<?php
/**
 * 登录账号。一个人最多一个账号，账号依附于「人」而存在。
 */

declare(strict_types=1);

namespace App;

final class Account
{
    public const ROLES = ['admin', 'member', 'guest'];

    public static function findByPerson(int $personId): ?array
    {
        $st = Database::get()->prepare('SELECT * FROM accounts WHERE person_id = ?');
        $st->execute([$personId]);
        $row = $st->fetch();
        return $row ?: null;
    }

    public static function create(int $personId, string $password, string $role = 'member'): int
    {
        $role = in_array($role, self::ROLES, true) ? $role : 'member';
        $st = Database::get()->prepare(
            'INSERT INTO accounts (person_id, password_hash, role) VALUES (?, ?, ?)'
        );
        $st->execute([$personId, password_hash($password, PASSWORD_DEFAULT), $role]);
        return (int)Database::get()->lastInsertId();
    }

    public static function setPassword(int $accountId, string $password): void
    {
        Database::get()->prepare('UPDATE accounts SET password_hash = ? WHERE id = ?')
            ->execute([password_hash($password, PASSWORD_DEFAULT), $accountId]);
    }

    public static function setRole(int $accountId, string $role): void
    {
        $role = in_array($role, self::ROLES, true) ? $role : 'member';
        Database::get()->prepare('UPDATE accounts SET role = ? WHERE id = ?')
            ->execute([$role, $accountId]);
    }

    public static function setStatus(int $accountId, string $status): void
    {
        Database::get()->prepare('UPDATE accounts SET status = ? WHERE id = ?')
            ->execute([$status, $accountId]);
    }

    /** 各角色各有多少人（设置页显示） */
    public static function roleCounts(): array
    {
        $st = Database::get()->query(
            "SELECT role, COUNT(*) AS n FROM accounts WHERE status = 'active' GROUP BY role"
        );
        $out = ['admin' => 0, 'member' => 0, 'guest' => 0];
        foreach ($st->fetchAll() as $r) {
            $out[(string)$r['role']] = (int)$r['n'];
        }
        return $out;
    }

    public static function roleWord(string $role): string
    {
        return ['admin' => '管理员', 'member' => '家庭成员', 'guest' => '访客'][$role] ?? '成员';
    }

    /** 管理员不能被停用/降权 —— 否则全家人都会被锁在系统外面 */
    public static function adminCount(): int
    {
        $st = Database::get()->prepare(
            "SELECT COUNT(*) FROM accounts a
             JOIN persons p ON p.id = a.person_id
             WHERE a.role = 'admin' AND a.status = 'active'"
        );
        $st->execute();
        return (int)$st->fetchColumn();
    }

    public static function validatePassword(string $password): array
    {
        $err = [];
        if (strlen($password) < 8) {
            $err[] = '密码至少 8 位';
        }
        if (!preg_match('/[0-9]/', $password) || !preg_match('/[A-Za-z]/', $password)) {
            $err[] = '密码要同时包含字母和数字';
        }
        return $err;
    }
}