<?php
namespace Misuzu\Users;

use InvalidArgumentException;
use RuntimeException;
use Index\DateTime;
use Index\XString;
use Index\Colour\Colour;
use Index\Data\DbStatementCache;
use Index\Data\DbTools;
use Index\Data\IDbConnection;
use Index\Net\IPAddress;
use Misuzu\Pagination;
use Misuzu\Tools;
use Misuzu\Parsers\Parser;

class Users {
    private IDbConnection $dbConn;
    private DbStatementCache $cache;

    public function __construct(IDbConnection $dbConn) {
        $this->dbConn = $dbConn;
        $this->cache = new DbStatementCache($dbConn);
    }

    public const NAME_MIN_LENGTH = 3;
    public const NAME_MAX_LENGTH = 16;

    public const PASSWORD_ALGO = PASSWORD_ARGON2ID;
    public const PASSWORD_OPTS = [];
    public const PASSWORD_UNIQUE = 6;

    public const PROFILE_ABOUT_MAX_LENGTH = 50000;
    public const FORUM_SIGNATURE_MAX_LENGTH = 2000;

    public static function passwordHash(string $password): string {
        return password_hash($password, self::PASSWORD_ALGO, self::PASSWORD_OPTS);
    }

    public static function passwordNeedsRehash(string $passwordHash): bool {
        return password_needs_rehash($passwordHash, self::PASSWORD_ALGO, self::PASSWORD_OPTS);
    }

    public function countUsers(
        RoleInfo|string|null $roleInfo = null,
        UserInfo|string|null $after = null,
        ?int $lastActiveInMinutes = null,
        ?int $newerThanDays = null,
        ?DateTime $birthdate = null,
        ?bool $deleted = null
    ): int {
        if($roleInfo instanceof RoleInfo)
            $roleInfo = $roleInfo->getId();
        if($after instanceof UserInfo)
            $after = $after->getId();

        $hasRoleInfo = $roleInfo !== null;
        $hasAfter = $after !== null;
        $hasLastActiveInMinutes = $lastActiveInMinutes !== null;
        $hasNewerThanDays = $newerThanDays !== null;
        $hasBirthdate = $birthdate !== null;
        $hasDeleted = $deleted !== null;

        $args = 0;
        $query = 'SELECT COUNT(*) FROM msz_users';
        if($hasRoleInfo) {
            ++$args;
            $query .= ' WHERE user_id IN (SELECT user_id FROM msz_users_roles WHERE role_id = ?)';
        }
        if($hasAfter)
            $query .= sprintf(' %s user_id > ?', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasLastActiveInMinutes)
            $query .= sprintf(' %s user_active > NOW() - INTERVAL ? MINUTE', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasNewerThanDays)
            $query .= sprintf(' %s user_created > NOW() - INTERVAL ? DAY', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasDeleted)
            $query .= sprintf(' %s user_deleted %s NULL', ++$args > 1 ? 'AND' : 'WHERE', $deleted ? 'IS NOT' : 'IS');

        $args = 0;
        $stmt = $this->cache->get($query);
        if($hasRoleInfo)
            $stmt->addParameter(++$args, $roleInfo);
        if($hasAfter)
            $stmt->addParameter(++$args, $after);
        if($hasLastActiveInMinutes)
            $stmt->addParameter(++$args, $lastActiveInMinutes);
        if($hasNewerThanDays)
            $stmt->addParameter(++$args, $newerThanDays);
        $stmt->execute();

