<?php
declare (strict_types = 1);

namespace app\service;

use app\model\User;
use think\facade\Db;
use app\service\ConfigService;

/**
 * 用户服务类
 * 用于处理用户账号管理相关逻辑
 */
class UserService
{
    /**
     * 管理员账号（固定）
     */
    private const ADMIN_USERNAME = 'admin';
    private const ADMIN_PASSWORD_DEFAULT = '123456';
    private const ADMIN_PASSWORD_KEY = 'ADMIN_PASSWORD';
    
    /**
     * 获取管理员密码（优先读取配置，未设置则使用默认值）
     */
    private function getAdminPassword(): string
    {
        $configService = new ConfigService();
        $password = $configService->getConfig(self::ADMIN_PASSWORD_KEY, self::ADMIN_PASSWORD_DEFAULT);
        return $password === '' ? self::ADMIN_PASSWORD_DEFAULT : $password;
    }
    
    /**
     * 设置管理员密码
     */
    private function setAdminPassword(string $newPassword): array
    {
        if (empty($newPassword)) {
            return ['code' => 0, 'msg' => '新密码不能为空'];
        }
        $configService = new ConfigService();
        return $configService->setConfig(self::ADMIN_PASSWORD_KEY, $newPassword);
    }
    
    /**
     * 初始化数据库表
     */
    public function initDatabase(): void
    {
        $dbPath = dirname(dirname(__DIR__)) . '/runtime/database.db';
        $dbDir = dirname($dbPath);
        
        // 确保runtime目录存在
        if (!is_dir($dbDir)) {
            mkdir($dbDir, 0755, true);
        }
        
        // 连接SQLite数据库
        try {
            $connection = Db::connect('sqlite');
            
            // 创建用户表（如果不存在）
            $sql = "CREATE TABLE IF NOT EXISTS users (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                username VARCHAR(50) NOT NULL UNIQUE,
                password VARCHAR(255) NOT NULL,
                created_at DATETIME NOT NULL
            )";
            
            $connection->execute($sql);
        } catch (\Exception $e) {
            // 如果连接失败，尝试创建数据库文件
            if (!file_exists($dbPath)) {
                touch($dbPath);
                chmod($dbPath, 0666);
            }
        }
    }
    
    /**
     * 读取所有账号
     * @return array
     */
    public function getAllUsers(): array
    {
        $this->initDatabase();
        
        try {
            $users = User::select()->toArray();
            // 确保返回关联数组格式
            $result = [];
            foreach ($users as $user) {
                $result[] = [
                    'id' => $user['id'] ?? null,
                    'username' => $user['username'] ?? '',
                    'password' => $user['password'] ?? '',
                    'created_at' => $user['created_at'] ?? '',
                ];
            }
            return $result;
        } catch (\Exception $e) {
            // 如果表不存在，返回空数组
            return [];
        }
    }
    
    /**
     * 验证登录（包括管理员和普通用户）
     * @param string $username
     * @param string $password
     * @return array|false 返回用户信息或false
     */
    public function verifyLogin(string $username, string $password)
    {
        // 验证管理员账号
        if ($username === self::ADMIN_USERNAME && $password === $this->getAdminPassword()) {
            return [
                'username' => $username,
                'is_admin' => true,
            ];
        }
        
        // 验证普通用户账号
        $this->initDatabase();
        
        try {
            $user = User::where('username', $username)->find();
            
            if ($user && $user->password === $password) {
                return [
                    'username' => $username,
                    'is_admin' => false,
                ];
            }
        } catch (\Exception $e) {
            // 忽略数据库错误
        }
        
        return false;
    }
    
    /**
     * 添加账号
     * @param string $username
     * @param string $password
     * @return array ['code' => 1|0, 'msg' => string]
     */
    public function addUser(string $username, string $password): array
    {
        if (empty($username) || empty($password)) {
            return ['code' => 0, 'msg' => '用户名和密码不能为空'];
        }
        
        if ($username === self::ADMIN_USERNAME) {
            return ['code' => 0, 'msg' => '不能添加管理员账号'];
        }
        
