<?php
/*
* 2007-2014 PrestaShop
*
* NOTICE OF LICENSE
*
* This source file is subject to the Open Software License (OSL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/osl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2014 PrestaShop SA
*  @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*/

/**
 * Create a collection of ObjectModel objects
 *
 * @since 1.5.0
 */
class PrestaShopCollectionCore implements Iterator, ArrayAccess, Countable
{
	const LEFT_JOIN = 1;
	const INNER_JOIN = 2;
	const LEFT_OUTER_JOIN = 3;

	/**
	 * @var string Object class name
	 */
	protected $classname;

	/**
	 * @var int
	 */
	protected $id_lang;

	/**
	 * @var array Object definition
	 */
	protected $definition = array();

	/**
	 * @var DbQuery
	 */
	protected $query;

	/**
	 * @var array Collection of objects in an array
	 */
	protected $results = array();

	/**
	 * @var bool Is current collection already hydrated
	 */
	protected $is_hydrated = false;

	/**
	 * @var int Collection iterator
	 */
	protected $iterator = 0;

	/**
	 * @var int Total of elements for iteration
	 */
	protected $total;
	
	/**
	 * @var int Page number
	 */
	protected $page_number = 0;
	
	/**
	 * @var int Size of a page
	 */
	protected $page_size = 0;

	protected $fields = array();
	protected $alias = array();
	protected $alias_iterator = 0;
	protected $join_list = array();
	protected $association_definition = array();

	const LANG_ALIAS = 'l';

	/**
	 * @param string $classname
	 * @param int $id_lang
	 */
	public function __construct($classname, $id_lang = null)
	{
		$this->classname = $classname;
		$this->id_lang = $id_lang;

		$this->definition = ObjectModel::getDefinition($this->classname);
		if (!isset($this->definition['table']))
			throw new PrestaShopException('Miss table in definition for class '.$this->classname);
		else if (!isset($this->definition['primary']))
			throw new PrestaShopException('Miss primary in definition for class '.$this->classname);

		$this->query = new DbQuery();
	}

	/**
	 * Join current entity to an associated entity
	 *
	 * @param string $association Association name
	 * @param string $on
	 * @param int $type
	 * @return PrestaShopCollection
	 */
	public function join($association, $on = '', $type = null)
	{
		if (!$association)
			return;

		if (!isset($this->join_list[$association]))
		{
			$definition = $this->getDefinition($association);
			$on = '{'.$definition['asso']['complete_field'].'} = {'.$definition['asso']['complete_foreign_field'].'}';
			$type = self::LEFT_JOIN;
			$this->join_list[$association] = array(
				'table' =>	($definition['is_lang']) ? $definition['table'].'_lang' : $definition['table'],
				'alias' => $this->generateAlias($association),
				'on' => array(),
			);
		}

		if ($on)
			$this->join_list[$association]['on'][] = $this->parseFields($on);

		if ($type)
			$this->join_list[$association]['type'] = $type;

		return $this;
	}

	/**
	 * Add WHERE restriction on query
	 *
	 * @param string $field Field name
	 * @param string $operator List of operators : =, !=, <>, <, <=, >, >=, like, notlike, regexp, notregexp
	 * @param mixed $value
	 * @param string $type where|having
	 * @return PrestaShopCollection
	 */
	public function where($field, $operator, $value, $method = 'where')
	{
		if ($method != 'where' && $method != 'having')
			throw new PrestaShopException('Bad method argument for where() method (should be "where" or "having")');

		// Create WHERE clause with an array value (IN, NOT IN)
		if (is_array($value))
		{
			switch (strtolower($operator))
			{
				case '=' :
				case 'in' :
					$this->query->$method($this->parseField($field).' IN('.implode(', ', $this->formatValue($value, $field)).')');
				break;

				case '!=' :
				case '<>' :
				case 'notin' :
					$this->query->$method($this->parseField($field).' NOT IN('.implode(', ', $this->formatValue($value, $field)).')');
				break;

				default :
					throw new PrestaShopException('Operator not supported for array value');
			}
		}
		// Create WHERE clause
		else
		{
			switch (strtolower($operator))
			{
				case '=' :
				case '!=' :
				case '<>' :
				case '>' :
				case '>=' :
				case '<' :
				case '<=' :
				case 'like' :
				case 'regexp' :
					$this->query->$method($this->parseField($field).' '.$operator.' '.$this->formatValue($value, $field));
				break;

