xref: /plugin/botmon/action.php (revision cdc02cd4c39f99df88e41b6048475b40280560ad)
16980370bSSascha Leib<?php
26980370bSSascha Leib
36980370bSSascha Leibuse dokuwiki\Extension\EventHandler;
46980370bSSascha Leibuse dokuwiki\Extension\Event;
55fbe88f7SSascha Leibuse dokuwiki\Logger;
66980370bSSascha Leib
76980370bSSascha Leib/**
87bd08c30SSascha Leib * Action Component for the Bot Monitoring Plugin
96980370bSSascha Leib *
106980370bSSascha Leib * @license	GPL 3 (http://www.gnu.org/licenses/gpl.html)
116980370bSSascha Leib * @author	 Sascha Leib <sascha.leib(at)kolmio.com>
126980370bSSascha Leib */
136980370bSSascha Leib
147bd08c30SSascha Leibclass action_plugin_botmon extends DokuWiki_Action_Plugin {
156980370bSSascha Leib
166980370bSSascha Leib	/**
176980370bSSascha Leib	 * Registers a callback functions
186980370bSSascha Leib	 *
196980370bSSascha Leib	 * @param EventHandler $controller DokuWiki's event controller object
206980370bSSascha Leib	 * @return void
216980370bSSascha Leib	 */
226980370bSSascha Leib	public function register(EventHandler $controller) {
235f2c1759SSascha Leib
24e56d7b71SSascha Leib		global $ACT;
25e56d7b71SSascha Leib
265f2c1759SSascha Leib		// insert header data into the page:
27e56d7b71SSascha Leib		if ($ACT == 'show') {
286980370bSSascha Leib			$controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'insertHeader');
29e56d7b71SSascha Leib		} else if ($ACT == 'admin' && isset($_REQUEST['page']) && $_REQUEST['page'] == 'botmon') {
30e56d7b71SSascha Leib			$controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'insertAdminHeader');
31e56d7b71SSascha Leib		}
325f2c1759SSascha Leib
33f5f4ca13SSascha Leib		// Override the page rendering, if a captcha needs to be displayed:
34f5f4ca13SSascha Leib		if ($ACT !== 'admin') {
35f5f4ca13SSascha Leib			$controller->register_hook('TPL_ACT_RENDER', 'BEFORE', $this, 'showCaptcha');
36f5f4ca13SSascha Leib		}
37f5f4ca13SSascha Leib
385f2c1759SSascha Leib		// write to the log after the page content was displayed:
395f2c1759SSascha Leib		$controller->register_hook('TPL_CONTENT_DISPLAY', 'AFTER', $this, 'writeServerLog');
405f2c1759SSascha Leib
416980370bSSascha Leib	}
426980370bSSascha Leib
43b148c85eSSascha Leib	/* session information */
44f6a7ebc1SSascha Leib	private $sessionId = null;
45f6a7ebc1SSascha Leib	private $sessionType = '';
46b148c85eSSascha Leib
476980370bSSascha Leib	/**
486980370bSSascha Leib	 * Inserts tracking code to the page header
49e56d7b71SSascha Leib	 * (only called on 'show' actions)
506980370bSSascha Leib	 *
516980370bSSascha Leib	 * @param Event $event event object by reference
526980370bSSascha Leib	 * @return void
536980370bSSascha Leib	 */
546980370bSSascha Leib	public function insertHeader(Event $event, $param) {
556980370bSSascha Leib
566980370bSSascha Leib		global $INFO;
576980370bSSascha Leib
58b148c85eSSascha Leib		// populate the session id and type:
59b148c85eSSascha Leib		$this->getSessionInfo();
60b148c85eSSascha Leib
616980370bSSascha Leib		// is there a user logged in?
