<?php

// Warning: postlength function requires $retlds global variable to be defined,
// it has to be a reverse ordered list of "|" separated valid tlds, you can
// require gettlds.php in the calling script and use it to set it, like this:
// $retlds=gettlds(); $retlds=implode('|',$retlds);

function validtoken($token) {
	if (preg_match('#^[A-Za-z0-9_-]{43}$#',$token)===1)
		return true;
	else
		return false;
}

function mastreq($context,$host,$endpoint) {
	$context=stream_context_create($context);
	$endpoint="https://{$host}{$endpoint}";
	$res=@file_get_contents($endpoint,false,$context);
	if ($res===false)
		return ['ok'=>false,'error'=>"could not connect to «{$host}»",'headers'=>null];
	$res=@json_decode($res,true);
	if (is_null($res))
		return ['ok'=>false,'error'=>"could not decode JSON data from «{$endpoint}» (".json_last_error().': '.json_last_error_msg().")",'headers'=>$http_response_header];
	if (isset($res['error']))
		return ['ok'=>false,'error'=>lcfirst($res['error']),'headers'=>$http_response_header];
	/*print_r($http_response_header);
	preg_match('#^\S+\s+(\S+)\s+(\S+)#',$http_response_header[0],$matches);
	print_r($matches);
	$httpcode=$matches[1]+0;
	$httpcodetext=$matches[2];
	if (($httpcode>=400 && $httpcode<=499) || ($httpcode>=500 && $httpcode<=599))
		return ['ok'=>false,'error'=>"HTTP error: {$httpcodetext}"];*/
	return ['ok'=>true,'data'=>$res,'headers'=>$http_response_header];
}

function mastget($host,$token,$endpoint,$timeout) {
	$context=[
		'http'=>[
			'header'=>"Content-type: application/x-www-form-urlencoded\r\nAccept: application/json\r\n",
			'method'=>'GET',
			'ignore_errors'=>true,
			'timeout'=>$timeout
		]
	];
	if (!is_null($token))
		$context['http']['header'].="Authorization: Bearer {$token}\r\n";
	$res=mastreq($context,$host,$endpoint);
	return $res;
}

function mastpost($host,$token,$endpoint,$content,$timeout) {
	$content=http_build_query($content);
	$context=[
		'http'=>[
			'header'=>"Content-type: application/x-www-form-urlencoded\r\nAccept: application/json\r\n",
			'method'=>'POST',
			'ignore_errors'=>true,
			'content'=>$content,
			'timeout'=>$timeout
		]
	];
	if (!is_null($token))
		$context['http']['header'].="Authorization: Bearer {$token}\r\n";
	$res=mastreq($context,$host,$endpoint);
	return $res;
}

function mastpostfile($host,$token,$endpoint,$content,$timeout) {
	$content=http_build_query($content);
	$context=[
		'http'=>[
			'header'=>"Content-type: multipart/form-data;boundary=\"boundary\"\r\nAccept: application/json\r\n",
			'method'=>'POST',
			'ignore_errors'=>true,
			'content'=>$content,
			'timeout'=>$timeout
		]
	];
	if (!is_null($token))
		$context['http']['header'].="Authorization: Bearer {$token}\r\n";
	$res=mastreq($context,$host,$endpoint);
	return $res;
}

function mastdel($host,$token,$endpoint,$timeout) {
	$context=[
		'http'=>[
			'header'=>"Content-type: application/x-www-form-urlencoded\r\nAccept: application/json\r\n",
			'method'=>'DELETE',
			'ignore_errors'=>true,
			'timeout'=>$timeout
		]
	];
	if (!is_null($token))
		$context['http']['header'].="Authorization: Bearer {$token}\r\n";
	$res=mastreq($context,$host,$endpoint);
	return $res;
}