        $result = $stmt->getResult();
        return $result->next() ? $result->getInteger(0) : 0;
    }

    private const GET_USERS_SORT = [
        'id' => ['user_id', false],
        'name' => ['username', false],
        'country' => ['user_country', false],
        'created' => ['user_created', true],
        'active' => ['user_active', true],
        'random' => ['RAND()', null],
    ];

    public function getUsers(
        RoleInfo|string|null $roleInfo = null,
        UserInfo|string|null $after = null,
        ?int $lastActiveInMinutes = null,
        ?int $newerThanDays = null,
        ?DateTime $birthdate = null,
        ?bool $deleted = null,
        ?string $orderBy = null,
        ?bool $reverseOrder = null,
        ?array $searchQuery = null,
        ?Pagination $pagination = null
    ): iterable {
        // remove this hack when search server
        $hasSearchQuery = $searchQuery !== null;
        $searchLimitResults = false;
        if($hasSearchQuery) {
            if(!empty($searchQuery['type'])
                && $searchQuery['type'] !== 'member')
                return [];

            $roleInfo = null;
            $after = null;
            $lastActiveInMinutes = null;
            $newerThanDays = null;
            $birthdate = null;
            $deleted = false;
            $orderBy = 'id';
            $reverseOrder = false;
            $pagination = null;
            $searchLimitResults = true;

            if(!empty($searchQuery['after']))
                $after = $searchQuery['after'];

            $searchQuery = $searchQuery['query_string'];
            $hasSearchQuery = !empty($searchQuery);
        }

        if($roleInfo instanceof RoleInfo)
            $roleInfo = $roleInfo->getId();
        if($after instanceof UserInfo)
            $after = $after->getId();

        $hasRoleInfo = $roleInfo !== null;
        $hasAfter = $after !== null;
        $hasLastActiveInMinutes = $lastActiveInMinutes !== null;
        $hasNewerThanDays = $newerThanDays !== null;
        $hasBirthdate = $birthdate !== null;
        $hasDeleted = $deleted !== null;
        $hasOrderBy = $orderBy !== null;
        $hasReverseOrder = $reverseOrder !== null;
        $hasPagination = $pagination !== null;

        if($hasOrderBy) {
            if(!array_key_exists($orderBy, self::GET_USERS_SORT))
                throw new InvalidArgumentException('Invalid sort specified.');
            $orderBy = self::GET_USERS_SORT[$orderBy];

            if($hasReverseOrder && $reverseOrder && $orderBy[1] !== null)
                $orderBy[1] = !$orderBy[1];
        }

        $args = 0;
        $query = 'SELECT user_id, username, password, email, INET6_NTOA(register_ip), INET6_NTOA(last_ip), user_super, user_country, user_colour, UNIX_TIMESTAMP(user_created), UNIX_TIMESTAMP(user_active), UNIX_TIMESTAMP(user_deleted), display_role, user_totp_key, user_about_content, user_about_parser, user_signature_content, user_signature_parser, user_birthdate, user_background_settings, user_title FROM msz_users';
        if($hasRoleInfo) {
            ++$args;
            $query .= ' WHERE user_id IN (SELECT user_id FROM msz_users_roles WHERE role_id = ?)';
        }
        if($hasAfter)
            $query .= sprintf(' %s user_id > ?', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasLastActiveInMinutes)
            $query .= sprintf(' %s user_active > NOW() - INTERVAL ? MINUTE', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasNewerThanDays)
            $query .= sprintf(' %s user_created > NOW() - INTERVAL ? DAY', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasDeleted)
            $query .= sprintf(' %s user_deleted %s NULL', ++$args > 1 ? 'AND' : 'WHERE', $deleted ? 'IS NOT' : 'IS');
        if($hasBirthdate)
            $query .= sprintf(' %s user_birthdate LIKE ?', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasSearchQuery)
            $query .= sprintf(' %s username LIKE CONCAT("%%", ?, "%%")', ++$args > 1 ? 'AND' : 'WHERE');
        if($hasOrderBy) {
            $query .= sprintf(' ORDER BY %s', $orderBy[0]);
            if($orderBy[1] !== null)
                $query .= ' ' . ($orderBy[1] ? 'DESC' : 'ASC');
        }
        if($searchLimitResults)
            $query .= ' LIMIT 20';
        elseif($hasPagination)
            $query .= ' LIMIT ? OFFSET ?';

