Viên ngọc phương Đông

ruạṛ

<?php
/**
 * Product object
 */
class product {
	/**
	 * define variables matched to to database fields
	 * may not have identical names, see $this->load_from_data for conversions
	 */
	var $prod_id
		, $cat_id
		, $name
		, $code
		, $path
		, $description
		, $short
		, $price
		, $sale_price
		, $on_sale
		, $wholesale
		, $active
		, $stock
		, $filename
		, $featured
		, $sidebar
		, $position
		, $associated_ids
		, $visited
		, $added
		, $prodAttr = array()
		;
	
	/** 
	 * @var int $quantity used to track number in cart, potentially @todo number in stock
	 * @var int $discount_amount customer discount
	 */
	var $quantity, $discount_amount;
	
	/**
	 * @var object product_data_fields (option_list)
	 * @var object product_option_fields (option_list)
	 */
	var $product_data_fields, $product_option_fields;
	
	/**
	 * @var array $images contains images (mysql_fetch_array() form plus calculated extras)
	 * @var array $selected contains saved options when in cart or wishlist
	 * @var array $options contains product options fields
	 * @var array $data contains product data fields
	 * @var array $categories contains list of categories containing this product
	 */
	 var $images = array(), $options = array(), $selected = array(), $data = array(), $categories = array();
	 
	/**
	 * object construction function
	 * @param int $id unique database record id
	 */
	function __construct($id=0)
	{
		/*
		 * set miminum visibility
		 */
		$this->prod_id = 0;
		$this->active = 0;
		$this->product_data_fields = new options_list(PRODUCT_DATA_LIST);
		$this->product_data_fields->load_options(false);
		$this->product_options_fields = new options_list(PRODUCT_OPTIONS_LIST);
		$this->product_options_fields->load_options(false);
		
		/**
		 * if no id supplied simply prepare product to be populated from dataset eg in category object
		 */
		if(!$id)
		{
			return;
		}
		
		/**
		 * else get product data 
		 * assumes database connection already established at global level
		 * @var resource $product mysql dataset
		 */
		$record = mysql_query("select * 
							from products 
							where prod_id = '$id'
							");
		
		if($record && mysql_num_rows($record)==1)
		{
			$this->load_from_data(mysql_fetch_assoc($record));
			mysql_free_result($record); // clean up
		}
		
		return;
	}
	
	/**
	 * populate object - can be done on init or manually
	 * @param array $d data;
	 */
	function load_from_data($d=array())
	{
		if(!empty($d))
		{
			$this->prod_id = $d['prod_id'];
			$this->cat_id = $d['category_id'];
			$this->name = $d['product_name'];
			$this->code = $d['product_code'];
			$this->path = $d['product_path'];
			$this->description = $d['product_description'];
			$this->short = $d['short_description'];
			$this->price = $d['price'];
			$this->sale_price = $d['sale_price'];
			$this->on_sale = $d['on_sale'];
			//$this->wholesale = $d['wholesale_price'];
			//$this->filename = $d['filename'];
			$this->active = $d['active'];
			$this->stock = $d['number_in_stock'];
			$this->featured = $d['featured'];
			$this->sidebar = $d['sidebar'];
			$this->position = $d['position'];
			$this->associated_ids = json_decode($d['associated_products'],true); //true: make sure data is interpreted as an array not an object
			$this->visited = $d['visited'];	
			$this->added = $d['date_added'];	
			
		}
		
		$this->load_fields('data');
		$this->load_fields('options');
		
		$categories = mysql_query("select x.*, c.cat_name, c.cat_path, x.product_path from
									product_category_xref as x 
										left join categories as c on c.cat_id = x.category_id
									where x.product_id = '$this->prod_id'
									order by c.cat_name");
		
		$this->categories = array(); //empty		
		if($categories && mysql_num_rows($categories)>0)
		{
			while($c = mysql_fetch_assoc($categories))
			{
				//@todo just put category objects in here
				$this->categories["{$c['category_id']}"] = array('name'=>$c['cat_name'], 'path'=>$c['cat_path'], 'product_path'=>$c['product_path'], 'position'=>$c['position']); 
			}
		}
		