/*
some endpoints
	get
		auth required
			verify app creds and get app info: /api/v1/apps/verify_credentials
			verify user creds and get account info: /api/v1/accounts/verify_credentials
			get a post: /api/v1/statuses/[id]
	post
		auth required
			post a status: /api/v1/statuses
			send follow request to an account: /api/v1/accounts/[id]/follow
			unfollow an account: /api/v1/accounts/[id]/unfollow
*/

function splitpost($post,$avchars,$cw,$pre,$cntup) {
	// decided use $matches[1] instead of $matches[0]
	// to stay safe, $avchars should be at least 30 (didn't test with less);
	// $pre can be used to list recipients (in this case it has to end with
	// a "\n" or " "), or for anything else
	$post=preg_replace('#[ \t\f\r]+\n#',"\n",$post);
	$post=rtrim($post);
	$postrlen=strlen($post);
	$postlen=postlength($post);
	$cwlen=mb_strlen($cw,'UTF-8');
	$prelen=postlength($pre);
	if ($postlen+$prelen+$cwlen<=$avchars)
		return [['cw'=>$cw,'post'=>$pre.$post,'mastlen'=>$postlen+$prelen+$cwlen]];
	// there is no way to know the total of posts before splitting, and its
	// string length modifies the total, so we roughly estimate it very
	// cautiosly to the decrease, just to spare cycles
	$tot='';
	$gtot=ceil($postlen/($avchars-7-2-$prelen-$cwlen));// "7" is the min length of the counter ("\n\n[x/x]"); 2 counts for start and end "…"
	for ($i=0; $i<strlen($gtot); $i++)
		$tot.='x';
	$c=0;
	while (true) {
		$c++;
		$totlen=strlen($tot);
		$spost=[];
		$buf='';
		$off=0;
		$i=1;
		while (true) {
			//echo "========================\n";
			if (strlen($i)>$totlen) break;// do another cycle
			$cnt="__[{$i}/{$tot}]";
			//$lastcons=substr($post,$off,40);
			preg_match('#(\S+)(\s+|$)#',$post,$matches,0,$off);
			//var_dump($matches);
			if (count($matches)==0) {// done, last post
				$spost[]=['cw'=>$cw,'post'=>rtrim($buf)];
				break 2;
			}
			$offadd=strlen($matches[0]);
			($off+$offadd>=$postrlen) ? $dotsaddlen=0 : $dotsaddlen=2;// if we are on the last word, we don't add "…"
			if ($prelen+$cwlen+postlength($buf.$matches[1].$cnt)+$dotsaddlen>$avchars) {// if current match would make buf+overhead overcome avchars
				//echo "LONGMATCH: «$matches[0]»\n";
				$nxcntlen=$totlen+strlen($i+1)+5;// next cnt may be different, so we precalc its length
				($i==1 || $dotsaddlen==0) ? $nxdotsaddlen=2 : $nxdotsaddlen=4;// if we are on first or last post, we add 1 "…"; otherwise we add 2
				if ($prelen+$cwlen+postlength($matches[1])+$nxcntlen+$nxdotsaddlen>$avchars) {// if next match+overhead is by itself longer than avchars
					//echo "BLOCKMATCH: «$matches[0]»\n";
					//$len=$avchars-$nxcntlen-$prelen-$nxdotsaddlen;
					$len=$avchars-postlength($buf.$cnt)-$prelen-$cwlen-$dotsaddlen;
					if ($len>0) {
						// deactivate possible links because they will be broken
						$matches[0]=preg_replace('#^http(s)?://#','zttp$1://',$matches[0]);
						$matches[0]=preg_replace('#^@([a-zA-Z0-9_]+@[a-z0-9-]+)#','+$1',$matches[0]);
						$matches[0]=mb_substr($matches[0],0,$len,'UTF-8');
						//echo "SUBSTRING: «$matches[0]»\n";
						$offadd=strlen($matches[0]);
						//echo "{$matches[0]}: OFF: {$off}; OFFADD: {$offadd}\n";
						$buf.=$matches[0];
						$matches[0]='';
					}
				}
				$spost[]=['cw'=>$cw,'post'=>rtrim($buf).' …'];
				$buf='… ';
				$i++;
			}/* else {
				echo "NORMATCH: «$matches[0]»\n";
			}*/
			$buf.=$matches[0];
			$off+=$offadd;
		}
		$tot.='x';
	}
	//echo '<pre>'.print_r($spost,true).'</pre>';
	if ($cntup)
		foreach ($spost as $key=>$post) {
			$spost[$key]['post']="{$pre}[".($key+1)."/{$i}]\n\n{$post['post']}";
			$spost[$key]['mastlen']=postlength($spost[$key]['post'])+$cwlen;
		}
	else
		foreach ($spost as $key=>$post) {
			$spost[$key]['post']="{$pre}{$post['post']}\n\n[".($key+1)."/{$i}]";
			$spost[$key]['mastlen']=postlength($spost[$key]['post'])+$cwlen;
		}
	//echo "CYCLES: {$c}\n";
	//echo "LASTCONS: {$lastcons}\n";
	return $spost;
}

