refactor(web/group): group_v3 (#17)

2024-11-22 14:48:41 +00:00 · 2022-11-11 14:01:21 +08:00 · 2022-11-11 14:01:21 +08:00 · d7446b9fa9
commit d7446b9fa9
parent 91fb9c8e01 287889b60f
17 changed files with 837 additions and 629 deletions
--- a/web/app/controllers/contest_members.php
+++ b/web/app/controllers/contest_members.php
@ -48,15 +48,12 @@ if ($is_manager) {
 		'小组 ID',
 		'',
 		function ($group_id, &$vdata) {
-			if (!validateUInt($group_id)) {
-				return '小组 ID 不合法';
-			}
-			$group = queryGroup($group_id);
+			$group = UOJGroup::query($group_id);
 			if (!$group) {
 				return '小组不存在';
 			}

-			$vdata['group_id'] = $group_id;
+			$vdata['group'] = $group;

 			return '';
 		},
@ -65,9 +62,11 @@ if ($is_manager) {
 	$add_group_to_contest_form->submit_button_config['align'] = 'compressed';
 	$add_group_to_contest_form->submit_button_config['text'] = '注册该小组中的用户';
 	$add_group_to_contest_form->handle = function (&$vdata) {
-		$users = queryGroupUsers($vdata['group_id']);
+		$usernames = $vdata['group']->getUsernames();
+
+		foreach ($usernames as $username) {
+			$user = UOJUser::query($username);

-		foreach ($users as $user) {
 			UOJContest::cur()->userRegister($user);
 		}
 	};
@ -177,7 +176,8 @@ if ($contest['cur_progress'] == CONTEST_NOT_STARTED) {
 <?php endif ?>

 <?php
-$header_row = '<tr><th>#</th><th>' . UOJLocale::get('username') . '</th>';
+$header_row = '<tr>';
+$header_row .= '<th>#</th><th>' . UOJLocale::get('username') . '</th>';
 if ($show_ip) {
 	$header_row .= '<th>remote_addr</th><th>http_x_forwarded_for</th>';
 }
--- a/web/app/controllers/group.php
+++ b/web/app/controllers/group.php
@ -4,41 +4,38 @@
 requirePHPLib('judger');
 requirePHPLib('data');

-	if (!Auth::check()) {
-		redirectToLogin();
-	}
-
-	$group_id = $_GET['id'];
-	if (!validateUInt($group_id) || !($group = queryGroup($group_id))) {
-		become404Page();
-	}
-
-	if (!isSuperUser($myUser) && $group['is_hidden']) {
-		become403Page();
-	}
+Auth::check() || redirectToLogin();
+UOJGroup::init(UOJRequest::get('id')) || UOJResponse::page404();
+UOJGroup::cur()->userCanView(Auth::user(), ['ensure' => true]);
 ?>

-<?php echoUOJPageHeader(UOJLocale::get('groups')) ?>
+<?php echoUOJPageHeader('小组：' . UOJGroup::info('title')) ?>

 <div class="row">
 	<!-- left col -->
 	<div class="col-lg-9">
-
 		<!-- title -->
 		<div class="d-flex justify-content-between">
 			<h1>
-	<?php if ($group['is_hidden']): ?>
-		<span class="fs-5 text-danger">[隐藏]</span>
+				<?= UOJGroup::info('title') ?>
+				<span class="fs-5">(ID: #<?= UOJGroup::info('id') ?>)</span>
+				<?php if (UOJGroup::info('is_hidden')) : ?>
+					<span class="badge text-bg-danger fs-6">
+						<i class="bi bi-eye-slash-fill"></i>
+						<?= UOJLocale::get('hidden') ?>
+					</span>
 				<?php endif ?>
-	<?= $group['title'] ?>
-	<span class="fs-5">(ID: #<?= $group['id'] ?>)</span>
 			</h1>

-<?php if (isSuperUser($myUser)): ?>
+			<?php if (UOJGroup::cur()->userCanManage(Auth::user())) : ?>
 				<div class="text-end">
-	<a class="btn btn-primary" href="/group/<?= $group['id'] ?>/manage" role="button">
-		<?= UOJLocale::get('problems::manage') ?>
-	</a>
+					<?=
+					UOJGroup::cur()->getLink([
+						'where' => '/manage',
+						'class' => 'btn btn-primary',
+						'text' => UOJLocale::get('problems::manage'),
+					]);
+					?>
 				</div>
 			<?php endif ?>
 		</div>
@ -50,9 +47,9 @@
 				<h2 class="h3">
 					<?= UOJLocale::get('group announcement') ?>
 				</h2>
-		<?php if ($group['announcement']): ?>
+				<?php if (UOJGroup::info('announcement')) : ?>
 					<div class="text-break">
-			<?= HTML::purifier_inline()->purify(HTML::parsedown()->line($group['announcement'])) ?>
+						<?= HTML::purifier_inline()->purify(HTML::parsedown()->line(UOJGroup::info('announcement'))) ?>
 					</div>
 				<?php else : ?>
 					<div class="text-muted">
@ -66,22 +63,21 @@
 			<div class="card-body">
 				<h2 class="card-title h3">
 					<?= UOJLocale::get('news') ?>
-		</h5>
+				</h2>
 				<ul class="mb-0">
+					<?php foreach (UOJGroup::cur()->getLatestGroupmatesAcceptedSubmissionIds(Auth::user()) as $id) : ?>
 						<?php
-			$current_ac = queryGroupCurrentAC($group['id']);
-	foreach ($current_ac as $ac) {
-		echo '<li>';
-		echo getUserLink($ac['submitter']);
-		echo ' 解决了问题 ';
-		echo '<a class="text-decoration-none" href="/problem/', $ac['problem_id'], '">', $ac['problem_title'], '</a> ';
-		echo '<time class="time">(', $ac['submit_time'], ')</time>';
-		echo '</li>';
-	}
-	if (count($current_ac) == 0) {
-		echo '暂无最新动态';
-	}
+						$submission = UOJSubmission::query($id);
+						$submission->setProblem();
+						$user = UOJUser::query($submission->info['submitter']);
 						?>
+						<li>
+							<?= UOJUser::getLink($user) ?>
+							解决了问题
+							<?= $submission->problem->getLink(['with' => 'id']) ?>
+							(<time><?= $submission->info['submit_time'] ?></time>)
+						</li>
+					<?php endforeach ?>
 				</ul>
 			</div>
 		</div>
@ -90,17 +86,22 @@
 			<div class="card-body">
 				<h2 class="card-title h3">
 					<?= UOJLocale::get('assignments') ?>
-		</h5>
+				</h2>
 				<?php
 				echoLongTable(
+					['*'],
 					[
-					'groups_assignments.list_id as list_id',
-					'lists.title as title',
-					'groups_assignments.end_time as end_time'
+						"groups_assignments",
+						"left join lists",
+						"on", [
+							"lists.id" => DB::raw("groups_assignments.list_id"),
+						]
 					],
-				'groups_assignments left join lists on lists.id = groups_assignments.list_id',
-				"groups_assignments.group_id = {$group['id']} and groups_assignments.end_time > addtime(now(), '-168:00:00')",
-				'order by end_time desc, list_id desc',
+					[
+						"groups_assignments.group_id" => UOJGroup::info('id'),
+						["groups_assignments.end_time", ">", DB::raw("addtime(now(), '-168:00:00')")]
+					],
+					'order by groups_assignments.end_time desc, groups_assignments.list_id desc',
 					<<<EOD
 						<tr>
 							<th style="width:3em" class="text-center">ID</th>
@ -109,25 +110,25 @@
 							<th style="width:8em">结束时间</th>
 						</tr>
 					EOD,
-				function($row) use ($group) {
-					$end_time = DateTime::createFromFormat('Y-m-d H:i:s', $row['end_time']);
+					function ($info) {
+						$assignment = new UOJGroupAssignment($info, UOJGroup::cur());