625f2c1759SSascha Leib		$username = ( !empty($INFO['userinfo']) && !empty($INFO['userinfo']['name']) ?  $INFO['userinfo']['name'] : '');
636980370bSSascha Leib
646980370bSSascha Leib		// build the tracker code:
6512993035SSascha Leib		$code = "document._botmon = {t0: Date.now(), session: " . json_encode($this->sessionId) . ", seed: " . json_encode($this->getConf('captchaSeed')) . ", ip: " . json_encode($_SERVER['REMOTE_ADDR']) . "};" . NL;
666980370bSSascha Leib		if ($username) {
67e56d7b71SSascha Leib			$code .= DOKU_TAB . DOKU_TAB . 'document._botmon.user = "' . $username . '";'. NL;
686980370bSSascha Leib		}
696980370bSSascha Leib
705f2c1759SSascha Leib		// add the deferred script loader::
71e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . "addEventListener('DOMContentLoaded', function(){" . NL;
72e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . DOKU_TAB . "const e=document.createElement('script');" . NL;
73e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . DOKU_TAB . "e.async=true;e.defer=true;" . NL;
74e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . DOKU_TAB . "e.src='".DOKU_BASE."lib/plugins/botmon/client.js';" . NL;
75e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . DOKU_TAB . "document.getElementsByTagName('head')[0].appendChild(e);" . NL;
76e56d7b71SSascha Leib		$code .= DOKU_TAB . DOKU_TAB . "});";
775f2c1759SSascha Leib		$event->data['script'][] = ['_data' => $code];
78451abfadSSascha Leib	}
79451abfadSSascha Leib
80451abfadSSascha Leib	/**
81e56d7b71SSascha Leib	 * Inserts tracking code to the page header
82e56d7b71SSascha Leib	 * (only called on 'show' actions)
83e56d7b71SSascha Leib	 *
84e56d7b71SSascha Leib	 * @param Event $event event object by reference
85e56d7b71SSascha Leib	 * @return void
86e56d7b71SSascha Leib	 */
87e56d7b71SSascha Leib	public function insertAdminHeader(Event $event, $param) {
88e56d7b71SSascha Leib
89e56d7b71SSascha Leib		$event->data['link'][] = ['rel' => 'stylesheet', 'href' => DOKU_BASE.'lib/plugins/botmon/admin.css', 'defer' => 'defer'];
900edf1a56SSascha Leib		$event->data['script'][] = ['src' => DOKU_BASE.'lib/plugins/botmon/admin.js', 'defer' => 'defer', '_data' => ''];
91e56d7b71SSascha Leib	}
92e56d7b71SSascha Leib
93e56d7b71SSascha Leib	/**
94451abfadSSascha Leib	 * Writes data to the server log.
95451abfadSSascha Leib	 *
96451abfadSSascha Leib	 * @return void
97451abfadSSascha Leib	 */
985f2c1759SSascha Leib	public function writeServerLog(Event $event, $param) {
99451abfadSSascha Leib
100451abfadSSascha Leib		global $conf;
101451abfadSSascha Leib		global $INFO;
102091b5998SSascha Leib
1035f2c1759SSascha Leib		// is there a user logged in?