		$this->images = array(); //empty
		$images = mysql_query("select * from image_data where image_type = 'product-gallery' and container_id='".$this->prod_id ."' order by image_position");
		if($images && mysql_num_rows($images)>0){
			while ($i = mysql_fetch_assoc($images))
			{
				$i['image'] = $i['image_path'].$i['image_filename'];
				$i['thumbnail'] = $i['image_path'].THUMBNAIL_PREFIX.$i['image_filename']; 
				$this->images[] = $i;
			}
		}
		
		return;
	}
	
	/**
	 * create product options
	 * @param object $l options_list reference
	 */
	function create_fields($l = '')
	{
		$f = 'product_'.$l.'_fields';
		$list = $this->$f;
		/*
		 * san check
		 */
		if(!is_object($list) || !$list->count_options())
		{
			return false; 
		}
		//else
		
		$query = "insert into product_$l (product_id, option_id) values ";
		foreach($list->options as $o)
		{
			$query .= "('$this->prod_id', '$o->option_id'),";
		}
		
		$query = rtrim($query,',');
		
		mysql_query($query) or die(mysql_error());
		
		return true;
	}
	
	/**
	 * save product options
	 * @param object $l options_list reference
	 */
	function save_fields($l = '')
	{
		$f = 'product_'.$l.'_fields';
		$list = $this->$f;
		/*
		 * san check
		 */
		if(!is_a($list,'options_list'))
		{
			return false; 
		}
		//else
		/*
		 * check that option records exist (in case option was created after product
		 *	- actually this only seems to matter if -no- options have been created before the product
		 */
		/*if(!select_one('product_'.$l,'option_id','product_id', $this->prod_id))
		{
			$this->create_fields($l);
		}*/
		//else
		
		$values = array();
		foreach($list->options as $o)
		{
			$v = clean_plain_data($_POST[$l.'_'.$o->option_id]);
			//mysql_query("update product_$l set option_value = '$v' where product_id = '$this->prod_id' and option_id = '$o->option_id'") or die(mysql_error());
			
			$query = "REPLACE INTO product_" . $l . "(product_id, option_id, option_value) "
				 . "VALUES('" . $this->prod_id . "', '" . $o->option_id . "', '" . $v . "')";
				 
			mysql_query($query) or die(mysql_error());
			
			$values[$o->option_id] = $v;
		}
		
		$this->$l = $values;
		
		return true;
	}
	
	/**
	 * load (all) product options; which ones to display are handled at output
	 * @param object $l options_list reference
	 */
	function load_fields($l = '')
	{
		$f = 'product_'.$l.'_fields';
		$list = $this->$f;
		/*
		 * san check
		 */
		if(!is_object($list))
		{
			return false; 
		}
		//else
		
		//empty
		$this->$l = array();
		
		$data = mysql_query("select * from product_$l where product_id = '$this->prod_id'");
		if(!$data)
		{
			// echo mysql_error();
			return false;
		}
		// else
		
		$values = array();
		while($o = mysql_fetch_assoc($data))
		{
			$values[$o['option_id']] = $o['option_value'];
		}
		
		$this->$l = $values;
		return true;
	}
	
	/**
	 * delete options
	 * @param object $l options_list reference
	 */
	function delete_fields($l = '')
	{
		mysql_query("delete from product_$l where product_id = '$this->prod_id'");		
		return true;
	}
	
	/**
	 * load categories
	 */
	function load_categories()
	{
		/*
		$categories = mysql_query("select x.*, c.cat_name, c.cat_path, x.product_path from
									product_category_xref as x 
										left join categories as c on c.cat_id = x.category_id
									where x.product_id = '$this->prod_id'
									order by c.cat_name");
		
		$this->categories = array(); //empty		
		if($categories && mysql_num_rows($categories)>0)
		{
			while($c = mysql_fetch_assoc($categories))
			{
				//@todo just put category objects in here
				$this->categories["{$c['category_id']}"] = array('name'=>$c['cat_name'], 'path'=>$c['cat_path'], 'product_path'=>$c['product_path'], 'position'=>$c['position']); 
			}
		}
		*/
		return;
	}
	