-					echo '<tr>';
-					echo '<td class="text-center">', $row['list_id'], '</td>';
-					echo '<td>', '<a class="text-decoration-none" href="/group/', $group['id'], '/assignment/', $row['list_id'],'">', HTML::escape($row['title']), '</a>', '</td>';
-					if ($end_time < UOJTime::$time_now) {
-						echo '<td class="text-danger">已结束</td>';
+						echo HTML::tag_begin('tr');
+						echo HTML::tag('td', ['class' => 'text-center'], $assignment->info['id']);
+						echo HTML::tag('td', [], $assignment->getLink());
+						if ($assignment->info['end_time'] < UOJTime::$time_now) {
+							echo HTML::tag('td', ['class' => 'text-danger'], '已结束');
 						} else {
-						echo '<td class="text-success">进行中</td>';
+							echo HTML::tag('td', ['class' => 'text-success'], '进行中');
 						}
-					echo '<td>', $end_time->format('Y-m-d H:i:s'), '</td>';
-					echo '</tr>';
+						echo HTML::tag('td', [], $assignment->info['end_time_str']);
+						echo HTML::tag_end('tr');
 					},
 					[
 						'echo_full' => true,
 						'div_classes' => ['table-responsive'],
 						'table_classes' => ['table', 'align-middle', 'mb-0'],
-				]
+					],
 				);
 				?>
 			</div>
@ -137,23 +138,19 @@ EOD,
 			<div class="card-body">
 				<h2 class="card-title h3">
 					<?= UOJLocale::get('top solver') ?>
-		</h5>
-		<?php echoRanklist([
-			'page_len' => 50,
-			'group_id' => $group_id,
-			'by_accepted' => true,
-			'div_classes' => ['table-responsive', 'mb-3'],
-			'table_classes' => ['table', 'text-center', 'mb-0'],
+				</h2>
+				<?php UOJRanklist::printHTML([
+					'page_len' => 25,
+					'group_id' => UOJGroup::info('id'),
 				]) ?>
 			</div>
 		</div>
-
 		<!-- end left col -->
 	</div>

 	<!-- right col -->
 	<aside class="col-lg-3 mt-3 mt-lg-0">
-<?php uojIncludeView('sidebar'); ?>
+		<?php uojIncludeView('sidebar') ?>
 	</aside>

 </div>
--- a/web/app/controllers/group_assignment.php
+++ b/web/app/controllers/group_assignment.php
@ -11,23 +11,13 @@ if (!validateUInt($group_id)) {
 	become404Page();
 }

-UOJList::init(UOJRequest::get('list_id')) || UOJResponse::page404();
-
-$assignment = queryAssignmentByGroupListID($group_id, UOJList::info('id'));
-
-if (!$assignment) {
-	become404Page();
-}
-
-$group = queryGroup($assignment['group_id']);
-$list = UOJList::info();
-
-if (($group['is_hidden'] || $list['is_hidden']) && !isSuperUser($myUser)) {
-	become403Page();
-}
+UOJGroup::init(UOJRequest::get('id')) || UOJResponse::page404();
+UOJGroupAssignment::init(UOJRequest::get('list_id')) || UOJResponse::page404();
+UOJGroupAssignment::cur()->valid() || UOJResponse::page404();
+UOJGroupAssignment::cur()->userCanView(['ensure' => true]);
 ?>

-<?php echoUOJPageHeader(UOJLocale::get('assignments')) ?>
+<?php echoUOJPageHeader(UOJLocale::get('assignments') . ' ' . UOJGroupAssignment::info('title')) ?>

 <div class="row">
 	<!-- left col -->
@ -36,48 +26,48 @@ if (($group['is_hidden'] || $list['is_hidden']) && !isSuperUser($myUser)) {
 			<small class="fs-4">作业：</small><?= UOJList::info('title') ?>
 		</h1>
 		<ul class="mt-3">
-			<li>对应题单：<a class="text-decoration-none" href="<?= HTML::url('/list/' . UOJList::info('id')) ?>">#<?= UOJList::info('id') ?></a></li>
-			<li>所属小组：<a class="text-decoration-none" href="<?= HTML::url('/group/' . $group['id']) ?>"><?= $group['title'] ?></a></li>
-			<li>结束时间：<?= $assignment['end_time'] ?></li>
+			<li>对应题单：<a href="<?= HTML::url('/list/' . UOJGroupAssignment::info('id')) ?>">#<?= UOJGroupAssignment::info('id') ?></a></li>
+			<li>所属小组：<?= UOJGroup::cur()->getLink() ?>
+			<li>结束时间：<?= UOJGroupAssignment::info('end_time_str') ?></li>
 		</ul>

 		<?php
-		$problems = UOJList::cur()->getProblemIDs();
-		$users = queryGroupUsers($group['id']);
-		$usernames = [];
+		$problems = UOJGroupAssignment::cur()->getProblemIDs();
+		$usernames = UOJGroup::cur()->getUsernames();
 		$n_users = count($users);
-		$submission_end_time = min(new DateTime(), DateTime::createFromFormat('Y-m-d H:i:s', $assignment['end_time']));
+		$submission_end_time = min(new DateTime(), UOJGroupAssignment::info('end_time'));

-		foreach ($users as $user) {
-			$usernames[] = $user['username'];
-		}
-
-		// standings: rank => [total_score, user => [username, realname], scores[]]
+		// standings: rank => [total_score, [username, realname], scores[]]
 		$standings = [];

 		foreach ($usernames as $username) {
 			$user = UOJUser::query($username);
-			$row = ['total_score' => 0];
-			$scores = [];
+			$row = [0, [$user['username'], $user['realname']], []];

-			$row['user'] = [
-				'username' => $user['username'],
-				'realname' => $user['realname'],
-			];
-
-			$cond = "submitter = '{$user['username']}' AND unix_timestamp(submit_time) <= " . $submission_end_time->getTimestamp();
+			$conds = DB::land([
+				"submitter" => $user['username'],
+				["unix_timestamp(submit_time)", "<=", $submission_end_time->getTimestamp()],
+			]);

 			foreach ($problems as $problem_id) {
-				$submission = DB::selectFirst("SELECT id, score FROM submissions WHERE problem_id = $problem_id AND $cond ORDER BY score DESC, id DESC");
+				$submission = DB::selectFirst([
+					"select", DB::fields(["id", "score"]),
+					"from submissions",
+					"where", [
+						"problem_id" => $problem_id,
+						$conds,
+					],
+					"order by score desc, id desc",
+				]);

 				if ($submission) {
-					$row['scores'][] = [
-						'submission_id' => (int)$submission['id'],
-						'score' => (int)$submission['score'],
+					$row[2][] = [
+						(int)$submission['id'],
+						(int)$submission['score'],
 					];
-					$row['total_score'] += $submission['score'];
+					$row[0] += $submission['score'];
 				} else {
-					$row['scores'][] = null;
+					$row[2][] = null;
 				}
 			}

@ -85,11 +75,11 @@ if (($group['is_hidden'] || $list['is_hidden']) && !isSuperUser($myUser)) {
 		}

 		usort($standings, function ($lhs, $rhs) {
-			if ($lhs['total_score'] != $rhs['total_score']) {
-				return $rhs['total_score'] - $lhs['total_score'];
+			if ($lhs[0] != $rhs[0]) {
+				return $rhs[0] - $lhs[0];
 			}

-			return strcmp($lhs['user']['username'], $rhs['user']['username']);
+			return strcmp($lhs[1][0], $rhs[1][0]);
 		});
 		?>

@ -112,26 +102,26 @@ if (($group['is_hidden'] || $list['is_hidden']) && !isSuperUser($myUser)) {
 				function(row) {
 					var col_tr = '';

-					if (row['total_score'] == problems.length * 100) {
+					if (row[0] == problems.length * 100) {
 						col_tr += '<tr class="table-success">';
 					} else {
 						col_tr += '<tr>';
 					}

-					col_tr += '<td>' + getUserLink(row['user']['username'], row['user']['realname']) + '</td>';
+					col_tr += '<td>' + getUserLink(row[1][0], row[1][1]) + '</td>';
 					col_tr += '<td>' +
-						'<span class="uoj-score" data-max="' + (problems.length * 100) + '" style="color:' + getColOfScore(row['total_score'] / problems.length) + '">' + row['total_score'] + '</span>' +
+						'<span class="uoj-score" data-max="' + (problems.length * 100) + '" style="color:' + getColOfScore(row[0] / problems.length) + '">' + row[0] + '</span>' +
 						'</td>';
-					for (var i = 0; i < row['scores'].length; i++) {
-						var col = row['scores'][i];
+					for (var i = 0; i < row[2].length; i++) {
+						var col = row[2][i];

 						if (col) {
-							if (col['score'] == 100) {
+							if (col[1] == 100) {
 								col_tr += '<td class="table-success">';
 							} else {
 								col_tr += '<td>';
 							}
-							col_tr += '<a class="text-decoration-none uoj-score" href="/submission/' + col['submission_id'] + '" style="color:' + getColOfScore(col['score']) + '">' + col['score'] + '</a>';
+							col_tr += '<a class="text-decoration-none uoj-score" href="/submission/' + col[0] + '" style="color:' + getColOfScore(col[1]) + '">' + col[1] + '</a>';
 							col_tr += '</td>';
 						} else {
 							col_tr += '<td></td>';
--- a/web/app/controllers/group_manage.php
+++ b/web/app/controllers/group_manage.php
@ -1,45 +1,33 @@
 <?php
-if (!Auth::check()) {
-	redirectToLogin();
-}

 requireLib('bootstrap5');
 requirePHPLib('form');
 requirePHPLib('judger');
 requirePHPLib('data');

