App = new Object();
 
App.Book = (function() {
 
    var menu = [];
	var base;
	var delay = (function(){
		var timer = 0;
		return function(callback, ms){
			clearTimeout (timer);
			timer = setTimeout(callback, ms);
		};
	})();

    function init() {
		base = location.href.replace(location.protocol + '//' + location.host, '').split('/').slice(0, 3).join('/') + '/'; 
        // SEARCH EVENT
        $('#searchform input.search-input').keyup(function() {
            if ($(this).val() == '') {
                $('#search-results ul').fadeOut(150, function() {
                    $(this).empty();
                    $('ul.current').fadeIn(150);
                });
            } else {
				var self = this;
				delay(function() {
					$('ul.current').fadeOut(150);
					$('#search-results ul').show();
					search_menu($(self).val());
				}, 200);
            }
        });


        $(document).keyup(
                function(e) {
                    // escape key
                    if (e.keyCode == 27) {
                        if ($('#searchform input.search-input').val() == '') {
							$('#search-results ul').fadeOut(150, function() {
			                    $(this).empty();
						        $('ul.current').fadeIn(150);
							});
                        }
                    }
        });

        $("p.searchtip").after("<div id='search-results'><ul></ul></div>");

        $.getJSON(base + '_static/menu.json', function(data) {
			menu = data;
        });
	}
 
	function wait() {

	}

    function search_menu(query) {
        $('#search-results ul').empty();
        var matches = [];
        $.each(menu, function(index, item) {
            var scored_node = {
                score : item.text.toLowerCase().score(query.toLowerCase()),
                node : item
            };
            matches.push(scored_node);
        });
        matches.sort(compare_scores);
        results = matches.slice(0, 20);
        $.each(results, function(index, item) {
            if (item.score > 0) {
                $('#search-results ul').append(
                        "<li><a href='" + base + item.node.link + "'>"
                                + item.node.text + "</a></li>");
            }
        });
    }
 
    function compare_scores(a, b) {
        return b.score - a.score;
    }
 
    return {
        init : init,
    }
})();


function levenshtein (s1, s2) {
      // http://kevin.vanzonneveld.net
      // +            original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com)
      // +            bugfixed by: Onno Marsman
      // +             revised by: Andrea Giammarchi (http://webreflection.blogspot.com)
      // + reimplemented by: Brett Zamir (http://brett-zamir.me)
      // + reimplemented by: Alexander M Beedie
      // *                example 1: levenshtein('Kevin van Zonneveld', 'Kevin van Sommeveld');
      // *                returns 1: 3

    if (s1 == s2) {
        return 0;
    }

    var s1_len = s1.length;
    var s2_len = s2.length;
    if (s1_len === 0) {
        return s2_len;
    }
    if (s2_len === 0) {
        return s1_len;
    }

    // BEGIN STATIC
    var split = false;
    try{
        split=!('0')[0];
    } catch (e){
        split=true; // Earlier IE may not support access by string index
    }
    // END STATIC
    if (split){
        s1 = s1.split('');
        s2 = s2.split('');
    }

    var v0 = new Array(s1_len+1);
    var v1 = new Array(s1_len+1);

    var s1_idx=0, s2_idx=0, cost=0;
    for (s1_idx=0; s1_idx<s1_len+1; s1_idx++) {
        v0[s1_idx] = s1_idx;
    }
    var char_s1='', char_s2='';
    for (s2_idx=1; s2_idx<=s2_len; s2_idx++) {
        v1[0] = s2_idx;
        char_s2 = s2[s2_idx - 1];

        for (s1_idx=0; s1_idx<s1_len;s1_idx++) {
            char_s1 = s1[s1_idx];
            cost = (char_s1 == char_s2) ? 0 : 1;
            var m_min = v0[s1_idx+1] + 1;
            var b = v1[s1_idx] + 1;
            var c = v0[s1_idx] + cost;
            if (b < m_min) {
                m_min = b; }
            if (c < m_min) {
                m_min = c; }
            v1[s1_idx+1] = m_min;
        }
        var v_tmp = v0;
        v0 = v1;
        v1 = v_tmp;
    }
    return v0[s1_len];
}

// qs_score - Quicksilver Score
// 
// A port of the Quicksilver string ranking algorithm
// 
// "hello world".score("axl") //=> 0.0
// "hello world".score("ow") //=> 0.6
// "hello world".score("hello world") //=> 1.0
//
// Tested in Firefox 2 and Safari 3
//
// The Quicksilver code is available here
// http://code.google.com/p/blacktree-alchemy/
// http://blacktree-alchemy.googlecode.com/svn/trunk/Crucible/Code/NSString+BLTRRanking.m
//
// The MIT License
// 
// Copyright (c) 2008 Lachie Cox
// 
// 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.


String.prototype.score = function(abbreviation,offset) {
  offset = offset || 0 // TODO: I think this is unused... remove
 
  if(abbreviation.length == 0) return 0.9
  if(abbreviation.length > this.length) return 0.0

  for (var i = abbreviation.length; i > 0; i--) {
    var sub_abbreviation = abbreviation.substring(0,i)
    var index = this.indexOf(sub_abbreviation)


    if(index < 0) continue;
    if(index + abbreviation.length > this.length + offset) continue;

    var next_string       = this.substring(index+sub_abbreviation.length)
    var next_abbreviation = null

    if(i >= abbreviation.length)
      next_abbreviation = ''
    else
      next_abbreviation = abbreviation.substring(i)
 
    var remaining_score   = next_string.score(next_abbreviation,offset+index)
 
    if (remaining_score > 0) {
      var score = this.length-next_string.length;

      if(index != 0) {
        var j = 0;

        var c = this.charCodeAt(index-1)
        if(c==32 || c == 9) {
          for(var j=(index-2); j >= 0; j--) {
            c = this.charCodeAt(j)
            score -= ((c == 32 || c == 9) ? 1 : 0.15)
          }

          // XXX maybe not port this heuristic
          // 
          //          } else if ([[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:[self characterAtIndex:matchedRange.location]]) {
          //            for (j = matchedRange.location-1; j >= (int) searchRange.location; j--) {
          //              if ([[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:[self characterAtIndex:j]])
          //                score--;
          //              else
          //                score -= 0.15;
          //            }
        } else {
          score -= index
        }
      }
   
      score += remaining_score * next_string.length
      score /= this.length;
      return score
    }
  }
  return 0.0
}

// http://stackoverflow.com/questions/967096/using-jquery-to-test-if-an-input-has-focus
jQuery.extend(jQuery.expr[':'], {
    focus: function(element) { 
        return element == document.activeElement; 
    }
});


$(App.Book.init);