<?php

class kColumnPickerHelper extends kHelper {
	var $PickerData;
	var $GridName;

	function LoadColumns($prefix)
	{
		$view_name = $this->Application->RecallVar($prefix.'_current_view');
		$val = $this->Application->RecallPersistentVar($prefix.'_columns_.'.$view_name);

		if (!$val) {
			$cols = $this->RebuildColumns($prefix);
		}
		else {
			$cols = unserialize($val);
			$current_cols = $this->GetColumns($prefix);

			if ($cols === false || $cols['crc'] != $current_cols['crc'])
			{
				$cols = $this->RebuildColumns($prefix, $cols);
			}
		}
		return $cols;
	}

	function ApplyPicker($prefix, &$fields, $grid_name)
	{
		$this->SetGridName($grid_name);
		$this->PickerData = $this->LoadColumns($prefix);

		uksort($fields, array($this, 'CmpElems'));
		$this->RemoveHiddenColumns($fields);
	}

	function SetGridName($grid_name)
	{
		$this->GridName = $grid_name;
	}

	function CmpElems($a, $b)
	{
		$a_index = array_search($a, $this->PickerData['order']);
		$b_index = array_search($b, $this->PickerData['order']);

		if ($a_index == $b_index) {
        return 0;
    }
    return ($a_index < $b_index) ? -1 : 1;
	}

	function RebuildColumns($prefix, $current=null)
	{
		$cols = $this->GetColumns($prefix);

		if (is_array($current)) {
			//get common fields both in db and xml
			$common = array_intersect($current['order'], $cols['order']);

			//get added columns - present in xml, but not in db
			$added = array_diff($cols['order'], $current['order']);

			$cols['order'] = array_merge($common, $added);
			$cols['hidden_fields'] = array_intersect($current['order'], $current['hidden_fields']);
			$this->SetCRC($cols);
		}
		$this->StoreCols($prefix, $cols);

		return $cols;
	}

	function StoreCols($prefix, $cols)
	{
		$view_name = $this->Application->RecallVar($prefix.'_current_view');
		$this->Application->StorePersistentVar($prefix.'_columns_.'.$view_name, serialize($cols));
	}

	function GetColumns($prefix)
	{
		$splited = $this->Application->processPrefix($prefix);
		$grids = $this->Application->getUnitOption($splited['prefix'], 'Grids');
		$conf_fields = $grids[$this->GridName]['Fields'];

		// we NEED to recall dummy here to apply fields changes imposed by formatters,
		// such as replacing multilingual field titles etc.
		$dummy =& $this->Application->recallObject($prefix, null, array('skip_autoload'=>1));

		$counter = 0;
		$hidden = array();
		$fields = array();
		$titles = array();
		foreach ($conf_fields as $name => $options) {
			$fields[$counter] = $name;
			$titles[$name] = $options['title'];
			if (isset($options['hidden']) && $options['hidden'])
			{
				$hidden[$counter] = $name;
			}
			$counter++;
		}
		$sorted_fields = $fields;
		sort($sorted_fields);
		$cols = array(
			'order' => $fields,
			'titles' => $titles,
			'hidden_fields' => $hidden
		);
		$this->SetCRC($cols);
		return $cols;
	}

	function SetCRC(&$cols)
	{
		$sorted_fields = $cols['order'];
		$sorted_titles = $cols['titles'];
		asort($sorted_fields);
		asort($sorted_titles);
		$cols['crc'] = crc32(implode(',', $sorted_fields).implode(',', $sorted_titles));
	}

	function RemoveHiddenColumns(&$fields)
	{
		$to_remove = array();
		foreach ($fields as $name => $options) {
			if (array_search($name, $this->PickerData['hidden_fields']) !== false) {
				$to_remove[] = $name;
			}
		}
		foreach ($to_remove as $name) {
			unset($fields[$name]);
		}
	}

	function SaveColumns($prefix, $picked, $hidden)
	{
		$order = $picked ? explode('|', $picked) : array();
		$hidden = $hidden ? explode('|', $hidden) : array();
		$order = array_merge($order, $hidden);

		$cols = array();
		$cols['order'] = $order;
		$cols['hidden_fields'] = $hidden;

		$this->SetCRC($cols);
		$this->StoreCols($prefix, $cols);
	}
}