-$group_id = $_GET['id'];
-if (!validateUInt($group_id) || !($group = queryGroup($group_id))) {
-	become404Page();
-}
+Auth::check() || redirectToLogin();
+UOJGroup::init(UOJRequest::get('id')) || UOJResponse::page404();
+UOJGroup::cur()->userCanManage(Auth::user()) || UOJResponse::page403();

-if (!isSuperUser($myUser)) {
-	become403Page();
-}
-
-if (isset($_GET['tab'])) {
-	$cur_tab = $_GET['tab'];
-} else {
-	$cur_tab = 'profile';
-}
+$cur_tab = UOJRequest::get('tab', 'is_string', 'profile');

 $tabs_info = [
 	'profile' => [
 		'name' => '基本信息',
-		'url' => "/group/{$group['id']}/manage/profile",
+		'url' => '/group/' . UOJGroup::info('id') . '/manage/profile',
 	],
 	'assignments' => [
 		'name' => '作业管理',
-		'url' => "/group/{$group['id']}/manage/assignments",
+		'url' => '/group/' . UOJGroup::info('id') . '/manage/assignments',
 	],
 	'users' => [
 		'name' => '用户管理',
-		'url' => "/group/{$group['id']}/manage/users",
+		'url' => '/group/' . UOJGroup::info('id') . '/manage/users',
 	]
 ];

 if (!isset($tabs_info[$cur_tab])) {
-	become404Page();
+	UOJResponse::page404();
 }

 if ($cur_tab == 'profile') {
@ -48,7 +36,7 @@ if ($cur_tab == 'profile') {
 		'name',
 		'text',
 		'名称',
-		$group['title'],
+		UOJGroup::info('title'),
 		function ($title, &$vdata) {
 			if ($title == '') {
 				return '名称不能为空';
@ -72,11 +60,11 @@ if ($cur_tab == 'profile') {
 	$update_profile_form->addVCheckboxes('is_hidden', [
 		'0' => '公开',
 		'1' => '隐藏',
-	], '可见性', $group['is_hidden']);
+	], '可见性', UOJGroup::info('is_hidden'));
 	$update_profile_form->addVTextArea(
 		'announcement',
 		'公告',
-		$group['announcement'],
+		UOJGroup::info('announcement'),
 		function ($announcement, &$vdata) {
 			if (strlen($announcement) > 3000) {
 				return '公告过长';
@ -88,12 +76,18 @@ if ($cur_tab == 'profile') {
 		},
 		null
 	);
-	$update_profile_form->handle = function ($vdata) use ($group) {
-		$esc_title = DB::escape($vdata['title']);
-		$is_hidden = $_POST['is_hidden'];
-		$esc_announcement = DB::escape($vdata['announcement']);
-
-		DB::update("UPDATE `groups` SET title = '$esc_title', is_hidden = '$is_hidden', announcement = '$esc_announcement' WHERE id = {$group['id']}");
+	$update_profile_form->handle = function ($vdata) {
+		DB::update([
+			"update `groups`",
+			"set", [
+				"title" => $vdata['title'],
+				"is_hidden" => $_POST['is_hidden'],
+				"announcement" => $vdata['announcement'],
+			],
+			"where", [
+				"id" => UOJGroup::info('id'),
+			],
+		]);

 		dieWithJsonData(['status' => 'success', 'message' => '修改成功']);
 	};
@ -121,17 +115,20 @@ EOD);
 	$update_profile_form->runAtServer();
 } elseif ($cur_tab == 'assignments') {
 	if (isset($_POST['submit-remove_assignment']) && $_POST['submit-remove_assignment'] == 'remove_assignment') {
-		$list_id = $_POST['list_id'];
+		$list_id = UOJRequest::post('list_id');

-		if (!validateUInt($list_id)) {
-			dieWithAlert('题单 ID 不合法。');
+		$list = UOJGroupAssignment::query($list_id);
+		if (!$list || !$list->valid()) {
+			dieWithAlert('题单不合法。');
 		}

-		if (!queryAssignmentByGroupListID($group['id'], $list_id)) {
-			dieWithAlert('该题单不在作业中。');
-		}
-
-		DB::delete("DELETE FROM `groups_assignments` WHERE `list_id` = $list_id AND `group_id` = {$group['id']}");
+		DB::delete([
+			"delete from groups_assignments",
+			"where", [
+				"list_id" => $list->info['id'],
+				"group_id" => UOJGroup::info('id'),
+			],
+		]);

 		dieWithAlert('移除成功！');
 	}
@ -142,7 +139,7 @@ EOD);
 		'text',
 		'题单 ID',
 		'',
-		function ($list_id, &$vdata) use ($group) {
+		function ($list_id, &$vdata) {
 			if (!validateUInt($list_id)) {
 				return '题单 ID 不合法';
 			}
@ -157,7 +154,7 @@ EOD);
 				return '题单是隐藏的';
 			}

-			if (queryAssignmentByGroupListID($group['id'], $list->info['id'])) {
+			if (UOJGroup::cur()->hasAssignment($list)) {
 				return '该题单已经在作业中';
 			}

@ -186,10 +183,16 @@ EOD);
 		},
 		null
 	);
-	$add_new_assignment_form->handle = function (&$vdata) use ($group) {
-		$esc_end_time = DB::escape($vdata['end_time']->format('Y-m-d H:i:s'));
-
-		DB::insert("insert into groups_assignments (group_id, list_id, end_time) values ({$group['id']}, '{$vdata['list_id']}', '{$esc_end_time}')");
+	$add_new_assignment_form->handle = function (&$vdata) {
+		DB::insert([
+			"insert into groups_assignments",
+			DB::bracketed_fields(["group_id", "list_id", "end_time"]),
+			"values", DB::tuple([
+				UOJGroup::info('id'),
+				$vdata['list_id'],
+				$vdata['end_time']->format('Y-m-d H:i:s'),
+			]),
+		]);

 		dieWithJsonData([
 			'status' => 'success',
@ -220,24 +223,26 @@ EOD);
 	$add_new_assignment_form->runAtServer();

 	$hidden_time = new DateTime();
-	$hidden_time->sub(new DateInterval('P7D'));
+	$hidden_time->sub(new DateInterval('P3D'));
 } elseif ($cur_tab == 'users') {
 	if (isset($_POST['submit-remove_user']) && $_POST['submit-remove_user'] == 'remove_user') {
-		$username = $_POST['remove_username'];
+		$user = UOJUser::query(UOJRequest::post('remove_username'));

-		if (!validateUsername($username)) {
-			dieWithAlert('用户名不合法。');
-		}
-
-		if (!queryUser($username)) {
+		if (!$user) {
 			dieWithAlert('用户不存在。');
 		}

-		if (!queryUserInGroup($group['id'], $username)) {
+		if (!UOJGroup::cur()->hasUser($user)) {
 			dieWithAlert('该用户不在小组中。');
 		}

-		DB::delete("DELETE FROM `groups_users` WHERE `username` = '$username' AND `group_id` = {$group['id']}");
+		DB::delete([
+			"delete from groups_users",
+			"where", [
+				"username" => $user['username'],
+				"group_id" => UOJGroup::info('id'),
+			],
+		]);

 		dieWithAlert('移除成功！');
 	}
@ -249,21 +254,17 @@ EOD);
 		'用户名',
 		'',
 		function ($username, &$vdata) {
-			global $group_id;
+			$user = UOJUser::query($username);

-			if (!validateUsername($username)) {
-				return '用户名不合法';
+			if (!$user) {
+				return '用户不存在。';
 			}

-			if (!queryUser($username)) {
-				return '用户不存在';
-			}
-
-			if (queryUserInGroup($group_id, $username)) {
+			if (UOJGroup::cur()->hasUser($user)) {
 				return '该用户已经在小组中';
 			}

