<?php

namespace app\common\service;

use app\common\model\account\TransferAuthorizations;
use app\common\traits\ServiceTrait;
use think\Log;

/**
 * 免确认收款授权（商家转账-用户确认模式的前置授权）
 * 流程：
 *  1. 用户发起提现时，前端调本服务 apply() 发起授权申请，
 *     拿到 package_info 后用 wx.requestMerchantTransfer 拉起授权页；
 *  2. 用户授权成功后，微信异步回调 transferAuthorizationNotify，
 *     本服务记录 authorization_id 并将状态置为 TAKING_EFFECT；
 *  3. 后台审核提现时，校验授权为 TAKING_EFFECT 后走
 *     /v3/fund-app/mch-transfer/transfer-bills/transfer 完成免确认转账。
 * 文档：https://pay.weixin.qq.com/doc/v3/merchant/4015901167
 */
class TransferAuthorizationService
{
    use ServiceTrait;

    /** @var TransferAuthorizations */
    public static $Model = TransferAuthorizations::class;

    // 授权状态
    const STATE_WAIT_USER_CONFIRM = 'WAIT_USER_CONFIRM'; //已受理，待用户确认
    const STATE_TAKING_EFFECT = 'TAKING_EFFECT'; //已授权，生效中（长期有效，直至主动解除）

    /**
     * 生成商户侧授权单号：一个用户固定一个单号。
     * 微信规则：未确认的授权单 30 天后单号可复用重新发起，因此复用同一单号即可
     * @param int $userId
     * @return string 仅含字母数字，最长 32 位
     */
    public static function generateAuthNo($userId): string
    {
        return 'TXAUTH' . str_pad((string)intval($userId), 10, '0', STR_PAD_LEFT);
    }

    /**
     * 获取用户的授权记录
     * @param int $userId
     * @return TransferAuthorizations|null
     */
    public static function getByUserId($userId)
    {
        return self::getOne(['user_id' => $userId]);
    }

    /**
     * 用户是否已完成免确认收款授权
     * @param int $userId
     * @return bool
     */
    public static function isAuthorized($userId): bool
    {
        $record = self::getByUserId($userId);

        return $record
            && $record->state == self::STATE_TAKING_EFFECT
            && $record->authorization_id;
    }

    /**
     * 发起/获取免确认收款授权，供前端拉起授权页
     * @param \app\common\model\Users $user 用户（需含 openid）
     * @param string $displayName 授权详情中展示的开通账号名称
     * @return array {authorized: bool, state, package_info?, mch_id?, app_id?}
     * @throws \Exception
     */
    public static function apply($user, string $displayName = ''): array
    {
        $userId = $user->id;
        if (empty($user->openid)) {
            throw new \Exception('无法获取用户微信身份，请先登录小程序');
        }

        //已授权的用户直接返回，不再重复发起
        $record = self::getByUserId($userId);
        if ($record && self::isAuthorized($userId)) {
            return [
                'authorized' => true,
                'state'       => $record->state,
            ];
        }

        //发起授权申请（授权单号固定，复用同一单号可重新发起）
        $authNo = self::generateAuthNo($userId);
        $wechat = new EasyWeChatService();
        $displayName = mb_substr($displayName ?: ($user->nickname ?: ('用户' . $userId)), 0, 32);
        $res = $wechat->applyTransferAuthorization($authNo, $user->openid, $displayName);

        if (empty($res['package_info'])) {
            throw new \Exception($res['message'] ?? '发起免确认收款授权失败');
        }

        //保存/更新授权记录（package_info 用于前端拉起授权页，state 当前为待用户确认）
        $data = [
            'state'        => $res['state'] ?? self::STATE_WAIT_USER_CONFIRM,
            'package_info' => $res['package_info'],
        ];
        if ($record) {
            $record->save($data);
        } else {
            self::create(array_merge([
                'user_id'              => $userId,
                'out_authorization_no' => $authNo,
                'authorization_id'     => '',
            ], $data));
        }

        return [
            'authorized'   => false,
            'state'        => $data['state'],
            'package_info' => $res['package_info'],
            //前端 wx.requestMerchantTransfer 需要：商户号 + AppID + package
            'mch_id'       => (string)$wechat->payApp->getMerchant()->getMerchantId(),
            'app_id'       => $wechat->config['app_id'],
        ];
    }

    /**
     * 处理免确认收款授权结果回调（用户授权成功后微信异步通知）
     * @param array $message 解密后的授权结果，含 out_authorization_no / authorization_id / state
     * @return bool
     */
    public static function handleAuthorizationNotify(array $message): bool
    {
        $outAuthNo = trim((string)($message['out_authorization_no'] ?? ''));
        $authorizationId = trim((string)($message['authorization_id'] ?? ''));
        $state = trim((string)($message['state'] ?? ''));
        if (!$outAuthNo || !$authorizationId) {
            Log::error('免确认收款授权回调参数缺失:' . json_encode($message, JSON_UNESCAPED_UNICODE));
            return false;
        }

        $record = self::getOne(['out_authorization_no' => $outAuthNo]);
        if (!$record) {
            Log::error('免确认收款授权回调找不到授权记录:' . $outAuthNo);
            return false;
        }

        //记录微信侧授权单号，标记授权生效（授权长期有效，直至用户或商户主动解除）
        $record->authorization_id = $authorizationId;
        $record->state = $state ?: self::STATE_TAKING_EFFECT;
        $record->save();
        Log::info('免确认收款授权生效:' . json_encode([
            'user_id' => $record->user_id,
            'state'   => $record->state,
        ], JSON_UNESCAPED_UNICODE));

        return true;
    }
}