<?php
class OAIClient {
	public $urlbase = '';
	public $proxy = false;
	public $proxyUser = false;
	public $proxyPass = false;

	function __construct($url, $proxy=false, $proxyUser=false, $proxyPass=false) {
		$this->urlbase = $url;
		if ($proxy !== false) $this->proxy = $proxy;
		if ($proxyUser !== false) $this->proxyUser = $proxy;
		if ($proxyPass !== false) $this->proxyPass = $proxy;
	}

	function post($url, $data) {
		$postSerialised = array();
		foreach($data as $key=>$value) { $postSerialised[] = $key.'='.$value; }
		$postSerialised = implode('&',$postSerialised);

		$ch = curl_init();

		if ($this->proxy !== false)
			curl_setopt($ch, CURLOPT_PROXY, $this->proxy);
		if ($this->proxyUser !== false && $this->ProxyPass !== false)
			curl_setopt($ch, CURLOPT_PROXYUSERPWD, $this->proxyUser . ':' . $this->ProxyPass);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_URL,$url . '?' . $postSerialised);
		//curl_setopt($ch,CURLOPT_POSTFIELDS, $postSerialised);
		//curl_setopt($ch,CURLOPT_POST, 1);
		$response = curl_exec($ch);
		curl_close($ch);
		return $response;
	}

	function listSets() {
		$xml = $this->post($this->urlbase,array('verb'=>'ListSets'));
		$xmlP = simplexml_load_string($xml);
		if (!isset($xmlP->ListSets)) return false;
		$sets = array();
		foreach ($xmlP->ListSets->children() as $set) {
			$sets[$set->setSpec->__toString()] = array('Name'=>$set->setName->__toString(),'Description'=>$set->setDescription->__toString());
		}
		return $sets;
	}

	function listMetadataPrefixes() {
		$xml = $this->post($this->urlbase,array('verb'=>'ListMetadataFormats'));
		$xmlP = simplexml_load_string($xml);
		$metadataPrefixes = array();
		foreach ($xmlP->ListMetadataFormats->children() as $metadataFormat) {
			$metadataPrefixes[] = $metadataFormat->metadataPrefix->__toString();
		}
		return $metadataPrefixes;
	}

	function ListRecords($set, $metadataPrefix, $fromDate=false, $toDate=false, $resumptionToken=false) {
		$returnData = array();
		$data = array();
		$data['verb'] = 'ListRecords';
		if ($resumptionToken !== false) $data['resumptionToken'] = $resumptionToken;
		else {
			$data['set'] = $set;
			$data['metadataPrefix'] = $metadataPrefix;
			if ($fromDate !== false) $data['from'] = $fromDate;
			if ($fromDate !== false) $data['to'] = $toDate;
		}
		$dom = new DOMDocument();
		$dom->loadXml($this->post($this->urlbase, $data));
		//echo $this->post($this->urlbase, $data);
		//die;
		foreach ($dom->getElementsByTagName('record') as $node) {
			$id = $node->getElementsByTagName('header')[0]->getElementsByTagName('identifier')[0]->nodeValue;
			$returnData[$id] = array();
			foreach ($node->getElementsByTagName('metadata')[0]->getElementsByTagName('dc')[0]->childNodes as $data) {
				if (substr($data->nodeName,0,3) != 'dc:') continue;
				if (!empty($data->nodeValue)) $returnData[$id][$data->nodeName][] = $data->nodeValue;
			}
		}
		if (isset($dom->getElementsByTagName('resumptionToken')[0])) {
			$returnData = array_merge($returnData, $this->ListRecords($set, $metadataPrefix, $fromDate, $toDate,$dom->getElementsByTagName('resumptionToken')[0]->nodeValue));
		}
		return $returnData;
	}
}