<?php

@require_once('include/zot.php');

function magic_init(&$a) {

	$ret = array('success' => false, 'url' => '', 'message' => '');
	logger('mod_magic: invoked', LOGGER_DEBUG);

	logger('mod_magic: args: ' . print_r($_REQUEST,true),LOGGER_DATA);

	$addr = ((x($_REQUEST,'addr')) ? $_REQUEST['addr'] : '');
	$dest = ((x($_REQUEST,'dest')) ? $_REQUEST['dest'] : '');
	$test = ((x($_REQUEST,'test')) ? intval($_REQUEST['test']) : 0);
	$rev  = ((x($_REQUEST,'rev'))  ? intval($_REQUEST['rev'])  : 0);
	$delegate = ((x($_REQUEST,'delegate')) ? $_REQUEST['delegate']  : '');

	$parsed = parse_url($dest);
	if(! $parsed) {
		if($test) {
			$ret['message'] .= 'could not parse ' . $dest . EOL;
			return($ret);
		}
		goaway($dest);
	}

	$basepath = $parsed['scheme'] . '://' . $parsed['host'] . (($parsed['port']) ? ':' . $parsed['port'] : ''); 

	$x = q("select * from hubloc where hubloc_url = '%s' order by hubloc_connected desc limit 1",
		dbesc($basepath)
	);
	
	if(! $x) {

		/*
		 * We have no records for, or prior communications with this hub. 
		 * If an address was supplied, let's finger them to create a hub record. 
		 * Otherwise we'll use the special address '[system]' which will return
		 * either a system channel or the first available normal channel. We don't
		 * really care about what channel is returned - we need the hub information 
		 * from that response so that we can create signed auth packets destined 
		 * for that hub.
		 *
		 */

		$ret = zot_finger((($addr) ? $addr : '[system]@' . $parsed['host']),null);
		if($ret['success']) {
			$j = json_decode($ret['body'],true);
			if($j)
				import_xchan($j);

			// Now try again

			$x = q("select * from hubloc where hubloc_url = '%s' order by hubloc_connected desc limit 1",
				dbesc($basepath)
			);
		}
	}

	if(! $x) {
		if($rev)
			goaway($dest);
		else {
			logger('mod_magic: no channels found for requested hub.' . print_r($_REQUEST,true));
			if($test) {
				$ret['message'] .= 'This site has no previous connections with ' . $basepath . EOL;
				return $ret;
			} 
			notice( t('Hub not found.') . EOL);
			return;
		}
	}

	// This is ready-made for a plugin that provides a blacklist or "ask me" before blindly authenticating. 
	// By default, we'll proceed without asking.

	$arr = array(
		'channel_id' => local_channel(),
		'xchan' => $x[0],
		'destination' => $dest, 
		'proceed' => true
	);

	call_hooks('magic_auth',$arr);
	$dest = $arr['destination'];
	if(! $arr['proceed']) {
		if($test) {
			$ret['message'] .= 'cancelled by plugin.' . EOL;
			return $ret;
		}
		goaway($dest);
	}

	if((get_observer_hash()) && ($x[0]['hubloc_url'] === z_root())) {
		// We are already authenticated on this site and a registered observer.
		// Just redirect.
		if($test) {
			$ret['success'] = true;
			$ret['message'] .= 'Local site - you are already authenticated.' . EOL;
			return $ret;
		}

		$delegation_success = false;
		if($delegate) {
			$r = q("select * from channel left join hubloc on channel_hash = hubloc_hash where hubloc_addr = '%s' limit 1",
				dbesc($delegate)
			);
			if($r && intval($r[0]['channel_id'])) {
				$allowed = perm_is_allowed($r[0]['channel_id'],get_observer_hash(),'delegate');
				if($allowed) {
					$_SESSION['delegate_channel'] = $r[0]['channel_id'];
					$_SESSION['delegate'] = get_observer_hash();
					$_SESSION['account_id'] = intval($r[0]['channel_account_id']);
					change_channel($r[0]['channel_id']);
					$delegation_success = true;
				}
			}
		}
			

		// FIXME: check and honour local delegation


		goaway($dest);
	}

	if(local_channel()) {
		$channel = $a->get_channel();

		$token = random_string();
		$token_sig = base64url_encode(rsa_sign($token,$channel['channel_prvkey']));
 
		$channel['token'] = $token;
		$channel['token_sig'] = $token_sig;

		$r = q("insert into verify ( type, channel, token, meta, created) values ('%s','%d','%s','%s','%s')",
			dbesc('auth'),
			intval($channel['channel_id']),
			dbesc($token),
			dbesc($x[0]['hubloc_url']),
			dbesc(datetime_convert())
		);

		$target_url = $x[0]['hubloc_callback'] . '/?f=&auth=' . urlencode($channel['channel_address'] . '@' . $a->get_hostname())
			. '&sec=' . $token . '&dest=' . urlencode($dest) . '&version=' . ZOT_REVISION;

		if($delegate)
			$target_url .= '&delegate=' . urlencode($delegate);

		logger('mod_magic: redirecting to: ' . $target_url, LOGGER_DEBUG); 

		if($test) {
			$ret['success'] = true;
			$ret['url'] = $target_url;
			$ret['message'] = 'token ' . $token . ' created for channel ' . $channel['channel_id'] . ' for url ' . $x[0]['hubloc_url'] . EOL;
			return $ret;
		}

		goaway($target_url);
			
	}

	if($test) {
		$ret['message'] = 'Not authenticated or invalid arguments to mod_magic' . EOL;
		return $ret;
	}

	goaway($dest);

}