	/**
	 * change active category
	 * @param int $cat_id
	 * @param bool $past if this is historical (eg from an order) in which case if not a current category assign old category anyway
	 */
	function set_category($cat_id,$path='',$past=false)
	{
		$cat_id = is_numeric_id($cat_id,0);
		$current = false;
		if(isset($this->categories["$cat_id"]))
		{
			$this->cat_id = $cat_id;
			$this->path = $this->categories["$cat_id"]['product_path'];
			$this->position = $this->categories["$cat_id"]['position'];
			$current = true;
		}
		elseif($cat_id && $past)
		{
			$this->cat_id = $cat_id;
		}
		
		if($path != '')
		{
			$this->path = $path;
		}

return;
	}
		
	/**
	 * return category name
	 * @return string
	 */
	function category_name()
	{
		$cat_id = $this->cat_id;
		return $this->categories["$cat_id"]['name'];
	}
	
	/**
	 * get price
	 */
	function price()
	{
		/**
		 * @var float $price
		 */
		$price = ($this->on_sale) ? $this->sale_price : $this->price;

foreach($this->options as $o)
		{
			$marker = strrpos($o->text,'$');
			if($marker!==false)
			{
				$price += (float) substr($o,$marker+1);
			}
		}
		
		return $price;
	}
	
	/**
	 * calculate discount based on supplied %
	 * @param string $discount_type (ie '%', '$')
	 * @param float $discount (% or $ eg 12.5, 15, 25.50)
	 * @return float
	 */
	function set_discount($discount_type='%',$discount=0)
	{
		if($this->on_sale)
		{
			return 0;
		}
		//else
		switch($discount_type) //whitelist
		{
			case '$':
				$this->discount_amount = min($discount,$this->price); //don't allow -ve values
				break;
			case '%':
				$this->discount_amount = round(($this->price/100)*$discount,2); //($this->price/100)*$percent == $this->price*($percent/100) but reduces the chance of floating point and rounding error
				break;
			default: //invalid value
				$this->discount_amount = 0;
		}
		return $this->discount_amount;
	}
	
	/**
	 * get links for the previous and next products
	 * @param bool $active include all products inthe category or just displayed products
	 * @return array
	 */
	function adjacent_product_paths($active=false)
	{
		/**
		 * @var array $paths intialise with empty paths 
		 * @var string $query assemble query
		 * @var resource $all all matching products form the database
		 * @var boot $stop flag to indicate this product has been reached
		 */
		$paths = array('previous'=>'','next'=>'');
		
		$query = "select x.product_path 
					from category_product_xref as x 
						left join products as p on p.prod_id = x.prod_id 
					where x.category_id = '$this->cat_id' and x.position > '$this->position' ";
		$query .= $active ? "and p.active = '1' " : '';
		$query .= 'order by x.position limit 1';
		
		$result = mysql_query($query);
		if($result && mysql_num_rows($result)>0)
		{
			$r = mysql_fetch_assoc($result);
			$paths['next'] = $r['product_path'];
		}
		
		$query = "select x.product_path 
					from category_product_xref as x 
						left join products as p on p.prod_id = x.prod_id 
					where x.category_id = '$this->cat_id' and x.position < '$this->position' ";
		$query .= $active ? "and p.active = '1' " : '';
		$query .= 'order by x.position desc limit 1';
		
		$result = mysql_query($query);
		if($result && mysql_num_rows($result)>0)
		{
			$r = mysql_fetch_assoc($result);
			$paths['prev'] = $r['product_path'];
		}
		
		mysql_free_result($result);
		
		return $paths;
	}
	
	/**
	 * load related products
	 * @param int $limit number to load
	 * @param bool $all limit to active products
	 */
	function load_associated($limit=0,$all=true)
	{
		$ids = $this->associated_ids;
		$this->associated = array(); //empty
		//die(print_r($ids,true));
		if(!empty($ids) && is_array($ids))
		{
			$ids = implode("','",$ids);
			
