<?php
$mailbox = 'mail/inbox';
@list ($msgid) = explode('/', ltrim($Page->path, '/'));

if (!function_exists('parsemailhead')) {
function parsemailhead($headerdata)
{
	$headlist = iconv_mime_decode_headers($headerdata, ICONV_MIME_DECODE_CONTINUE_ON_ERROR);
	$headlist['date'] = DateTime::createFromFormat(DateTimeInterface::RFC2822.'+', $headlist['Date']);
	$headlist['from'] = imap_rfc822_parse_adrlist($headlist['From'], '');
	array_walk($headlist['from'], function ($row) {
		$row->display = $row->personal ?? $row->mailbox;
	});
	return $headlist;
}
}

if ($msgid) {
	$filename = "$mailbox/$msgid";
	if (!is_readable($filename)) {
		return TRUE;
	}

	list ($headerdata, $rawbody) = explode("\n\n", file_get_contents($filename), 2);
	$head = parsemailhead($headerdata);
	$head['date']->setTimezone(new DateTimeZone(date_default_timezone_get()));

	$Page->title = 'Mailbericht ' . $head['date']->format('Y-m-d H:i');
	printf("<h2>%s</h2>\n", htmlspecialchars($head['Subject'] ?? 'Mailbericht zonder onderwerp'));

	printf('<h3><a href="mailto:%s">%s</a> <small class="date" title="%s">%s</small></h3>'."\n",
		htmlspecialchars($head['From']),
		htmlspecialchars(implode(', ', array_column($head['from'], 'display'))),
		htmlspecialchars($head['Date']),
		showdate(preg_split('/\D/', $head['date']->format('c')))
	);
	print '</dl>';

	$type = preg_replace('/;.*/', '', $head['Content-Type'] ?? 'text/plain', 1);
	switch ($type) {
	case 'text/plain':
		$body = $rawbody;
		if (($head['Content-Transfer-Encoding'] ?? '') === 'quoted-printable') {
			$body = quoted_printable_decode($body);
		}
		$body = nl2br(htmlspecialchars($body));
		print "<p>$body</p>\n";
		break;
	case 'multipart/alternative':
		$mime = mailparse_msg_parse_file($filename);
		foreach (mailparse_msg_get_structure($mime) as $section) {
			print "<h3>$section</h3>\n";
			$part = mailparse_msg_get_part($mime, $section);
			if ($section === '1') {
				continue; // do not access container to prevent segfault
			}
			$pinfo = mailparse_msg_get_part_data($part);
		#printf('<pre>%s</pre>', htmlspecialchars(print_r($pinfo,TRUE)));
			$phead = $pinfo['headers'];
			list ($ptype) = explode(';', strtolower($phead['content-type']));
			list ($pmedia) = explode('/', $ptype);
			switch ($pmedia) {
			case 'multipart':
				continue 2;
			case 'text':
				$body = mailparse_msg_extract_part_file($part, $filename, NULL);
				#iconv($pinfo['charset'], 'UTF-8', $body); #TODO test if needed
				switch ($ptype) {
				case 'text/plain':
					$body = htmlspecialchars($body);
					print "<pre><p>$body</p></pre>\n";
					break;
				case 'text/html':
					$body = preg_replace('{
						(<br */?>) | <[^>]+> # keep line breaks, replace other elements
					}x', "\\1\n", $body); # strip_tags
					print "<p>$body</p>\n";
					break;
				}
				break;
			case 'image':
				if (!preg_match('/^inline;/', $phead['content-disposition'])) {
					continue 2;
				}
				$name = iconv_mime_decode($phead['disposition-filename']);
				$body = mailparse_msg_extract_part_file($part, $filename, NULL);
				printf('<img src="data:%s;base64,%s" alt="%s" />',
					$ptype, base64_encode($body),
					htmlspecialchars($phead['name'] ?? '-')
				);
				break;
			}
		}
		mailparse_msg_free($mime);
		break;
	default:
		printf('<p>Geen ondersteuning voor <em>%s</em>.</p>', htmlspecialchars($type));
	}
	return;
}

if ($Page->api) {
	return;
}
if (!$User->admin('user')) {
	http_response_code(403);
	$Page->place['warn'] = "Geen gebruikersrechten om e-mails in te zien.";
	$Page->place['maillist'] = '';
	return TRUE;
}

$rows = glob("$mailbox/*");
if (!$rows) {
	throw new Exception('Kon inbox niet openen.');
}

$nav = [
	'start' => $_GET['start'] ?? 0,
	'n'     => $_GET['n'] ?? 10,
	'total' => count($rows),
];
$rows = array_slice(array_reverse($rows), $nav['start'], $nav['n']);

ob_start();
print '<ul>';
foreach (array_reverse($rows) as $filename) {
	if (!is_readable($filename)) {
		continue;
	}

	printf('<li><a href="%s">', "/{$Page->handler}/".basename($filename));

	list ($headerdata) = explode("\n\n", file_get_contents($filename));
	$head = parsemailhead($headerdata);

	print $head['Subject'];
	printf(' <small class="date" title="%s">%s</small>',
		htmlspecialchars($head['Date']),
		showdate(explode('-', $head['date']->format('Y-m-d')))
	);
	printf(' <em class="right" title="%s">%s</em>',
		htmlspecialchars($head['From']),
		htmlspecialchars(implode(', ', array_column($head['from'], 'display')))
	);
	print "</a></li>\n";
}
print "</ul>\n";

print $Page->widget('nav', $nav);

$Page->place['maillist'] = ob_get_clean();