        $args = 0;
        $stmt = $this->cache->get($query);
        if($hasRoleInfo)
            $stmt->addParameter(++$args, $roleInfo);
        if($hasAfter)
            $stmt->addParameter(++$args, $after);
        if($hasLastActiveInMinutes)
            $stmt->addParameter(++$args, $lastActiveInMinutes);
        if($hasNewerThanDays)
            $stmt->addParameter(++$args, $newerThanDays);
        if($hasBirthdate)
            $stmt->addParameter(++$args, $birthdate->format('%-m-d'));
        if($hasSearchQuery)
            $stmt->addParameter(++$args, $searchQuery);
        if($hasPagination) {
            $stmt->addParameter(++$args, $pagination->getRange());
            $stmt->addParameter(++$args, $pagination->getOffset());
        }
        $stmt->execute();

        return $stmt->getResult()->getIterator(UserInfo::fromResult(...));
    }

    public const GET_USER_ID = 0x01;
    public const GET_USER_NAME = 0x02;
    public const GET_USER_MAIL = 0x04;

    private const GET_USER_SELECT_ALIASES = [
        'id' => self::GET_USER_ID,
        'name' => self::GET_USER_NAME,
        'email' => self::GET_USER_MAIL,
        'profile' => self::GET_USER_ID | self::GET_USER_NAME,
        'search' => self::GET_USER_ID | self::GET_USER_NAME,
        'messaging' => self::GET_USER_ID | self::GET_USER_NAME,
        'login' => self::GET_USER_NAME | self::GET_USER_MAIL,
        'recovery' => self::GET_USER_MAIL,
    ];

    public static function resolveGetUserSelectAlias(int|string $select): int {
        if(is_string($select)) {
            if(!array_key_exists($select, self::GET_USER_SELECT_ALIASES))
                throw new InvalidArgumentException('Invalid $select alias.');
            $select = self::GET_USER_SELECT_ALIASES[$select];
        } elseif($select === 0)
            throw new InvalidArgumentException('$select may not be zero.');

        return $select;
    }

    public function getUser(string $value, int|string $select = self::GET_USER_ID): UserInfo {
        if($value === '')
            throw new InvalidArgumentException('$value may not be empty.');

        $select = self::resolveGetUserSelectAlias($select);
        $selectId = ($select & self::GET_USER_ID) > 0;
        $selectName = ($select & self::GET_USER_NAME) > 0;
        $selectMail = ($select & self::GET_USER_MAIL) > 0;

        if(!$selectId && !$selectName && !$selectMail)
            throw new InvalidArgumentException('$select flagset is invalid.');

        $args = 0;
        $query = 'SELECT user_id, username, password, email, INET6_NTOA(register_ip), INET6_NTOA(last_ip), user_super, user_country, user_colour, UNIX_TIMESTAMP(user_created), UNIX_TIMESTAMP(user_active), UNIX_TIMESTAMP(user_deleted), display_role, user_totp_key, user_about_content, user_about_parser, user_signature_content, user_signature_parser, user_birthdate, user_background_settings, user_title FROM msz_users';
        if($selectId) {
            ++$args;
            $query .= ' WHERE user_id = ?';
        }
        if($selectName)
            $query .= sprintf(' %s username = ?', ++$args > 1 ? 'OR' : 'WHERE');
        if($selectMail)
            $query .= sprintf(' %s email = ?', ++$args > 1 ? 'OR' : 'WHERE');

        $args = 0;
        $stmt = $this->cache->get($query);
        if($selectId)
            $stmt->addParameter(++$args, $value);
        if($selectName)
            $stmt->addParameter(++$args, $value);
        if($selectMail)
            $stmt->addParameter(++$args, $value);
        $stmt->execute();