			$query = "select * from products where prod_id in ('$ids') ";
			$query .= ($all) ? '' : "and active = '1' ";
			$query .= ($limit) ? " order by rand() limit $limit" : "order by product_name";
			//die($query); //debugging
			$products = mysql_query($query) or die($query.mysql_error());
			if($products && mysql_num_rows($products)>0)
			{
				while($row = mysql_fetch_assoc($products))
				{	
					$p = new product();
					$p->load_from_data($row);
					array_push($this->associated,$p);
				}
			}			
		}
		
		return;
	}
	
	/**
	 * add record to the database
	 * page file creation, product_category_xref and so on is still in process-product-new.php
	 * @return bool
	 */
	function create()
	{
		global $message;
		
		/**
		 * get from POST
		 */
		$this->cat_id = $cat_id = clean_plain_data($_POST['category']);
		$this->name = $name = clean_plain_data($_POST['product_name']);
		$this->code = $code = clean_plain_data($_POST['product_code']);
		$this->short = $short = clean_plain_data($_POST['description']);
		$this->description = $description = clean_html_data($_POST['content']);

/*
		foreach($this->prodAttr as $a)
		{
			$this->$a = $$a = clean_plain_data($_POST[$a]);
		}
		*/
		
		$this->featured = $featured = ($_POST['featured']) ? 1 : 0;
		$this->sidebar = $sidebar = ($_POST['sidebar']) ? 1 : 0;
		$this->on_sale = $on_sale = ($_POST['on_sale']) ? 1 : 0;
		
		$this->price = $price= clean_plain_data($_POST['price']);
		$this->sale_price = $sale_price= clean_plain_data($_POST['sale_price']);
		
		$this->stock = $stock = clean_plain_data($_POST['stock']);
		
		/**
		 * validate required fields
		 */
		$m = '';
		if(!$cat_id || (!is_numeric_id($cat_id, false) || !select_one('categories', 'cat_id', 'cat_id', $cat_id) ) )
		{
			$m .= 'Invalid category id ';
		}
		
		if($name==''){
			$m .= 'Please enter a product name ';
		}
		
		/* @todo validate price */
		
		if($m != '')
		{
			$message .= $m;
			return false;
		}
		
		/**
		 * add to database
		 * category infomation is added later by $this->add_to_category()
		 * @var int $date_added
		 * @var string $fields
		 * @var string $values
		 */
		$date_added = time();
		
		$fields = 'product_name
					,product_code
					, product_description
					, short_description
					, price
					, sale_price
					, on_sale
					, number_in_stock
					, featured
					, sidebar	
					, date_added
					';

$values = "'$name'
					, '$code'
					, '$description'
					, '$short'
					, '$price'
					, '$sale_price'
					, '$on_sale'
					, '$stock'
					, '$featured'
					, '$sidebar'
					, '$date_added'
					";
		
		/*		
		foreach($this->prodAttr as $a)
		{
			$fields .= ' ,'.$a;
			$values .= ", '".$$a."'";
		}
		*/
		
		$query = "insert into products (
						$fields
					) values (
						$values
					)";
		
		if(!mysql_query($query))
		{
			$message .= mysql_error();
			return false;
		}
		
		$message .= 'Product record created ';
		$this->prod_id = mysql_insert_id();	
		
		$this->create_fields('data');
		$this->save_fields('data');
		$this->create_fields('options');
		$this->save_fields('options');
		
		/**
		 * add to category/ies
		 */
		if(!$this->add_to_category($cat_id,true))
		{
			$this->remove_from_database();
			clean_dir(DOC_ROOT.$this->path, true);
			return false;
		}

/**
		 * initial image
		 */
		//$this->add_image('new_image');
		
		return true;
		
	}
	
	/**
	 * update record in the database
	 * update image positions
	 * add new image
	 * @return bool 
	 */
	function update()
	{
		global $message;
		
		/**
		 * san check
		 */
		if(!$this->prod_id)
		{
			$message .= 'Invalid product ';
			return false;
		}
		
