/**
 * This layout allows you to easily render content into an HTML table. The total number of columns can be specified, and
 * rowspan and colspan can be used to create complex layouts within the table. This class is intended to be extended or
 * created via the `layout: {type: 'table'}` {@link Ext.container.Container#layout} config, and should generally not
 * need to be created directly via the new keyword.
 *
 * Note that when creating a layout via config, the layout-specific config properties must be passed in via the {@link
 * Ext.container.Container#layout} object which will then be applied internally to the layout. In the case of
 * TableLayout, the only valid layout config properties are {@link #columns} and {@link #tableAttrs}. However, the items
 * added to a TableLayout can supply the following table-specific config properties:
 *
 *   - **rowspan** Applied to the table cell containing the item.
 *   - **colspan** Applied to the table cell containing the item.
 *   - **cellId** An id applied to the table cell containing the item.
 *   - **cellCls** A CSS class name added to the table cell containing the item.
 *
 * The basic concept of building up a TableLayout is conceptually very similar to building up a standard HTML table. You
 * simply add each panel (or "cell") that you want to include along with any span attributes specified as the special
 * config properties of rowspan and colspan which work exactly like their HTML counterparts. Rather than explicitly
 * creating and nesting rows and columns as you would in HTML, you simply specify the total column count in the
 * layoutConfig and start adding panels in their natural order from left to right, top to bottom. The layout will
 * automatically figure out, based on the column count, rowspans and colspans, how to position each panel within the
 * table. Just like with HTML tables, your rowspans and colspans must add up correctly in your overall layout or you'll
 * end up with missing and/or extra cells! Example usage:
 *
 *     @example
 *     Ext.create('Ext.panel.Panel', {
 *         title: 'Table Layout',
 *         width: 300,
 *         height: 150,
 *         layout: {
 *             type: 'table',
 *             // The total column count must be specified here
 *             columns: 3
 *         },
 *         defaults: {
 *             // applied to each contained panel
 *             bodyStyle: 'padding:20px'
 *         },
 *         items: [{
 *             html: 'Cell A content',
 *             rowspan: 2
 *         },{
 *             html: 'Cell B content',
 *             colspan: 2
 *         },{
 *             html: 'Cell C content',
 *             cellCls: 'highlight'
 *         },{
 *             html: 'Cell D content'
 *         }],
 *         renderTo: Ext.getBody()
 *     });
 */
Ext.define('Ext.layout.container.Table', {

    /* Begin Definitions */

    alias: ['layout.table'],
    extend: 'Ext.layout.container.Auto',
    alternateClassName: 'Ext.layout.TableLayout',

    /* End Definitions */

    /**
     * @cfg {Number} columns
     * The total number of columns to create in the table for this layout. If not specified, all Components added to
     * this layout will be rendered into a single row using one column per Component.
     */

    // private
    monitorResize:false,

    type: 'table',

    // Table layout is a self-sizing layout. When an item of for example, a dock layout, the Panel must expand to accommodate
    // a table layout. See in particular AbstractDock::onLayout for use of this flag.
    autoSize: true,

    clearEl: true, // Base class will not create it if already truthy. Not needed in tables.

    targetCls: Ext.baseCSSPrefix + 'table-layout-ct',
    tableCls: Ext.baseCSSPrefix + 'table-layout',
    cellCls: Ext.baseCSSPrefix + 'table-layout-cell',

    /**
     * @cfg {Object} tableAttrs
     * An object containing properties which are added to the {@link Ext.DomHelper DomHelper} specification used to
     * create the layout's `<table>` element. Example:
     *
     *     {
     *         xtype: 'panel',
     *         layout: {
     *             type: 'table',
     *             columns: 3,
     *             tableAttrs: {
     *                 style: {
     *                     width: '100%'
     *                 }
     *             }
     *         }
     *     }
     */
    tableAttrs:null,

    /**
     * @cfg {Object} trAttrs
     * An object containing properties which are added to the {@link Ext.DomHelper DomHelper} specification used to
     * create the layout's <tr> elements.
     */

    /**
     * @cfg {Object} tdAttrs
     * An object containing properties which are added to the {@link Ext.DomHelper DomHelper} specification used to
     * create the layout's <td> elements.
     */

    /**
     * @private
     * Iterates over all passed items, ensuring they are rendered in a cell in the proper
     * location in the table structure.
     */
    renderItems: function(items) {
        var tbody = this.getTable().tBodies[0],
            rows = tbody.rows,
            i = 0,
            len = items.length,
            cells, curCell, rowIdx, cellIdx, item, trEl, tdEl, itemCt;

        // Calculate the correct cell structure for the current items
        cells = this.calculateCells(items);

