<?php

function hasProblemPermissionGroup($group, $problem) {
	if ($group == null)
		return false;
	return in_array($problem['id'], explode(',', $group['privs']));
}

function hasProblemViewPermission($user, $problem) {
	if ($user == null)
		return false;
	if (isSuperUser($user))
		return true;
	if (DB::selectFirst("select * from problems_permissions where username = '{$user['username']}' and problem_id = {$problem['id']}") != null)
		return true;
	$groups = explode(',', $user['extgroups']);
	foreach ($groups as $key => $grp)
		if (hasProblemPermissionGroup(queryUser($grp), $problem))
			return true;
	return false;
}

function hasProblemCtrlPermission($user, $problem) {
	if (!hasProblemViewPermission($user, $problem))
		return false;
	if (isSuperUser($user))
		return true;
	$grp = $problem['ctrl'];
	if ($grp == '') return false;
	$grp = queryUser($grp);
	if (!$grp) return false;
	if (in_array($user['username'], explode(',', $grp['ctrls'])))
		return true;
	return false;
}

function giveGroupPermission($user, $group) {
	if ($user == null || $group == null) return;
	$q = explode(',', $group['ctrls']);
	if (in_array($user['username'], $q)) return;
	$q[] = $user['username'];
	$s = join(',', $q);
	$groupname = $group['username'];
	DB::update("update user_info set ctrls = '$s' where username = '$groupname'");
}

function removeGroupPermission($user, $group) {
	if ($user == null || $group == null) return;
	$q = explode(',', $group['ctrls']);
	$p = array();
	foreach ($q as $i => $k) if ($k != $user['username']) $p[] = $k;
	$s = join(',', $p);
	$groupname = $group['username'];
	DB::update("update user_info set ctrls = '$s' where username = '$groupname'");
}

function attachProblemToGroup($problem, $group) {
	if ($problem == null || $group == null)
		return;
	if (in_array($problem['id'], explode(',', $group['privs'])))
		return;
	if ($group['privs'] == '') $privs = $problem['id'];
	else $privs = $group['privs'] . ',' . $problem['id'];
	$name = $group['username'];
	DB::update("update user_info set privs = '$privs' where username = '$name'");
}

function attachUserToGroup($user, $group) {
	if ($user == null || $group == null)
		return;
	if (in_array($group['username'], explode(',', $user['extgroups'])))
		return;
	if ($user['extgroups'] == '') $extgrps = $group['username'];
	else $extgrps = $user['extgroups'] . ',' . $group['username'];
	$name = $user['username'];
	DB::update("update user_info set extgroups = '$extgrps' where username = '$name'");
}

function deattachUserFromGroup($user, $group) {
	if ($user == null || $group == null) return;
	removeGroupPermission($user, $group);
	$q = explode(',', $user['extgroups']);
	if (!in_array($group['username'], $q)) return;
	$p = array();
	foreach ($q as $i => $k) if ($k != $group['username']) $p[] = $k;
	$s = join(',', $p);
	$name = $user['username'];
	DB::update("update user_info set extgroups = '$s' where username = '$name'");
}

function queryUserExtgroups($user) {
	if ($user == null) return;
	return explode(',', $user['extgroups']);
}

function queryGroupControllers($grp) {
	if ($grp == null) return;
	return explode(',', $grp['ctrls']);
}

function queryGroupMembers($grp) {
	$grpname = $grp['username'];
	return DB::selectAll("select username from user_info where find_in_set('$grpname', extgroups)");
}

function queryGroupProblems($grp) {
	$p = $grp['privs'];
	if ($p == '') return array ();
	return explode(',', $grp['privs']);
}

function queryProblemSize($pid) {
	return filesize("/var/uoj_data/$pid.zip");
}

function queryGroupTotalSize($grp) {
	$size = 0;
	foreach (queryGroupProblems($grp) as $i => $pid)
		if (queryProblemBrief($pid)['ctrl'] == $grp['username'])
			$size += queryProblemSize($pid);
	return $size;
}