				case 'notlike' :
					$this->query->$method($this->parseField($field).' NOT LIKE '.$this->formatValue($value, $field));
				break;

				case 'notregexp' :
					$this->query->$method($this->parseField($field).' NOT REGEXP '.$this->formatValue($value, $field));
				break;

				default :
					throw new PrestaShopException('Operator not supported');
			}
		}

		return $this;
	}

	/**
	 * Add WHERE restriction on query using real SQL syntax
	 *
	 * @param string $sql
	 * @return PrestaShopCollection
	 */
	public function sqlWhere($sql)
	{
		$this->query->where($this->parseFields($sql));
		return $this;
	}

	/**
	 * Add HAVING restriction on query
	 *
	 * @param string $field Field name
	 * @param string $operator List of operators : =, !=, <>, <, <=, >, >=, like, notlike, regexp, notregexp
	 * @param mixed $value
	 * @return PrestaShopCollection
	 */
	public function having($field, $operator, $value)
	{
		return $this->where($field, $operator, $value, 'having');
	}

	/**
	 * Add HAVING restriction on query using real SQL syntax
	 *
	 * @param string $sql
	 * @return PrestaShopCollection
	 */
	public function sqlHaving($sql)
	{
		$this->query->having($this->parseFields($sql));
		return $this;
	}

	/**
	 * Add ORDER BY restriction on query
	 *
	 * @param string $field Field name
	 * @param string $order asc|desc
	 * @return PrestaShopCollection
	 */
	public function orderBy($field, $order = 'asc')
	{
		$order = strtolower($order);
		if ($order != 'asc' && $order != 'desc')
			throw new PrestaShopException('Order must be asc or desc');
		$this->query->orderBy($this->parseField($field).' '.$order);
		return $this;
	}

	/**
	 * Add ORDER BY restriction on query using real SQL syntax
	 *
	 * @param string $sql
	 * @return PrestaShopCollection
	 */
	public function sqlOrderBy($sql)
	{
		$this->query->orderBy($this->parseFields($sql));
		return $this;
	}

	/**
	 * Add GROUP BY restriction on query
	 *
	 * @param string $field Field name
	 * @return PrestaShopCollection
	 */
	public function groupBy($field)
	{
		$this->query->groupBy($this->parseField($field));
		return $this;
	}

	/**
	 * Add GROUP BY restriction on query using real SQL syntax
	 *
	 * @param string $sql
	 * @return PrestaShopCollection
	 */
	public function sqlGroupBy($sql)
	{
		$this->query->groupBy($this->parseFields($sql));
		return $this;
	}

	/**
	 * Launch sql query to create collection of objects
	 *
	 * @param bool $display_query If true, query will be displayed (for debug purpose)
	 * @return PrestaShopCollection
	 */
	public function getAll($display_query = false)
	{
		if ($this->is_hydrated)
			return $this;
		$this->is_hydrated = true;

		$alias = $this->generateAlias();
		//$this->query->select($alias.'.*');
		$this->query->from($this->definition['table'], $alias);

		// If multilang, create association to lang table
		if (!empty($this->definition['multilang']))
		{
			$this->join(self::LANG_ALIAS);
			if ($this->id_lang)
				$this->where(self::LANG_ALIAS.'.id_lang', '=', $this->id_lang);
		}

		// Add join clause
		foreach ($this->join_list as $data)
		{
			$on = '('.implode(') AND (', $data['on']).')';
			switch ($data['type'])
			{
				case self::LEFT_JOIN :
					$this->query->leftJoin($data['table'], $data['alias'], $on);
				break;

				case self::INNER_JOIN :
					$this->query->innerJoin($data['table'], $data['alias'], $on);
				break;

				case self::LEFT_OUTER_JOIN :
					$this->query->leftOuterJoin($data['table'], $data['alias'], $on);
				break;
			}
		}
		
		// All limit clause
		if ($this->page_size)
			$this->query->limit($this->page_size, $this->page_number * $this->page_size);
		

		// Shall we display query for debug ?
		if ($display_query)
			echo $this->query.'<br />';