-			$vdata['username'] = $username;
+			$vdata['username'] = $user['username'];

 			return '';
 		},
@ -271,8 +272,16 @@ EOD);
 	);
 	$add_new_user_form->submit_button_config['class_str'] = 'btn btn-secondary mt-3';
 	$add_new_user_form->submit_button_config['text'] = '添加';
-	$add_new_user_form->handle = function (&$vdata) use ($group) {
-		DB::insert("insert into groups_users (group_id, username) values ({$group['id']}, '{$vdata['username']}')");
+	$add_new_user_form->handle = function (&$vdata) {
+		DB::insert([
+			"insert into groups_users",
+			DB::bracketed_fields(["group_id", "username"]),
+			"values",
+			DB::tuple([
+				UOJGroup::info('id'),
+				$vdata['username']
+			]),
+		]);

 		dieWithJsonData(['status' => 'success', 'message' => '已将用户名为 ' . $vdata['username'] . ' 的用户添加到本小组。']);
 	};
@ -298,24 +307,25 @@ EOD);
 	$add_new_user_form->runAtServer();
 }
 ?>
-<?php echoUOJPageHeader('管理 - ' . $group['title']); ?>
+<?php echoUOJPageHeader('管理 - ' . UOJGroup::info('title')); ?>

 <h1 class="d-block d-md-inline-block">
-	<?= $group['title'] ?>
-	<small class="fs-5">(ID: #<?= $group['id'] ?>)</small>
+	<?= UOJGroup::info('title') ?>
+	<small class="fs-5">(ID: #<?= UOJGroup::info('id') ?>)</small>
 	管理
 </h1>

 <div class="row mt-4">
 	<!-- left col -->
 	<div class="col-md-3">
-
 		<?= HTML::navListGroup($tabs_info, $cur_tab) ?>

-		<a class="btn btn-light d-block mt-2 w-100 text-start text-primary" style="--bs-btn-hover-bg: #d3d4d570; --bs-btn-hover-border-color: transparent;" href="<?= HTML::url("/group/{$group['id']}") ?>">
-			<i class="bi bi-arrow-left"></i> 返回
-		</a>
-
+		<?=
+		UOJGroup::cur()->getLink([
+			'class' => 'btn btn-light d-block mt-2 w-100 text-start text-primary uoj-back-btn',
+			'text' => '<i class="bi bi-arrow-left"></i> 返回',
+		]);
+		?>
 	</div>
 	<!-- end left col -->

@ -358,7 +368,7 @@ EOD);
 							echoLongTable(
 								['*'],
 								'groups_assignments',
-								"group_id = {$group['id']}",
+								["group_id" => UOJGroup::info('id')],
 								'order by end_time desc, list_id desc',
 								<<<EOD
 									<tr>
@ -369,31 +379,30 @@ EOD);
 										<th style="width:8em">操作</th>
 									</tr>
 								EOD,
-								function ($row) use ($group, $hidden_time) {
-									$list = UOJList::query($row['list_id']);
-									$end_time = DateTime::createFromFormat('Y-m-d H:i:s', $row['end_time']);
+								function ($row) use ($hidden_time) {
+									$assignment = UOJGroupAssignment::query($row['list_id']);

-									echo '<tr>';
-									echo '<td class="text-center">', $list->info['id'], '</td>';
-									echo '<td>';
-									echo '<a class="text-decoration-none" href="/group/', $group['id'], '/assignment/', $list->info['id'], '">', $list->info['title'], '</a>';
-									if ($list->info['is_hidden']) {
+									echo HTML::tag_begin('tr');
+									echo HTML::tag('td', ['class' => 'text-center'], $assignment->info['id']);
+									echo HTML::tag_begin('td');
+									echo $assignment->getLink();
+									if ($assignment->info['is_hidden']) {
 										echo ' <span class="badge text-bg-danger"><i class="bi bi-eye-slash-fill"></i> ', UOJLocale::get('hidden'), '</span> ';
 									}
-									echo '</td>';
-									if ($end_time < $hidden_time) {
-										echo '<td class="text-secondary">已隐藏</td>';
-									} elseif ($end_time < UOJTime::$time_now) {
-										echo '<td class="text-danger">已结束</td>';
+									echo HTML::tag_end('td');
+									if ($assignment->info['end_time'] < $hidden_time) {
+										echo HTML::tag('td', ['class' => 'text-secondary'], '已隐藏');
+									} elseif ($assignment->info['end_time'] < UOJTime::$time_now) {
+										echo HTML::tag('td', ['class' => 'text-danger'], '已结束');
 									} else {
-										echo '<td class="text-success">进行中</td>';
+										echo HTML::tag('td', ['class' => 'text-success'], '进行中');
 									}
-									echo '<td>', $end_time->format('Y-m-d H:i:s'), '</td>';
+									echo HTML::tag('td', [], $assignment->info['end_time_str']);
 									echo '<td>';
-									echo ' <a class="text-decoration-none d-inline-block align-middle" href="/list/', $list->info['id'], '/manage">编辑</a> ';
-									echo ' <form class="d-inline-block" method="POST" onsubmit=\'return confirm("你真的要移除这份作业（题单 #', $list->info['id'], '）吗？移除作业不会删除题单。")\'>'
-										. '<input type="hidden" name="_token" value="' . crsf_token() . '">'
-										. '<input type="hidden" name="list_id" value="' . $list->info['id'] . '">'
+									echo ' <a class="text-decoration-none d-inline-block align-middle" href="/list/', $assignment->info['id'], '/manage">编辑</a> ';
+									echo ' <form class="d-inline-block" method="POST" onsubmit=\'return confirm("你真的要移除这份作业（题单 #', $assignment->info['id'], '）吗？移除作业不会删除题单。")\'>'
+										. HTML::hiddenToken()
+										. '<input type="hidden" name="list_id" value="' . $assignment->info['id'] . '">'
 										. '<button class="btn btn-link text-danger text-decoration-none p-0" type="submit" name="submit-remove_assignment" value="remove_assignment">移除</button>'
 										. '</form>';
 									echo '</td>';
@ -447,7 +456,7 @@ EOD,
 							echoLongTable(
 								['*'],
 								'groups_users',
-								"group_id = {$group['id']}",
+								["group_id" => UOJGroup::info('id')],
 								'order by username asc',
 								<<<EOD
 									<tr>
@ -455,9 +464,9 @@ EOD,
 										<th>操作</th>
 									</tr>
 								EOD,
-								function ($row) use ($group) {
-									echo '<tr>';
-									echo '<td>', getUserLink($row['username']), '</td>';
+								function ($row) {
+									echo HTML::tag_begin('tr');
+									echo HTML::tag('td', [], UOJUser::getLink($row['username']));
 									echo '<td>';
 									echo '<form class="d-inline-block" method="POST" onsubmit=\'return confirm("你真的要从小组中移除这个用户吗？")\'>'
 										. '<input type="hidden" name="_token" value="' . crsf_token() . '">'
@ -465,7 +474,7 @@ EOD,
 										. '<button class="btn btn-link text-danger text-decoration-none p-0" type="submit" name="submit-remove_user" value="remove_user">移除</button>'
 										. '</form>';
 									echo '</td>';
-									echo '</tr>';
+									echo HTML::tag_end('tr');
 								},
 								[
 									'page_len' => 20,
--- a/web/app/controllers/lists.php
+++ b/web/app/controllers/lists.php
@ -23,26 +23,30 @@ if (isSuperUser($myUser)) {
 function getListTR($info) {
 	$list = new UOJList($info);
 	$problems = $list->getProblemIDs();
+	if (Auth::check() && !empty($problems)) {
 		$accepted = DB::selectCount([
 			"select count(*)",
 			"from best_ac_submissions",
 			"where", [
 				"submitter" => Auth::id(),
-			["problem_id", "in", DB::tuple($problems)],
+				["problem_id", "in", DB::rawtuple($problems)],
 			],
 		]);
+	} else {
+		$accepted = -1;
+	}

