<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\WechatUser;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;

class H5WechatController extends Controller
{
    /**
     * 公众号网页授权 code 换用户信息，并签发 Sanctum 令牌（WechatUser）
     */
    public function oauth(Request $request): JsonResponse
    {
        $data = $request->validate([
            'code' => ['required', 'string'],
        ]);

        $appId = (string) config('wechat.app_id');
        $secret = (string) config('wechat.app_secret');
        if ($appId === '' || $secret === '') {
            return response()->json(['message' => '服务端未配置微信公众号 AppId/AppSecret'], 503);
        }

        $tokenRes = Http::timeout(15)
            ->get('https://api.weixin.qq.com/sns/oauth2/access_token', [
                'appid' => $appId,
                'secret' => $secret,
                'code' => $data['code'],
                'grant_type' => 'authorization_code',
            ])
            ->json();

        if (! empty($tokenRes['errcode'])) {
            throw ValidationException::withMessages([
                'code' => [$tokenRes['errmsg'] ?? '微信 code 无效或已使用'],
            ]);
        }

        $accessToken = (string) ($tokenRes['access_token'] ?? '');
        $openid = (string) ($tokenRes['openid'] ?? '');
        if ($accessToken === '' || $openid === '') {
            return response()->json(['message' => '微信未返回 access_token'], 422);
        }

        $unionid = $tokenRes['unionid'] ?? null;

        $info = Http::timeout(15)
            ->get('https://api.weixin.qq.com/sns/userinfo', [
                'access_token' => $accessToken,
                'openid' => $openid,
                'lang' => 'zh_CN',
            ])
            ->json();

        if (! empty($info['errcode'])) {
            $info = [];
        }

        if ($unionid === null && ! empty($info['unionid'])) {
            $unionid = $info['unionid'];
        }

        $wu = WechatUser::query()->updateOrCreate(
            ['openid' => $openid],
            [
                'unionid' => $unionid,
                'nickname' => $info['nickname'] ?? null,
                'avatar_url' => $info['headimgurl'] ?? null,
            ]
        );

        $plain = $wu->createToken('wechat-h5')->plainTextToken;

        return response()->json([
            'token' => $plain,
            'user' => [
                'id' => $wu->id,
                'nickname' => $wu->nickname,
                'avatar_url' => $wu->avatar_url,
            ],
        ]);
    }

    /**
     * 公众号 JS-SDK 签名（分享、getLocation 等），与前端 wx.config 字段一致。
     *
     * @see https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/JS-SDK.html
     */
    public function jssdkSignature(Request $request): JsonResponse
    {
        $data = $request->validate([
            'url' => ['required', 'string', 'max:2048'],
        ]);

        $appId = (string) config('wechat.app_id');
        $secret = (string) config('wechat.app_secret');
        if ($appId === '' || $secret === '') {
            return response()->json(['message' => '服务端未配置微信公众号 AppId/AppSecret'], 503);
        }

        $url = $data['url'];
        $ticket = $this->getWechatJsapiTicket($appId, $secret);
        if ($ticket === '') {
            return response()->json(['message' => '获取微信 jsapi_ticket 失败，请检查 AppId/AppSecret 与网络'], 503);
        }

        $timestamp = time();
        $nonceStr = Str::random(16);
        $plain = "jsapi_ticket={$ticket}&noncestr={$nonceStr}&timestamp={$timestamp}&url={$url}";
        $signature = sha1($plain);

        return response()->json([
            'appId' => $appId,
            'timestamp' => $timestamp,
            'nonceStr' => $nonceStr,
            'signature' => $signature,
        ]);
    }

    private function getWechatJsapiTicket(string $appId, string $secret): string
    {
        try {
            return Cache::remember('wechat_jsapi_ticket_'.$appId, 7000, function () use ($appId, $secret) {
                $token = $this->getWechatAccessToken($appId, $secret);
                if ($token === '') {
                    throw new \RuntimeException('empty access_token');
                }
                $res = Http::timeout(15)
                    ->get('https://api.weixin.qq.com/cgi-bin/ticket/getticket', [
                        'access_token' => $token,
                        'type' => 'jsapi',
                    ])
                    ->json();

                if (! empty($res['errcode']) && (int) $res['errcode'] !== 0) {
                    throw new \RuntimeException($res['errmsg'] ?? 'getticket failed');
                }

                $ticket = (string) ($res['ticket'] ?? '');
                if ($ticket === '') {
                    throw new \RuntimeException('empty ticket');
                }

                return $ticket;
            });
        } catch (\Throwable) {
            Cache::forget('wechat_jsapi_ticket_'.$appId);

            return '';
        }
    }

    private function getWechatAccessToken(string $appId, string $secret): string
    {
        try {
            return Cache::remember('wechat_access_token_'.$appId, 7000, function () use ($appId, $secret) {
                $res = Http::timeout(15)
                    ->get('https://api.weixin.qq.com/cgi-bin/token', [
                        'grant_type' => 'client_credential',
                        'appid' => $appId,
                        'secret' => $secret,
                    ])
                    ->json();

                if (! empty($res['errcode'])) {
                    throw new \RuntimeException($res['errmsg'] ?? 'access_token failed');
                }

                $token = (string) ($res['access_token'] ?? '');
                if ($token === '') {
                    throw new \RuntimeException('empty access_token');
                }

                return $token;
            });
        } catch (\Throwable) {
            Cache::forget('wechat_access_token_'.$appId);

            return '';
        }
    }
}