1045f2c1759SSascha Leib		$username = ( !empty($INFO['userinfo']) && !empty($INFO['userinfo']['name'])
1055f2c1759SSascha Leib					?  $INFO['userinfo']['name'] : '');
1065f2c1759SSascha Leib
107b2e3bd8bSSascha Leib		// clean the page ID
108b2e3bd8bSSascha Leib		$pageId = preg_replace('/[\x00-\x1F]/', "\u{FFFD}", $INFO['id'] ?? '');
109b2e3bd8bSSascha Leib
110451abfadSSascha Leib		// create the log array:
111cf9f7fe8SSascha Leib		$logArr = Array(
112f5f4ca13SSascha Leib			$_SERVER['REMOTE_ADDR'], /* remote IP */
113b2e3bd8bSSascha Leib			$pageId, /* page ID */
114b148c85eSSascha Leib			$this->sessionId, /* Session ID */
115b148c85eSSascha Leib			$this->sessionType, /* session ID type */
1165f2c1759SSascha Leib			$username, /* user name */
1172f2bc93aSSascha Leib			$_SERVER['HTTP_USER_AGENT'] ?? '', /* User agent */
118451abfadSSascha Leib			$_SERVER['HTTP_REFERER'] ?? '', /* HTTP Referrer */
119451abfadSSascha Leib			substr($conf['lang'],0,2), /* page language */
120a93de874SSascha Leib			implode(',', array_unique(array_map( function($it) { return substr(trim($it),0,2); }, explode(',',trim($_SERVER['HTTP_ACCEPT_LANGUAGE'], " \t;,*"))))), /* accepted client languages */
1215f2c1759SSascha Leib			$this->getCountryCode() /* GeoIP country code */
122cf9f7fe8SSascha Leib		);
123cf9f7fe8SSascha Leib
124cf9f7fe8SSascha Leib		//* create the log line */
1254cddc661SSascha Leib		$filename = __DIR__ .'/logs/' . gmdate('Y-m-d') . '.srv.txt'; /* use GMT date for filename */
126cf9f7fe8SSascha Leib		$logline = gmdate('Y-m-d H:i:s'); /* use GMT time for log entries */
127cf9f7fe8SSascha Leib		foreach ($logArr as $tab) {
128cf9f7fe8SSascha Leib			$logline .= "\t" . $tab;
129cf9f7fe8SSascha Leib		};
130cf9f7fe8SSascha Leib
131cf9f7fe8SSascha Leib		/* write the log line to the file */
132cf9f7fe8SSascha Leib		$logfile = fopen($filename, 'a');
133cf9f7fe8SSascha Leib		if (!$logfile) die();
134cf9f7fe8SSascha Leib		if (fwrite($logfile, $logline . "\n") === false) {
135cf9f7fe8SSascha Leib			fclose($logfile);
136cf9f7fe8SSascha Leib			die();
1376980370bSSascha Leib		}
138cf9f7fe8SSascha Leib
139cf9f7fe8SSascha Leib		/* Done */
140cf9f7fe8SSascha Leib		fclose($logfile);
141cf9f7fe8SSascha Leib	}
142b148c85eSSascha Leib
1435f2c1759SSascha Leib	private function getCountryCode() {
1445f2c1759SSascha Leib
145f5f4ca13SSascha Leib		$country = ( $_SERVER['REMOTE_ADDR'] == '127.0.0.1' ? 'local' : 'ZZ' ); // default if no geoip is available!
1465f2c1759SSascha Leib
1475f2c1759SSascha Leib		$lib = $this->getConf('geoiplib'); /* which library to use? (can only be phpgeoip or disabled) */
1485f2c1759SSascha Leib
1495f2c1759SSascha Leib		try {
1505f2c1759SSascha Leib
1515f2c1759SSascha Leib			// use GeoIP module?
1525f2c1759SSascha Leib			if ($lib == 'phpgeoip' && extension_loaded('geoip') && geoip_db_avail(GEOIP_COUNTRY_EDITION)) { // Use PHP GeoIP module
1535f2c1759SSascha Leib				$result = geoip_country_code_by_name($_SERVER['REMOTE_ADDR']);
1545f2c1759SSascha Leib				$country = ($result ? $result : $country);
1555f2c1759SSascha Leib			}
1565f2c1759SSascha Leib		} catch (Exception $e) {
1575f2c1759SSascha Leib			Logger::error('BotMon Plugin: GeoIP Error', $e->getMessage());
1585f2c1759SSascha Leib		}
1595f2c1759SSascha Leib
1605f2c1759SSascha Leib		return $country;
1615f2c1759SSascha Leib	}
1625f2c1759SSascha Leib
163b148c85eSSascha Leib	private function getSessionInfo() {
164b148c85eSSascha Leib
165b148c85eSSascha Leib		// what is the session identifier?