 	$html = HTML::tag_begin('tr', ['class' => 'text-center']);
 	$html .= HTML::tag('td', ['class' => $accepted == count($problems) ? 'table-success' : ''], "#{$list->info['id']}");
 	$html .= HTML::tag_begin('td', ['class' => 'text-start']);
-	$html .= HTML::tag('a', ['href' => "/list/{$list->info['id']}"], $list->info['title']);
+	$html .= $list->getLink();
 	if ($list->info['is_hidden']) {
 		$html .= ' <span class="badge text-bg-danger"><i class="bi bi-eye-slash-fill"></i> ' . UOJLocale::get('hidden') . '</span> ';
 	}
 	foreach ($list->queryTags() as $tag) {
 		$html .= ' <a class="uoj-list-tag"><span class="badge text-bg-secondary">' . $tag['tag'] . '</span></a> ';
 	}
-	$html .= HTML::tag('td', [], $accepted);
+	$html .= HTML::tag('td', [], max(0, $accepted));
 	$html .= HTML::tag('td', [], count($problems));
 	$html .= HTML::tag_end('td');

--- a/web/app/libs/uoj-query-lib.php
+++ b/web/app/libs/uoj-query-lib.php
@ -52,46 +52,6 @@ function queryContest($id) {
 	return DB::selectFirst("select * from contests where id = $id", MYSQLI_ASSOC);
 }

-function queryGroup($id) {
-	return DB::selectFirst("select * from `groups` where id = $id", MYSQLI_ASSOC);
-}
-function queryGroupUsers($id) {
-	return DB::selectAll("SELECT * FROM groups_users WHERE group_id = $id");
-}
-function queryUserInGroup($group_id, $username) {
-	return DB::selectFirst("select * from groups_users where username='$username' and group_id='$group_id'", MYSQLI_ASSOC);
-}
-function queryGroupsOfUser($username) {
-	return DB::selectAll([
-		"select", DB::fields([
-			"title" => "groups.title",
-			"id" => "groups.id",
-		]),
-		"from groups_users",
-		"inner join `groups`", "on", [
-			"groups_users.group_id" => DB::raw("groups.id"),
-		],
-		"where", [
-			"groups_users.username" => $username,
-			"groups.is_hidden" => false,
-		],
-	]);
-}
-function queryGroupmateCurrentAC($username) {
-	return DB::selectAll("select a.problem_id as problem_id, a.submitter as submitter, a.submission_id as submission_id, b.submit_time as submit_time, c.group_id as group_id, c.group_name as group_name, d.title as problem_title, b.submit_time as submit_time, e.realname as realname from best_ac_submissions a inner join submissions b on (a.submission_id = b.id) inner join (select a.username as username, any_value(a.group_id) as group_id, any_value(c.title) as group_name from groups_users a inner join (select a.group_id as group_id from groups_users a inner join `groups` b on a.group_id = b.id where a.username = '$username' and b.is_hidden = 0) b on a.group_id = b.group_id inner join `groups` c on a.group_id = c.id group by a.username) c on a.submitter = c.username inner join problems d on (a.problem_id = d.id and d.is_hidden = 0) inner join user_info e on a.submitter = e.username where b.submit_time > addtime(now(), '-360:00:00') order by b.submit_time desc limit 10", MYSQLI_ASSOC);
-}
-function queryGroupCurrentAC($group_id) {
-	return DB::selectAll("select a.problem_id as problem_id, a.submitter as submitter, a.submission_id as submission_id, b.submit_time as submit_time, d.title as problem_title, b.submit_time as submit_time, e.realname as realname from best_ac_submissions a inner join submissions b on (a.submission_id = b.id) inner join groups_users c on (a.submitter = c.username and c.group_id = $group_id) inner join problems d on (a.problem_id = d.id and d.is_hidden = 0) inner join user_info e on (a.submitter = e.username) where b.submit_time > addtime(now(), '-360:00:00') order by b.submit_time desc limit 10", MYSQLI_ASSOC);
-}
-function queryGroupAssignments($group_id) {
-	return DB::selectAll("select a.list_id as list_id, a.end_time as end_time, b.title from groups_assignments a left join lists b on a.list_id = b.id where a.group_id = $group_id order by a.end_time asc", MYSQLI_ASSOC);
-}
-function queryGroupActiveAssignments($group_id) {
-	return DB::selectAll("select a.group_id as group_id, a.list_id as list_id, a.end_time as end_time, b.title from groups_assignments a left join lists b on a.list_id = b.id where a.group_id = $group_id and a.end_time >= addtime(now(), '-168:00:00') order by a.end_time asc", MYSQLI_ASSOC);
-}
-function queryAssignmentByGroupListID($group_id, $list_id) {
-	return DB::selectFirst("select * from groups_assignments where list_id='$list_id' and group_id='$group_id'", MYSQLI_ASSOC);
-}
 function queryBlog($id) {
 	return DB::selectFirst("select * from blogs where id='$id'", MYSQLI_ASSOC);
 }
--- a/web/app/models/UOJContest.php
+++ b/web/app/models/UOJContest.php
@ -17,6 +17,34 @@ class UOJContest {
 		return new UOJContest($info);
 	}

+	public static function queryUpcomingContestIds(array $user = null, $limit = -1) {
+		return array_map(fn ($x) => $x['id'], DB::selectAll([
+			"select id from contests",
+			"where", [
+				"status" => "unfinished",
+			],
+			"order by start_time asc, id asc",
+			$limit == -1 ? "" : DB::limit($limit),
+		]));
+	}
+
+	public static function userCanManageSomeContest(array $user = null) {
+		if (!$user) {
+			return false;
+		}
+
+		if (isSuperUser($user)) {
+			return true;
+		}
+
+		return DB::selectFirst([
+			DB::lc(), "select 1 from contests_permissions",
+			"where", [
+				'username' => $user['username']
+			], DB::limit(1)
+		]) != null;
+	}
+
 	public static function finalTest() {
 		$contest = self::info();

@ -436,6 +464,15 @@ class UOJContest {
 		return "/contest/{$this->info['id']}{$where}";
 	}