		/**
		 * get from POST
		 */
		$this->cat_id = $cat_id = clean_plain_data($_POST['category']);
		$this->name = $name = clean_plain_data($_POST['product_name']);
		$this->code = $code = clean_plain_data($_POST['product_code']);
		$this->short = $short = clean_plain_data($_POST['description']);
		$this->description = $description = clean_html_data($_POST['content']); 
		//$message .= '!'.$description;
		/*
		foreach($this->prodAttr as $a)
		{
			$this->$a = $$a = clean_plain_data($_POST[$a]);
		}
		*/
		$this->featured = $featured = ($_POST['featured']) ? 1 : 0;
		$this->sidebar = $sidebar = ($_POST['sidebar']) ? 1 : 0;
		$this->on_sale = $on_sale = ($_POST['on_sale']) ? 1 : 0;
		
		$this->price = $price= clean_plain_data($_POST['price']);
		$this->sale_price = $sale_price= clean_plain_data($_POST['sale_price']);
		
		$this->stock = $stock = clean_plain_data($_POST['stock']);

/**
		 * validate required fields
		 */
		$m = '';
		
		if($name==''){
			$m .= 'Please enter a product name ';
		}
		
		/* @todo validate price */
		
		if($m != '')
		{
			$message .= $m;
			return false;
		}
		
		/**
		 * @var string $query update query
		 */
		$query = "update products set 
				product_name = '$name'
				, product_code = '$code'
				, product_description = '$description'
				, short_description = '$short'
				, price = '$price'
				, sale_price = '$sale_price'
				, on_sale = '$on_sale'
				, featured = '$featured'
				, sidebar = '$sidebar'
				, number_in_stock = '$stock'
				";
		
		/*		
		foreach($this->prodAttr as $a)
		{
			$query .= ", $a = '".$$a."' 
					";
		}
		*/
		
		$query .= "where prod_id = '$this->prod_id'
					";
					
		$update = mysql_query($query);			
		if(!$update)
		{
			$message .= mysql_error();
			return false;
		}
		
		/*
		 * if site uses a single featured product and this is set as a featured product unset any other featured product
		 */
		/*
		if([global flag here] && $featured)
		{
			mysql_query("update products set featured='0' where featured='1' and prod_id!='$this->prod_id'"); 
		}
		*/
		
		$message .= 'Product record updated ';
		
		$this->save_fields('data');
		$this->save_fields('options');
		
		return true;				
	}
	
	/**
	 * remove records from database
	 * @return bool
	 */
	function remove_from_database()
	{
		global $message;
		
		/**
		 * san check
		 */
		if(!is_numeric_id($this->prod_id,0))
		{
			$message .= 'Unable to remove product from database: invalid id ';
			return false;
		}
		
		/*
		 * delete auxilary data
		 */
		$this->delete_fields('data');
		$this->delete_fields('options');
		
		/**
		 * delete product record
		 * @var string $query delete query
		 */
		$query = "delete from products where prod_id = '$this->prod_id'";
		$result = mysql_query($query);
		if(!$result || mysql_affected_rows() != 1)
		{
			$message .= 'There was an error '.mysql_error().' Affected rows: '.mysql_affected_rows();
			return false;
		}
		//
		$message .= $this->name.' record deleted ';
		return true;
	}
	
	/**
	 * add to category and any parent categories
	 * @param int $cat_id
	 * @param bool $default make this the default category
	 * @return bool
	 */
	function add_to_category($cat_id,$default = false )
	{
		global $message;
		/**
		 * @var int $page_id
		 * @var int $prod_id
		 * @var string $dir_name
		 */
		$page_id = select_one('page_data','page_id','page_type','products');
		$prod_id = $this->prod_id;
		$dir_name = dir_name($this->name);
		
		/**
		 * san check
		 */
		if(!is_numeric_id($cat_id,0) || !is_numeric_id($prod_id,0) || !$page_id || $dir_name == '' )
		{
			$message .= "Unable to create category: one of the following is invalid page id $page_id, category id $cat_id, product id $prod_id, product name $dir_name ";
			return false;
		}
		