		$this->results = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($this->query);
		$this->results = ObjectModel::hydrateCollection($this->classname, $this->results, $this->id_lang);

		return $this;
	}

	/**
	 * Retrieve the first result
	 *
	 * @return ObjectModel
	 */
	public function getFirst()
	{
		$this->getAll();
		if (!count($this))
			return false;
		return $this[0];
	}

	/**
	 * Get results array
	 *
	 * @return array
	 */
	public function getResults()
	{
		$this->getAll();
		return $this->results;
	}

	/**
	 * This method is called when a foreach begin
	 *
	 * @see Iterator::rewind()
	 */
	public function rewind()
	{
		$this->getAll();
		$this->results = array_merge($this->results);
		$this->iterator = 0;
		$this->total = count($this->results);
	}

	/**
	 * Get current result
	 *
	 * @see Iterator::current()
	 * @return ObjectModel
	 */
	public function current()
	{
		return isset($this->results[$this->iterator]) ? $this->results[$this->iterator] : null;
	}

	/**
	 * Check if there is a current result
	 *
	 * @see Iterator::valid()
	 * @return bool
	 */
	public function valid()
	{
		return $this->iterator < $this->total;
	}

	/**
	 * Get current result index
	 *
	 * @see Iterator::key()
	 * @return int
	 */
	public function key()
	{
		return $this->iterator;
	}

	/**
	 * Go to next result
	 *
	 * @see Iterator::next()
	 */
	public function next()
	{
		$this->iterator++;
	}

	/**
	 * Get total of results
	 *
	 * @see Countable::count()
	 * @return int
	 */
	public function count()
	{
		$this->getAll();
		return count($this->results);
	}

	/**
	 * Check if a result exist
	 *
	 * @see ArrayAccess::offsetExists()
	 * @param $offset
	 * @return bool
	 */
	public function offsetExists($offset)
	{
		$this->getAll();
		return isset($this->results[$offset]);
	}

	/**
	 * Get a result by offset
	 *
	 * @see ArrayAccess::offsetGet()
	 * @param $offset
	 * @return ObjectModel
	 */
	public function offsetGet($offset)
	{
		$this->getAll();
		if (!isset($this->results[$offset]))
			throw new PrestaShopException('Unknown offset '.$offset.' for collection '.$this->classname);
		return $this->results[$offset];
	}

	/**
	 * Add an element in the collection
	 *
	 * @see ArrayAccess::offsetSet()
	 * @param $offset
	 * @param $value
	 */
	public function offsetSet($offset, $value)
	{
		if (!$value instanceof $this->classname)
			throw new PrestaShopException('You cannot add an element which is not an instance of '.$this->classname);

		$this->getAll();
		if (is_null($offset))
			$this->results[] = $value;
		else
			$this->results[$offset] = $value;
	}

	/**
	 * Delete an element from the collection
	 *
	 * @see ArrayAccess::offsetUnset()
	 * @param $offset
	 */
	public function offsetUnset($offset)
	{
		$this->getAll();
		unset($this->results[$offset]);
	}

	/**
	 * Get definition of an association
	 *
	 * @param string $association
	 * @return array
	 */
	protected function getDefinition($association)
	{
		if (!$association)
			return $this->definition;

		if (!isset($this->association_definition[$association]))
		{
			$definition = $this->definition;
			$split = explode('.', $association);
			$is_lang = false;
			for ($i = 0, $total_association = count($split); $i < $total_association; $i++)
			{
				$asso = $split[$i];

				// Check is current association exists in current definition
				if (!isset($definition['associations'][$asso]))
					throw new PrestaShopException('Association '.$asso.' not found for class '.$this->definition['classname']);
				$current_def = $definition['associations'][$asso];

				// Special case for lang alias
				if ($asso == self::LANG_ALIAS)
				{
					$is_lang = true;
					break;
				}

				$classname = (isset($current_def['object'])) ? $current_def['object'] : Tools::toCamelCase($asso, true);
				$definition = ObjectModel::getDefinition($classname);
			}

			// Get definition of associated entity and add information on current association
			$current_def['name'] = $asso;
			if (!isset($current_def['object']))
				$current_def['object'] = Tools::toCamelCase($asso, true);
			if (!isset($current_def['field']))
				$current_def['field'] = 'id_'.$asso;
			if (!isset($current_def['foreign_field']))
				$current_def['foreign_field'] = 'id_'.$asso;
			if ($total_association > 1)
			{
				unset($split[$total_association - 1]);
				$current_def['complete_field'] = implode('.', $split).'.'.$current_def['field'];
			}
			else
				$current_def['complete_field'] = $current_def['field'];
			$current_def['complete_foreign_field'] = $association.'.'.$current_def['field'];