+	public function getLink($cfg = []) {
+		$cfg += [
+			'where' => '',
+			'class' => '',
+		];
+
+		return HTML::tag('a', ['class' => $cfg['class'], 'href' => $this->getUri($cfg['where'])], $this->info['name']);
+	}
+
 	public function redirectToAnnouncementBlog() {
 		$url = getContestBlogLink($this->info, '公告');
 		if ($url !== null) {
--- a/web/app/models/UOJGroup.php
+++ b/web/app/models/UOJGroup.php
@ -0,0 +1,131 @@
+<?php
+
+class UOJGroup {
+	use UOJDataTrait;
+
+	public static function query($id) {
+		if (!isset($id) || !validateUInt($id)) {
+			return null;
+		}
+		$info = DB::selectFirst([
+			"select * from `groups`",
+			"where", ["id" => $id]
+		]);
+		if (!$info) {
+			return null;
+		}
+		return new UOJGroup($info);
+	}
+
+	public static function queryGroupsOfUser(array $user = null) {
+		if ($user == null) {
+			return [];
+		}
+
+		return array_map(fn ($x) => UOJGroup::query($x['group_id']), DB::selectAll([
+			DB::lc(), "select group_id from groups_users",
+			"where", ['username' => $user['username']],
+			"order by group_id"
+		]));
+	}
+
+	public function __construct($info) {
+		$this->info = $info;
+	}
+
+	public function userCanManage(array $user = null) {
+		return isSuperUser($user);
+	}
+
+	public function userCanView(array $user = null, array $cfg = []) {
+		$cfg += ['ensure' => false];
+		if ($this->info['is_hidden'] && !$this->userCanManage($user)) {
+			$cfg['ensure'] && UOJResponse::page404();
+			return false;
+		}
+		return true;
+	}
+
+	public function getUri($where = '') {
+		return "/group/{$this->info['id']}{$where}";
+	}
+
+	public function getLink($cfg = []) {
+		$cfg += [
+			'where' => '',
+			'class' => '',
+			'text' => $this->info['title'],
+		];
+
+		return HTML::tag('a', [
+			'href' => $this->getUri($cfg['where']),
+			'class' => $cfg['class'],
+		], $cfg['text']);
+	}
+
+	public function getUsernames() {
+		return array_map(fn ($x) => $x['username'], DB::selectAll([
+			DB::lc(), "select username from groups_users",
+			"where", ['group_id' => $this->info['id']],
+			"order by username",
+		]));
+	}
+
+	public function getLatestGroupmatesAcceptedSubmissionIds(array $user = null, int $limit = 10) {
+		return array_map(fn ($x) => $x['id'], DB::selectAll([
+			"select", DB::fields(["id" => "max(id)"]),
+			"from submissions",
+			"where", [
+				"score" => 100,
+				["submitter", "in", DB::rawtuple($this->getUsernames())],
+				UOJSubmission::sqlForUserCanView($user),
+			],
+			"group by problem_id",
+			"order by id desc",
+		]));
+	}
+
+	public function getAssignmentIds($limit = -1) {
+		return array_map(fn ($x) => $x['list_id'], DB::selectAll([
+			DB::lc(), "select list_id from groups_assignments",
+			"where", ['group_id' => $this->info['id']],
+			"order by end_time desc, list_id asc",
+			$limit == -1 ? "" : DB::limit($limit),
+		]));
+	}
+
+	public function getActiveAssignmentIds($limit = -1) {
+		return array_map(fn ($x) => $x['list_id'], DB::selectAll([
+			DB::lc(), "select list_id from groups_assignments",
+			"where", [
+				"group_id" => $this->info['id'],
+				["end_time", ">=", DB::raw("addtime(now(), '-72:00:00')")],
+			],
+			"order by end_time desc, list_id asc",
+			$limit == -1 ? "" : DB::limit($limit),
+		]));
+	}
+
+	public function hasUser(array $user = null) {
+		if ($user == null) {
+			return false;
+		}
+		return DB::selectFirst([
+			DB::lc(), "select 1 from groups_users",
+			"where", [
+				'group_id' => $this->info['id'],
+				'username' => $user['username'],
+			],
+		]) != null;
+	}
+
+	public function hasAssignment(UOJList $assignment) {
+		return DB::selectFirst([
+			DB::lc(), "select 1 from groups_assignments",
+			"where", [
+				'group_id' => $this->info['id'],
+				'list_id' => $assignment->info['id']
+			]
+		]) != null;
+	}
+}
--- a/web/app/models/UOJGroupAssignment.php
+++ b/web/app/models/UOJGroupAssignment.php
@ -0,0 +1,76 @@
+<?php
+
+class UOJGroupAssignment extends UOJList {
+	public $group = null;
+
+	public static function query($id, UOJGroup $group = null) {
+		$list = parent::query($id);
+		if ($list === null) {
+			return $list;
+		}
+		if ($group === null) {
+			$group = UOJGroup::cur();
+		}
+		return new UOJGroupAssignment($list->info, $group);
+	}
+
+	public function __construct($info, UOJGroup $group) {
+		parent::__construct($info);
+		$this->group = $group;
+		$this->completeInfo();
+	}
+
+	public function completeInfo() {
+		if ($this->info['end_time_str']) {
+			return;
+		}
+
+		if (!$this->info['end_time']) {
+			$this->info['end_time'] = DB::selectSingle([
+				"select end_time from groups_assignments",
+				"where", [
+					"list_id" => $this->info['id'],
+					"group_id" => $this->group->info['id'],
+				],
+			]);
+		}
+
+		$this->info['end_time_str'] = $this->info['end_time'] ?: UOJTime::$time_now_str;
+		$this->info['end_time'] = new DateTime($this->info['end_time_str']);
+	}
+
+	public function valid() {
+		return $this->group && $this->group->hasAssignment($this);
+	}
+
+	public function getUri($where = '') {
+		return $this->group->getUri("/assignment/{$this->info['id']}");
+	}
+
+	public function getLink($cfg = []) {
+		$cfg += [
+			'class' => '',
+			'text' => $this->info['title'],
+			'with' => 'none',
+		];
+
+		if ($cfg['with'] == 'sup') {
+			if ($this->info['end_time'] < UOJTime::$time_now) {
+				$cfg['text'] .= HTML::tag('sup', ["class" => "fw-normal text-danger ms-1"], 'overdue');
+			} elseif ($this->info['end_time']->getTimestamp() - UOJTime::$time_now->getTimestamp() < 86400) {
+				$cfg['text'] .= HTML::tag('sup', ["class" => "fw-normal text-danger ms-1"], 'soon');
+			}
+		}
+
+		return HTML::tag('a', [
+			'href' => $this->getUri(),
+			'class' => $cfg['class'],
+		], $cfg['text']);
+	}
+
+	public function userCanView(array $user = null, $cfg = []) {
+		$cfg += ['ensure' => false];
+
+		return parent::userCanView($user, $cfg) && $this->group->userCanView($user, $cfg);
+	}
+}
--- a/web/app/models/UOJList.php
+++ b/web/app/models/UOJList.php
@ -22,6 +22,24 @@ class UOJList {
 		$this->info = $info;
 	}

+	public function getUri($where = '') {
+		return "/list/{$this->info['id']}{$where}";
+	}
+
+	public function getLink($cfg = []) {
+		$cfg += [
+			'where' => '',
+			'class' => '',
+			'text' => $this->info['title'],
+			'with' => 'id',
+		];
+
+		return HTML::tag('a', [
+			'href' => $this->getUri($cfg['where']),
+			'class' => $cfg['class'],
+		], $cfg['text']);
+	}
+
 	public function getProblemIDs() {
 		return array_map(fn ($x) => $x['problem_id'], DB::selectAll([
 			DB::lc(), "select problem_id from lists_problems",
--- a/web/app/models/UOJProblem.php
+++ b/web/app/models/UOJProblem.php
@ -30,11 +30,17 @@ class UOJProblem {
 		if (!$user) {
 			return false;
 		}
+
 		return DB::selectFirst([
 			DB::lc(), "select 1 from problems_permissions",
 			"where", [
 				'username' => $user['username']
 			], DB::limit(1)
+		]) != null || DB::selectFirst([
+			DB::lc(), "select 1 from problems",
+			"where", [
+				"uploader" => $user['username'],
+			], DB::limit(1),
 		]) != null;
 	}

--- a/web/app/models/UOJRanklist.php
+++ b/web/app/models/UOJRanklist.php
@ -5,9 +5,21 @@ class UOJRanklist {
 		$cfg += [
 			'top10' => false,
 			'card' => false,
+			'group_id' => null,
+			'page_len' => 50,
 		];

+		$conds = [];
+
+		if ($cfg['group_id']) {
+			$conds[] = [
+				"username", "in", DB::rawtuple(UOJGroup::query($cfg['group_id'])->getUsernames()),
+			];
+		}
+
+		if (empty($conds)) {
 			$conds = '1';
+		}

 		$last_user = null;
 		$parsedown = HTML::parsedown();
@ -55,7 +67,6 @@ class UOJRanklist {
 			$last_user = $user;
 		};

-
 		$pag_config = [
 			'get_row_index' => '',
 			'table_name' => 'user_info',
@ -68,7 +79,7 @@ class UOJRanklist {
 			$pag_config['tail'] .= ' limit 10';
 			$pag_config['echo_full'] = '';
 		} else {
-			$pag_config['page_len'] = 50;
+			$pag_config['page_len'] = $cfg['page_len'];
 		}

 		$pag = new Paginator($pag_config);
@ -102,9 +113,21 @@ class UOJRanklist {
 	public static function printTableHTML($cfg = []) {
 		$cfg += [
 			'top10' => false,
+			'group_id' => null,
+			'page_len' => 100,
 		];

+		$conds = [];
+
+		if ($cfg['group_id']) {
+			$conds[] = [
+				"username", "in", DB::rawtuple(UOJGroup::query($cfg['group_id'])->getUsernames()),
+			];
+		}
+
+		if (empty($conds)) {
 			$conds = '1';
+		}

 		$header_row = '';
 		$header_row .= '<tr>';
@ -157,7 +180,7 @@ class UOJRanklist {
 			$tail .= ' limit 10';
 			$table_config['echo_full'] = '';
 		} else {
-			$table_config['page_len'] = 100;
+			$table_config['page_len'] = $cfg['page_len'];
 		}

 		echoLongTable($col_names, 'user_info', $conds, $tail, $header_row, $print_row, $table_config);
--- a/web/app/models/UOJSubmission.php
+++ b/web/app/models/UOJSubmission.php
@ -38,7 +38,7 @@ class UOJSubmission {
 	 * Need to be consistent with the member function userCanView
 	 */
 	public static function sqlForUserCanView(array $user = null, UOJProblem $problem = null) {
-		if (isSuperUser($user)) {
+		if (isSuperUser($user) || isProblemManager($user)) {
 			// MySQL can find appropriate keys to speed up the query if we write "true" in this way.
 			return "(submissions.is_hidden = true or submissions.is_hidden = false)";
 		} elseif ($problem) {
--- a/web/app/views/page-header.php
+++ b/web/app/views/page-header.php
@ -313,34 +313,6 @@ if (!isset($ShowPageHeader)) {
 				<?php endif ?>

