/* Parameter -- General digilib parameter class.

  Digital Image Library servlet components

  Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de)

  This program is free software; you can redistribute  it and/or modify it
  under  the terms of  the GNU General  Public License as published by the
  Free Software Foundation;  either version 2 of the  License, or (at your
  option) any later version.
   
  Please read license.txt for the full details. A copy of the GPL
  may be found at http://www.gnu.org/copyleft/lgpl.html

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  
 *
 * Created on 02.09.2003 by casties
 * 
 */
package digilib.servlet;

/** General digilib parameter class.
 * 
 * @author casties
 *
 */
public class Parameter {
	/** real value */
	protected Object value = null;

	/** default value */
	protected Object defval = null;

	/** parameter name (e.g. in config file) */
	protected String name = null;

	/** parameter type */
	protected int type = 0;

	/** Default constructor.
	 * 
	 */
	public Parameter() {
		super();
	}

	/** Constructor with name, default, and value.
	 * 
	 * @param value
	 * @param defval
	 */
	public Parameter(String name, Object defval, Object value) {
		this.name = name;
		this.value = value;
		this.defval = defval;
	}

	/** Constructor with name, default, value, and type.
	 * @param value
	 * @param defval
	 */
	public Parameter(String name, Object defval, Object value, int type) {
		this.name = name;
		this.value = value;
		this.defval = defval;
		this.type = type;
	}

	/** Is the value valid.
	 * 
	 * @return
	 */
	public boolean hasValue() {
		return (value != null);
	}

	/** Try to set the value from a String.
	 * 
	 * Tries to convert the String to the same type as the default value.
	 * Sets the value anyway if the default is null.
	 * Returns if the value could be set. 
	 * 
	 * @param val
	 * @return
	 */
	public boolean setValueFromString(String val) {
		if (defval == null) {
			this.value = val;
			return true;
		}
		Class c = defval.getClass();
		// take String as is
		if (c == String.class) {
			this.value = val;
			return true;
		}
		// set Boolean if string == "true"
		if (c == Boolean.class) {
			this.value = new Boolean(val.compareToIgnoreCase("true") == 0);
			return true;
		}
		// set Integer
		if (c == Integer.class) {
			this.value = new Integer(Integer.parseInt(val));
			return true;
		}
		// set Float
		if (c == Float.class) {
			this.value = new Float(Float.parseFloat(val));
			return true;
		}
		// then it's unknown		
		return false;
	}

	/** Get the default as Object.
	 *  
	 * @return
	 */
	public Object getDefault() {
		return defval;
	}

	/** Set the default.
	 * @param defval
	 */
	public void setDefault(Object defval) {
		this.defval = defval;
	}

	/** Get the value as Object.
	 * 
	 * Returns the default if the value is not set.
	 * 
	 * @return
	 */
	public Object getValue() {
		return (value != null) ? value : defval;
	}

	public int getAsInt() {
		Integer i = (Integer) getValue();
		return (i != null) ? i.intValue() : 0;
	}

	public float getAsFloat() {
		Float f = (Float) getValue();
		return (f != null) ? f.floatValue() : 0f;
	}

	public String getAsString() {
		return (String) getValue();
	}

	public boolean getAsBoolean() {
		Boolean b = (Boolean) getValue();
		return (b != null) ? b.booleanValue() : false;
	}

	/** Set the value.
	 * 
	 * @param value
	 */
	public void setValue(Object value) {
		this.value = value;
	}

	/**
	 * @return
	 */
	public String getName() {
		return name;
	}

	/**
	 * @param name
	 */
	public void setName(String name) {
		this.name = name;
	}

	/**
	 * @return
	 */
	public int getType() {
		return type;
	}

	/**
	 * @param type
	 */
	public void setType(int type) {
		this.type = type;
	}

}