<?php

class Cacher extends PhpObject
{
	const CACHE_FOLDER = 'cache/';
	const DATA_RETENTION = 60 * 60 * 24 * 90; //3 months
	
	private $sPattern;
	
	//Params
	private $sId;
	private $iX;
	private $iY;
	private $iZ;
	private $sToken;
	private $asDomains;
	
	public function __construct($sPattern, $sId='')
	{
		parent::__construct(__CLASS__, Settings::DEBUG);
		$this->setPattern($sPattern);
		$this->setId($sId);
		$this->iX = 0;
		$this->iY = 0;
		$this->iZ = 0;
		$this->sToken = '';
		$this->asDomains = array();
	}
	
	public function setId($sId) {
		$this->sId = $sId;
	}
	
	public function setPattern($sPattern) {
		$this->sPattern = $sPattern;
	}
	
	public function setToken($sToken) {
		$this->sToken = $sToken;
	}
	
	public function setDomains($asDomains) {
		$this->asDomains = $asDomains;
	}
	
	public function setGeoPos($iX, $iY, $iZ) {
		$this->iX = $iX;
		$this->iY = $iY;
		$this->iZ = $iZ;
	}
	
	public function pushTile($iX, $iY, $iZ) {
		$this->setGeoPos($iX, $iY, $iZ);
		$sTilePath = $this->getFilePath();
		if(!$this->isFileAvailable($sTilePath)) {
			$oCurl = curl_init();
			curl_setopt($oCurl, CURLOPT_URL, $this->getUrl());
			curl_setopt($oCurl, CURLOPT_HEADER, false);
			curl_setopt($oCurl, CURLOPT_RETURNTRANSFER, true);
			curl_setopt($oCurl, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
			curl_setopt($oCurl, CURLOPT_REFERER, 'http://spot.lutran.fr');
			$sContent = curl_exec($oCurl);
			curl_close($oCurl);
			
			file_put_contents($sTilePath, $sContent);
		}
		else $sContent = file_get_contents($sTilePath);
		
		header('Content-type: '.mime_content_type($sTilePath));
		return $sContent;
	}
	
	public function getUrl() {
		$asParams = $this->getUrlParams();
		$sUrl = $this->sPattern;
		foreach($asParams as $sParam=>$sValue) {
			$sUrl = str_replace('{'.$sParam.'}', $sValue, $sUrl);
		}
		return $sUrl;
	}
	
	private function isFileAvailable($sTilePath) {
		if(!file_exists($sTilePath)) return false;
		else return (time() - filemtime($sTilePath) < self::DATA_RETENTION);
	}
	
	private function getFilePath() {
		$asParams = $this->getUrlParams();
		return self::CACHE_FOLDER.'/'.$asParams['id'].'_'.$asParams['x'].'_'.$asParams['y'].'_'.$asParams['z'].'.tile';
	}
	
	private function getUrlParams() {
		return array(
			'id'	=> $this->sId,
			'x'		=> $this->iX,
			'y'		=> $this->iY,
			'z'		=> $this->iZ,
			'token' => $this->sToken,
			's'		=> empty($this->asDomains)?'':$this->asDomains[array_rand($this->asDomains)]
		);
	}
}