 				<?php uojIncludeView($PageNav, array('REQUIRE_LIB' => $REQUIRE_LIB)) ?>
-
-				<?php if (!isset($REQUIRE_LIB['bootstrap5'])) : ?>
-					<?php if (Auth::check()) : ?>
-						<?php $groups = queryGroupsOfUser(Auth::id()); ?>
-						<?php if (count($groups)) : ?>
-							<div class="card card-default mb-2" id="group-user-announcements">
-								<div class="card-header">
-									小组公告
-								</div>
-								<ul class="list-group list-group-flush">
-									<?php foreach ($groups as $group) : ?>
-										<?php $group_announcement = DB::selectSingle("select announcement from `groups` where id = {$group['id']}"); ?>
-										<li class="list-group-item">
-											<a href="<?= HTML::url('/group/' . $group['id']) ?>">
-												<b><?= $group['title'] ?></b>
-											</a>
-											<?php if ($group_announcement) : ?>
-												<div><?= HTML::purifier_inline()->purify($group_announcement) ?></div>
-											<?php else : ?>
-												<div>（暂无公告）</div>
-											<?php endif ?>
-										</li>
-									<?php endforeach ?>
-								</ul>
-							</div>
-						<?php endif ?>
-					<?php endif ?>
-				<?php endif ?>
 			<?php endif ?>


--- a/web/app/views/sidebar.php
+++ b/web/app/views/sidebar.php
@ -1,6 +1,11 @@
+<?php
+$purifier = HTML::purifier_inline();
+$parsedown = HTML::parsedown();
+?>
+
 <?php if (Auth::check()) : ?>
 	<?php if (!isset($groups_hidden)) : ?>
-		<?php $groups = queryGroupsOfUser(Auth::id()); ?>
+		<?php $groups = UOJGroup::queryGroupsOfUser(Auth::user()); ?>
 		<?php if (!empty($groups)) : ?>
 			<div class="card card-default mb-2" id="group-user-announcements">
 				<div class="card-header fw-bold bg-transparent">
@ -8,18 +13,11 @@
 				</div>
 				<ul class="list-group list-group-flush">
 					<?php foreach ($groups as $group) : ?>
-						<?php
-						$group_announcement = DB::selectSingle("select announcement from `groups` where id = {$group['id']}");
-						$purifier = HTML::purifier_inline();
-						$parsedown = HTML::parsedown();
-						?>
 						<li class="list-group-item">
-							<a class="fw-bold text-decoration-none" href="<?= HTML::url('/group/' . $group['id']) ?>">
-								<?= $group['title'] ?>
-							</a>
-							<?php if ($group_announcement) : ?>
+							<?= $group->getLink(['class' => 'fw-bold']) ?>
+							<?php if ($group->info['announcement']) : ?>
 								<div class="text-break">
-									<?= $purifier->purify($parsedown->line($group_announcement)) ?>
+									<?= $purifier->purify($parsedown->line($group->info['announcement'])) ?>
 								</div>
 							<?php else : ?>
 								<div class="text-muted">
@ -35,19 +33,13 @@
 				<?php
 				$assignments = [];
 				foreach ($groups as $group) {
-					$assignments = array_merge($assignments, queryGroupActiveAssignments($group['id']));
+					$assignments = array_merge($assignments, array_map(fn ($x) => UOJGroupAssignment::query($x, $group), $group->getActiveAssignmentIds()));
 				}

-				usort($assignments, function ($a, $b) {
-					$end_time_a = DateTime::createFromFormat('Y-m-d H:i:s', $a['end_time']);
-					$end_time_b = DateTime::createFromFormat('Y-m-d H:i:s', $b['end_time']);
-
-					return $end_time_b->getTimestamp() - $end_time_a->getTimestamp();
-				});
-
+				usort($assignments, fn ($a, $b) => $b->info['end_time']->getTimestamp() - $a->info['end_time']->getTimestamp());
 				$assignments = array_slice($assignments, 0, 5);
 				?>
-				<?php if (count($assignments)) : ?>
+				<?php if (!empty($assignments)) : ?>
 					<div class="card card-default mb-2" id="group-assignments">
 						<div class="card-header fw-bold bg-transparent">
 							<?= UOJLocale::get('assignments') ?>
@ -55,17 +47,9 @@
 						<ul class="list-group list-group-flush">
 							<?php foreach ($assignments as $assignment) : ?>
 								<li class="list-group-item">
-									<?php $end_time = DateTime::createFromFormat('Y-m-d H:i:s', $assignment['end_time']); ?>
-									<a href="<?= HTML::url('/group/' . $assignment['group_id'] . '/assignment/' . $assignment['list_id']) ?>" class="fw-bold text-decoration-none">
-										<?= $assignment['title'] ?>
-										<?php if ($end_time < UOJTime::$time_now) : ?>
-											<sup class="fw-normal text-danger">overdue</sup>
-										<?php elseif ($end_time->getTimestamp() - UOJTime::$time_now->getTimestamp() < 86400) : ?>
-											<sup class="fw-normal text-danger">soon</sup>
-										<?php endif ?>
-									</a>
+									<?= $assignment->getLink(['class' => 'fw-bold', 'with' => 'sup']) ?>
 									<div class="text-end small text-muted">
-										截止时间: <?= $end_time->format('Y-m-d H:i') ?>
+										截止时间: <?= $assignment->info['end_time']->format('Y-m-d H:i') ?>
 									</div>
 								</li>
 							<?php endforeach ?>
@ -79,36 +63,28 @@

