//
// $.ui.cycling
// 
// Cycling widget
// 
// depends on:
//   - jquery.js
//   - jquery.ui.core.js
//   - jquery.ui.widget.js
//
// Copyright:   © 2012 Is Cool Entertainment
// Author:      Antoine BERNIER (abernier)
//
// Usage:       $(el).cycling({
//                  items:  Collection's items  (jQuery|selector|el)    Default: '> *', eg: children
//                  value:  Current value       (Number)                Default: 0,
//                  min:    Min value           (Number)                Default: 0
//                  max:    Max value           (Number)                Default: $(items).length - 1
//                  loop:   Loop?               (Boolean)               Default: true
//                  step:   Step                (Number >= 0)           Default: 1
//              })
//
(function ($) {
    $.widget("ui.cycling", {
        
        //
        // Defaults options
        //
        // /!\ Order below matters
        //
        options: {
            items: '> *',   // The collection of elements to cycle around
            min: -Infinity, // The min index below stop cycling
            max: Infinity,  // The max index below stop cycling
            value: 0,       // The index of the current element
            loop: true,     // Whether to loop
            step: 1,        // step used for prev/next actions
        },
        _create: function () {
            $.Widget.prototype._create.apply(this, arguments);
            
            // Force setting options in order to normalize them
            this._setOptions(this.options);
            
            this.element.bind(this.widgetName + 'setoption.' + this.widgetName, $.proxy(function (event, data) {
                
                //
                // Options dependencies computation
                //
                // TODO: 
                //
                // value = f(min, max, loop)
                // min   = f(max)
                // max   = f(items, min)
                //
                // So, for example, updating 'min' => updating 'max' then 'value'
                //
                
                //console.info("option '%s' has just set to '%s'(original: '%s')", data.option, data.current, data.original);
                switch (data.option) {
                case 'min':
                    this._setOption('max', this.options.max, true);
                    this._setOption('value', this.options.value);
                    break;
                case 'max':
                    this._setOption('min', this.options.min, true);
                    this._setOption('value', this.options.value);
                    break;
                case 'items':
                    this._setOption('max', this.options.max, true);
                    break;
                case 'loop':
                    this._setOption('value', this.options.value);
                    break;
                case 'value':
                    
                    //
                    // Trigger the 'cyclingchange' event
                    //
                    
                    this._trigger('change', null, {
                        value: data.current,
                        $activeItem: this.options.items.eq(data.current)
                    });
                    
                    break;
                }
            }, this));
            
            // 
            this.go(this.options.value);
            
            return this;
        },
        go: function (value) {
            this._setOption('value', value);
            
            return this;
        },
        jump: function (increment) {
            this.go(this.options.value + increment);
            
            return this;
        },
        next: function (step) {
            if (step) {
                this._setOption('step', step);
            }
            this.jump(this.options.step);
            
            return this;
        },
        prev: function (step) {
            if (step) {
                this._setOption('step', step);
            }
            this.jump(-this.options.step);
            
            return this;
        },
        _setOption: function (k, v, silently) {
            
            var oldValue = this.options[k];
            
            switch (k) {
            case 'items':
                v = $(v, this.element);
                break;
            case 'min':
                if (v < 0) {
                    v = 0;
                }
                if (v > this.options.max) {
                    v = this.options.max;
                }
                break;
            case 'max':
                if (v > this.options.items.length - 1) {
                    v = this.options.items.length - 1;
                }
                if (v < this.options.min) {
                    v = this.options.min;
                }
                break;
            case 'value':
                if (v > this.options.max) {
                    v = (this.options.loop && this.options.value === this.options.max) ? this.options.min : this.options.max;
                }
                if (v < this.options.min) {
                    v = (this.options.loop && this.options.value == this.options.min) ? this.options.max : this.options.min;
                }
                break;
            case 'step':
                if (v < 0) {
                    v = Math.abs(v);
                }
                break;
            }
            $.Widget.prototype._setOption.apply(this, arguments);
            
            //
            // Trigger an event when setting a option
            //
            
            !silently && this._trigger("setoption", null, {
                option: k,
                original: oldValue,
                current: v
              });
            
            return this;
        }
    });
}(jQuery));