/*
 *
 * Copyright (c) 2006-2014 Sam Collett (http://www.texotela.co.uk)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * Version 1.4.1
 * Demo: http://www.texotela.co.uk/code/jquery/numeric/
 *
 */
(function ($) {
   /*
    * Allows only valid characters to be entered into input boxes.
    * Note: fixes value when pasting via Ctrl+V, but not when using the mouse to paste
     *      side-effect: Ctrl+A does not work, though you can still use the mouse to select (or double-click to select all)
    *
    * @name     numeric
    * @param    config      { decimal : "." , negative : true }
    * @param    callback     A function that runs if the number is not valid (fires onblur)
    * @author   Sam Collett (http://www.texotela.co.uk)
    * @example  $(".numeric").numeric();
    * @example  $(".numeric").numeric(","); // use , as separator
    * @example  $(".numeric").numeric({ decimal : "," }); // use , as separator
    * @example  $(".numeric").numeric({ negative : false }); // do not allow negative values
    * @example  $(".numeric").numeric({ decimalPlaces : 2 }); // only allow 2 decimal places
    * @example  $(".numeric").numeric(null, callback); // use default values, pass on the 'callback' function
    *
    */
   $.fn.numeric = function (config, callback) {
      if (typeof config === 'boolean') {
         config = { decimal: config, negative: true, decimalPlaces: -1 };
      }
      config = config || {};
      // if config.negative undefined, set to true (default is to allow negative numbers)
      if (typeof config.negative == "undefined") { config.negative = true; }
      // set decimal point
      var decimal = (config.decimal === false) ? "" : config.decimal || ".";
      // allow negatives
      var negative = (config.negative === true) ? true : false;
      // set decimal places
      var decimalPlaces = (typeof config.decimalPlaces == "undefined") ? -1 : config.decimalPlaces;
      // callback function
      callback = (typeof (callback) == "function" ? callback : function () { });
      // set data and methods
      return this.data("numeric.decimal", decimal).data("numeric.negative", negative).data("numeric.callback", callback).data("numeric.decimalPlaces", decimalPlaces).keypress($.fn.numeric.keypress).keyup($.fn.numeric.keyup).blur($.fn.numeric.blur);
   };

   $.fn.numeric.keypress = function (e) {
      // get decimal character and determine if negatives are allowed
      var decimal = $.data(this, "numeric.decimal");
      var negative = $.data(this, "numeric.negative");
      var decimalPlaces = $.data(this, "numeric.decimalPlaces");
      // get the key that was pressed
      var key = e.charCode ? e.charCode : e.keyCode ? e.keyCode : 0;
      // allow enter/return key (only when in an input box)
      if (key == 13 && this.nodeName.toLowerCase() == "input") {
         return true;
      }
      else if (key == 13) {
         return false;
      }
      var allow = false;
      // allow Ctrl+A
      if ((e.ctrlKey && key == 97 /* firefox */) || (e.ctrlKey && key == 65) /* opera */) { return true; }
      // allow Ctrl+X (cut)
      if ((e.ctrlKey && key == 120 /* firefox */) || (e.ctrlKey && key == 88) /* opera */) { return true; }
      // allow Ctrl+C (copy)
      if ((e.ctrlKey && key == 99 /* firefox */) || (e.ctrlKey && key == 67) /* opera */) { return true; }
      // allow Ctrl+Z (undo)
      if ((e.ctrlKey && key == 122 /* firefox */) || (e.ctrlKey && key == 90) /* opera */) { return true; }
      // allow or deny Ctrl+V (paste), Shift+Ins
      if ((e.ctrlKey && key == 118 /* firefox */) || (e.ctrlKey && key == 86) /* opera */ ||
        (e.shiftKey && key == 45)) { return true; }
      // if a number was not pressed
      if (key < 48 || key > 57) {
         var value = $(this).val();
         /* '-' only allowed at start and if negative numbers allowed */
         if ($.inArray('-', value.split('')) !== 0 && negative && key == 45 && (value.length === 0 || parseInt($.fn.getSelectionStart(this), 10) === 0)) { return true; }
         /* only one decimal separator allowed */
         if (decimal && key == decimal.charCodeAt(0) && $.inArray(decimal, value.split('')) != -1) {
            allow = false;
         }
         // check for other keys that have special purposes
         if (
            key != 8 /* backspace */ &&
            key != 9 /* tab */ &&
            key != 13 /* enter */ &&
            key != 35 /* end */ &&
            key != 36 /* home */ &&
            key != 37 /* left */ &&
            key != 39 /* right */ &&
            key != 46 /* del */
         ) {
            allow = false;
         }
         else {
            // for detecting special keys (listed above)
            // IE does not support 'charCode' and ignores them in keypress anyway
            if (typeof e.charCode != "undefined") {
               // special keys have 'keyCode' and 'which' the same (e.g. backspace)
               if (e.keyCode == e.which && e.which !== 0) {
                  allow = true;
                  // . and delete share the same code, don't allow . (will be set to true later if it is the decimal point)
                  if (e.which == 46) { allow = false; }
               }
                  // or keyCode != 0 and 'charCode'/'which' = 0
               else if (e.keyCode !== 0 && e.charCode === 0 && e.which === 0) {
                  allow = true;
               }
            }
         }
         // if key pressed is the decimal and it is not already in the field
         if (decimal && key == decimal.charCodeAt(0)) {
            if ($.inArray(decimal, value.split('')) == -1) {
               allow = true;
            }
            else {
               allow = false;
            }
         }
      }
      else {
         allow = true;
         // remove extra decimal places
         if (decimal && decimalPlaces > 0) {
            var dot = $.inArray(decimal, $(this).val().split(''));
            if (dot >= 0 && $(this).val().length > dot + decimalPlaces) {
               allow = false;
            }
         }

