parse.php

<?php

/**

BSD 2-Clause License

Copyright (c) 2020, Alexandre Janon <alex14fr@gmail.com>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
	list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
	this list of conditions and the following disclaimer in the documentation
	and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

include_once "utils.php";
include_once "conf/conf.php";
include_once "auth.php";

$tags = array("*" => "b","/" => "i","_" => "u");
function parse_inline($l, $parseTags = true)
{
	global $tags, $pageId;
	global $mediaPrefix,$pagePrefix,$pageSuffix;
	$out = "";
	$n = strlen($l);
	for ($i = 0; $i < $n; ++$i) {
		switch ($l[$i]) {
				case "<":
					$out .= "&lt;";
					break;
				case ">":
					$out .= "&gt;";
					break;
				case "\"":
					$out .= "&quot;";
					break;
				case "*":
				case "_":
				case "/":
					if ($i + 1 < $n && $l[$i + 1] == $l[$i] && $parseTags) {
						$c = $l[$i];
						$i += 2;
						$s = "";
						$inlink = false;
						for (; $i < $n - 1 && ($inlink || ($l[$i] != $c && $l[$i + 1] != $c)); ++$i) {
								if ($l[$i] == "{" || $l[$i] == "[") {
									$inlink = true;
								}
								if ($l[$i] == "]" || $l[$i] == "}") {
									$inlink = false;
								}
								$s .= $l[$i];
						}
						if ($i < $n) {
								$s .= $l[$i];
						}
						$i += 2;
						$out .= "<" . $tags[$c] . ">" . parse_inline($s) . "</" . $tags[$c] . ">";
					} else {
						$out .= $l[$i];
					}
					break;
				case "[":
				case "{":
					$c = $l[$i];
					if ($i + 1 < $n && $l[$i + 1] == $c) {
						$i += 2;
						$s = "";
						if ($c == "[") {
								$clC = "]";
						} elseif ($c == "{") {
								$clC = "}";
						}
						for (
								; $i < $n - 1 && $l[$i] != $clC && $l[$i + 1] != $clC;
								++$i
						) {
								$s .= $l[$i];
						}
						if ($i < $n) {
								$s .= $l[$i];
						}
						$i += 2;
						if (!empty($s) && $s[0] == ":") {
								$s = substr($s, 1);
						}
						$mm = explode("|", $s);
						$ptags = true;
						if (count($mm) == 1) {
								$mm[1] = $mm[0];
								$ptags = false;
						}
						$asimg = false;
						$mm[0] = str_replace(array(" ","\""), "", $mm[0]);
						if ($c == "{") {
								$mmex = explode("?", $mm[0]);
								$baseurl = $mmex[0];
								if (count($mmex) > 1) {
									$wid = $mmex[1];
									$wid = preg_replace("/[^0-9]/", "", $wid);
								}
								$u = strlen($baseurl) - 4;
								if (
									strripos($baseurl, ".png") == $u ||
									strripos($baseurl, ".gif") == $u ||
									strripos($baseurl, ".jpg") == $u ||
									strripos($baseurl, ".webp") == $u - 1
								) {
										$asimg = true;
								}
						}
						if (substr_compare($mm[0], 'mailto:', 0, 7) !== 0 && strpos($mm[0], "@") > 0) {
								$mm[0] = "mailto:" . $mm[0];
						} elseif (substr_compare($mm[0], 'http', 0, 4) !== 0 && substr_compare($mm[0], 'ftp', 0, 3) !== 0) {
								if ($c == "{") {
									$mm[0] = $mediaPrefix . san_filename($baseurl);
								} elseif ($c == "[") {
									$mm[0] = $pagePrefix . san_pageId($mm[0]) . $pageSuffix;
								}
						}
						if (!$asimg) {
								$out .= "<a href=\"" . $mm[0] . "\">" . parse_inline($mm[1], $ptags) . "</a>";
						} else {
								$out .= "<img " . (!empty($wid) ? "width=$wid " : "") . "src=\"" . $mm[0] . "\">";
						}
					} else {
						$out .= $l[$i];
					}
					break;
				case "\\":
					if ($i + 1 < $n && $l[$i + 1] == "\\") {
						$i = $i + 2;
					} else {
						$out .= $l[$i];
					}
					break;
				case "&":
					if ($i + 11 < $n && substr_compare($l, '&#039;&#039;', $i, 12)===0) {
						$out .= "<span class=inline-fixed>";
						$i += 12;
						while ($i + 11 < $n && substr_compare($l, '&#039;&#039;', $i, 12)!==0 ) {
							$out .= $l[$i++];
						}
						$out .= "</span>";
						$i += 11;
					} else {
						$out .= $l[$i];
					}
					break;
				default:
					$out .= $l[$i];
					break;
		}
	}
	return($out);
}