        $result = $stmt->getResult();
        if(!$result->next())
            throw new RuntimeException('User not found.');

        return UserInfo::fromResult($result);
    }

    public function createUser(
        string $name,
        string $password,
        string $email,
        IPAddress|string $remoteAddr,
        string $countryCode,
        RoleInfo|string|null $displayRoleInfo = null
    ): UserInfo {
        if($remoteAddr instanceof IPAddress)
            $remoteAddr = (string)$remoteAddr;
        if($displayRoleInfo instanceof RoleInfo)
            $displayRoleInfo = $displayRoleInfo->getId();
        elseif($displayRoleInfo === null)
            $displayRoleInfo = Roles::DEFAULT_ROLE;

        $password = self::passwordHash($password);

        if(self::validateName($name, true) !== '')
            throw new InvalidArgumentException('$name is not a valid user name.');
        if(self::validateEMailAddress($email, true) !== '')
            throw new InvalidArgumentException('$email is not a valid e-mail address.');

        $stmt = $this->cache->get('INSERT INTO msz_users (username, password, email, register_ip, last_ip, user_country, display_role) VALUES (?, ?, ?, INET6_ATON(?), INET6_ATON(?), ?, ?)');
        $stmt->addParameter(1, $name);
        $stmt->addParameter(2, $password);
        $stmt->addParameter(3, $email);
        $stmt->addParameter(4, $remoteAddr);
        $stmt->addParameter(5, $remoteAddr);
        $stmt->addParameter(6, $countryCode);
        $stmt->addParameter(7, $displayRoleInfo);
        $stmt->execute();

        return $this->getUser((string)$this->dbConn->getLastInsertId(), self::GET_USER_ID);
    }

    public function updateUser(
        UserInfo|string $userInfo,
        ?string $name = null,
        ?string $emailAddr = null,
        ?string $password = null,
        ?string $countryCode = null,
        ?Colour $colour = null,
        RoleInfo|string|null $displayRoleInfo = null,
        ?string $totpKey = null,
        ?string $aboutContent = null,
        ?int $aboutParser = null,
        ?string $signatureContent = null,
        ?int $signatureParser = null,
        ?int $birthYear = null,
        ?int $birthMonth = null,
        ?int $birthDay = null,
        ?int $backgroundSettings = null,
        ?string $title = null
    ): void {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if($displayRoleInfo instanceof RoleInfo)
            $displayRoleInfo = $displayRoleInfo->getId();

        $fields = [];
        $values = [];

        if($name !== null) {
            if(self::validateName($name, true) !== '')
                throw new InvalidArgumentException('$name is not valid.');

            $fields[] = 'username = ?';
            $values[] = $name;
        }

        if($emailAddr !== null) {
            if(self::validateEMailAddress($emailAddr, true) !== '')
                throw new InvalidArgumentException('$emailAddr is not valid.');

            $fields[] = 'email = ?';
            $values[] = $emailAddr;
        }

        if($password !== null) {
            $fields[] = 'password = ?';
            $values[] = $password === '' ? null : self::passwordHash($password);
        }

        if($countryCode !== null) {
            $fields[] = 'user_country = ?';
            $values[] = $countryCode;
        }

        if($colour !== null) {
            $fields[] = 'user_colour = ?';
            $values[] = $colour->shouldInherit() ? null : Colour::toMisuzu($colour);
        }

        if($displayRoleInfo !== null) {
            $fields[] = 'display_role = ?';
            $values[] = $displayRoleInfo;
        }

        if($totpKey !== null) {
            $fields[] = 'user_totp_key = ?';
            $values[] = $totpKey === '' ? null : $totpKey;
        }

        if($aboutContent !== null && $aboutParser !== null) {
            if(self::validateProfileAbout($aboutParser, $aboutContent) !== '')
                throw new InvalidArgumentException('$aboutContent and $aboutParser contain invalid data!');

            $fields[] = 'user_about_content = ?';
            $values[] = $aboutContent;
            $fields[] = 'user_about_parser = ?';
            $values[] = $aboutParser;
        }

        if($signatureContent !== null && $signatureParser !== null) {
            if(self::validateForumSignature($signatureParser, $signatureContent) !== '')
                throw new InvalidArgumentException('$signatureContent and $signatureParser contain invalid data!');

