import java.io.*;
import java.util.*;
import java.util.*;


/**
* A class for handling Windows-style INI files. The file format is as 
* follows:  <dl>
*<dd>   [subject]       - anything beginning with [ and ending with ] is a subject 
*<dd>   ;comment        - anything beginning with a ; is a comment 
*<dd>   variable=value  - anything of the format string=string is an assignment 
*<dd>   comment         - anything that doesn't match any of the above is a comment 
* </dl>
* @author Steve DeGroof
* @author <A HREF="mailto:degroof@mindspring.com"><I>degroof@mindspring.com</A></I>
* @author <A HREF="http://www.mindspring.com/~degroof"><I>http://www.mindspring.com/~degroof</A></I><BR>
* @modified by Laurent Courbet (April 97)<A HREF="http://www.essi.fr/~courbet"><I>http://www.essi.fr/~courbet</A></I>
*/
public class IniFile extends Object
{
   /**Actual text lines of the file stored in a vector.*/
   protected Vector lines;       
   /**A vector of all subjects*/
   protected Vector subjects;    
   /**A vector of variable name vectors grouped by subject*/
   protected Vector variables;   
   /**A vector of variable value vectors grouped by subject*/
   protected Vector values;      
   /**Name of the file*/
   protected String fileName;   
   /**If true, INI file will be saved every time a value is changed. Defaults to false*/
   protected boolean saveOnChange = false;

   /*If true, INI file will be saved at end of use. Defaults to false*/
   protected boolean saveOnQuit = false;

   /**
   * Creates an INI file object using the specified name
   * If the named file doesn't exist, create one
   * @param name the name of the file
   */
   public IniFile(String name)  
   {
      this(name,false);
   }

   /**
   * Creates an INI file object using the specified name
   * If the named file doesn't exist, create one
   * @param name the name of the file
   * @param saveOnSet save file whenever a value is set
   */
   public IniFile(String name, boolean save)  
   {
      saveOnChange = save;
      fileName = name;
      if (!((new File(name)).exists()))
      {
         if (!createFile()) return;
      }
      loadFile();
      parseLines();
   }

   /**
   * Loads and parses the INI file. Can be used to reload from file.
   */
   public void loadFile()
   {
      //reset all vectors
      lines = new Vector();     
      subjects = new Vector();  
      variables = new Vector(); 
      values = new Vector();    
      //open the file
      try 
      {
         DataInputStream ini = new DataInputStream(
                                   new BufferedInputStream(
                                       new FileInputStream(fileName)));
         String line = "";
         //read all the lines in
         while (true)
         {
            line = ini.readLine();
            if (line == null)
               break;
            else
               lines.addElement(line.trim());
         }
      }
      catch (IOException e)
      {
         System.out.println("IniFile load failed: " + e.getMessage());
         e.printStackTrace();
      }
   }


   /**
   * Create a new INI file.
   */
   protected boolean createFile()
   {
      try 
      {
         DataOutputStream newFile = new DataOutputStream(new FileOutputStream(fileName));
         newFile.writeBytes(";INI File: "+fileName+System.getProperty("line.separator"));
         newFile.close();
         return true;
      }
      catch (IOException e)
      {
         System.out.println("IniFile create failed: " + e.getMessage());
         e.printStackTrace();
         return false;
      }
   }


   /**
   * Reads lines, filling in subjects, variables and values.
   */
   protected void parseLines()
   {
      String currentLine = null;    //current line being parsed
      String currentSubject = null; //the last subject found
      for (int i=0;i<lines.size();i++) //parse all lines
      {
         currentLine = (String)lines.elementAt(i); 
         if (isaSubject(currentLine)) //if line is a subject, set currentSubject
         {
            currentSubject = currentLine.substring(1,currentLine.length()-1);
         }
         else if (isanAssignment(currentLine)) //if line is an assignment, add it
         {
            String assignment = currentLine;
            addAssignment(currentSubject,assignment);
         }
      }
   }


   /**
   * Adds and assignment (i.e. "variable=value") to a subject.
   */
   protected boolean addAssignment(String subject, String assignment)
   {
      String value;
      String variable;
      int index = assignment.indexOf("=");
      variable = assignment.substring(0,index);
      value = assignment.substring(index+1,assignment.length());
      if ((value.length()==0) || (variable.length()==0)) return false;
      else return addValue(subject, variable, value, false);
   }


   /**
   * Sets a specific subject/variable combination the given value. If the subject
   * doesn't exist, create it. If the variable doesn't exist, create it. If 
   * saveOnChange is true, save the file;
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   * @param value the value of the variable (e.g. "green")
   * @return true if successful
   */
   public boolean setValue(String subject, String variable, String value)
   {
      boolean result = addValue(subject, variable, value, true);
      saveOnQuit=true;
      if (saveOnChange) saveFile();
      return result;
   }

