<?php

if(class_exists('Widget')) {
	
	/**
	 * Shows a widget with viewing blog entries
	 * by months or years.
	 * 
	 * @package blog
	 */
	class ArchiveWidget extends Widget {
		
		private static $db = array(
			'DisplayMode' => 'Varchar'
		);
		
		private static $defaults = array(
			'DisplayMode' => 'month'
		);
		
		private static $title = 'Browse by Date';
		
		private static $cmsTitle = 'Blog Archive';
		
		private static $description =
			'Show a list of months or years in which there are blog posts, and provide links to them.';
		
		function getCMSFields() {
			$fields = parent::getCMSFields(); 
			
			$fields->merge( 

				new FieldList(
					new OptionsetField(
						'DisplayMode',
						_t('ArchiveWidget.DispBY', 'Display by'),
						array(
							'month' => _t('ArchiveWidget.MONTH', 'month'),
							'year' => _t('ArchiveWidget.YEAR', 'year')
						)
					)
				)	
			);
			
			$this->extend('updateCMSFields', $fields);
			
			return $fields;
		}
		
		function getDates() {
			Requirements::themedCSS('archivewidget');
			
			$results = new ArrayList();
			$container = BlogTree::current();
			$ids = $container->BlogHolderIDs();
			
			$stage = Versioned::current_stage();
			$suffix = (!$stage || $stage == 'Stage') ? "" : "_$stage";

			if(method_exists(DB::getConn(), 'formattedDatetimeClause')) {
				$monthclause = DB::getConn()->formattedDatetimeClause('"Date"', '%m');
				$yearclause  = DB::getConn()->formattedDatetimeClause('"Date"', '%Y');
			} else {
				$monthclause = 'MONTH("Date")';
				$yearclause  = 'YEAR("Date")';
			}
			
			if($this->DisplayMode == 'month') {
				$sqlResults = DB::query("
					SELECT DISTINCT CAST($monthclause AS " . DB::getConn()->dbDataType('unsigned integer') . ")
						AS Month,
						$yearclause AS Year
					FROM SiteTree$suffix INNER JOIN BlogEntry$suffix
						ON SiteTree$suffix.ID = BlogEntry$suffix.ID
					WHERE SiteTree$suffix.ParentID IN (" . implode(', ', $ids) . ")
					ORDER BY Year DESC, Month DESC;"
				);
			} else {
				$sqlResults = DB::query("
					SELECT DISTINCT $yearclause AS Year 
					FROM SiteTree$suffix INNER JOIN BlogEntry$suffix
						ON SiteTree$suffix.ID = BlogEntry$suffix.ID
					WHERE SiteTree$suffix.ParentID IN (" . implode(', ', $ids) . ")
					ORDER BY Year DESC"
				);
			}
			
			if($sqlResults) foreach($sqlResults as $sqlResult) {
				$isMonthDisplay = $this->DisplayMode == 'month';
				
				$monthVal = (isset($sqlResult['Month'])) ? (int) $sqlResult['Month'] : 1;
				$month = ($isMonthDisplay) ? $monthVal : 1;
				$year = ($sqlResult['Year']) ? (int) $sqlResult['Year'] : date('Y');
				
				$date = DBField::create_field('Date', array(
					'Day' => 1,
					'Month' => $month,
					'Year' => $year
				));
				
				if($isMonthDisplay) {
					$link = $container->Link('date') . '/' . $sqlResult['Year'] . '/' . sprintf("%'02d", $monthVal);
				} else {
					$link = $container->Link('date') . '/' . $sqlResult['Year'];
				}
				
				$results->push(new ArrayData(array(
					'Date' => $date,
					'Link' => $link
				)));
			}
			
			return $results;
		}	
	}

}