function exit_par()
{
	global $list_lvl, $in_tbl;
	$out = "";
	for (; $list_lvl > 0; $list_lvl--) {
		$out .= "</ul>";
	}
	if ($in_tbl) {
		$out .= "</table>";
	}
	$in_tbl = false;
	return $out;
}

function parse_line($l)
{
	global $list_lvl, $title, $toc, $toc_level, $in_tbl, $title_lvl, $head_lvl, $pageId, $sectok, $codeBlock, $codeLanguage, $highlightOk;
	$l = rtrim($l);

	if($codeLanguage!==false) {
		if($l=="```") {
			$out = "";
			if($codeLanguage!==false) {
				if(!$highlightOk) {
					require_once "Highlight/Autoloader.php";
					spl_autoload_register("\\Highlight\\Autoloader::load");
					$highlightOk=new \Highlight\Highlighter();
					$out .= "<link rel=stylesheet href=Highlight/styles/github.css>";
				}
				try {
					$out .= "<pre><code class=\"hljs $codeLanguage\">".$highlightOk->highlight($codeLanguage,$codeBlock)->value."</code></pre>";
				} catch(Exception $e) {
					$out .= " -- Invalid language -- ";
				}
			}
			$codeLanguage=false;
			$codeBlock="";
			return $out;
		} else {
			$codeBlock .= $l."\n";
			return;
		}
	}

	$l = str_replace("\"","&quot;", str_replace("'","&#039;",str_replace("<","&lt;",str_replace(">","&gt;",$l))));
	$n = strlen($l);

	if ($n == 0) {
		if ($list_lvl > 0 || $in_tbl) {
				return exit_par();
		} else {
				return "<p>";
		}
	}

	if (substr_compare($l, '/* toc */ ', 0, 10) === 0) {
		$l = substr($l, 10);
		$n = strlen($l);
	}

	for ($i = 0; $i < $n; ++$i) {
		$out = "";
		switch ($l[$i]) {
				case "=":
					$head_lvl = 0;
					for (
						; $l[$i] == "=" && $i++ < $n;
						++$head_lvl
					);
					for (
						; $l[$i] == " " && $i++ <$n ;
					);
					$header = "";
					for (
						; $i < $n && $l[$i] != "=";
						$header .= $l[$i++]
					);
					if ($head_lvl >= 5) {
						$head_lvl = 1;
					} else {
						$head_lvl = 6 - $head_lvl;
					}
					$txt = parse_inline($header);
					$linkId = md5($txt);
					if(strpos($txt,"#") !==false) {
						$txtspl=explode("#",$txt);
						$txt=$txtspl[0];
						$linkId=$txtspl[1];
					}
					$titleTag = " id=" . $linkId;
					if ($head_lvl < $title_lvl) {
						$title = rmhtmltags($txt);
						$title_lvl = $head_lvl;
					} elseif ($head_lvl <= $toc_level && $head_lvl >= 2) {
						$toc .= "<li ".($head_lvl >= 3 ? "class=subtoc" : "")."><a href=#" . $linkId . ">" . $txt . "</a>";
					}
					return "<h" . $head_lvl . (empty($titleTag) ? "" : $titleTag) . ">" . $txt . "</h" . $head_lvl . ">" . ($head_lvl == 1 ? "~~TOC~~<p>" : "");

				case "-":
					if ($i++ < $n && $l[$i] == "-") {
						return "<hr>";
					}

				case " ":
					$spc_cnt = 0;
					for (
						; $l[$i] == " " && $i++ < $n;
						++$spc_cnt
					);
					if ($l[$i] == "-" || $l[$i] == "*" || $l[$i] == ".") {
						$list_gap = ($spc_cnt - 2 * $list_lvl) / 2;
						for (
								; $list_gap > 0;
								$list_gap--
						) {
								$out .= "<ul>";
						}
						for (
								; $list_gap < 0;
								++$list_gap
						) {
								$out .= "</ul>";
						}
						$list_lvl = $spc_cnt / 2;
						if ($list_lvl > 0) {
								$out .= "<li>";
						}
						return $out . parse_inline(substr($l, $i + 1));
					} else {
						return parse_inline($l);
					}

