.xaspecteditor.view.XView
  */ 
 void showTrace(Vector trace) {
  String string = trace.elementAt(2).toString() + "\n\n" + trace.elementAt(0).toString();
  xview.refresh(string, 0, 0, 200);
 }

 /** 
  * Clear trace data when the editor window is closed. 
  */  
 public void dispose() {
  xview.refresh("",0,0,0);
  super.dispose();
 }
}