// Copyright (c) 2005-2008 spinelz.org (http://script.spinelz.org/)
// 
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

var AutoKana = Class.create();

Object.extend(AutoKana, {
  kana_extraction_pattern: new RegExp('[^ 　ぁあ-んー]', 'g'),
  kana_compacting_pattern: new RegExp('[ぁぃぅぇぉっゃゅょ]', 'g'),
  label_string_hiragana:   'かな自動補完',
  label_string_katakana:   'カナ自動補完'
});

Object.extend(AutoKana.prototype, {
  initialize: function(element1, element2) {
    this.elName = $(element1);
    this.elKana = $(element2);
    var defaultOptions  = {
      build:    true,
      katakana: false,
      toggle:   true
    }
    this.options = Object.extend(defaultOptions, arguments[2] || {});
    this.active  = true;
    this._stateClear();
    this._build();
  },
  start: function() {
    this.active = true;
  },
  stop: function() {
    this.active = false;
  },
  toggle: function(event) {
    var ev = event || window.event;
    if(event) {
      var el = Event.element(event);
      if(el.checked) {
        this.active = true;
      } else {
        this.active = false;
      }
    } else {
      this.active = !this.active;
    }
  },
  _addEvents: function() {
    Event.observe(this.elName, 'blur',      this._eventBlur.bindAsEventListener(this));
    Event.observe(this.elName, 'focus',     this._eventFocus.bindAsEventListener(this));
    Event.observe(this.elName, 'keydown',   this._eventKeyDown.bindAsEventListener(this));
  },
  _build: function() {
    if(this.options.build) {
      this._addEvents();
    }
    if(this.options.toggle) {
      this._buildToggle();
    }
  },
  _buildToggle: function() {
    var el_parent       = this.elName.parentNode;
    var el_new_frame    = document.createElement('div');
    var el_new_checkbox = this._buildToggleCheckBox();
    var el_new_label    = this._buildToggleLabel();
    el_parent.replaceChild(el_new_frame, this.elName);
    el_new_frame.appendChild(this.elName);
    el_new_frame.appendChild(el_new_checkbox);
    el_new_frame.appendChild(el_new_label);
  },
  _buildToggleCheckBox: function() {
    var self = this;
    var el = document.createElement('input');
    el.type             = 'checkbox';
    el.id               = this.elName.id + '_toggle';
    el.checked          = true;
    el.style.border     = 'none';
    el.style.background = 'transparent';
    el.style.cursor     = 'pointer';
    Event.observe(el, 'click', this.toggle.bindAsEventListener(this));
    return el;
  },
  _buildToggleLabel: function() {
    var el = document.createElement('label');
    el.htmlFor          = this.elName.id + '_toggle';
    el.style.cursor     = 'pointer';
    el.innerHTML        = ((this.options.katakana) ? AutoKana.label_string_katakana : AutoKana.label_string_hiragana);
    return el;
  },
  _checkConvert: function(new_values) {
    if(!this.flagConvert) {
      if(Math.abs(this.values.length - new_values.length) > 1) {
        var tmp_values = new_values.join('').replace(AutoKana.kana_compacting_pattern, '').split('');
        if(Math.abs(this.values.length - tmp_values.length) > 1) {
          this._stateConvert();
        }
      } else {
        if(this.values.length == this.input.length && this.values.join('') != this.input) {
          this._stateConvert();
        }
      }
    }
  },
  _checkValue: function() {
    var new_input, new_values;
    new_input = this.elName.value
    if(new_input == '') {
      this._stateClear();
      this._setKana();
    } else {
      new_input = this._removeString(new_input);
      if(this.input == new_input) {
        return;
      } else {
        this.input = new_input;
        if(!this.flagConvert) {
          new_values = new_input.replace(AutoKana.kana_extraction_pattern, '').split('');
          this._checkConvert(new_values);
          this._setKana(new_values);
        }
      }
    }
  },
  _clearInterval: function() {
    clearInterval(this.timer);
  },
  _eventBlur: function(event) {
    this._clearInterval();
  },
  _eventFocus: function(event) {
    this._stateInput();
    this._setInterval();
  },
  _eventKeyDown: function(event) {
    if(this.flagConvert) {
      this._stateInput();
    }
  },
  _isHiragana: function(char) {
    return ((char >= 12353 && char <= 12435) || char == 12445 || char == 12446);
  },
  _removeString: function(new_input) {
    if(new_input.match(this.ignoreString)) {
      return new_input.replace(this.ignoreString, '');
    } else {
      var i, ignoreArray, inputArray;
      ignoreArray   = this.ignoreString.split('');
      inputArray    = new_input.split('');
      for(i=0; i<ignoreArray.length; i++) {
        if(ignoreArray[i] == inputArray[i]) {
          inputArray[i] = '';
        }
      }
      return inputArray.join('');
    }
  },
  _setInterval: function() {
    var self = this;
    this.timer = setInterval(function() {self._checkValue();}, 30);
  },
  _setKana: function(new_values) {
    if(!this.flagConvert) {
      if(new_values) {
        this.values = new_values;
      }
      if(this.active) {
        this.elKana.value = this._toKatakana(this.baseKana + this.values.join(''));
      }
    }
  },
  _stateClear: function() {
    this.baseKana       = '';
    this.flagConvert    = false;
    this.ignoreString   = '';
    this.input          = '';
    this.values         = [];
  },
  _stateInput: function() {
    this.baseKana       = this.elKana.value;
    this.flagConvert    = false;
    this.ignoreString   = this.elName.value;
  },
  _stateConvert: function() {
    this.baseKana       = this.baseKana + this.values.join('');
    this.flagConvert    = true;
    this.values         = [];
  },
  _toKatakana: function(src) {
    if(this.options.katakana) {
      var c, i, str;
      str = new String;
      for(i=0; i<src.length; i++) {
        c = src.charCodeAt(i);
        if(this._isHiragana(c)) {
          str += String.fromCharCode(c + 96);
        } else {
          str += src.charAt(i);
        }
      }
      return str;
    } else {
      return src;
    }
  }
});