				case "^":
					if (!$in_tbl) {
						$in_tbl = true;
						$out .= "<table border=1>";
					}
					$out .= "<tr>";
					$in_link = false;
					++$i;
					for (; $i < $n; ++$i) {
						$s = "";
						for (; $i < $n && ($in_link || $l[$i] != "|"); ++$i) {
								if ($l[$i] == "[" || $l[$i] == "{") {
									$in_link = true;
								} elseif ($l[$i] == "]" || $l[$i] == "}") {
									$in_link = false;
								}
								$s .= $l[$i];
						}
						if ($i + 1 < $n && $l[$i + 1] == "|") {
								$out .= "<td colspan=2>" . parse_inline($s);
								$i += 2;
						} elseif ($s != "") {
								$out .= "<td>" . parse_inline($s);
						}
					}
					return $out;
				case "~":
					if ($i + 1 < $n && $l[$i] == $l[$i + 1]) {
						$i += 2;
						$s = "";
						for (
								; $i < $n && $l[$i] == "~";
								++$i
						);
						for (
								; $i < $n && $l[$i] != "~";
								++$i
						) {
								$s .= $l[$i];
						}
						for (
								; $i < $n && $l[$i] == "~";
								++$i
						);
						if ($s == "br") {
								$out .= "<br>";
						} elseif ($s == "/div") {
								$out .= "</div>";
						} elseif (strpos($s, "div") !== false) {
								$sxplod = explode(" ", $s);
								if (count($sxplod) > 1) {
									$cl = str_replace("\"", "", $sxplod[1]);
								} else {
									$cl = "";
								}
								$out .= "<div class=\"$cl\">";
						} elseif (strpos($s, "FORM") !== false) {
								$expire = true;
								$out .= "<ul><li><a href=event.php?action=view&id=$pageId&sectok=$sectok>List of participants</a>";
								if ($s != "FORM expire") {
									$expire = false;
									$out .= "<li><a href=event.php?id=$pageId&sectok=$sectok>Registration form</a>";
								}
								$out .= "</ul>";
								global $dbevents;
								try {
									$db = new SQLite3("$dbevents");
									if($expire) {
										$db->exec("INSERT OR IGNORE INTO expire VALUES('".$db->escapeString($pageId)."')");
									} else {
										$db->exec("DELETE FROM expire WHERE id='".$db->escapeString($pageId)."'");
									}
								} catch (Exception $e) {
									die("db error " . $e->getMessage());
								}
						} elseif ($s == "HAL") {
								$out .= file_get_contents("ephemeral/hal.html");
						} elseif ($s == "rss2") {
								$out .= file_get_contents("ephemeral/rss2.html");
						} elseif ($s == "rssshort") {
								$out .= file_get_contents("ephemeral/rssshort.html");
						} elseif ($s == "swupdates" && $pageId!="software_updates") {
								$pageIdx=$pageId;
								$pageId="software_updates";
								$fp=fopen("data/pages/software_updates.txt","r");
								do {
									$l=fgets($fp, 1024);
									if(($nnn=strpos($l, "*"))!==false) {
										$brk=true;
										for($iii=0; $iii<$nnn && $brk; ++$iii) {
											if($l[$iii]!=" " && $l[$iii]!="\t") {
												//$out.= "\n\n<!--- (".$l[$iii].") ".ord($l[$iii])." -->\n\n";
												$brk=false;
											}
										}
										if($brk) break;
									}
								} while($l!==false);
								$iii=0;
								while($iii++<5 && $l!==false) {
									$out.=parse_line($l);
									$l=fgets($fp, 1024);
								}
								$pageId=$pageIdx;
						} elseif (strpos($s, "toclevel") !== false) {
								$sxplod = explode(" ", $s);
								if (count($sxplod) > 1) 
									$toc_level = $sxplod[1];
						}
					} else {
						$out .= $l[$i];
					}
					return $out;
				case "`":
					for(++$i; $i<$n && $l[$i]=="`"; ++$i);
					if($i==$n) {
						return $l;
					} else {
						$codeLanguage=substr($l, $i, $n-$i);
						$codeBlock="";
						for($jj=0;$jj<strlen($codeLanguage);++$jj) {
							if($codeLanguage[$jj]>'z' || $codeLanguage[$jj]<'a') {
								$codeLanguage=false;
								return " -- CODE BLOCK ERROR -- ";
							}
						}
						return "";
					}
				default:
					$eli = exit_par();
					$pil = parse_inline($l);
					$br = "";
					if (strlen($pil) > 0) {
						$br = "<br>";
					}
					return $eli . $pil . $br;
		}
	}
}

function render_str($str)
{
	global $list_lvl, $title, $title_lvl, $toc_level, $toc, $codeBlock, $codeLanguage, $highlightOk;
	$codeBlock="";
	$codeLanguage=false;
	$highlightOk=false;
	$list_lvl = 0;
	$toc = "";
	$toc_level = 2;
	$out = "";
	foreach (explode("\n", $str) as $l) {
		$out .= parse_line($l);
	}
	$out = str_replace_first("~~TOC~~", "<ul class=toc>$toc</ul>", $out);
	$out = str_replace("~~TOC~~", "", $out);
	return($out);
}