		/**
		 * if we're not explicitly setting this as the default check if the current default category is also in the xref table
		 * if not then replace it with the this one
		 * although those fields are really redundant now
		 * we need to get the default from the database because $this->cat_id may have been changed (see $this->set_category())
		 */
		if(!$default)
		{
			$default_id = select_one('products','category_id','prod_id',$this->prod_id);
			if(!select_one('category_product_xref','product_path',"concat_ws(':',category_id,product_id)","$default_id:$prod_id"))
			{
				$default = true;
			}
		}
		
		/**
		 * add to category and parents
		 * @var array $categories
		 * @var int $child category to get parent for
		 * @var int $parent id of parent
		 */ 
		$categories = array($cat_id);
		
		/**
		 * get parents
		 * @var int $child (id)
		 */
		$child = $cat_id;
		do{
			$parent = select_one('categories', 'parent_id', 'cat_id', $child);
			if($parent != 0 && !in_array($parent,$categories))
			{
				$categories[] = $parent;
			}
			$child = $parent;
		}
		while($parent !=0);
		
		asort($categories); //make sure parents will always be added before children, not strictly necessary but tidy

/**
		 * add to categories
		 * @var string $path
		 * @todo put a counter in here and report?
		 */
		$path = '';
		foreach($categories as $id)
		{
			if(select_one('product_category_xref', 'category_id', "concat_ws(':',category_id,product_id)", $id.':'.$prod_id))
			{	
				//already present
				continue;
			}
			//else
			$path = select_one('categories','cat_path','cat_id',$id).$dir_name;
			$contents = array(
					'page_id' => $page_id
					, 'cat_id' => $id
					, 'prod_id' => $prod_id
			);
			
			if(create_stub_file($path, $contents))
			{
				// mysql_query("insert into product_category_xref (product_id, category_id, product_path) values('$prod_id', '$id', '$path/')");
				//$position = ($this->position) ? $this->position : select_one('product_category_xref','max(position)','category_id',$cat_id)+10;
				$position = select_one('product_category_xref','max(position)','category_id',$cat_id)+10;
				mysql_query("insert into product_category_xref (product_id, category_id, product_path, position) values('$prod_id', '$id', '$path/', '$position')");
				mysql_query("update categories set num_products=num_products+1 where cat_id = '$id'");
				
				if($id == $cat_id && $default)
				{
					mysql_query("update products set category_id = '$cat_id', product_path = '$path' where prod_id = '$prod_id'"); 
					$this->set_category($cat_id,$path);
				}
				$message .= $this->name.' added to '.select_one('categories','cat_name','cat_id',$id).' ';
			}
		}
		
		/**
		 * finally check to make sure the product is actually in at least one category
		 * this is particularly important when adding products
		 */
		if(!select_one('product_category_xref', 'category_id', 'product_id',$prod_id))
		{
			return false;
		}
		//else
		
		return true;
	}
		
	/**
	 * remove from category and children
	 * @param int $cat_id
	 * @return bool
	 */
	function remove_from_category($cat_id=NULL)
	{
		global $message;
		/**
		 * san check
		 */
		if(!is_numeric_id($cat_id,0) || !is_numeric_id($this->prod_id,0))
		{
			$message .= 'Unable to remove product from categories: invalid id ';
			return false;
		}
		
		/**
		 * @var string $path (or false)
		 */
		if(!$path = select_one('product_category_xref','product_path',"concat_ws(':',category_id,product_id)","$cat_id:$this->prod_id"))
		{
			//$message .= "Path not found in database for category $cat_id product $this->prod_id "; //debugging
			return true; //it's not there so report a success, but don't add anything to the message chain
		}
		
		/**
		 * get children and recursively delete
		 * by doing children before this category we make sure that deletion will process fromthe lowest branch of the tree ie no orphans if there is a fail
		 * @var int $parent (id)
		 */
		$children = mysql_query("select cat_id from categories where parent_id = '$cat_id'");
		if($children) //note we don't check count - it's perfectly acceptable to run the while on an empty result set
		{
			while($c = mysql_fetch_assoc($children))
			{
				if(!$this->remove_from_category($c['cat_id']))
				{
					return false; //abort on any error
				}
			}
		}
		else
		{
			$message .= "Database error selecting children for $cat_id ".mysql_error().'';
			return false;
		}
		
