package com.swabunga.spell.engine;


/**
 * The various settings used to control how a spell checker works are read from here.
 * Includes the COST_* constants that decide how to figure the cost of converting one word to
 * another in the EditDistance class.
 * 

 * Also includes SPELL_* constants that control how misspellings are detected, for example, how to handle
 * mixed-case words, etc.
 *
 * @author aim4min
 * @see EditDistance
 */
public abstract class Configuration {

  /** used by EditDistance: the cost of having to remove a character 
(integer greater than 0) */
  public static final String COST_REMOVE_CHAR = "EDIT_DEL1";

  /** used by EditDistance: the cost of having to insert a character 
(integer greater than 0)*/
  public static final String COST_INSERT_CHAR = "EDIT_DEL2";

  /**
   * used by EditDistance: the cost of having to swap two adjoinging characters
   * for the swap value to ever be used, it should be smaller than the COST_REMOVE_CHAR or COST_INSERT_CHAR values
   * 
(integer greater than 0)
   */
  public static final String COST_SWAP_CHARS = "EDIT_SWAP";

  /**
   * used by EditDistance: the cost of having to change case, for example, from i to I.
   * 
(integer greater than 0)
   */
  public static final String COST_CHANGE_CASE = "EDIT_CASE";

  /**
   * used by EditDistance: the cost of having to substitute one character for another
   * for the sub value to ever be used, it should be smaller than the COST_REMOVE_CHAR or COST_INSERT_CHAR values
   * 
(integer greater than 0)
   */
  public static final String COST_SUBST_CHARS = "EDIT_SUB";

//    public static final String EDIT_SIMILAR = "EDIT_SIMILAR"; //DMV: these does not seem to be used at all
//    public static final String EDIT_MIN = "EDIT_MIN";
//    public static final String EDIT_MAX = "EDIT_MAX";

  /** the maximum cost of suggested spelling. Any suggestions that cost more are thrown away
   * 
 integer greater than 1)
   */
  public static final String SPELL_THRESHOLD = "SPELL_THRESHOLD";

  /** words that are all upper case are not spell checked, example: "CIA" 
(boolean) */
  public static final String SPELL_IGNOREUPPERCASE = "SPELL_IGNOREUPPERCASE";
  /**  words that have mixed case are not spell checked, example: "SpellChecker"
(boolean) */
  public static final String SPELL_IGNOREMIXEDCASE = "SPELL_IGNOREMIXEDCASE";
  /** words that look like an internet address are not spell checked, example: "http://www.google.com" 
(boolean)*/
  public static final String SPELL_IGNOREINTERNETADDRESSES = "SPELL_IGNOREINTERNETADDRESS";
  /** words that have digits in them are not spell checked, example: "mach5" 
(boolean) */
  public static final String SPELL_IGNOREDIGITWORDS = "SPELL_IGNOREDIGITWORDS";
  /** I don't know what this does. It doesn't seem to be used 
(boolean) */
  public static final String SPELL_IGNOREMULTIPLEWORDS = "SPELL_IGNOREMULTIPLEWORDS";
  /** the first word of a sentance is expected to start with an upper case letter 
(boolean) */
  public static final String SPELL_IGNORESENTENCECAPITALIZATION = "SPELL_IGNORESENTENCECAPTILIZATION";

  /**
   * Gets one of the integer constants
   * @param key one of the integer constants defined in this class
   * @return int value of the setting
   */
  public abstract int getInteger(String key);

  /**
   * Gets one of the boolean constants
   * @param key one of the boolean constants defined in this class
   * @return boolean value of the setting
   */
  public abstract boolean getBoolean(String key);

  /**
   * Sets one of the integer constants
   * @param key one of the integer constants defined in this class
   * @param value new integer value of the constant
   */
  public abstract void setInteger(String key, int value);

  /**
   * Sets one of the boolean constants
   * @param key one of the boolean constants defined in this class
   * @param value new boolean value of this setting
   */
  public abstract void setBoolean(String key, boolean value);

  /**
   * gets a new default Configuration
   * @return Configuration
   */
  public static final Configuration getConfiguration() {
    return getConfiguration(null);
  }

  /**
   * Returns a new instance of a Configuration class
   * @param className - the class to return, must be based on Configuration
   * @return Configuration
   */
  public static final Configuration getConfiguration(String className) {

    Configuration result;

    if (className != null && className.length() > 0) {
      try {
        result = (Configuration) Class.forName(className).newInstance();
      } catch (InstantiationException e) {
        result = new PropertyConfiguration();
      } catch (IllegalAccessException e) {
        result = new PropertyConfiguration();
      } catch (ClassNotFoundException e) {
        result = new PropertyConfiguration();
      }
    } else {
      result = new PropertyConfiguration();
    }
    return result;
  }
}