function render_page($page, $rev = "")
{
	global $list_lvl, $title, $title_lvl, $toc, $toc_level, $pageId, $sectok, $codeBlock, $codeLanguage, $highlightOk;
	include_once "conf/conf.php";
	global $secret1, $secret2, $pageDir, $atticDir;
	$codeBlock="";
	$codeLanguage=false;
	$highlightOk=false;
	$list_lvl = 0;
	$pageId = san_pageId($page);
	$title = $pageId;
	$title_lvl = 4;
	$toc = "";
	$toc_level = 2;
	$rev = san_pageRev($rev);
	$out = "";
	$sectok = hash("sha256", $secret1 . $pageId . $secret2);
	if (empty($rev)) {
		$fnam = "$pageDir/$pageId.txt";
		if (!is_readable($fnam)) {
				header("HTTP/1.1 404 Not found");
				print "Page not found. ";
				if (!empty(get_login()) && auth_isCommittee()) {
					print "<a href=\"index.php?do=edit&id=$pageId\">Create this page</a>";
				}
				exit;
		}
		$fd = fopen($fnam, "r");
		if (!$fd) {
				die("err");
		}
		while ($line = fgets($fd)) {
				$out .= parse_line($line);
		}
		fclose($fd);
	} else {
		$fd = gzopen("$atticDir/$pageId.$rev.txt.gz", "r");
		if (!$fd) {
				die("err");
		}
		while ($line = gzgets($fd)) {
				$out .= parse_line($line);
		}
		fclose($fd);
	}
	$out .= exit_par();
	$out = str_replace_first("~~TOC~~", "<ul class=toc>$toc</ul>", $out);
	$out = str_replace("~~TOC~~", "", $out);
	return($out);
}

function render_page_cache($page, $rev = "")
{
	global $pageDir, $cacheDir, $title;
	$pageId = san_pageId($page);
	if (!empty($rev)) {
		$rev = preg_replace("/[^0-9]/", "", $rev);
	}
	if (
		!empty($rev) ||
		$rev != "" ||
		!file_exists("$cacheDir/$pageId") ||
		filemtime("$cacheDir/$pageId") < filemtime("$pageDir/$pageId.txt")
	) {
				$rp = render_page($pageId, $rev);
		if ((empty($rev) || $rev == "") && !empty($cacheDir)) {
				file_put_contents("$cacheDir/$pageId", $rp);
				file_put_contents("$cacheDir/$pageId.t", $title);
		}
				return($rp);
	} else {
				$title = file_get_contents("$cacheDir/$pageId.t");
				return(file_get_contents("$cacheDir/$pageId"));
	}
}

function render_html($str, $pageId = "", $title = "")
{
	global $editableDir, $baseUrl;
	$actions = "";
	if (!empty($pageId)) {
		if (!empty(get_login())) {
				$actions = (auth_canEdit($pageId) ? "<a href=\"index.php?do=edit&id=$pageId\">Edit this page</a>" : "") .
							(auth_isCommittee() ? "<a href=\"index.php?do=revisions&id=$pageId\">Old revisions</a>" : "") .
								(auth_isAdmin() ? "<a href=\"index.php?do=edit&id=sidebar\">Edit sidebar</a><a href=admpasswd.php>Edit passwd / perms</a>" : "") .
								(auth_isAdmin() && file_exists($editableDir . "/" . $pageId) ? "<a href=\"index.php?do=revokeEdit&id=$pageId\">Unset contrib-writable</a>" : "") .
								(auth_isAdmin() && !file_exists($editableDir . "/" . $pageId) ? "<a href=\"index.php?do=allowEdit&id=$pageId\">Set contrib-writable</a>" : "") .
								"<a href=\"index.php?do=logout&id=$pageId\">Logout " . get_login() . "</a>";
		} else {
				$actions = "<a href=\"index.php?do=login&id=$pageId\">Login / Register</a>";
		}
	}
	$pgh = str_replace(
		array("~~ACTIONS~~","~~TITLE~~","~~SIDEBAR~~","~~CANONICAL~~"),
		array($actions, $title, render_page_cache("sidebar"), $baseUrl.($pageId === "index" ? "" : $pageId)),
		readtmpl("htmlhead")
	);
	return $pgh . $str . readtmpl("htmlfoot");
}

function render_page_full($page, $rev = "")
{
	global $title;
	$pageId = san_pageId($page);
	$rp = render_page_cache($pageId, $rev);
	return render_html($rp, $page, $title);
}