166b148c85eSSascha Leib		if (isset($_SESSION)) {
167b148c85eSSascha Leib			$sesKeys = array_keys($_SESSION); /* DokuWiki Session ID preferred */
168b148c85eSSascha Leib			foreach ($sesKeys as $key) {
169b148c85eSSascha Leib				if (substr($key, 0, 2) == 'DW') {
170b148c85eSSascha Leib					$this->sessionId = $key;
171b148c85eSSascha Leib					$this->sessionType = 'dw';
172b148c85eSSascha Leib					return;
173b148c85eSSascha Leib				}
174b148c85eSSascha Leib			}
175b148c85eSSascha Leib		}
176f6a7ebc1SSascha Leib		if (!$this->sessionId) { /* no DokuWiki Session ID, try PHP session ID */
177b148c85eSSascha Leib			$this->sessionId = session_id();
178b148c85eSSascha Leib			$this->sessionType = 'php';
179b148c85eSSascha Leib		}
180f5f4ca13SSascha Leib		if (!$this->sessionId) { /* no PHP session ID, try IP address */
181f5f4ca13SSascha Leib			$this->sessionId = $_SERVER['REMOTE_ADDR'];
182b148c85eSSascha Leib			$this->sessionType = 'ip';
183b148c85eSSascha Leib		}
184f6a7ebc1SSascha Leib		if (!$this->sessionId) { /* if everything else fails, just us a random ID */
185b148c85eSSascha Leib			$this->sessionId = rand(1000000, 9999999);
186b148c85eSSascha Leib			$this->sessionType = 'rand';
187b148c85eSSascha Leib		}
188b148c85eSSascha Leib	}
189f5f4ca13SSascha Leib
190f5f4ca13SSascha Leib	public function showCaptcha(Event $event) {
191f5f4ca13SSascha Leib
19212993035SSascha Leib		$useCaptcha = $this->getConf('useCaptcha');
193f5f4ca13SSascha Leib
19412993035SSascha Leib		if ($useCaptcha !== 'disabled' && $this->checkCaptchaCookie()) {
19512993035SSascha Leib			echo '<h1 class="sectionedit1">'; tpl_pagetitle(); echo "</h1>\n"; // always show the original page title
196f5f4ca13SSascha Leib			$event->preventDefault(); // don't show normal content
19712993035SSascha Leib			switch ($useCaptcha) {
19812993035SSascha Leib				case 'blank':
19912993035SSascha Leib					$this->insertBlankBox();  // show dada filler instead of text
20012993035SSascha Leib					break;
20112993035SSascha Leib				case 'dada':
20212993035SSascha Leib					$this->insertDadaFiller();  // show dada filler instead of text
20312993035SSascha Leib					break;
20412993035SSascha Leib			}
205f5f4ca13SSascha Leib			$this->insertCaptchaLoader(); // and load the captcha
206f5f4ca13SSascha Leib		}
207f5f4ca13SSascha Leib	}
208f5f4ca13SSascha Leib
209f5f4ca13SSascha Leib	private function checkCaptchaCookie() {
210f5f4ca13SSascha Leib
211*cdc02cd4SSascha Leib		$cookieVal = isset($_COOKIE['DWConfirm']) ? $_COOKIE['DWConfirm'] : null;
212f5f4ca13SSascha Leib
213*cdc02cd4SSascha Leib		$today = substr((new DateTime())->format('c'), 0, 10);
21412993035SSascha Leib
215*cdc02cd4SSascha Leib		$raw = $this->getConf('captchaSeed') . '|' . $_SERVER['SERVER_NAME'] . '|' . $_SERVER['REMOTE_ADDR'] . '|' . $today;
216*cdc02cd4SSascha Leib		$expected = hash('sha256', $raw);
21712993035SSascha Leib
218*cdc02cd4SSascha Leib		//echo '<ul><li>cookie: ' . $cookieVal . '</li><li>expected: ' . $expected . '</li><li>matches: ' .($cookieVal == $expected ? 'true' : 'false') . '</li></ul>';
219*cdc02cd4SSascha Leib
220*cdc02cd4SSascha Leib		return $cookieVal !== $expected;
