/* <copyright>
 This file contains proprietary software owned by Motorola Mobility, Inc.<br/>
 No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/>
 (c) Copyright 2011 Motorola Mobility, Inc.  All Rights Reserved.
 </copyright> */
/**
	@module montage/ui/controller/paged-array-controller
    @requires montage/core/core
    @requires ui/controller/array-controller
    @requires core/event/mutable-event
*/
var Montage = require("montage").Montage,
    ArrayController = require("ui/controller/array-controller").ArrayController,
    MutableEvent = require("core/event/mutable-event").MutableEvent;
/**
    @class module:montage/ui/controller/paged-array-controller.PagedArrayController
    @extends module:montage/ui/controller/array-controller.ArrayController
*/
exports.PagedArrayController = Montage.create(ArrayController,/** @lends module:montage/ui/controller/paged-array-controller.PagedArrayController# */ {
/**
  Description TODO
  @private
*/
    _pageSize: {
        value: 10
    },
        //changing this should recalculate pageIndex to contain first item of previous current page
        // via gotoOffset ?
/**
        Description TODO
        @type {Function}
        @default {Number} 10
    */
    pageSize: {
        get: function() {
            return this._pageSize;
        },
        set: function(value) {
            if (value !== this._pageSize) {
                this._calculate(value, this._pageIndex, this._padding);
            }
        }
    },

/**
  Description TODO
  @private
*/
    _padding: {
        value: 0
    },
    // changing this should change the organized object to have the new padding
/**
        Description TODO
        @type {Function}
        @default {Number} 0
    */
    padding: {
        get: function() {
            return this._padding;
        },
        set: function(value) {
            if (value !== this._padding) {
                this._calculate(this._pageSize, this._pageIndex, value);
            }
        }
    },
/**
  Description TODO
  @private
*/
    _pageIndex: {
        value: 0,
        enumerable: false
    },
        // changing this should change the start and endIndex
/**
        Description TODO
        @type {Function}
        @default {Number} 0
    */
    pageIndex: {
        get: function() {
            return this._pageIndex;
        },
        set: function(pageIndex) {
            if (pageIndex !== this._pageIndex) {
                pageIndex = pageIndex >= this.pageCount ? this.pageCount - 1 : pageIndex < 0 ? 0 : pageIndex;
                this._calculate(this._pageSize, pageIndex, this._padding);
            }
        }
    },

 /**
  Description TODO
  @private
*/
    _pageCount: {
        value: null,
        enumerable: false
    },
/**
        Description TODO
        @type {Function}
        @default null
    */
    pageCount: {
        get: function() {
            return this._pageCount;
        }
    },

/**
        Description TODO
        @type {Function}
        @default {Array} array
    */
    pageNumber: {
        dependencies: ["pageIndex"],
        get: function() {
            return this._pageIndex + 1;
        }
    },

 /**
  Description TODO
  @private
*/
    _calculate: {
        value: function(pageSize, pageIndex, padding) {
            var contentLength = this.content.length,
                pageCount = this._pageCount,
                startIndex, endIndex,
                pageSizeChangeEvent,
                pageIndexChangeEvent,
                paddingChangeEvent,
                pageCountChangeEvent,
                startIndexChangeEvent,
                endIndexChangeEvent;

            if (pageSize !== this._pageSize) {
                pageSizeChangeEvent = MutableEvent.changeEventForKeyAndValue("pageSize", this._pageSize);
                this._pageSize = pageSize;
            }
            if (pageIndex !== this._pageIndex) {
                pageIndexChangeEvent = MutableEvent.changeEventForKeyAndValue("pageIndex", this._pageIndex);
                this._pageIndex = pageIndex;
            }
            if (padding !== this._padding) {
                paddingChangeEvent = MutableEvent.changeEventForKeyAndValue("padding", this._padding);
                this._padding = padding;
            }

            pageCountChangeEvent = MutableEvent.changeEventForKeyAndValue("pageCount", pageCount);
            this._pageCount = pageCount = Math.ceil(contentLength / pageSize);

            startIndexChangeEvent = MutableEvent.changeEventForKeyAndValue("startIndex", this._startIndex);
            startIndex = pageIndex * pageSize - padding;
            this._startIndex = startIndex = startIndex < 0 ? 0 : startIndex;

            endIndexChangeEvent = MutableEvent.changeEventForKeyAndValue("endIndex", this._endIndex);
            endIndex = pageIndex * pageSize + pageSize + padding;
            this._endIndex = endIndex = endIndex > contentLength ? contentLength : endIndex;

            if (pageCountChangeEvent.minus !== pageCount) {
                this.dispatchEvent(pageCountChangeEvent.withPlusValue(pageCount));
            }
            if (startIndexChangeEvent.minus !== startIndex) {
                this.dispatchEvent(startIndexChangeEvent.withPlusValue(startIndex));
            }
            if (endIndexChangeEvent.minus !== endIndex) {
                this.dispatchEvent(endIndexChangeEvent.withPlusValue(endIndex));
            }
            if (pageSizeChangeEvent) {
                this.dispatchEvent(pageSizeChangeEvent.withPlusValue(pageSize));
            }
            if (pageIndexChangeEvent) {
                this.dispatchEvent(pageIndexChangeEvent.withPlusValue(pageIndex));
            }
            if (paddingChangeEvent) {
                this.dispatchEvent(paddingChangeEvent.withPlusValue(padding));
            }
        }
    },
/**
    Description TODO
    @function
    */
    gotoFirstPage: {
        value: function() {
            this.gotoPage(0);
        }
    },
/**
    Description TODO
    @function
    */
    gotoLastPage: {
        value: function() {
            this.gotoPage(this.pageCount - 1);
        }
    },
/**
    Description TODO
    @function
    */
    gotoNextPage: {
        value: function() {
            this.gotoPage(this.pageIndex + 1);
        }
    },
/**
    Description TODO
    @function
    */
    gotoPreviousPage: {
        value: function() {
            this.gotoPage(this.pageIndex - 1);
        }
    },
/**
    Sets the currentPage so that the desired item is contained in that page.
    @function
    @param {Array} pageIndex The index of the item to be shown.
    */
    gotoPage: {
        value: function(pageIndex) {
            this.pageIndex = pageIndex;
        }
    },
/**
    Sets the currentPage so that the desired item is contained in that page.
    @function
    @param {Math} offset The index of the item to be shown.
    */
    gotoContentIndex: {
        value: function(offset) {
            this.gotoPage(Math.floor(offset / this.pageSize));
        }
    },

 /**
        Description TODO
        @type {Function}
        @default null
    */
    content: {
        get: function() {
            return Object.getPropertyDescriptor(ArrayController, "content").get.call(this);
        },
        set: function(value) {
            if (value !== this.content) {
                Object.getPropertyDescriptor(ArrayController, "content").set.call(this, value);
                this._calculate(this._pageSize, this._pageIndex, this._padding);
            }
        }
    }


});