            $fields[] = 'user_signature_content = ?';
            $values[] = $signatureContent;
            $fields[] = 'user_signature_parser = ?';
            $values[] = $signatureParser;
        }

        if($birthMonth !== null && $birthDay !== null) {
            if(self::validateBirthdate($birthYear, $birthMonth, $birthDay) !== '')
                throw new InvalidArgumentException('$birthYear, $birthMonth and $birthDay contain invalid data!');

            // lowest leap year MariaDB accepts, used a 'no year' value
            if($birthYear < 1004)
                $birthYear = 1004;

            $fields[] = 'user_birthdate = ?';
            $values[] = $birthMonth < 1 || $birthDay < 1 ? null : sprintf('%04d-%02d-%02d', $birthYear, $birthMonth, $birthDay);
        }

        if($backgroundSettings !== null) {
            $fields[] = 'user_background_settings = ?';
            $values[] = $backgroundSettings;
        }

        if($title !== null) {
            $fields[] = 'user_title = ?';
            $values[] = $title;
        }

        if(empty($fields))
            return;

        $args = 0;
        $stmt = $this->cache->get(sprintf('UPDATE msz_users SET %s WHERE user_id = ?', implode(', ', $fields)));
        foreach($values as $value)
            $stmt->addParameter(++$args, $value);
        $stmt->addParameter(++$args, $userInfo);
        $stmt->execute();
    }

    public function recordUserActivity(
        UserInfo|string $userInfo,
        IPAddress|string $remoteAddr
    ): void {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if($remoteAddr instanceof IPAddress)
            $remoteAddr = (string)$remoteAddr;

        $stmt = $this->cache->get('UPDATE msz_users SET user_active = NOW(), last_ip = INET6_ATON(?) WHERE user_id = ?');
        $stmt->addParameter(1, $remoteAddr);
        $stmt->addParameter(2, $userInfo);
        $stmt->execute();
    }

    public function hasRole(
        UserInfo|string $userInfo,
        RoleInfo|string $roleInfo
    ): bool {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if($roleInfo instanceof RoleInfo)
            $roleInfo = $roleInfo->getId();

        return in_array($roleInfo, $this->hasRoles($userInfo, $roleInfo));
    }

    public function hasRoles(
        UserInfo|string $userInfo,
        RoleInfo|string|array $roleInfos
    ): array {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if(!is_array($roleInfos))
            $roleInfos = [$roleInfos];
        elseif(empty($roleInfos))
            return [];

        $args = 0;
        $stmt = $this->cache->get(sprintf(
            'SELECT role_id FROM msz_users_roles WHERE user_id = ? AND role_id IN (%s)',
            DbTools::prepareListString($roleInfos)
        ));
        $stmt->addParameter(++$args, $userInfo);

        foreach($roleInfos as $roleInfo) {
            if($roleInfo instanceof RoleInfo)
                $roleInfo = $roleInfo->getId();
            elseif(!is_string($roleInfo))
                throw new InvalidArgumentException('$roleInfos must be strings of instances of RoleInfo.');

            $stmt->addParameter(++$args, $roleInfo);
        }

        $stmt->execute();

        $roleIds = [];
        $result = $stmt->getResult();

        while($result->next())
            $roleIds[] = (string)$result->getInteger(0);

        return $roleIds;
    }

    public function addRoles(
        UserInfo|string $userInfo,
        RoleInfo|string|array $roleInfos
    ): void {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if(!is_array($roleInfos))
            $roleInfos = [$roleInfos];
        elseif(empty($roleInfos))
            return;

        $stmt = $this->cache->get(sprintf(
            'REPLACE INTO msz_users_roles (user_id, role_id) VALUES %s',
            DbTools::prepareListString($roleInfos, '(?, ?)')
        ));

        $args = 0;
        foreach($roleInfos as $roleInfo) {
            if($roleInfo instanceof RoleInfo)
                $roleInfo = $roleInfo->getId();
            elseif(!is_string($roleInfo))
                throw new InvalidArgumentException('$roleInfos must be strings of instances of RoleInfo.');