function queryGroupCtrlProblems($grp) {
	$q = array();
	foreach (queryGroupProblems($grp) as $i => $pid)
		if (queryProblemBrief($pid)['ctrl'] == $grp['username']) $q[] = $pid;
	return $q;
}

function queryGroupQuota($grp) {
	return $grp['ac_num'] * 1048576;
}

function queryGroupProblemQuota($grp) {
	return 20;
}

function queryUserCtrlgroups($user) {
	if ($user == null) return;
	if (isSuperUser($user)) {
		$q = array();
		foreach (DB::selectAll("select username from user_info where username like 'group_%'") as $i => $k)
			$q[] = $k['username'];
		return $q;
	}
	$res = array();
	foreach (queryUserExtgroups($user) as $i => $grp) {
		if (in_array($user['username'], queryGroupControllers(queryUser($grp))))
			$res[] = $grp;
	}
	return $res;
}

function hasGroupCtrlPermission($user, $grp) {
	if ($user == null) return false;
	if (isSuperUser($user)) return true;
	if (in_array($user['username'], explode(',', $grp['ctrls'])))
		return true;
	else return false;
}

function hasViewPermission($str,$user,$problem,$submission) {
	if ($str=='ALL') {
		return true;
	}
	if ($str=='ALL_AFTER_AC') {
		return hasAC($user,$problem);
	}
	if ($str=='SELF') {
		return $submission['submitter']==$user['username'];
	}
	return false;
}

function hasContestPermission($user, $contest) {
	if ($user == null) {
		return false;
	}
	if (isSuperUser($user)) {
		return true;
	}
	return DB::selectFirst("select * from contests_permissions where username = '{$user['username']}' and contest_id = {$contest['id']}") != null;
}

function hasRegistered($user, $contest) {
	return DB::selectFirst("select * from contests_registrants where username = '${user['username']}' and contest_id = ${contest['id']}") != null;
}
function hasAC($user, $problem) {
	return DB::selectFirst("select * from best_ac_submissions where submitter = '${user['username']}' and problem_id = ${problem['id']}") != null;
}

function queryUser($username) {
	if (!validateUsername($username)) {
		return null;
	}
	return DB::selectFirst("select * from user_info where username='$username'", MYSQLI_ASSOC);
}

function queryProblemContent($id) {
	return DB::selectFirst("select * from problems_contents where id = $id", MYSQLI_ASSOC);
}
function queryProblemBrief($id) {
	return DB::selectFirst("select * from problems where id = $id", MYSQLI_ASSOC);
}

function queryRemoteProblemBrief($pid) {
	return DB::selectFirst("select pid, title from rp where pid = '$pid'", MYSQLI_ASSOC);
}

function queryRemoteProblemFull($pid) {
	return DB::selectFirst("select pid, title, statement from rp where pid = '$pid'", MYSQLI_ASSOC);
}

function queryProblemTags($id) {
	$tags = array();
	$result = DB::query("select tag from problems_tags where problem_id = $id order by id");
	while ($row = DB::fetch($result, MYSQLI_NUM)) {
		$tags[] = $row[0];
	}
	return $tags;
}
function queryContestProblemRank($contest, $problem) {
	if (!DB::selectFirst("select * from contests_problems where contest_id = {$contest['id']} and problem_id = {$problem['id']}")) {
		return null;
	}
	return DB::selectCount("select count(*) from contests_problems where contest_id = {$contest['id']} and problem_id <= {$problem['id']}");
}

function queryDatumStream($id) {
	return DB::selectFirst("select * from datum_streams where id = $id", MYSQLI_ASSOC);
}