			$definition['is_lang'] = $is_lang;
			$definition['asso'] = $current_def;
			$this->association_definition[$association] = $definition;
		}
		else
			$definition = $this->association_definition[$association];

		return $definition;
	}

	/**
	 * Parse all fields with {field} syntax in a string
	 *
	 * @param string $str
	 * @return string
	 */
	protected function parseFields($str)
	{
		preg_match_all('#\{(([a-z0-9_]+\.)*[a-z0-9_]+)\}#i', $str, $m);
		for ($i = 0, $total = count($m[0]); $i < $total; $i++)
			$str = str_replace($m[0][$i], $this->parseField($m[1][$i]), $str);
		return $str;
	}

	/**
	 * Replace a field with its SQL version (E.g. manufacturer.name with a2.name)
	 *
	 * @param string $field Field name
	 * @return string
	 */
	protected function parseField($field)
	{
		$info = $this->getFieldInfo($field);
		return $info['alias'].'.`'.$info['name'].'`';
	}

	/**
	 * Format a value with the type of the given field
	 *
	 * @param mixed $value
	 * @param string $field Field name
	 * @return mixed
	 */
	protected function formatValue($value, $field)
	{
		$info = $this->getFieldInfo($field);
		if (is_array($value))
		{
			$results = array();
			foreach ($value as $item)
				$results[] = ObjectModel::formatValue($item, $info['type'], true);
			return $results;
		}
		return ObjectModel::formatValue($value, $info['type'], true);
	}

	/**
	 * Obtain some information on a field (alias, name, type, etc.)
	 *
	 * @param string $field Field name
	 * @return array
	 */
	protected function getFieldInfo($field)
	{
		if (!isset($this->fields[$field]))
		{
			$split = explode('.', $field);
			$total = count($split);
			if ($total > 1)
			{
				$fieldname = $split[$total - 1];
				unset($split[$total - 1]);
				$association = implode('.', $split);
			}
			else
			{
				$fieldname = $field;
				$association = '';
			}

			$definition = $this->getDefinition($association);
			if ($association && !isset($this->join_list[$association]))
				$this->join($association);

			if ($fieldname == $definition['primary'] || (!empty($definition['is_lang']) && $fieldname == 'id_lang'))
				$type = ObjectModel::TYPE_INT;
			else
			{
				// Test if field exists
				if (!isset($definition['fields'][$fieldname]))
					throw new PrestaShopException('Field '.$fieldname.' not found in class '.$definition['classname']);

				// Test field validity for language fields
				if (empty($definition['is_lang']) && !empty($definition['fields'][$fieldname]['lang']))
					throw new PrestaShopException('Field '.$fieldname.' is declared as lang field but is used in non multilang context');
				else if (!empty($definition['is_lang']) && empty($definition['fields'][$fieldname]['lang']))
					throw new PrestaShopException('Field '.$fieldname.' is not declared as lang field but is used in multilang context');

				$type = $definition['fields'][$fieldname]['type'];
			}

			$this->fields[$field] = array(
				'name' => 			$fieldname,
				'association' =>	$association,
				'alias' =>			$this->generateAlias($association),
				'type' =>			$type,
			);
		}
		return $this->fields[$field];
	}
	
	/**
	 * Set the page number
	 *
	 * @param int $page_number
	 * @return PrestaShopCollection
	 */
	public function setPageNumber($page_number)
	{
		$page_number = (int)$page_number;
		if ($page_number > 0)
			$page_number--;
		
		$this->page_number = $page_number;
		return $this;
	}
	
	/**
	 * Set the nuber of item per page
	 *
	 * @param int $page_size
	 * @return PrestaShopCollection
	 */
	public function setPageSize($page_size)
	{
		$this->page_size = (int)$page_size;
		return $this;
	}

	/**
	 * Generate uniq alias from association name
	 *
	 * @param string $association Use empty association for alias on current table
	 * @return string
	 */
	protected function generateAlias($association = '')
	{
		if (!isset($this->alias[$association]))
			$this->alias[$association] = 'a'.$this->alias_iterator++;
		return $this->alias[$association];
	}
}
