<?php
/****************************************************************************************************************************************************
 *
 *
 *	PHP ENTREZ TOOLS
 *	~~~~~~~~~~~~~~~~~~
 *	- v0.1 - last changed 2008-10-26 by joe@cotch.net
 *	- eFetch: http://www.ncbi.nlm.nih.gov/entrez/query/static/efetch_help.html
 *
 *	License
 *	~~~~~~~
 *   		This file is part of PHP Entrez Tools (PET)
 *
 *    		PET is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by
 *    		the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
 *
 *    		PET is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 *
 *    		You should have received a copy of the GNU General Public License along with PET.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 ***************************************************************************************************************************************************/

require_once("Variables.php"); 
require_once("HttpRequest.php");

class eFetch
{
	var $DB;
	var $QueryKey;
	var $WebEnv;
	var $Translation;
	var $RetStart;
	var $RetMax;
	var $IdList;
	var $RetType;
	
	var $CacheName;	
	var $QueryData;
	var $Xml;
	var $Array;
	
	function eFetch( $DB = 'pubmed', $QueryKey = null, $WebEnv = null, $Translation = null, $RetStart = 0, $RetMax = 20, $RetType = 'abstract' )
	{
		$this->DB 	   = $DB;
		if (isset($QueryKey)) $this->QueryKey = $QueryKey;
		if (isset($WebEnv))   $this->WebEnv   = $WebEnv;
		$this->Translation = md5($Translation);
		if (isset($RetStart)) $this->RetStart = $RetStart;
		if (isset($RetMax))   $this->RetMax   = $RetMax;
		if (isset($RetType))  $this->RetType  = $RetType;
	}

	function Run($Level = 0)
	{
		$this->MakeCacheName();
		$this->MakeQueryData();
		$this->GetXmlFile();
		if ($Level == 1) $this->MakeArray();
	}
	
	function MakeCacheName()
	{
		Global $ncbi_CachePath;
		
		$this->CacheName = $ncbi_CachePath . $this->DB;
		if (!file_exists($this->CacheName)) mkdir($this->CacheName);
		$this->CacheName .= "/eFetch/";
		if (!file_exists($this->CacheName)) mkdir($this->CacheName);
		if (isset($this->Translation)) {
			$this->CacheName .= substr($this->Translation, 0, 1) . "/";
			if (!file_exists($this->CacheName)) mkdir($this->CacheName);
			$this->CacheName .= $this->Translation . "," . (isset($this->RetStart) ? $this->RetStart : '') . "," . (isset($this->RetMax) ? $this->RetMax : '') . "," . (isset($this->RetType) ? $this->RetType : '') . ".xml";			
		}
		elseif (isset($this->IdList)) {
			$this->CacheName .= "byid/";
			if (!file_exists($this->CacheName)) mkdir($this->CacheName);
			$this->CacheName .= implode(",", $this->IdList) . "," . (isset($this->RetStart) ? $this->RetStart : '') . "," . (isset($this->RetMax) ? $this->RetMax : '') . "," . (isset($this->RetType) ? $this->RetType : '') . ".xml";			
		}
		else throw new Exception( "No WebEnv or IdList specified." );
	}
	
	function MakeQueryData()
	{
		$this->QueryData = array(
			"db"		=> $this->DB,
			"rettype"	=> $this->RetType,
		);
    		if (!empty($this->QueryKey)) $this->QueryData['query_key'] = $this->QueryKey;
    		if (!empty($this->WebEnv))   $this->QueryData['WebEnv']    = $this->WebEnv;
    		if (!empty($this->IdList))   $this->QueryData['id']	   = implode(",", $this->IdList);
    		if (!empty($this->RetStart)) $this->QueryData['retstart']  = $this->RetStart;
    		if (!empty($this->RetMax))   $this->QueryData['retmax']    = $this->RetMax;
	}

	function GetXmlFile()
	{
		try { $Request = new EntrezRequest( "eFetch", $this->CacheName, $this->QueryData ); }
		catch (Exception $e) { throw new Exception($e->getMessage()); }					// Pass on any errors
		if (!empty($Request->Html)) $this->Html .= $Request->Html;					// Pass on any HTML messages
		if (empty($Request->Xml)) { throw new Exception( "Empty XML file." ); }
		$this->Xml = $Request->Xml;
		unset($Request);
	}
	

	function MakeArray()
	{
		if (empty($this->Xml)) return false;
		require_once("XmlArray.php");
		try {
			$Arr = new XmlArray($this->Xml, true);
			$this->Array = $Arr->Array;
			unset($Arr);
		}
		catch (Exception $e) {
			$this->DeleteCache();				// The failure of XmlArray may be because PubMed's servers broke -- delete the cache and we could try it again
			return false;					// If using Run(), this will now cause an exception to be thrown.  Applications should catch this and either try Run() again, reload, or give up
		}
		return $this->Array;
	}


	function DeleteCache()
	{
		if (empty($this->CacheName)) $this->MakeCacheName();
		if (file_exists($this->CacheName)) unlink($this->CacheName);
		return true;
	}
}

?>