		/**
		 * remove product from category
		 * $path found in san check
		 * @var bool $query
		 */
		if(!clean_dir(DOC_ROOT.$path, true))
		{
			$message .= "Warning: Unable to remove product subdirectory $path ";
		} 
		
		$query = mysql_query("delete from product_category_xref where product_id = '$this->prod_id' and category_id = $cat_id"); 
		if(!$query || mysql_affected_rows()!=1)
		{
			$message .= "SQL error deleting product $this->prod_id from category $cat_id ".mysql_error().' '.mysql_affected_rows().' ';
			return false;
		}
		//else
		mysql_query("update categories set num_products = num_products-1 where cat_id = '$cat_id'");
		clean_dir(DOC_ROOT.$path,true);
		
		unset($this->categories["$cat_id"]);
		$message .= 'Product removed from '.select_one('categories','cat_name','cat_id',$cat_id).' ';
		
		/**
		 * see if this is the default category
		 * if so replace it with another, assuming there is one
		 * otherwise leave this one in the products table as a default
		 * although those fields are really redundant now
		 * we need to get the default from the database because $this->cat_id may have been changed (see $this->set_category())
		 */
		if(select_one('products','category_id','prod_id',$this->prod_id) == $cat_id )
		{
			if($new_cat_id = select_one('product_category_xref','category_id','product_id',$this->prod_id))
			{
				mysql_query("update products set category_id = '$new_cat_id', product_path = '"
				. select_one('product_category_xref','product_path',"concat_ws(':',category_id,product_id)","$new_cat_id:$this->prod_id")
				. "' where prod_id = '$this->prod_id'");
			}
		}
		
		return true;
	}
	
	/**
	 * remove from all categories
	 * more efficient than repeatedly calling remove_from_category
	 * @return bool
	 */
	function remove_from_categories()
	{
		global $message;
		
		/**
		 * san check
		 */
		if(!is_numeric_id($this->prod_id,0))
		{
			$message .= 'Unable to remove product from categories: invalid id ';
			return false;
		}
		
		/**
		 * remove product from all categories
		 * @var string $query
		 * @var string $path directory we will be deleting
		 */
		$query = "select * from product_category_xref where product_id = '$this->prod_id'";
		//$query .= ($cat_id) ? " and category_id = '$cat_id'" : '';
		$paths = mysql_query($query);
		while($p = mysql_fetch_assoc($paths))
		{
			clean_dir(DOC_ROOT.$p['product_path'],true);
			mysql_query("update categories set num_products = num_products-1 where cat_id = '".$p['category_id']."'");
		}
				
		$query = "delete from product_category_xref where product_id = '$this->prod_id'";
		//$query .= ($cat_id) ? " and category_id = '$cat_id'" : '';
		mysql_query($query);
		$message .= (mysql_num_rows($paths) > 0) ? $this->name.' removed from '.mysql_num_rows($paths).' categories ' : ''	;
		
		$this->categories = array();
		return true;
	}
	
	/**
	 * add an image
	 * @var string $upload form field
	 * @return bool
	 * @todo we probably need to tidy up all the image functions into one or two - move databasing into upload_image() function
	 */
	function add_image($upload)
	{
		global $message;
		/**
		 * san check
		 */
		if(!$upload || !is_numeric_id($this->prod_id))
		{
			return false;
		}
		
		/**
		 * make sure we have a product image directory
		 */
		$path = '/resources/images/product/'.$this->prod_id;
		$dir = DOC_ROOT.$path; 
		if(!is_dir($dir))
		{
			mkdir($dir,0755,true);
			chmod($dir, DIR_PERMS);
		}
		