function postlength($post) {
	global $retlds;
//	echo "-A-> |{$post}|\n";
	// for some reason, mastodon seems to check tld existence only on http(s) links - see next regexp
	$res=preg_replace('#(^|\W)(@[a-zA-Z0-9_]+)@(([a-z0-9]([a-z0-9-]+[a-z0-9])?){1,63}\.)+([a-z0-9]([a-z0-9-]+[a-z0-9])?){1,63}\b#u', '$1$2', $post);
	if (!is_null($res)) $post=$res;
//	$res=preg_replace('#(^|\W)https?://(([a-z0-9]([a-z0-9-]+[a-z0-9])?){1,63}\.)+([a-z0-9]([a-z0-9-]+[a-z0-9])?){1,63}(/\S*[\w=?_-])?#u', '$1HTTP://UUUUUUUUUUUUUUUU', $post);
	// on http(s) links mastodon checks if tld exists...
	$res=preg_replace('#(^|\W)https?://(([a-z0-9]([a-z0-9-]+[a-z0-9])?){1,63}\.)+('.$retlds.')(/\S*[\w/=_\-])?#u', '$1UUUUUUUUUUUUUUUUUUUUUUU', $post);
	if (!is_null($res)) $post=$res;
//	echo "-B-> |{$post}|\n";
	return mb_strlen($post,'UTF-8');
}

// this function requires these to be defined:
// - an "evhandle" function to handle events
// - an "eecho" function to handle output
// - a "$doshut" global variable and a "shutdown" function that, since it's placed in secure places, can be used eg to safely shut down the program when "$doshut" is set to true by eg a function bound to a signal, like pcntl_signal(SIGTERM,'sighandler')
// see ocrbot for an example
function evlisten($host,$port,$endpoint,$token,$timeout) {
	global $doshut;
	while (true) {
		shutdown($doshut);
		$dispurl="tls://{$host}:{$port}";
		eecho(1,"trying to connect to «{$dispurl}».");
		$sh=@fsockopen("tls://{$host}",$port,$errno,$errstr,$timeout);
		if ($sh===false) {
			eecho(3,"could not connect to «{$dispurl}»: {$errstr} ({$errno}); will try again in 1 second.");
			sleep(1);
		} else {
			//stream_set_blocking($sh,false);
			stream_set_timeout($sh,1,0);
			eecho(1,"succesfully connected to «{$dispurl}».");
			$req="GET {$endpoint} HTTP/1.1\r\nHost: {$host}\r\nUser-Agent: a_bot\r\nAuthorization: Bearer {$token}\r\n\r\n";
			if (fwrite($sh,$req)===false) {
				eecho(3,"could not subscribe to user notifications on «{$dispurl}»; will try again in 1 second.");
				fclose($sh);
				unset($sh);// this is because shutdown can check if $sh is set and if it is, try to fclose it
				sleep(1);
			} else {
				eecho(1,"listening for user notifications on «{$dispurl}».");
				//$lc=0;
				while (!feof($sh)) {
					shutdown($doshut);
					//$lc++;
					$line=rtrim(fgets($sh),"\r\n");
					//echo "{$lc}> {$line}\n";
					if (preg_match('#^event: #',$line)===1) {
						$event=['type'=>preg_replace('#^event: #','',$line),'data'=>''];
						$line=rtrim(fgets($sh),"\r\n");
						//echo "{$lc} DATA> {$line}\n";
						if (preg_match('#^data: #',$line)===1) {
							$event['data'].=preg_replace('#^data: #','',$line);
							while ($line!='') {
								$line=rtrim(fgets($sh),"\r\n");
								if ($line=='') break;
								//echo "{$lc} LENGTH> {$line}\n";
								$line=rtrim(fgets($sh),"\r\n");
								//echo "{$lc} DATA> {$line}\n";
								$event['data'].=$line;
							}
							$event['data']=@json_decode($event['data'],true);
							if ($event['data']===false) {
								eecho(2,"could not decode data for event of type «{$event['type']}».");
							} else {
								//print_r($event);
								evhandle($event);
							}
						}
					}
				}
				fclose($sh);
				unset($sh);// this is because shutdown can check if $sh is set and if it is, try to fclose it
				eecho(3,"lost connection to «{$dispurl}»; will try reconnecting in 1 second.");
				sleep(1);
			}
		}
	}
}

?>