221f5f4ca13SSascha Leib	}
222f5f4ca13SSascha Leib
223f5f4ca13SSascha Leib	private function insertCaptchaLoader() {
22412993035SSascha Leib		echo '<script>' . NL;
22512993035SSascha Leib
22612993035SSascha Leib		// add the deferred script loader::
22712993035SSascha Leib		echo  DOKU_TAB . "addEventListener('DOMContentLoaded', function(){" . NL;
22812993035SSascha Leib		echo  DOKU_TAB . DOKU_TAB . "const cj=document.createElement('script');" . NL;
22912993035SSascha Leib		echo  DOKU_TAB . DOKU_TAB . "cj.async=true;cj.defer=true;cj.type='text/javascript';" . NL;
23012993035SSascha Leib		echo  DOKU_TAB . DOKU_TAB . "cj.src='".DOKU_BASE."lib/plugins/botmon/captcha.js';" . NL;
23112993035SSascha Leib		echo  DOKU_TAB . DOKU_TAB . "document.getElementsByTagName('head')[0].appendChild(cj);" . NL;
23212993035SSascha Leib		echo  DOKU_TAB . "});";
23312993035SSascha Leib		echo '</script>' . NL;
234f5f4ca13SSascha Leib
235f5f4ca13SSascha Leib	}
236f5f4ca13SSascha Leib
23712993035SSascha Leib	// inserts a blank box to ensure there is enough space for the captcha:
23812993035SSascha Leib	private function insertBlankBox() {
23912993035SSascha Leib
24012993035SSascha Leib		echo '<p style="min-height: 100px;">&nbsp;</p>';
24112993035SSascha Leib	}
24212993035SSascha Leib
24312993035SSascha Leib	/* Generates a few paragraphs of Dada text to show instead of the article content */
244f5f4ca13SSascha Leib	private function insertDadaFiller() {
245f5f4ca13SSascha Leib
24612993035SSascha Leib		global $conf;
24712993035SSascha Leib		global $TOC;
24812993035SSascha Leib		global $ID;
249f5f4ca13SSascha Leib
25012993035SSascha Leib		// list of languages to search for the wordlist
25112993035SSascha Leib		$langs = array_unique([$conf['lang'], 'la']);
252f5f4ca13SSascha Leib
25312993035SSascha Leib		// find path to the first available wordlist:
25412993035SSascha Leib		foreach ($langs as $lang) {
25512993035SSascha Leib			$filename = __DIR__ .'/lang/' . $lang . '/wordlist.txt'; /* language-specific wordlist */
25612993035SSascha Leib			if (file_exists($filename)) {
25712993035SSascha Leib				break;
25812993035SSascha Leib			}
25912993035SSascha Leib		}
260f5f4ca13SSascha Leib
26112993035SSascha Leib		// load the wordlist file:
26212993035SSascha Leib		if (file_exists($filename)) {
26312993035SSascha Leib			$words = array();
26412993035SSascha Leib			$totalWeight = 0;
26512993035SSascha Leib			$lines = file($filename, FILE_SKIP_EMPTY_LINES);
26612993035SSascha Leib			foreach ($lines as $line) {
26712993035SSascha Leib				$arr = explode("\t", $line);
26812993035SSascha Leib				$arr[1] = ( count($arr) > 1 ? (int) trim($arr[1]) : 1 );
26912993035SSascha Leib				$totalWeight += (int) $arr[1];
27012993035SSascha Leib				array_push($words, $arr);
27112993035SSascha Leib			}
27212993035SSascha Leib		} else {
27312993035SSascha Leib			echo '<script> console.log("Can’t generate filler text: wordlist file not found!"); </script>';
27412993035SSascha Leib			return;
27512993035SSascha Leib		}
276f5f4ca13SSascha Leib
27712993035SSascha Leib		// If a TOC exists, use it for the headlines:
27812993035SSascha Leib		if(is_array($TOC)) {
