<?php

namespace App\Services\Client;

use Illuminate\Support\Facades\Log;
use App\Exceptions\BusinessException;
use Illuminate\Support\Facades\Cache;
use App\Services\Client\AccountService;
use EasyWeChat\OfficialAccount\Application;
use Overtrue\Socialite\Contracts\UserInterface;
use Overtrue\Socialite\Contracts\ProviderInterface;

class WechatService
{
    protected Application $app;

    protected AccountService $accountService;

    protected ProviderInterface $socialite;

    public function __construct(AccountService $accountService)
    {
        $this->app = new Application(config('wechat.official_account.default'));
        $this->accountService = $accountService;
        $this->socialite = $this->app->getOAuth();
    }

    /**
     * 获取微信授权URL
     *
     * @param  string  $redirectUrl  授权后重定向地址
     * @param  string  $scope  授权范围 snsapi_base或snsapi_userinfo
     * @return array{auth_url: string, state: string}
     *
     * @throws BusinessException
     */
    public function getAuthUrl(string $redirectUrl, ?string $scope = null): array
    {
        $scope = $scope ?? config('wechat.auth.default_scope');

        try {
            $state = $this->generateState();
            $this->cacheAuthState($state);

            $url = $this->socialite
                ->scopes([$scope])
                ->withState($state)
                ->redirect($redirectUrl);

            return [
                'auth_url' => $url,
                'state' => $state,
            ];
        } catch (\Exception $e) {
            $this->logError('生成微信授权URL失败', $e);
            throw new BusinessException('生成授权链接失败，请稍后重试');
        }
    }

    /**
     * 处理微信授权回调
     *
     * @param  string  $code  授权码
     * @param  string  $state  状态码
     * @param  string|null  $inviteCode  邀请码
     * @return array{token: string, user: array}
     *
     * @throws BusinessException
     */
    public function handleAuthCallback(string $code, string $state, ?string $inviteCode = null): array
    {
        // 验证state
        $this->validateState($state);

        // 获取用户信息
        $user = $this->socialite->userFromCode($code);

        // 验证openid
        $openid = $user->getId();
        abort_if(empty($openid), 400, '获取微信openid失败');

        // 整理用户信息
        $userInfo = $this->formatUserInfo($user);

        // 添加邀请人信息
        if ($inviteCode) {
            $userInfo['invite_code'] = $inviteCode;
        }

        // 执行登录
        return $this->accountService->wxLogin($openid, $userInfo);
    }

    /**
     * 缓存授权state
     */
    protected function cacheAuthState(string $state): void
    {
        try {
            $states = Cache::get('wechat_auth_states', []);
            $states[$state] = true;
            Cache::put('wechat_auth_states', $states, now()->addMinutes(30));
        } catch (\Exception $e) {
            Log::error('缓存微信授权state失败', [
                'state' => $state,
                'error' => $e->getMessage(),
            ]);
            throw new BusinessException('系统错误，请稍后重试');
        }
    }

    /**
     * 验证state
     *
     * @throws BusinessException
     */
    protected function validateState(string $state): void
    {
        try {
            $states = Cache::get('wechat_auth_states', []);

            if (! isset($states[$state])) {
                Log::warning('微信授权state无效', ['state' => $state]);
                throw new BusinessException('授权已过期，请重新授权');
            }

            // 移除已使用的state
            unset($states[$state]);
            Cache::put('wechat_auth_states', $states, now()->addMinutes(30));
        } catch (BusinessException $e) {
            throw $e;
        } catch (\Exception $e) {
            Log::error('验证微信授权state失败', [
                'state' => $state,
                'error' => $e->getMessage(),
            ]);
            throw new BusinessException('系统错误，请稍后重试');
        }
    }

    /**
     * 生成随机state
     */
    protected function generateState(): string
    {
        return md5(uniqid((string) mt_rand(), true));
    }

    /**
     * 格式化用户信息
     *
     * @return array{
     *     nickname: string,
     *     avatar: string,
     *     gender: string|null,
     *     country: string|null,
     *     province: string|null,
     *     city: string|null
     * }
     */
    protected function formatUserInfo(UserInterface $user): array
    {
        return [
            'nickname' => $user->getName(),
            'avatar' => $user->getAvatar(),
            'gender' => $this->formatGender($user->getRaw()['sex'] ?? null),
            'country' => $user->getRaw()['country'] ?? null,
            'province' => $user->getRaw()['province'] ?? null,
            'city' => $user->getRaw()['city'] ?? null,
        ];
    }

    /**
     * 格式化性别信息
     *
     * @param  int|null  $gender  微信返回的性别值：1为男性，2为女性，0为未知
     * @return string|null male/female/null
     */
    protected function formatGender(?int $gender): ?string
    {
        return match ($gender) {
            1 => 'male',
            2 => 'female',
            default => null,
        };
    }

    /**
     * 记录错误日志
     */
    protected function logError(string $message, \Exception $e, array $context = []): void
    {
        Log::error($message, array_merge($context, [
            'error' => $e->getMessage(),
            'trace' => $e->getTraceAsString(),
        ]));
    }

    protected function getAuthStateKey(string $state): string
    {
        return config('wechat.auth.cache_prefix') . $state;
    }

    /**
     * 获取JSAPI配置
     *
     * @param  string  $url  当前网页的URL，不包含#及其后面部分
     * @return array JSAPI配置信息
     *
     * @throws BusinessException
     */
    public function getJsConfig(string $url): array
    {
        $apis = [
            'updateAppMessageShareData',
            'updateTimelineShareData',
            'chooseImage',
            'previewImage',
            'uploadImage',
            'downloadImage',
            'getLocation',
            'openLocation',
            'scanQRCode',
        ];

        return $this->app->getUtils()->buildJsSdkConfig($url, $apis);
    }
}