            $stmt->addParameter(++$args, $userInfo);
            $stmt->addParameter(++$args, $roleInfo);
        }

        $stmt->execute();
    }

    public function removeRoles(
        UserInfo|string $userInfo,
        RoleInfo|string|array $roleInfos
    ): void {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();
        if(!is_array($roleInfos))
            $roleInfos = [$roleInfos];
        elseif(empty($roleInfos))
            return;

        $args = 0;
        $stmt = $this->cache->get(sprintf(
            'DELETE FROM msz_users_roles WHERE user_id = ? AND role_id IN (%s)',
            DbTools::prepareListString($roleInfos)
        ));
        $stmt->addParameter(++$args, $userInfo);

        foreach($roleInfos as $roleInfo) {
            if($roleInfo instanceof RoleInfo)
                $roleInfo = $roleInfo->getId();
            elseif(!is_string($roleInfo))
                throw new InvalidArgumentException('$roleInfos must be strings of instances of RoleInfo.');

            $stmt->addParameter(++$args, $roleInfo);
        }

        $stmt->execute();
    }

    // the below two funcs should probably be moved to a higher level location so caching can be introduced
    // without cluttering the data source interface <-- real words i just wrote

    public function getUserColour(UserInfo|string $userInfo): Colour {
        if($userInfo instanceof UserInfo) {
            if($userInfo->hasColour())
                return $userInfo->getColour();

            $query = '?';
            $value = $userInfo->getDisplayRoleId();
        } else {
            $query = '(SELECT display_role FROM msz_users WHERE user_id = ?)';
            $value = $userInfo;
        }

        $stmt = $this->cache->get(sprintf('SELECT role_colour FROM msz_roles WHERE role_id = %s', $query));
        $stmt->addParameter(1, $value);
        $stmt->execute();

        $result = $stmt->getResult();
        return $result->next() ? Colour::fromMisuzu($result->getInteger(0)) : Colour::none();
    }

    public function getUserRank(UserInfo|string $userInfo): int {
        if($userInfo instanceof UserInfo)
            $userInfo = $userInfo->getId();

        $stmt = $this->cache->get('SELECT MAX(role_hierarchy) FROM msz_roles WHERE role_id IN (SELECT role_id FROM msz_users_roles WHERE user_id = ?)');
        $stmt->addParameter(1, $userInfo);
        $stmt->execute();

        $result = $stmt->getResult();
        return $result->next() ? $result->getInteger(0) : 0;
    }

    public function checkNameInUse(string $name): bool {
        $stmt = $this->cache->get('SELECT COUNT(*) FROM msz_users WHERE username = ?');
        $stmt->addParameter(1, $name);
        $stmt->execute();
        $result = $stmt->getResult();
        if(!$result->next())
            throw new RuntimeException('Was not able to check if name is already in use.');
        return $result->getInteger(0) > 0;
    }

    public function validateName(string $name, bool $skipInUse = false): string {
        if($name !== trim($name))
            return 'trim';

        if(str_starts_with(mb_strtolower($name), 'flappyzor'))
            return 'flapp';

        $length = mb_strlen($name);
        if($length < self::NAME_MIN_LENGTH)
            return 'short';
        if($length > self::NAME_MAX_LENGTH)
            return 'long';

        if(!preg_match('#^[A-Za-z0-9-_]+$#u', $name))
            return 'invalid';

        if(!$skipInUse && $this->checkNameInUse($name))
            return 'used';

        return '';
    }

    public static function validateNameText(string $error): string {
        return match($error) {
            'trim' => 'Your username may not start or end with spaces.',
            'short' => sprintf('Your username is too short, it has to be at least %d characters.', self::NAME_MIN_LENGTH),
            'long' => sprintf("Your username is too long, it can't be longer than %d characters.", self::NAME_MAX_LENGTH),
            'invalid' => 'Your username contains invalid characters.',
            'used' => 'That username is already taken.',
            'flapp' => 'Your username may not start with Flappyzor.',
            '' => 'Your username is correctly formatted, why are you seeing this?',
            default => 'This username is incorrectly formatted.',
        };
    }