   
   /**
   * Sets a specific subject/variable combination the given value. If the subject
   * doesn't exist, create it. If the variable doesn't exist, create it.
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   * @param value the value of the variable (e.g. "green")
   * @param addToLines add the information to the lines vector
   * @return true if successful
   */
   protected boolean addValue(String subject, String variable, String value, boolean addToLines)
   {
      //if no subject, quit
      if ((subject == null) || (subject.length()==0)) return false;

      //if no variable, quit
      if ((variable == null) || (variable.length()==0)) return false;

      //if the subject doesn't exist, add it to the end
      if (!subjects.contains(subject)) 
      {
         subjects.addElement(subject);
         variables.addElement(new Vector());
         values.addElement(new Vector());
      }

      //set the value, if the variable doesn't exist, add it to the end of the subject
      int subjectIndex = subjects.indexOf(subject);
      Vector subjectVariables = (Vector)(variables.elementAt(subjectIndex));
      Vector subjectValues = (Vector)(values.elementAt(subjectIndex));
      if (!subjectVariables.contains(variable))
      {
         subjectVariables.addElement(variable);
         subjectValues.addElement(value);
      }
      int variableIndex = subjectVariables.indexOf(variable);
      subjectValues.setElementAt(value,variableIndex);

      //add it to the lines vector?
      if (addToLines)
         setLine(subject,variable,value);

      return true;
   }

   /**
   * does the line represent a subject?
   * @param line a string representing a line from an INI file
   * @return true if line is a subject
   */
   protected boolean isaSubject(String line)
   {
      return (line.startsWith("[") && line.endsWith("]"));
   }

   /**
   * set a line in the lines vector 
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   * @param value the value of the variable (e.g. "green")
   */
   protected void setLine(String subject, String variable, String value)
   {
      //find the line containing the subject
      int subjectLine = findSubjectLine(subject);
      if (subjectLine == -1)
      {
         addSubjectLine(subject);
         subjectLine = lines.size()-1;
      }
      //find the last line of the subject
      int endOfSubject = endOfSubject(subjectLine);
      //find the assignment within the subject
      int lineNumber =  findAssignmentBetween(variable,subjectLine,endOfSubject);

      //if an assignment line doesn't exist, insert one, else change the existing one
      if (lineNumber == -1)
         lines.insertElementAt(variable+"="+value,endOfSubject);
      else
         lines.setElementAt(variable+"="+value,lineNumber);
   }

   /**
   * find the line containing a variable within a subject
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   * @return the line number of the assignment, -1 if not found
   */
   protected int findAssignmentLine(String subject, String variable)
   {
      int start = findSubjectLine(subject);
      int end = endOfSubject(start);
      return findAssignmentBetween(variable,start,end);
   }

   /**
   * find the line containing a variable within a range of lines
   * @param variable the variable name (e.g. "Color")
   * @param start the start of the range (inclusive)
   * @param end the end of the range (exclusive)
   * @return the line number of the assignment, -1 if not found
   */
   protected int findAssignmentBetween(String variable, int start, int end)
   {
      for (int i=start;i<end;i++)
      {
         if (((String)lines.elementAt(i)).startsWith(variable+"="))
            return i;
      }
      return -1;
   }

   /**
   * add a subject line to the end of the lines vector
   * @param subject the subject heading (e.g. "Widget Settings")
   */
   protected void addSubjectLine(String subject)
   {
      lines.addElement("["+subject+"]");
   }

   /**
   * find a subject line within the lines vector
   * @param subject the subject heading (e.g. "Widget Settings")
   * @return the line number of the subject, -1 if not found
   */
   protected int findSubjectLine(String subject)
   {
      String line;
      String formattedSubject = "["+subject+"]";
      for (int i=0;i<lines.size();i++)
      {
         line = (String)lines.elementAt(i);
         if (formattedSubject.equals(line))  return i;
      }
      return -1;
   }


   /**
   * find the line number which is 1 past the last assignment in a subject
   * starting at a given line
   * @param start the line number at which to start looking
   * @return the line number of the last assignment + 1
   */
   protected int endOfSubject(int start)
   {
      int endIndex = start+1;
      if (start>=lines.size()) return lines.size();
      for (int i=start+1;i<lines.size();i++)
      {
         if (isanAssignment((String)lines.elementAt(i)))
            endIndex = i+1;
         if (isaSubject((String)lines.elementAt(i)))
            return endIndex;
      }
      return endIndex;
   }