        // Loop over each cell and compare to the current cells in the table, inserting/
        // removing/moving cells as needed, and making sure each item is rendered into
        // the correct cell.
        for (; i < len; i++) {
            curCell = cells[i];
            rowIdx = curCell.rowIdx;
            cellIdx = curCell.cellIdx;
            item = items[i];

            // If no row present, create and insert one
            trEl = rows[rowIdx];
            if (!trEl) {
                trEl = tbody.insertRow(rowIdx);
                if (this.trAttrs) {
                    trEl.set(this.trAttrs);
                }
            }

            // If no cell present, create and insert one
            itemCt = tdEl = Ext.get(trEl.cells[cellIdx] || trEl.insertCell(cellIdx));
            if (this.needsDivWrap()) { //create wrapper div if needed - see docs below
                itemCt = tdEl.first() || tdEl.createChild({tag: 'div'});
                itemCt.setWidth(null);
            }

            // Render or move the component into the cell
            if (!item.rendered) {
                this.renderItem(item, itemCt, 0);
            }
            else if (!this.isValidParent(item, itemCt, 0)) {
                this.moveItem(item, itemCt, 0);
            }

            // Set the cell properties
            if (this.tdAttrs) {
                tdEl.set(this.tdAttrs);
            }
            tdEl.set({
                colSpan: item.colspan || 1,
                rowSpan: item.rowspan || 1,
                id: item.cellId || '',
                cls: this.cellCls + ' ' + (item.cellCls || '')
            });

            // If at the end of a row, remove any extra cells
            if (!cells[i + 1] || cells[i + 1].rowIdx !== rowIdx) {
                cellIdx++;
                while (trEl.cells[cellIdx]) {
                    trEl.deleteCell(cellIdx);
                }
            }
        }

        // Delete any extra rows
        rowIdx++;
        while (tbody.rows[rowIdx]) {
            tbody.deleteRow(rowIdx);
        }
    },

    afterLayout: function() {
        this.callParent();

        if (this.needsDivWrap()) {
            // set wrapper div width to match layed out item - see docs below
            Ext.Array.forEach(this.getLayoutItems(), function(item) {
                Ext.fly(item.el.dom.parentNode).setWidth(item.getWidth());
            });
        }
    },

    /**
     * @private
     * Determine the row and cell indexes for each component, taking into consideration
     * the number of columns and each item's configured colspan/rowspan values.
     * @param {Array} items The layout components
     * @return {Object[]} List of row and cell indexes for each of the components
     */
    calculateCells: function(items) {
        var cells = [],
            rowIdx = 0,
            colIdx = 0,
            cellIdx = 0,
            totalCols = this.columns || Infinity,
            rowspans = [], //rolling list of active rowspans for each column
            i = 0, j,
            len = items.length,
            item;

        for (; i < len; i++) {
            item = items[i];

            // Find the first available row/col slot not taken up by a spanning cell
            while (colIdx >= totalCols || rowspans[colIdx] > 0) {
                if (colIdx >= totalCols) {
                    // move down to next row
                    colIdx = 0;
                    cellIdx = 0;
                    rowIdx++;

                    // decrement all rowspans
                    for (j = 0; j < totalCols; j++) {
                        if (rowspans[j] > 0) {
                            rowspans[j]--;
                        }
                    }
                } else {
                    colIdx++;
                }
            }

            // Add the cell info to the list
            cells.push({
                rowIdx: rowIdx,
                cellIdx: cellIdx
            });

            // Increment
            for (j = item.colspan || 1; j; --j) {
                rowspans[colIdx] = item.rowspan || 1;
                ++colIdx;
            }
            ++cellIdx;
        }

        return cells;
    },

    /**
     * @private
     * Return the layout's table element, creating it if necessary.
     */
    getTable: function() {
        var table = this.table;
        if (!table) {
            table = this.table = this.getTarget().createChild(
                Ext.apply({
                    tag: 'table',
                    role: 'presentation',
                    cls: this.tableCls,
                    cellspacing: 0, //TODO should this be specified or should CSS handle it?
                    cn: {tag: 'tbody'}
                }, this.tableAttrs),
                null, true
            );
        }
        return table;
    },

    /**
     * @private
     * Opera 10.5 has a bug where if a table cell's child has box-sizing:border-box and padding, it
     * will include that padding in the size of the cell, making it always larger than the
     * shrink-wrapped size of its contents. To get around this we have to wrap the contents in a div
     * and then set that div's width to match the item rendered within it afterLayout. This method
     * determines whether we need the wrapper div; it currently does a straight UA sniff as this bug
     * seems isolated to just Opera 10.5, but feature detection could be added here if needed.
     */
    needsDivWrap: function() {
        return Ext.isOpera10_5;
    }
});