function querySubmission($id) {
	return DB::selectFirst("select * from submissions where id = $id", MYSQLI_ASSOC);
}
function queryHack($id) {
	return DB::selectFirst("select * from hacks where id = $id", MYSQLI_ASSOC);
}
function queryContest($id) {
	return DB::selectFirst("select * from contests where id = $id", MYSQLI_ASSOC);
}
function queryContestProblem($id) {
	return DB::selectFirst("select * from contest_problems where contest_id = $id", MYSQLI_ASSOC);
}

function queryDatumBrief($id) {
	return DB::selectFirst("select id, pid, status from datum_requests where id = $id", MYSQLI_ASSOC);
}

function queryDatum($id) {
	return DB::selectFirst("select * from datum_requests where id = $id", MYSQLI_ASSOC);
}

function queryZanVal($id, $type, $user) {
	if ($user == null) {
		return 0;
	}
	$esc_type = DB::escape($type);
	$row = DB::selectFirst("select val from click_zans where username='{$user['username']}' and type='$esc_type' and target_id='$id'");
	if ($row == null) {
		return 0;
	}
	return $row['val'];
}

function queryBlog($id) {
	return DB::selectFirst("select * from blogs where id='$id'", MYSQLI_ASSOC);
}
function queryBlogTags($id) {
	$tags = array();
	$result = DB::select("select tag from blogs_tags where blog_id = $id order by id");
	while ($row = DB::fetch($result, MYSQLI_NUM)) {
		$tags[] = $row[0];
	}
	return $tags;
}
function queryBlogComment($id) {
	return DB::selectFirst("select * from blogs_comments where id='$id'", MYSQLI_ASSOC);
}

function isProblemVisibleToUser($problem, $user) {
	return !$problem['is_hidden'] || hasProblemViewPermission($user, $problem);
}
function isContestProblemVisibleToUser($problem, $contest, $user) {
	if (isProblemVisibleToUser($problem, $user)) {
		return true;
	}
	if ($contest['cur_progress'] >= CONTEST_PENDING_FINAL_TEST) {
		return true;
	}
	if ($contest['cur_progress'] == CONTEST_NOT_STARTED) {
		return false;
	}
	return hasRegistered($user, $contest);
}

function isSubmissionVisibleToUser($submission, $problem, $user) {
	if (isSuperUser($user)) {
		return true;
	} elseif (!$submission['is_hidden']) {
		return true;
	} else {
		return hasProblemViewPermission($user, $problem);
	}
}
function isHackVisibleToUser($hack, $problem, $user) {
	if (isSuperUser($user)) {
		return true;
	} elseif (!$hack['is_hidden']) {
		return true;
	} else {
		return hasProblemViewPermission($user, $problem);
	}
}

function isSubmissionFullVisibleToUser($submission, $contest, $problem, $user) {
	if (isSuperUser($user)) {
		return true;
	} elseif (!$contest) {
		return true;
	} elseif ($contest['cur_progress'] > CONTEST_IN_PROGRESS) {
		return true;
	} elseif ($submission['submitter'] == $user['username']) {
		return true;
	} else {
		return hasProblemCtrlPermission($user, $problem);
	}
}
function isHackFullVisibleToUser($hack, $contest, $problem, $user) {
	if (isSuperUser($user)) {
		return true;
	} elseif (!$contest) {
		return true;
	} elseif ($contest['cur_progress'] > CONTEST_IN_PROGRESS) {
		return true;
	} elseif ($hack['hacker'] == $user['username']) {
		return true;
	} else {
		return hasProblemCtrlPermission($user, $problem);
	}
}

function deleteBlog($id) {
	if (!validateUInt($id)) {
		return;
	}
	DB::delete("delete from click_zans where type = 'B' and target_id = $id");
	DB::delete("delete from click_zans where type = 'BC' and target_id in (select id from blogs_comments where blog_id = $id)");
	DB::delete("delete from blogs where id = $id");
	DB::delete("delete from blogs_comments where blog_id = $id");
	DB::delete("delete from important_blogs where blog_id = $id");
	DB::delete("delete from blogs_tags where blog_id = $id");
}