    public function checkEMailAddressInUse(string $address): bool {
        $stmt = $this->cache->get('SELECT COUNT(*) FROM msz_users WHERE email = ?');
        $stmt->addParameter(1, $address);
        $stmt->execute();
        $result = $stmt->getResult();
        if(!$result->next())
            throw new RuntimeException('Was not able to check if e-mail address is already in use.');
        return $result->getInteger(0) > 0;
    }

    public function validateEMailAddress(string $address, bool $skipInUse = false): string {
        if(filter_var($address, FILTER_VALIDATE_EMAIL) === false)
            return 'invalid';

        if(!checkdnsrr(mb_substr(mb_strstr($address, '@'), 1), 'MX'))
            return 'dns';

        if(!$skipInUse && $this->checkEMailAddressInUse($address))
            return 'used';

        return '';
    }

    public static function validateEMailAddressText(string $error): string {
        return match($error) {
            'dns' => 'Was unable to find a mail server running on the domain in your e-mail address.',
            '' => 'Your e-mail address is correctly formatted, why are you seeing this?',
            default => 'Your e-mail address is not correctly formatted.',
        };
    }

    public static function validatePassword(string $password): string {
        if(XString::countUnique($password) < self::PASSWORD_UNIQUE)
            return 'weak';

        return '';
    }

    public static function validatePasswordText(string $error): string {
        return match($error) {
            'weak' => sprintf("Your password is too weak, it must contain at least %d unique characters.", self::PASSWORD_UNIQUE),
            '' => 'Your password is strong enough, why are you seeing this?',
            default => 'Your password is not acceptable.',
        };
    }

    public static function validateBirthdate(?int $year, int $month, int $day, int $yearRange = 100): string {
        $year ??= 0;

        if($day !== 0 && $month !== 0) {
            $currentYear = (int)date('Y');
            if($year > 0 && ($year < $currentYear - $yearRange || $year > $currentYear))
                return 'year';

            if(!Tools::isValidDate($year, $month, $day))
                return 'date';
        }

        return '';
    }

    public static function validateBirthdateText(string $error): string {
        return match($error) {
            'year' => 'The year in your birthdate is too ridiculous.',
            'date' => 'The birthdate you attempted to set is not a valid date.',
            '' => 'Your birthdate is fine, why are you seeing this?',
            default => 'Your birthdate is not acceptable.',
        };
    }

    public static function validateProfileAbout(int $parser, string $text): string {
        if(!Parser::isValid($parser))
            return 'parser';

        $length = strlen($text);
        if($length > self::PROFILE_ABOUT_MAX_LENGTH)
            return 'long';

        return '';
    }

    public static function validateProfileAboutText(string $error): string {
        return match($error) {
            'parser' => 'You attempted to select an invalid parser for your profile about section.',
            'long' => sprintf('Please keep the length of your profile about section below %d characters.', self::PROFILE_ABOUT_MAX_LENGTH),
            '' => 'Your profile about section is fine, why are you seeing this?',
            default => 'Your profile about section is not acceptable.',
        };
    }

    public static function validateForumSignature(int $parser, string $text): string {
        if(!Parser::isValid($parser))
            return 'parser';

        $length = strlen($text);
        if($length > self::FORUM_SIGNATURE_MAX_LENGTH)
            return 'long';

        return '';
    }

    public static function validateForumSignatureText(string $error): string {
        return match($error) {
            'parser' => 'You attempted to select an invalid parser for your forum signature.',
            'long' => sprintf('Please keep the length of your forum signature below %d characters.', self::FORUM_SIGNATURE_MAX_LENGTH),
            '' => 'Your forum signature is fine, why are you seeing this?',
            default => 'Your forum signature is not acceptable.',
        };
    }
}