<?php

/**
 * Class to select, sort and transform object data into array data,
 * used for the teacher's flat view
 * @author Bert Steppé
 */
class FlatViewDataGenerator
{

	// Sorting types constants
	const FVDG_SORT_LASTNAME = 1;
	const FVDG_SORT_FIRSTNAME = 2;
	const FVDG_SORT_ASC = 4;
	const FVDG_SORT_DESC = 8;

	private $users;
	private $evals;
	private $links;
	private $evals_links;

	/**
	 * Constructor
	 */
    public function FlatViewDataGenerator ($users= array (), $evals= array (), $links= array ())
    {
		$this->users = (isset($users) ? $users : array());
		$this->evals = (isset($evals) ? $evals : array());
		$this->links = (isset($links) ? $links : array());
		$this->evals_links = array_merge($this->evals, $this->links);
    }


	/**
	 * Get total number of users (rows)
	 */
	public function get_total_users_count()
	{
		return count($this->users);
	}
	
	/**
	 * Get total number of evaluations/links (columns) (the 2 users columns not included)
	 */
	public function get_total_items_count()
	{
		return count($this->evals_links);
	}
	

	/**
	 * Get array containing column header names (incl user columns)
	 */
	public function get_header_names ($items_start = 0, $items_count = null)
	{
		$headers = array();
		$headers[] = get_lang('LastName');
		$headers[] = get_lang('FirstName');

		if (!isset($items_count))
			$items_count = count($this->evals_links) - $items_start;

		for ($count=0;
			 ($count < $items_count ) && ($items_start + $count < count($this->evals_links));
			 $count++)
		{
			$item = $this->evals_links [$count + $items_start];
			$headers[] = $item->get_name();
		}
		
		return $headers;
	}


	/**
	 * Get actual array data
	 * @return array 2-dimensional array - each array contains the elements:
	 * 0: user id
	 * 1: user lastname
	 * 2: user firstname
	 * 3+: evaluation/link scores
	 */
	public function get_data ($users_sorting = 0,
							  $users_start = 0, $users_count = null, 
							  $items_start = 0, $items_count = null,
							  $ignore_score_color = false)
	{

		// do some checks on users/items counts, redefine if invalid values
		if (!isset($users_count))
			$users_count = count ($this->users) - $users_start;
		if ($users_count < 0)
			$users_count = 0;
		if (!isset($items_count))
			$items_count = count ($this->evals) + count ($this->links) - $items_start;
		if ($items_count < 0)
			$items_count = 0;

		// copy users to a new array that we will sort
		// TODO - needed ?
		$usertable = array ();
		foreach ($this->users as $user)
			$usertable[] = $user;

		// sort users array
		if ($users_sorting & self :: FVDG_SORT_LASTNAME)
			usort($usertable, array ('FlatViewDataGenerator','sort_by_last_name'));
		elseif ($users_sorting & self :: FVDG_SORT_FIRSTNAME)
			usort($usertable, array ('FlatViewDataGenerator','sort_by_first_name'));
		if ($users_sorting & self :: FVDG_SORT_DESC)
			$usertable = array_reverse($usertable);

		// select the requested users
		$selected_users = array_slice($usertable, $users_start, $users_count);
		

		// generate actual data array

		$scoredisplay = ScoreDisplay :: instance();
		
		$data= array ();
		$displaytype = SCORE_DIV;
		if ($ignore_score_color)
			$displaytype |= SCORE_IGNORE_SPLIT;

		foreach ($selected_users as $user)
		{
			$row = array ();
			$row[] = $user[0];	// user id
			$row[] = $user[1];	// last name
			$row[] = $user[2];	// first name

			for ($count=0;
				 ($count < $items_count ) && ($items_start + $count < count($this->evals_links));
				 $count++)
			{
				$item = $this->evals_links [$count + $items_start];
				$score = $item->calc_score($user[0]);
				$row[] = $scoredisplay->display_score($score,$displaytype);
			}
			unset($score);
			$data[] = $row;
		}

		return $data;

	}




	// Sort functions - used internally

	function sort_by_last_name($item1, $item2)
	{
		if (strtolower($item1[1]) == strtolower($item2[1]))
			return 0;
		else
			return (strtolower($item1[1]) < strtolower($item2[1]) ? -1 : 1);
	}

	function sort_by_first_name($item1, $item2)
	{
		if (strtolower($item1[2]) == strtolower($item2[2]))
			return $this->sort_by_last_name($item1, $item2);
		else
			return (strtolower($item1[2]) < strtolower($item2[2]) ? -1 : 1);
	}

}
?>