      }
      return allow;
   };

   $.fn.numeric.keyup = function (e) {
      var val = $(this).val();
      if (val && val.length > 0) {
         // get carat (cursor) position
         var carat = $.fn.getSelectionStart(this);
         var selectionEnd = $.fn.getSelectionEnd(this);
         // get decimal character and determine if negatives are allowed
         var decimal = $.data(this, "numeric.decimal");
         var negative = $.data(this, "numeric.negative");
         var decimalPlaces = $.data(this, "numeric.decimalPlaces");

         // prepend a 0 if necessary
         if (decimal !== "" && decimal !== null) {
            // find decimal point
            var dot = $.inArray(decimal, val.split(''));
            // if dot at start, add 0 before
            if (dot === 0) {
               this.value = "0" + val;
               carat++;
               selectionEnd++;
            }
            // if dot at position 1, check if there is a - symbol before it
            if (dot == 1 && val.charAt(0) == "-") {
               this.value = "-0" + val.substring(1);
               carat++;
               selectionEnd++;
            }
            val = this.value;
         }

         // if pasted in, only allow the following characters
         var validChars = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, '-', decimal];
         // get length of the value (to loop through)
         var length = val.length;
         // loop backwards (to prevent going out of bounds)
         for (var i = length - 1; i >= 0; i--) {
            var ch = val.charAt(i);
            // remove '-' if it is in the wrong place
            if (i !== 0 && ch == "-") {
               val = val.substring(0, i) + val.substring(i + 1);
            }
               // remove character if it is at the start, a '-' and negatives aren't allowed
            else if (i === 0 && !negative && ch == "-") {
               val = val.substring(1);
            }
            var validChar = false;
            // loop through validChars
            for (var j = 0; j < validChars.length; j++) {
               // if it is valid, break out the loop
               if (ch == validChars[j]) {
                  validChar = true;
                  break;
               }
            }
            // if not a valid character, or a space, remove
            if (!validChar || ch == " ") {
               val = val.substring(0, i) + val.substring(i + 1);
            }
         }
         // remove extra decimal characters
         var firstDecimal = $.inArray(decimal, val.split(''));
         if (firstDecimal > 0) {
            for (var k = length - 1; k > firstDecimal; k--) {
               var chch = val.charAt(k);
               // remove decimal character
               if (chch == decimal) {
                  val = val.substring(0, k) + val.substring(k + 1);
               }
            }
         }

         // remove extra decimal places
         if (decimal && decimalPlaces > 0) {
            var dot = $.inArray(decimal, val.split(''));
            if (dot >= 0) {
               val = val.substring(0, dot + decimalPlaces + 1);
               selectionEnd = Math.min(val.length, selectionEnd);
            }
         }
         // set the value and prevent the cursor moving to the end
         this.value = val;
         $.fn.setSelection(this, [carat, selectionEnd]);
      }
   };

   $.fn.numeric.blur = function () {
      var decimal = $.data(this, "numeric.decimal");
      var callback = $.data(this, "numeric.callback");
      var negative = $.data(this, "numeric.negative");
      var val = this.value;
      if (val !== "") {
         var re = new RegExp(negative ? "-?" : "" + "^\\d+$|^\\d*" + decimal + "\\d+$");
         if (!re.exec(val)) {
            callback.apply(this);
         }
      }
   };

   $.fn.removeNumeric = function () {
      return this.data("numeric.decimal", null).data("numeric.negative", null).data("numeric.callback", null).data("numeric.decimalPlaces", null).unbind("keypress", $.fn.numeric.keypress).unbind("keyup", $.fn.numeric.keyup).unbind("blur", $.fn.numeric.blur);
   };

   // Based on code from http://javascript.nwbox.com/cursor_position/ (Diego Perini <dperini@nwbox.com>)
   $.fn.getSelectionStart = function (o) {
      if (o.type === "number") {
         return undefined;
      }
      else if (o.createTextRange && document.selection) {
         var r = document.selection.createRange().duplicate();
         r.moveEnd('character', o.value.length);
         if (r.text == '') return o.value.length;

         return Math.max(0, o.value.lastIndexOf(r.text));
      } else {
         try { return o.selectionStart; }
         catch (e) { return 0; }
      }
   };

   // Based on code from http://javascript.nwbox.com/cursor_position/ (Diego Perini <dperini@nwbox.com>)
   $.fn.getSelectionEnd = function (o) {
      if (o.type === "number") {
         return undefined;
      }
      else if (o.createTextRange && document.selection) {
         var r = document.selection.createRange().duplicate()
         r.moveStart('character', -o.value.length)
         return r.text.length
      } else return o.selectionEnd
   }

   // set the selection, o is the object (input), p is the position ([start, end] or just start)
   $.fn.setSelection = function (o, p) {
      // if p is number, start and end are the same
      if (typeof p == "number") { p = [p, p]; }
      // only set if p is an array of length 2
      if (p && p.constructor == Array && p.length == 2) {
         if (o.type === "number") {
            o.focus();
         }
         else if (o.createTextRange) {
            var r = o.createTextRange();
            r.collapse(true);
            r.moveStart('character', p[0]);
            r.moveEnd('character', p[1] - p[0]);
            r.select();
         }
         else {
            o.focus();
            try {
               if (o.setSelectionRange) {
                  o.setSelectionRange(p[0], p[1]);
               }
            } catch (e) {
            }
         }
      }
   };

})(jQuery);