		$dir .= '/';
		/**
		 * auxilary data
		 * @var string $link
		 * @var string $caption
		 * @var string $position
		 */
		$link = clean_plain_data($_POST[$upload.'_link']);
		$caption = clean_plain_data($_POST[$upload.'_caption']);
		$position = is_numeric_id($_POST[$upload.'_position'],false);
		if($position===false)
		{
			$position = select_one('image_data','max(image_position)',"concat_ws(':',image_type,container_id)",'product-gallery:'.$this->prod_id)+10;
		}
		
		/**
		 * @var array $dim config for image function
		 * @var int $img_id
		 */
		$dim = array('w'=>PRODUCT_IMAGE_WIDTH,'h'=>PRODUCT_IMAGE_HEIGHT, 'tw'=>PRODUCT_THUMBNAIL_WIDTH, 'th'=>PRODUCT_THUMBNAIL_HEIGHT, 'orient'=>'');
		$img_id = 0; //valid img_id which will match no records for position update
		
		if($_FILES[$upload]['name'])
		{
			if(!$insert = mysql_query("insert into image_data (image_type, container_id, image_path, title, link, active, image_position) values ('product-gallery', '$this->prod_id', '$path/', '$caption', '$link', '1', '$position')"))
			{
				$message .= 'Image upload database error. '.mysql_error().' ';
				return false;
			}
			//else
			
			$img_id = mysql_insert_id();
			
			/**
			 * @var string $suff
			 * @var string $filename
			 */
			$suff = image_suffix($_FILES[$upload]['tmp_name']);
			$filename = 'image'.$img_id.$suff;
			
			$message .= upload_image($upload,$dim,$dir,$filename,true); //upload and generate thumbnail
			if(!file_exists($dir.$filename))
			{
				// appropriate message should have been generated by upload_image()
				mysql_query("delete from image_data where image_id = '$img_id'");
				return false;
			}
			else
			{
				list($w, $h) = @getimagesize($dir.$filename);
				if(!$update = mysql_query("update image_data set image_filename = '$filename', width = '$w', height = '$h' where image_id = '$img_id'"))
				{
					$message .= 'There was a problem recording the image. Please try again.'.mysql_error().' ';
					unlink(($dir.$filename));
					mysql_query("delete from image_data where image_id = '$img_id'");
					return false;
				}
			}
			
			$message .= ucfirst(str_replace('_', ' ', $upload)).' uploaded ';
			return true;
		}
		//else
		return false;				 
	}
	
	/**
	 * check for a new image, update existing images
	 */
	function update_images()
	{
		/**
		 * new image?
		 */
		$this->add_image('new_image');
		
		/**
		 * update images
		 * global function
		 * @var string $path
		 * @var array $dim config for image function
		 */
		$dim = array('w'=>PRODUCT_IMAGE_WIDTH,'h'=>PRODUCT_IMAGE_HEIGHT, 'tw'=>PRODUCT_THUMBNAIL_WIDTH, 'th'=>PRODUCT_THUMBNAIL_HEIGHT, 'orient'=>'');
		update_images($dim); //global function
		
		return true;
	}
	
	/**
	 * remove all images
	 * @param bool $rmDir remove image directory as well
	 * @return bool
	 */
	function remove_images($rm_dir = false)
	{
		global $message;
		/**
		 * san check
		 */
		if(!is_numeric_id($this->prod_id,0))
		{
			$message .= 'Unable to remove product images: invalid id ';
			return false;
		}
		
		/*
		 * images
		 */
		// files
		$path = DOC_ROOT.'/resources/images/product/'.$this->prod_id;
		if(file_exists($path) && !clean_dir($path, $rm_dir))
		{
			$message .= 'Unable to remove '.$this->name.' images: dir failed ';
			return false;
		}

//delete image records
		mysql_query("delete from image_data where image_type like 'product%' and container_id = '$this->prod_id'");
		$message .= $this->name.' images deleted ';
		
		return true;
	}

/**
	 * remove everything
	 * @return bool
	 */
	function delete()
	{
		global $message;
		
		if($this->remove_from_categories() && $this->remove_images(true) && $this->remove_from_database())
		{
			$message .= $this->name.' successfully deleted ';
			return true;	
		}
		
		//else
		//$message .= 'Something failed ';
		return false;	
	}
}
?>