<?php

$vcard = $_GET['vcard'];


	function isIphone($user_agent=NULL) {
		if(!isset($user_agent)) {
			$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
		}
		return (strpos($user_agent, 'iPhone') !== FALSE) || (strstr($_SERVER['HTTP_USER_AGENT'],'iPod')!== FALSE) || (strstr($_SERVER['HTTP_USER_AGENT'],'iPad')!== FALSE);
	}

	# Output file contents - simple version
	if(!isIphone()) {
		# Send correct headers      
		header("Content-type: text/x-vcard; charset=utf-8"); 
					// Alternatively: application/octet-stream
					// Depending on the desired browser behaviour
					// Be sure to test thoroughly cross-browser

		header("Content-Disposition: attachment; filename=\"$vcard\";");
		# Output file contents 
		echo file_get_contents($vcard);
		exit();
	}

	function isMobileSafari($user_agent=NULL) {
		if(!isset($user_agent)) {
			$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
		}

        # Please note: Chrome for iPhone reports 'CriOS' instead of 'Version' in it's user agent string and as of Feb 2013 Chrome for iPhone
        # does not support either vCard (.vcf) or vCalendar (.ics) file types - that's even worse than Mobile Safari - shame on you Google!!!
		return (strstr($user_agent, " AppleWebKit/") && strstr($user_agent, " Mobile/") && strstr($user_agent, " Safari/") && strstr($user_agent, " Version/"));
	}
	
	# Output file contents - simple version
	if(!isMobileSafari()) {
		echo file_get_contents("safari.php");
		exit();
	}

	# Send correct headers      
	header("Content-type: text/x-vcalendar; charset=utf-8"); 
					// Alternatively: application/octet-stream
					// Depending on the desired browser behaviour
					// Be sure to test thoroughly cross-browser

	header("Content-Disposition: attachment; filename=\"iphonecontact.ics\";");
	
	# Generate file contents - advanced version
	# BEGIN:VCALENDAR
	# VERSION:2.0
	# BEGIN:VEVENT
	# DTSTART;TZID=Europe/London:20120617T090000
	# DTEND;TZID=Europe/London:20120617T100000
	# SUMMARY:iPhone Contact
	# DTSTAMP:20120617T080516Z
	# ATTACH;VALUE=BINARY;ENCODING=BASE64;FMTTYPE=text/directory;
	#  X-APPLE-FILENAME=iphonecontact.vcf:
	#  QkVHSU46VkNBUkQNClZFUlNJT046My4wDQpOOkNvbnRhY3Q7aVBob25lOzs7DQpGTjppUGhvbm
	#  UgQ29udGFjdA0KRU1BSUw7VFlQRT1JTlRFUk5FVDtUWVBFPVdPUks6aXBob25lQHRoZXNpbGlj
	#  b25nbG9iZS5jb20NClRFTDtUWVBFPUNFTEw7VFlQRT1WT0lDRTtUWVBFPXByZWY6KzQ0MTIzND
	#  U2Nzg5MA0KRU5EOlZDQVJE
	# END:VEVENT
	# END:VCALENDAR

	echo "BEGIN:VCALENDAR\n";
	echo "VERSION:2.0\n";
	echo "BEGIN:VEVENT\n";
	echo "SUMMARY:Bitte klicken Sie auf den Anhang um ihn in Ihren Kontakten zu speichern\n";
	$dtstart = date("Ymd")."T".date("Hi")."00";
	echo "DTSTART;TZID=Europe/London:".$dtstart."\n";
	$dtend = date("Ymd")."T".date("Hi")."01";
	echo "DTEND;TZID=Europe/London:".$dtend."\n";
	echo "DTSTAMP:".$dtstart."Z\n";
	echo "ATTACH;VALUE=BINARY;ENCODING=BASE64;FMTTYPE=text/directory;\n";
	echo " X-APPLE-FILENAME=$vcard:\n";
	$vcard = file_get_contents($vcard);		# read the file into memory
	$b64vcard = base64_encode($vcard);						# base64 encode it so that it can be used as an attachemnt to the "dummy" calendar appointment
	$b64mline = chunk_split($b64vcard,74,"\n");				# chunk the single long line of b64 text in accordance with RFC2045 (and the exact line length determined from the original .ics file exported from Apple calendar
	$b64final = preg_replace('/(.+)/', ' $1', $b64mline);	# need to indent all the lines by 1 space for the iphone (yes really?!!)
	echo $b64final;											# output the correctly formatted encoded text
	echo "END:VEVENT\n";
	echo "END:VCALENDAR\n";