/* @private
 * This is an internal helper class for the calendar views and should not be overridden.
 * It is responsible for the base event rendering logic underlying all views based on a 
 * box-oriented layout that supports day spanning (MonthView, MultiWeekView, DayHeaderView).
 */
Ext.define('Ext.calendar.util.WeekEventRenderer', {

    requires: ['Ext.calendar.util.Date'],
    
    statics: {
        // private
        getEventRow: function(id, week, index) {
            var indexOffset = 1,
                //skip row with date #'s
                evtRow,
                wkRow = Ext.get(id + '-wk-' + week);
            if (wkRow) {
                var table = wkRow.child('.ext-cal-evt-tbl', true);
                evtRow = table.tBodies[0].childNodes[index + indexOffset];
                if (!evtRow) {
                    evtRow = Ext.core.DomHelper.append(table.tBodies[0], '<tr></tr>');
                }
            }
            return Ext.get(evtRow);
        },

        render: function(o) {
            var w = 0,
                grid = o.eventGrid,
                dt = Ext.Date.clone(o.viewStart),
                eventTpl = o.tpl,
                max = o.maxEventsPerDay != undefined ? o.maxEventsPerDay: 999,
                weekCount = o.weekCount < 1 ? 6: o.weekCount,
                dayCount = o.weekCount == 1 ? o.dayCount: 7,
                cellCfg;

            for (; w < weekCount; w++) {
                if (!grid[w] || grid[w].length == 0) {
                    // no events or span cells for the entire week
                    if (weekCount == 1) {
                        row = this.getEventRow(o.id, w, 0);
                        cellCfg = {
                            tag: 'td',
                            cls: 'ext-cal-ev',
                            id: o.id + '-empty-0-day-' + Ext.Date.format(dt, 'Ymd'),
                            html: '&#160;'
                        };
                        if (dayCount > 1) {
                            cellCfg.colspan = dayCount;
                        }
                        Ext.core.DomHelper.append(row, cellCfg);
                    }
                    dt = Ext.calendar.util.Date.add(dt, {days: 7});
                } else {
                    var row,
                        d = 0,
                        wk = grid[w],
                        startOfWeek = Ext.Date.clone(dt),
                        endOfWeek = Ext.calendar.util.Date.add(startOfWeek, {days: dayCount, millis: -1});

                    for (; d < dayCount; d++) {
                        if (wk[d]) {
                            var ev = 0,
                                emptyCells = 0,
                                skipped = 0,
                                day = wk[d],
                                ct = day.length,
                                evt;

                            for (; ev < ct; ev++) {
                                if (!day[ev]) {
                                    emptyCells++;
                                    continue;
                                }
                                if (emptyCells > 0 && ev - emptyCells < max) {
                                    row = this.getEventRow(o.id, w, ev - emptyCells);
                                    cellCfg = {
                                        tag: 'td',
                                        cls: 'ext-cal-ev',
                                        id: o.id + '-empty-' + ct + '-day-' + Ext.Date.format(dt, 'Ymd')
                                    };
                                    if (emptyCells > 1 && max - ev > emptyCells) {
                                        cellCfg.rowspan = Math.min(emptyCells, max - ev);
                                    }
                                    Ext.core.DomHelper.append(row, cellCfg);
                                    emptyCells = 0;
                                }

                                if (ev >= max) {
                                    skipped++;
                                    continue;
                                }
                                evt = day[ev];

                                if (!evt.isSpan || evt.isSpanStart) {
                                    //skip non-starting span cells
                                    var item = evt.data || evt.event.data;
                                    item._weekIndex = w;
                                    item._renderAsAllDay = item[Ext.calendar.data.EventMappings.IsAllDay.name] || evt.isSpanStart;
                                    item.spanLeft = item[Ext.calendar.data.EventMappings.StartDate.name].getTime() < startOfWeek.getTime();
                                    item.spanRight = item[Ext.calendar.data.EventMappings.EndDate.name].getTime() > endOfWeek.getTime();
                                    item.spanCls = (item.spanLeft ? (item.spanRight ? 'ext-cal-ev-spanboth':
                                    'ext-cal-ev-spanleft') : (item.spanRight ? 'ext-cal-ev-spanright': ''));

                                    row = this.getEventRow(o.id, w, ev);
                                    cellCfg = {
                                        tag: 'td',
                                        cls: 'ext-cal-ev',
                                        cn: eventTpl.apply(o.templateDataFn(item))
                                    };
                                    var diff = Ext.calendar.util.Date.diffDays(dt, item[Ext.calendar.data.EventMappings.EndDate.name]) + 1,
                                        cspan = Math.min(diff, dayCount - d);

                                    if (cspan > 1) {
                                        cellCfg.colspan = cspan;
                                    }
                                    Ext.core.DomHelper.append(row, cellCfg);
                                }
                            }
                            if (ev > max) {
                                row = this.getEventRow(o.id, w, max);
                                Ext.core.DomHelper.append(row, {
                                    tag: 'td',
                                    cls: 'ext-cal-ev-more',
                                    id: 'ext-cal-ev-more-' + Ext.Date.format(dt, 'Ymd'),
                                    cn: {
                                        tag: 'a',
                                        html: '+' + skipped + ' more...'
                                    }
                                });
                            }
                            if (ct < o.evtMaxCount[w]) {
                                row = this.getEventRow(o.id, w, ct);
                                if (row) {
                                    cellCfg = {
                                        tag: 'td',
                                        cls: 'ext-cal-ev',
                                        id: o.id + '-empty-' + (ct + 1) + '-day-' + Ext.Date.format(dt, 'Ymd')
                                    };
                                    var rowspan = o.evtMaxCount[w] - ct;
                                    if (rowspan > 1) {
                                        cellCfg.rowspan = rowspan;
                                    }
                                    Ext.core.DomHelper.append(row, cellCfg);
                                }
                            }
                        } else {
                            row = this.getEventRow(o.id, w, 0);
                            if (row) {
                                cellCfg = {
                                    tag: 'td',
                                    cls: 'ext-cal-ev',
                                    id: o.id + '-empty-day-' + Ext.Date.format(dt, 'Ymd')
                                };
                                if (o.evtMaxCount[w] > 1) {
                                    cellCfg.rowSpan = o.evtMaxCount[w];
                                }
                                Ext.core.DomHelper.append(row, cellCfg);
                            }
                        }
                        dt = Ext.calendar.util.Date.add(dt, {days: 1});
                    }
                }
            }
        }
    }
});