 <?php if (Auth::check()) : ?>
 	<?php if (!isset($upcoming_contests_hidden)) : ?>
-		<?php
-		$upcoming_contests = DB::selectAll("SELECT * FROM contests WHERE status = 'unfinished' ORDER BY start_time ASC, id ASC LIMIT 7");
-		?>
+		<?php $upcoming_contests = UOJContest::queryUpcomingContestIds(Auth::user(), 5); ?>
 		<div class="card card-default mb-2" id="group-user-announcements">
 			<div class="card-header fw-bold bg-transparent">
 				近期比赛
 			</div>
-			<?php $count = 0; ?>
 			<ul class="list-group list-group-flush">
-				<?php foreach ($upcoming_contests as $contest) : ?>
-					<?php genMoreContestInfo($contest) ?>
-					<?php if ($contest['cur_progress'] == CONTEST_NOT_STARTED || $contest['cur_progress'] == CONTEST_IN_PROGRESS) : ?>
-						<?php $count++; ?>
+				<?php foreach ($upcoming_contests as $id) : ?>
+					<?php $contest = UOJContest::query($id); ?>
+					<?php if ($contest->info['cur_progress'] == CONTEST_NOT_STARTED || $contest->info['cur_progress'] == CONTEST_IN_PROGRESS) : ?>
 						<li class="list-group-item text-center">
-							<a class="fw-bold text-decoration-none" href="<?= HTML::url('/contest/' . $contest['id']) ?>">
-								<?= $contest['name'] ?>
-							</a>
+							<?= $contest->getLink(['class' => 'fw-bold']) ?>
 							<div class="small">
-								<?php if ($contest['cur_progress'] == CONTEST_IN_PROGRESS) : ?>
+								<?php if ($contest->info['cur_progress'] == CONTEST_IN_PROGRESS) : ?>
 									<?= UOJLocale::get('contests::in progress') ?>
 								<?php else : ?>
-									<?php
-									$rest_seconds = $contest['start_time']->getTimestamp() - UOJTime::$time_now->getTimestamp();
-									?>
+									<?php $rest_seconds = $contest->info['start_time']->getTimestamp() - UOJTime::$time_now->getTimestamp(); ?>
 									<?php if ($rest_seconds > 86400) : ?>
 										<?= UOJLocale::get('contests::will start in x days', ceil($rest_seconds / 86400)) ?>
 									<?php else : ?>
-										<div id="contest-<?= $contest['id'] ?>-countdown"></div>
+										<div id="contest-<?= $contest->info['id'] ?>-countdown"></div>
 										<script>
-											$('#contest-<?= $contest['id'] ?>-countdown').countdown(<?= $rest_seconds ?>, function() {}, 'inherit', false);
+											$('#contest-<?= $contest->info['id'] ?>-countdown').countdown(<?= $rest_seconds ?>, function() {}, 'inherit', false);
 										</script>
 									<?php endif ?>
 								<?php endif ?>
@ -116,7 +92,7 @@
 						</li>
 					<?php endif ?>
 				<?php endforeach ?>
-				<?php if ($count == 0) : ?>
+				<?php if (empty($upcoming_contests)) : ?>
 					<li class="list-group-item text-center">
 						<?= UOJLocale::get('none') ?>
 					</li>
--- a/web/app/views/user-info.php
+++ b/web/app/views/user-info.php
@ -12,9 +12,7 @@
 				<?php endif ?>
 				<h3>
 					<?= $user['username'] ?>
-					<span class="fs-6 align-middle"
-					<?php if ($user['sex'] == 'M'): ?>
-						style="color: blue"><i class="bi bi-gender-male"></i>
+					<span class="fs-6 align-middle" <?php if ($user['sex'] == 'M') : ?> style="color: blue"><i class="bi bi-gender-male"></i>
 					<?php elseif ($user['sex'] == 'F') : ?>
 						style="color: red"><i class="bi bi-gender-female"></i>
 					<?php else : ?>
@ -58,7 +56,9 @@
 				<?php endif ?>
 				<?php if ($user['qq']) : ?>
 					<li class="list-group-item">
-					<i class="align-text-bottom me-1"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" width="16" height="16"><path d="M433.754 420.445c-11.526 1.393-44.86-52.741-44.86-52.741 0 31.345-16.136 72.247-51.051 101.786 16.842 5.192 54.843 19.167 45.803 34.421-7.316 12.343-125.51 7.881-159.632 4.037-34.122 3.844-152.316 8.306-159.632-4.037-9.045-15.25 28.918-29.214 45.783-34.415-34.92-29.539-51.059-70.445-51.059-101.792 0 0-33.334 54.134-44.859 52.741-5.37-.65-12.424-29.644 9.347-99.704 10.261-33.024 21.995-60.478 40.144-105.779C60.683 98.063 108.982.006 224 0c113.737.006 163.156 96.133 160.264 214.963 18.118 45.223 29.912 72.85 40.144 105.778 21.768 70.06 14.716 99.053 9.346 99.704z" fill="currentColor"/></svg></i>
+						<i class="align-text-bottom me-1"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" width="16" height="16">
+								<path d="M433.754 420.445c-11.526 1.393-44.86-52.741-44.86-52.741 0 31.345-16.136 72.247-51.051 101.786 16.842 5.192 54.843 19.167 45.803 34.421-7.316 12.343-125.51 7.881-159.632 4.037-34.122 3.844-152.316 8.306-159.632-4.037-9.045-15.25 28.918-29.214 45.783-34.415-34.92-29.539-51.059-70.445-51.059-101.792 0 0-33.334 54.134-44.859 52.741-5.37-.65-12.424-29.644 9.347-99.704 10.261-33.024 21.995-60.478 40.144-105.779C60.683 98.063 108.982.006 224 0c113.737.006 163.156 96.133 160.264 214.963 18.118 45.223 29.912 72.85 40.144 105.778 21.768 70.06 14.716 99.053 9.346 99.704z" fill="currentColor" />
+							</svg></i>
 						<a class="text-decoration-none text-body" href="http://wpa.qq.com/msgrd?v=3&uin=<?= HTML::escape($user['qq']) ?>&site=qq&menu=yes" target="_blank">
 							<?= HTML::escape($user['qq']) ?>
 						</a>
@ -74,7 +74,10 @@
 				<?php endif ?>
 				<?php if ($extra['social']['codeforces']) : ?>
 					<li class="list-group-item d-flex align-items-center">
-					<div class="flex-shrink-0"><i class="align-text-bottom me-1"><svg xmlns="http://www.w3.org/2000/svg" role="img" viewBox="0 0 24 24" width="16" height="16"><title>Codeforces</title><path d="M4.5 7.5C5.328 7.5 6 8.172 6 9v10.5c0 .828-.672 1.5-1.5 1.5h-3C.673 21 0 20.328 0 19.5V9c0-.828.673-1.5 1.5-1.5h3zm9-4.5c.828 0 1.5.672 1.5 1.5v15c0 .828-.672 1.5-1.5 1.5h-3c-.827 0-1.5-.672-1.5-1.5v-15c0-.828.673-1.5 1.5-1.5h3zm9 7.5c.828 0 1.5.672 1.5 1.5v7.5c0 .828-.672 1.5-1.5 1.5h-3c-.828 0-1.5-.672-1.5-1.5V12c0-.828.672-1.5 1.5-1.5h3z" fill="currentColor"/></svg></i>&nbsp;</div>
+						<div class="flex-shrink-0"><i class="align-text-bottom me-1"><svg xmlns="http://www.w3.org/2000/svg" role="img" viewBox="0 0 24 24" width="16" height="16">
+									<title>Codeforces</title>
+									<path d="M4.5 7.5C5.328 7.5 6 8.172 6 9v10.5c0 .828-.672 1.5-1.5 1.5h-3C.673 21 0 20.328 0 19.5V9c0-.828.673-1.5 1.5-1.5h3zm9-4.5c.828 0 1.5.672 1.5 1.5v15c0 .828-.672 1.5-1.5 1.5h-3c-.827 0-1.5-.672-1.5-1.5v-15c0-.828.673-1.5 1.5-1.5h3zm9 7.5c.828 0 1.5.672 1.5 1.5v7.5c0 .828-.672 1.5-1.5 1.5h-3c-.828 0-1.5-.672-1.5-1.5V12c0-.828.672-1.5 1.5-1.5h3z" fill="currentColor" />
+								</svg></i>&nbsp;</div>
 						<div>
 							<a id="codeforces-profile-link" class="text-decoration-none" href="https://codeforces.com/profile/<?= $extra['social']['codeforces'] ?>" target="_blank" style="color: rgba(var(--bs-body-color-rgb), var(--bs-text-opacity)) !important;">
 								<?= $extra['social']['codeforces'] ?>
@ -137,7 +140,8 @@
 			</ul>
 			<div class="card-footer bg-transparent">
 				<?php $last_visit_time = strtotime($user['last_visit_time']) ?>
-				<?php if (time() - $last_visit_time < 60 * 15): // 15 mins ?>
+				<?php if (time() - $last_visit_time < 60 * 15) : // 15 mins 
+				?>
 					<span class="text-success">
 						<i class="bi bi-circle-fill me-1"></i>
 						<?= UOJLocale::get('user::online') ?>
@ -149,8 +153,8 @@
 					</span>
 					<?php if ($last_visit_time > 0) : ?>
 						<span class="text-muted small">
-							, <?= UOJLocale::get('user::last active at') ?>
-							<?= HTML::relative_time_str($last_visit_time, 0) ?>
+							(<?= UOJLocale::get('user::last active at') ?>
+							<?= HTML::relative_time_str($last_visit_time, 0) ?>)
 						</span>
 					<?php endif ?>
 				<?php endif ?>
@ -188,7 +192,7 @@
 		</nav>

 		<?php if (!isset($is_blog_aboutme)) : ?>
-		<?php $groups = queryGroupsOfUser($user['username']) ?>
+			<?php $groups = UOJGroup::queryGroupsOfUser($user['username']) ?>
 			<div class="card mb-2">
 				<div class="card-body">
 					<h4 class="card-title">
@ -197,9 +201,7 @@
 					<ul class="mb-0">
 						<?php foreach ($groups as $group) : ?>
 							<li>
-					<a class="text-decoration-none" href="<?= HTML::url('/group/'.$group['id']) ?>">
-						<?= $group['title'] ?>
-					</a>
+								<?= $group->getLink() ?>
 							</li>
 						<?php endforeach ?>
 						<?php if (empty($groups)) : ?>
@ -228,8 +230,10 @@ while ($row = DB::fetch($_result)) {
 				<div id="accepted-graph" style="font-size: 14px"></div>
 				<script>
 					var accepted_graph_data = [
-						<?php foreach ($result as $key => $val): ?>
-							{ date: '<?= $key ?>', count: <?= $val ?> },
+						<?php foreach ($result as $key => $val) : ?> {
+								date: '<?= $key ?>',
+								count: <?= $val ?>
+							},
 						<?php endforeach ?>
 					];

--- a/web/css/uoj-bs5.css
+++ b/web/css/uoj-bs5.css
@ -452,3 +452,8 @@ form.uoj-bs4-form-compressed button {
 .CodeMirror-linenumber {
 	font-size: 14px !important;
 }
+
+.uoj-back-btn {
+	--bs-btn-hover-bg: #d3d4d570;
+	--bs-btn-hover-border-color: transparent;
+}