        $this->initDatabase();
        
        try {
            // 检查用户名是否已存在
            $existUser = User::where('username', $username)->find();
            if ($existUser) {
                return ['code' => 0, 'msg' => '用户名已存在'];
            }
            
            // 添加新用户
            $user = new User();
            $user->username = $username;
            $user->password = $password;
            $user->created_at = date('Y-m-d H:i:s');
            $user->save();
            
            return ['code' => 1, 'msg' => '添加成功'];
        } catch (\Exception $e) {
            return ['code' => 0, 'msg' => '保存失败: ' . $e->getMessage()];
        }
    }
    
    /**
     * 删除账号
     * @param string $username
     * @return array ['code' => 1|0, 'msg' => string]
     */
    public function deleteUser(string $username): array
    {
        if ($username === self::ADMIN_USERNAME) {
            return ['code' => 0, 'msg' => '不能删除管理员账号'];
        }
        
        $this->initDatabase();
        
        try {
            $user = User::where('username', $username)->find();
            
            if (!$user) {
                return ['code' => 0, 'msg' => '用户不存在'];
            }
            
            $user->delete();
            
            return ['code' => 1, 'msg' => '删除成功'];
        } catch (\Exception $e) {
            return ['code' => 0, 'msg' => '删除失败: ' . $e->getMessage()];
        }
    }
    
    /**
     * 检查是否为管理员
     * @param string $username
     * @return bool
     */
    public function isAdmin(string $username): bool
    {
        return $username === self::ADMIN_USERNAME;
    }
    
    /**
     * 用户自助修改密码（需验证旧密码）
     */
    public function changeUserPassword(string $username, string $oldPassword, string $newPassword): array
    {
        if (empty($newPassword)) {
            return ['code' => 0, 'msg' => '新密码不能为空'];
        }
        
        // 管理员走配置
        if ($username === self::ADMIN_USERNAME) {
            $current = $this->getAdminPassword();
            if ($oldPassword !== $current) {
                return ['code' => 0, 'msg' => '旧密码错误'];
            }
            return $this->setAdminPassword($newPassword);
        }
        
        $this->initDatabase();
        $user = User::where('username', $username)->find();
        if (!$user) {
            return ['code' => 0, 'msg' => '用户不存在'];
        }
        if ($user->password !== $oldPassword) {
            return ['code' => 0, 'msg' => '旧密码错误'];
        }
        $user->password = $newPassword;
        $user->save();
        return ['code' => 1, 'msg' => '密码修改成功'];
    }
    
    /**
     * 管理员重置普通用户密码（无需旧密码）
     */
    public function resetUserPassword(string $username, string $newPassword): array
    {
        if ($username === self::ADMIN_USERNAME) {
            return ['code' => 0, 'msg' => '不能在此重置管理员密码'];
        }
        if (empty($username) || empty($newPassword)) {
            return ['code' => 0, 'msg' => '用户名和新密码不能为空'];
        }
        $this->initDatabase();
        $user = User::where('username', $username)->find();
        if (!$user) {
            return ['code' => 0, 'msg' => '用户不存在'];
        }
        $user->password = $newPassword;
        $user->save();
        return ['code' => 1, 'msg' => '重置成功'];
    }
    
    /**
     * 管理员修改管理员密码（需要旧密码）
     */
    public function changeAdminPassword(string $oldPassword, string $newPassword): array
    {
        if (empty($newPassword)) {
            return ['code' => 0, 'msg' => '新密码不能为空'];
        }
        $current = $this->getAdminPassword();
        if ($oldPassword !== $current) {
            return ['code' => 0, 'msg' => '旧密码错误'];
        }
        return $this->setAdminPassword($newPassword);
    }
}