27912993035SSascha Leib			$toc = $TOC;
28012993035SSascha Leib		} else {
28112993035SSascha Leib			$meta = p_get_metadata($ID, '', METADATA_RENDER_USING_CACHE);
28212993035SSascha Leib			//$tocok = (isset($meta['internal']['toc']) ? $meta['internal']['toc'] : $tocok = true);
28312993035SSascha Leib			$toc = isset($meta['description']['tableofcontents']) ? $meta['description']['tableofcontents'] : null;
28412993035SSascha Leib		}
28512993035SSascha Leib		if (!$toc) { // no TOC, generate my own:
28612993035SSascha Leib			$hlCount = mt_rand(0, (int) $conf['tocminheads']);
28712993035SSascha Leib			$toc = array();
28812993035SSascha Leib			for ($i=0; $i<$hlCount; $i++) {
28912993035SSascha Leib				array_push($toc, $this->dadaMakeHeadline($words, $totalWeight)); // $toc
29012993035SSascha Leib			}
29112993035SSascha Leib		}
29212993035SSascha Leib
29312993035SSascha Leib		// if H1 heading is not in the TOC, add a chappeau section:
29412993035SSascha Leib		$chapeauCount = mt_rand(1, 3);
29512993035SSascha Leib		if ((int) $conf['toptoclevel'] > 1) {
29612993035SSascha Leib			echo "<div class=\"level1\">\n";
29712993035SSascha Leib			for ($i=0; $i<$chapeauCount; $i++) {
29812993035SSascha Leib				echo $this->dadaMakeParagraph($words, $totalWeight);
29912993035SSascha Leib			}
30012993035SSascha Leib			echo "</div>\n";
30112993035SSascha Leib		}
30212993035SSascha Leib
30312993035SSascha Leib		//  text sections for each sub-headline:
30412993035SSascha Leib		foreach ($toc as $hl) {
30512993035SSascha Leib			echo $this->dadaMakeSection($words, $totalWeight, $hl);
30612993035SSascha Leib		}
30712993035SSascha Leib	}
30812993035SSascha Leib
30912993035SSascha Leib	private function dadaMakeSection($words, $totalWeight, $hl) {
31012993035SSascha Leib
31112993035SSascha Leib		global $conf;
31212993035SSascha Leib
31312993035SSascha Leib		// how many paragraphs?
31412993035SSascha Leib		$paragraphCount = mt_rand(1, 4);
31512993035SSascha Leib
31612993035SSascha Leib		// section level
31712993035SSascha Leib		$topTocLevel = (int) $conf['toptoclevel'];
31812993035SSascha Leib		$secLevel = $hl['level'] + 1;;
31912993035SSascha Leib
32012993035SSascha Leib		// return value:
32112993035SSascha Leib		$sec = "";
32212993035SSascha Leib
32312993035SSascha Leib		// make a headline:
32412993035SSascha Leib		if ($topTocLevel > 1 || $secLevel > 1) {
32512993035SSascha Leib			$sec .= "<h{$secLevel} id=\"{$hl['hid']}\">{$hl['title']}</h{$secLevel}>\n";
32612993035SSascha Leib		}
32712993035SSascha Leib
32812993035SSascha Leib		// add the paragraphs:
32912993035SSascha Leib		$sec .= "<div class=\"level{$secLevel}\">\n";
33012993035SSascha Leib		for ($i=0; $i<$paragraphCount; $i++) {
33112993035SSascha Leib			$sec .= $this->dadaMakeParagraph($words, $totalWeight);
33212993035SSascha Leib		}
33312993035SSascha Leib		$sec .= "</div>\n";
33412993035SSascha Leib
33512993035SSascha Leib		return $sec;
33612993035SSascha Leib	}
33712993035SSascha Leib
33812993035SSascha Leib	private function dadaMakeHeadline($words, $totalWeight) {
33912993035SSascha Leib
34012993035SSascha Leib		// how many words to generate?