   /**
   * does the line represent an assignment?
   * @param line a string representing a line from an INI file
   * @return true if line is an assignment
   */
   protected boolean isanAssignment(String line)
   {
      if ((line.indexOf("=")!=-1) && (!line.startsWith(";")))
         return true;
      else
         return false;
   }

   /**
   * get a copy of the lines vector
   */
   public Vector getLines()
   {
      return (Vector)lines.clone();
   }

   /**
   * get a vector containing all variables in a subject
   * @param subject the subject heading (e.g. "Widget Settings")
   * @return a list of variables, empty vector if subject not found
   */
   public String[] getVariables(String subject)
   {
      String[] v;
      int index = subjects.indexOf(subject);
      if (index != -1)
      {
         Vector vars = (Vector)(variables.elementAt(index));
         v = new String[vars.size()];
         vars.copyInto(v);
         return v;
      }
      else
      {
         v = new String[0]; 
         return v;
      }
   }

   /**
   * get an array containing all subjects
   * @return a list of subjects
   */
   public String[] getSubjects()
   {
      String[] s = new String[subjects.size()];
      subjects.copyInto(s);
      return s;
   }

   /**
   * get the value of a variable within a subject
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   * @return the value of the variable (e.g. "green"), empty string if not found
   */
   public String getValue(String subject, String variable)
   {
      int subjectIndex = subjects.indexOf(subject);
      if (subjectIndex == -1)
         return "";
      Vector valVector = (Vector)(values.elementAt(subjectIndex));
      Vector varVector = (Vector)(variables.elementAt(subjectIndex));
      int valueIndex = varVector.indexOf(variable) ;
      if (valueIndex != -1)
      {
         return (String)(valVector.elementAt(valueIndex));
      }
      return "";
   }


   /**
   * delete variable within a subject
   * @param subject the subject heading (e.g. "Widget Settings")
   * @param variable the variable name (e.g. "Color")
   */
   public void deleteValue(String subject, String variable)
   {
      int subjectIndex = subjects.indexOf(subject);
      if (subjectIndex == -1)
         return;

      Vector valVector = (Vector)(values.elementAt(subjectIndex));
      Vector varVector = (Vector)(variables.elementAt(subjectIndex));

      int valueIndex = varVector.indexOf(variable) ;
      if (valueIndex != -1)
      {
         //delete from variables and values vectors
         valVector.removeElementAt(valueIndex);
         varVector.removeElementAt(valueIndex);
         //delete from lines vector
         int assignmentLine = findAssignmentLine(subject, variable);
         if (assignmentLine != -1)
         {
            lines.removeElementAt(assignmentLine);
         }
         //if the subject is empty, delete it
         if (varVector.size()==0)
         {
            deleteSubject(subject);
         }
	 saveOnQuit=true;
         if (saveOnChange) saveFile();
      }
   }

   /**
   * delete a subject and all its variables
   * @param subject the subject heading (e.g. "Widget Settings")
   */
   public void deleteSubject(String subject)
   {
      int subjectIndex = subjects.indexOf(subject);
      if (subjectIndex == -1)
         return;
      //delete from subjects, variables and values vectors
      values.removeElementAt(subjectIndex);
      variables.removeElementAt(subjectIndex);
      subjects.removeElementAt(subjectIndex);
      //delete from lines vector
      int start = findSubjectLine(subject);
      int end = endOfSubject(start);
      for (int i=start;i<end;i++)
      {
         lines.removeElementAt(start);
      }
      saveOnQuit=true;
      if (saveOnChange) saveFile();
   }

   
   /**
   * save the lines vector back to the INI file
   */
   public void saveFile() 
   {
      try
      {
         DataOutputStream outFile = new DataOutputStream(
                                        new BufferedOutputStream(
                                            new FileOutputStream(fileName)));
         for (int i=0;i<lines.size();i++)
         {
            outFile.writeBytes((String)(lines.elementAt(i))+System.getProperty("line.separator"));
         }
         outFile.close();
      }
      catch (IOException e)
      {
         System.out.println("IniFile save failed: " + e.getMessage());
         e.printStackTrace();
      }
   }

   /**
   * clean up
   */
   protected void finalize()
   {
      if(saveOnQuit) saveFile();
   }


   public static void main(String[] args)
   {
      if (args.length != 1)
      {
         System.out.println("IniFile <filename>");
         System.exit(0);
      }
      else
      {
         String[] vars;
         IniFile f = new IniFile(args[0]);
         String[] subs = f.getSubjects();
         for (int i = 0;i<subs.length;i++)
         {
            System.out.println(subs[i]);
            vars = f.getVariables(subs[i]);
            for (int j = 0;j<vars.length;j++)
            {
               System.out.println("  "+vars[j]+" = "+f.getValue(subs[i],vars[j]));
            }
         }
      }  
   }


}