friendica-addons/nsfw/nsfw.php

<?php
/**
 * Name: NSFW
 * Description: Collapse posts with inappropriate content
 * Version: 1.0
 * Author: Mike Macgirvin <http://macgirvin.com/profile/mike>
 *
 */
use Friendica\Core\Addon;
use Friendica\Core\L10n;
use Friendica\Core\PConfig;

function nsfw_install()
{
	Addon::registerHook('prepare_body', 'addon/nsfw/nsfw.php', 'nsfw_prepare_body', 10);
	Addon::registerHook('addon_settings', 'addon/nsfw/nsfw.php', 'nsfw_addon_settings');
	Addon::registerHook('addon_settings_post', 'addon/nsfw/nsfw.php', 'nsfw_addon_settings_post');
}


function nsfw_uninstall()
{
	Addon::unregisterHook('prepare_body', 'addon/nsfw/nsfw.php', 'nsfw_prepare_body');
	Addon::unregisterHook('addon_settings', 'addon/nsfw/nsfw.php', 'nsfw_addon_settings');
	Addon::unregisterHook('addon_settings_post', 'addon/nsfw/nsfw.php', 'nsfw_addon_settings_post');
}

// This function isn't perfect and isn't trying to preserve the html structure - it's just a
// quick and dirty filter to pull out embedded photo blobs because 'nsfw' seems to come up
// inside them quite often. We don't need anything fancy, just pull out the data blob so we can
// check against the rest of the body.

function nsfw_extract_photos($body)
{
	$new_body = '';

	$img_start = strpos($body, 'src="data:');
	$img_end = (($img_start !== false) ? strpos(substr($body, $img_start), '>') : false);

	$cnt = 0;

	while($img_end !== false) {
		$img_end += $img_start;
		$new_body = $new_body . substr($body, 0, $img_start);

		$cnt ++;
		$body = substr($body, 0, $img_end);

		$img_start = strpos($body, 'src="data:');
		$img_end = (($img_start !== false) ? strpos(substr($body, $img_start), '>') : false);

	}

	if (!$cnt) {
		return $body;
	}
	return $new_body;
}

function nsfw_addon_settings(&$a, &$s)
{
	if (!local_user()) {
		return;
	}

	/* Add our stylesheet to the page so we can make our settings look nice */

	$a->page['htmlhead'] .= '<link rel="stylesheet"  type="text/css" href="' . $a->get_baseurl() . '/addon/nsfw/nsfw.css' . '" media="all" />' . "\r\n";

	$enable_checked = (intval(PConfig::get(local_user(), 'nsfw', 'disable')) ? '' : ' checked="checked" ');
	$words = PConfig::get(local_user(), 'nsfw', 'words');
	if (!$words) {
		$words = 'nsfw,';
	}

	$s .= '<span id="settings_nsfw_inflated" class="settings-block fakelink" style="display: block;" onclick="openClose(\'settings_nsfw_expanded\'); openClose(\'settings_nsfw_inflated\');">';
	$s .= '<h3>' . L10n::t('Not Safe For Work (General Purpose Content Filter)') . '</h3>';
	$s .= '</span>';
	$s .= '<div id="settings_nsfw_expanded" class="settings-block" style="display: none;">';
	$s .= '<span class="fakelink" onclick="openClose(\'settings_nsfw_expanded\'); openClose(\'settings_nsfw_inflated\');">';
	$s .= '<h3>' . L10n::t('Not Safe For Work (General Purpose Content Filter)') . '</h3>';
	$s .= '</span>';

	$s .= '<div id="nsfw-wrapper">';
	$s .= '<p>' . L10n::t('This addon looks in posts for the words/text you specify below, and collapses any content containing those keywords so it is not displayed at inappropriate times, such as sexual innuendo that may be improper in a work setting. It is polite and recommended to tag any content containing nudity with #NSFW.  This filter can also match any other word/text you specify, and can thereby be used as a general purpose content filter.') . '</p>';
	$s .= '<label id="nsfw-enable-label" for="nsfw-enable">' . L10n::t('Enable Content filter') . ' </label>';
	$s .= '<input id="nsfw-enable" type="checkbox" name="nsfw-enable" value="1"' . $enable_checked . ' />';
	$s .= '<div class="clear"></div>';
	$s .= '<label id="nsfw-label" for="nsfw-words">' . L10n::t('Comma separated list of keywords to hide') . ' </label>';
	$s .= '<textarea id="nsfw-words" type="text" name="nsfw-words">' . $words .'</textarea>';
	$s .= '</div><div class="clear"></div>';

	$s .= '<div class="settings-submit-wrapper" ><input type="submit" id="nsfw-submit" name="nsfw-submit" class="settings-submit" value="' . L10n::t('Save Settings') . '" /></div>';
	$s .= '<div class="nsfw-desc">' . L10n::t('Use /expression/ to provide regular expressions') . '</div></div>';
	return;
}

function nsfw_addon_settings_post(&$a, &$b)
{
	if (!local_user()) {
		return;
	}

	if ($_POST['nsfw-submit']) {
		PConfig::set(local_user(), 'nsfw', 'words', trim($_POST['nsfw-words']));
		$enable = (x($_POST,'nsfw-enable') ? intval($_POST['nsfw-enable']) : 0);
		$disable = 1-$enable;
		PConfig::set(local_user(), 'nsfw', 'disable', $disable);
		info(L10n::t('NSFW Settings saved.') . EOL);
	}
}

function nsfw_prepare_body(&$a, &$b)
{
	// Don't do the check when there is a content warning
	if (!empty($b['item']['content-warning'])) {
		return;
	}

	$words = null;
	if (PConfig::get(local_user(), 'nsfw', 'disable')) {
		return;
	}

	if (local_user()) {
		$words = PConfig::get(local_user(), 'nsfw', 'words');
	}
	if ($words) {
		$arr = explode(',', $words);
	} else {
		$arr = ['nsfw'];
	}

	$found = false;
	if (count($arr)) {
		$body = $b['item']['title'] . "\n" . nsfw_extract_photos($b['html']);

		foreach ($arr as $word) {
			$word = trim($word);
			if (!strlen($word)) {
				continue;
			}
			if (strpos($word,'/') === 0) {
				if (preg_match($word, $body)) {
					$found = true;
					break;
				}
			} else {
				if (stristr($body, $word)) {
					$found = true;
					break;
				}
				if (is_array($b['item']['tags']) && count($b['item']['tags'])) {
					foreach ($b['item']['tags'] as $t) {
						if (stristr($t, '>' . $word . '<')) {
							$found = true;
							break;
						}
					}
				}
			}
		}
	}

	if ($found) {
		$rnd = random_string(8);
		$b['html'] = '<div id="nsfw-wrap-' . $rnd . '" class="fakelink" onclick=openClose(\'nsfw-' . $rnd . '\'); >' . L10n::t('%s - Click to open/close', $word) . '</div><div id="nsfw-' . $rnd . '" style="display: none; " >' . $b['html'] . '</div>';
	}
}