34112993035SSascha Leib		$wordCount = mt_rand(2, 5);
34212993035SSascha Leib
34312993035SSascha Leib		// function returns an array:
34412993035SSascha Leib		$r = Array();
34512993035SSascha Leib
34612993035SSascha Leib		// generate the headline:
34712993035SSascha Leib		$hlArr = array();
34812993035SSascha Leib		for ($i=0; $i<$wordCount; $i++) {
34912993035SSascha Leib			array_push($hlArr, $this->dadaSelectRandomWord($words, $totalWeight));
35012993035SSascha Leib		}
35112993035SSascha Leib
35212993035SSascha Leib		$r['title'] =  ucfirst(implode(' ', $hlArr));
35312993035SSascha Leib
35412993035SSascha Leib		$r['hid'] = preg_replace('/[^\w\d\-]+/i', '_', strtolower($r['title']));
35512993035SSascha Leib		$r['type'] = 'ul'; // always ul!
35612993035SSascha Leib		$r['level'] = 1; // always level 1 for now
35712993035SSascha Leib
35812993035SSascha Leib		return $r;
35912993035SSascha Leib	}
36012993035SSascha Leib
36112993035SSascha Leib	private function dadaMakeParagraph($words, $totalWeight) {
36212993035SSascha Leib
36312993035SSascha Leib		// how many words to generate?
36412993035SSascha Leib		$sentenceCount = mt_rand(2, 5);
36512993035SSascha Leib
36612993035SSascha Leib		$paragraph = array();
36712993035SSascha Leib		for ($i=0; $i<$sentenceCount; $i++) {
36812993035SSascha Leib			array_push($paragraph, $this->dadaMakeSentence($words, $totalWeight));
36912993035SSascha Leib		}
37012993035SSascha Leib
37112993035SSascha Leib		return "<p>\n" . implode(' ', $paragraph) . "\n</p>\n";
37212993035SSascha Leib
37312993035SSascha Leib	}
37412993035SSascha Leib
37512993035SSascha Leib	private function dadaMakeSentence($words, $totalWeight) {
37612993035SSascha Leib
37712993035SSascha Leib		// how many words to generate?
37812993035SSascha Leib		$wordCount = mt_rand(4, 20);
37912993035SSascha Leib
38012993035SSascha Leib		// generate the sentence:
38112993035SSascha Leib		$sentence = array();
38212993035SSascha Leib		for ($i=0; $i<$wordCount; $i++) {
38312993035SSascha Leib			array_push($sentence, $this->dadaSelectRandomWord($words, $totalWeight));
38412993035SSascha Leib		}
38512993035SSascha Leib
38612993035SSascha Leib		return ucfirst(implode(' ', $sentence)) . '.';
38712993035SSascha Leib
38812993035SSascha Leib	}
38912993035SSascha Leib
39012993035SSascha Leib	private function dadaSelectRandomWord($list, $totalWeight) {
39112993035SSascha Leib
39212993035SSascha Leib		// get a random selection:
39312993035SSascha Leib		$rand = mt_rand(0, $totalWeight);
39412993035SSascha Leib
39512993035SSascha Leib		// match the selection to the weighted list:
39612993035SSascha Leib		$cumulativeWeight = 0;
39712993035SSascha Leib		for ($i=0; $i<count($list); $i++) {
39812993035SSascha Leib			$cumulativeWeight += $list[$i][1];
39912993035SSascha Leib			if ($cumulativeWeight >= $rand) {
40012993035SSascha Leib				return $list[$i][0];
40112993035SSascha Leib			}
40212993035SSascha Leib		}
40312993035SSascha Leib		return '***';
404f5f4ca13SSascha Leib	}
405f5f4ca13SSascha Leib
4066980370bSSascha Leib}