<?php

/**
 * Name: Privacy Image Cache
 * Version: 0.1
 * Author: Tobias Hößl <https://github.com/CatoTH/>
 */

define("PRIVACY_IMAGE_CACHE_DEFAULT_TIME", 86400); // 1 Day

require_once('include/security.php');

function privacy_image_cache_install() {
    register_hook('prepare_body', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_prepare_body_hook');
 //   register_hook('bbcode',       'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_bbcode_hook');
    register_hook('display_item', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_display_item_hook');
    register_hook('ping_xmlize',  'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_ping_xmlize_hook');
    register_hook('cron',         'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_cron');
}


function privacy_image_cache_uninstall() {
    unregister_hook('prepare_body', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_prepare_body_hook');
    unregister_hook('bbcode',       'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_bbcode_hook');
    unregister_hook('display_item', 'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_display_item_hook');
    unregister_hook('ping_xmlize',  'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_ping_xmlize_hook');
    unregister_hook('cron',         'addon/privacy_image_cache/privacy_image_cache.php', 'privacy_image_cache_cron');
}


function privacy_image_cache_module() {}


function privacy_image_cache_init() {
	global $a;

	if(function_exists('header_remove')) {
		header_remove('Pragma');
		header_remove('pragma');
	}

	$urlhash = 'pic:' . sha1($_REQUEST['url']);
	// Double encoded url - happens with Diaspora
	$urlhash2 = 'pic:' . sha1(urldecode($_REQUEST['url']));

	$cache = get_config('system','itemcache');
	if (($cache != '') and is_dir($cache)) {
		$cachefile = $cache."/".hash("md5", $urlhash);
		if (file_exists($cachefile)) {
			$img_str = file_get_contents($cachefile);

			$mime = image_type_to_mime_type(exif_imagetype($cachefile));

			header("Content-type: $mime");
			header("Expires: " . gmdate("D, d M Y H:i:s", time() + (3600*24)) . " GMT");
			header("Cache-Control: max-age=" . (3600*24));

			echo $img_str;

			killme();
		}
	}

	$r = q("SELECT * FROM `photo` WHERE `resource-id` in ('%s', '%s') LIMIT 1", $urlhash, $urlhash2);
	if (count($r)) {
        	$img_str = $r[0]['data'];
		$mime = $r[0]["desc"];
		if ($mime == "") $mime = "image/jpeg";
	} else {
		require_once("Photo.php");

		// It shouldn't happen but it does - spaces in URL
		$_REQUEST['url'] = str_replace(" ", "+", $_REQUEST['url']);

		$img_str = fetch_url($_REQUEST['url'],true);

		$tempfile = tempnam("", "cache");
		file_put_contents($tempfile, $img_str);
		$mime = image_type_to_mime_type(exif_imagetype($tempfile));
		unlink($tempfile);

		// If there is an error then return a blank image
		if ((substr($a->get_curl_code(), 0, 1) == "4") or (!$img_str)) {
			$img_str = file_get_contents("images/blank.png");
			$mime = "image/png";
		//} else if (substr($img_str, 0, 6) == "GIF89a") {
		} else if ($mime != "image/jpeg") {
			$image = @imagecreatefromstring($img_str);

			if($image === FALSE) die();

			q("INSERT INTO `photo`
			( `uid`, `contact-id`, `guid`, `resource-id`, `created`, `edited`, `filename`, `album`, `height`, `width`, `desc`, `data`, `scale`, `profile`, `allow_cid`, `allow_gid`, `deny_cid`, `deny_gid` )
			VALUES ( %d, %d, '%s', '%s', '%s', '%s', '%s', '%s', %d, %d, '%s', '%s', %d, %d, '%s', '%s', '%s', '%s' )",
				0, 0, get_guid(), dbesc($urlhash),
				dbesc(datetime_convert()),
				dbesc(datetime_convert()),
				dbesc(basename(dbesc($_REQUEST["url"]))),
				dbesc(''),
				intval(imagesy($image)),
				intval(imagesx($image)),
				$mime,
				dbesc($img_str),
				100,
				intval(0),
				dbesc(''), dbesc(''), dbesc(''), dbesc('')
			);

		} else {
			$img = new Photo($img_str);
			if($img->is_valid()) {
				$img->store(0, 0, $urlhash, $_REQUEST['url'], '', 100);
				$img_str = $img->imageString();
			}
			$mime = "image/jpeg";
		}
	}

	// Writing in cachefile
	if (isset($cachefile) && $cachefile != '')
		file_put_contents($cachefile, $img_str);

	header("Content-type: $mime");
	header("Expires: " . gmdate("D, d M Y H:i:s", time() + (3600*24)) . " GMT");
	header("Cache-Control: max-age=" . (3600*24));

	echo $img_str;

	killme();
}

/**
 * @param $url string
 * @return boolean
 */
function privacy_image_cache_is_local_image($url) {
    if ($url[0] == '/') return true;
	if (strtolower(substr($url, 0, 5)) == "data:") return true;

	// links normalised - bug #431
    $baseurl = normalise_link(get_app()->get_baseurl());
	$url = normalise_link($url);
    return (substr($url, 0, strlen($baseurl)) == $baseurl);
}

/**
 * @param array $matches
 * @return string
 */
function privacy_image_cache_img_cb($matches) {
	// following line changed per bug #431
	if (privacy_image_cache_is_local_image($matches[2]))
		return $matches[1] . $matches[2] . $matches[3];

	return $matches[1] . get_app()->get_baseurl() . "/privacy_image_cache/?url=" . addslashes(rawurlencode(htmlspecialchars_decode($matches[2]))) . $matches[3];
}

/**
 * @param App $a
 * @param string $o
 */
function privacy_image_cache_prepare_body_hook(&$a, &$o) {
	$o["html"] = preg_replace_callback("/(<img [^>]*src *= *[\"'])([^\"']+)([\"'][^>]*>)/siU", "privacy_image_cache_img_cb", $o["html"]);
}

/**
 * @param App $a
 * @param string $o
 * Function disabled because the plugin moved
 */
function privacy_image_cache_bbcode_hook(&$a, &$o) {
	//$o = preg_replace_callback("/(<img [^>]*src *= *[\"'])([^\"']+)([\"'][^>]*>)/siU", "privacy_image_cache_img_cb", $o);
}


/**
 * @param App $a
 * @param string $o
 */
function privacy_image_cache_display_item_hook(&$a, &$o) {
    if (isset($o["output"])) {
        if (isset($o["output"]["thumb"]) && !privacy_image_cache_is_local_image($o["output"]["thumb"]))
            $o["output"]["thumb"] = $a->get_baseurl() . "/privacy_image_cache/?url=" . escape_tags(addslashes(rawurlencode($o["output"]["thumb"])));
        if (isset($o["output"]["author-avatar"]) && !privacy_image_cache_is_local_image($o["output"]["author-avatar"]))
            $o["output"]["author-avatar"] = $a->get_baseurl() . "/privacy_image_cache/?url=" . escape_tags(addslashes(rawurlencode($o["output"]["author-avatar"])));
    }
}


/**
 * @param App $a
 * @param string $o
 */
function privacy_image_cache_ping_xmlize_hook(&$a, &$o) {
    if ($o["photo"] != "" && !privacy_image_cache_is_local_image($o["photo"]))
        $o["photo"] = $a->get_baseurl() . "/privacy_image_cache/?url=" . escape_tags(addslashes(rawurlencode($o["photo"])));
}


/**
 * @param App $a
 * @param null|object $b
 */
function privacy_image_cache_cron(&$a = null, &$b = null) {
    $cachetime = get_config('privacy_image_cache','cache_time');
    if (!$cachetime) $cachetime = PRIVACY_IMAGE_CACHE_DEFAULT_TIME;

    $last = get_config('pi_cache','last_delete');
    $time = time();
    if ($time < ($last + 3600)) return;

    logger("Purging old Cache of the Privacy Image Cache", LOGGER_DEBUG);
    q('DELETE FROM `photo` WHERE `uid` = 0 AND `resource-id` LIKE "pic:%%" AND `created` < NOW() - INTERVAL %d SECOND', $cachetime);
    set_config('pi_cache', 'last_delete', $time);
}


/**
 * @param App $a
 * @param null|object $o
 */
function privacy_image_cache_plugin_admin(&$a, &$o){


    $o = '<input type="hidden" name="form_security_token" value="' . get_form_security_token("picsave") . '">';

    $cachetime = get_config('privacy_image_cache','cache_time');
    if (!$cachetime) $cachetime = PRIVACY_IMAGE_CACHE_DEFAULT_TIME;
    $cachetime_h = Ceil($cachetime / 3600);

    $o .= '<label for="pic_cachetime">' . t('Lifetime of the cache (in hours)') . '</label>
        <input id="pic_cachetime" name="cachetime" type="text" value="' . escape_tags($cachetime_h) . '"><br style="clear: both;">';

    $o .= '<input type="submit" name="save" value="' . t('Save') . '">';

    $o .= '<h4>' . t('Cache Statistics') . '</h4>';

    $num = q('SELECT COUNT(*) num, SUM(LENGTH(data)) size FROM `photo` WHERE `uid`=0 AND `contact-id`=0 AND `resource-id` LIKE "pic:%%"');
    $o .= '<label for="statictics_num">' . t('Number of items') . '</label><input style="color: gray;" id="statistics_num" disabled value="' . escape_tags($num[0]['num']) . '"><br style="clear: both;">';
    $size = Ceil($num[0]['size'] / (1024 * 1024));
    $o .= '<label for="statictics_size">' . t('Size of the cache') . '</label><input style="color: gray;" id="statistics_size" disabled value="' . $size . ' MB"><br style="clear: both;">';

    $o .= '<input type="submit" name="delete_all" value="' . t('Delete the whole cache') . '">';
}


/**
 * @param App $a
 * @param null|object $o
 */
function privacy_image_cache_plugin_admin_post(&$a = null, &$o = null){
    check_form_security_token_redirectOnErr('/admin/plugins/privacy_image_cache', 'picsave');

    if (isset($_REQUEST['save'])) {
        $cachetime_h = IntVal($_REQUEST['cachetime']);
        if ($cachetime_h < 1) $cachetime_h = 1;
        set_config('privacy_image_cache','cache_time', $cachetime_h * 3600);
    }
    if (isset($_REQUEST['delete_all'])) {
        q('DELETE FROM `photo` WHERE `uid` = 0 AND `resource-id` LIKE "pic:%%"');
    }
}