<?php

namespace App\Http\Controllers;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use App\Models\Webauth;
use App\Models\User;
use Carbon\Carbon;

class FingerprintController extends Controller
{
    protected string $rpName = 'a.montask.ir';
    protected string $rpId   = 'a.montask.ir';

    /** برای ثبت اثر انگشت */
    public function generateRegisterOptions(Request $request)
    {
        $user_identity = $_COOKIE['user_identity'] ?? null;
        if (!$user_identity) {
            return response()->json(['error' => 'کاربر لاگین نیست'], 403);
        }

        $customer = User::where('user_name', $user_identity)->first();
        if (!$customer) {
            return response()->json(['error' => 'کاربر یافت نشد'], 404);
        }

        $challenge = random_bytes(32);
        $challengeBase64 = $this->b64e($challenge);

        Cache::put("register_challenge_{$customer->id}", $challengeBase64, 120);

        return response()->json([
            "publicKey" => [
                "rp" => [
                    "name" => $this->rpName,
                    "id"   => $this->rpId,
                ],
                "user" => [
                    "id"          => $this->b64e($customer->id),
                    "name"        => $customer->user_name,
                    "displayName" => $customer->name,
                    "number"      => $customer->number,
                ],
                "challenge" => $challengeBase64,
                "pubKeyCredParams" => [
                    ["type" => "public-key", "alg" => -7]
                ],
                "authenticatorSelection" => [
                    "userVerification" => "required"
                ]
            ]
        ]);
    }

    /** تایید ثبت اثر انگشت */
    public function verifyRegister(Request $request)
    {
        $user_identity = $_COOKIE['user_identity'] ?? null;
        if (!$user_identity) {
            return response()->json(['error' => 'کاربر لاگین نیست'], 403);
        }

        $customer = User::where('user_name', $user_identity)->first();
        if (!$customer) {
            return response()->json(['error' => 'کاربر یافت نشد'], 404);
        }

        $data = $request->all();
        $storedChallenge = Cache::pull("register_challenge_{$customer->id}");

        if (!$storedChallenge) return response()->json(["error" => "challenge not found"], 400);
        if (!isset($data['response']['clientDataJSON'])) return response()->json(["error" => "clientDataJSON missing"], 400);

        $clientDataJSON = base64_decode(strtr($data['response']['clientDataJSON'], '-_', '+/'));
        $clientData = json_decode($clientDataJSON, true);
        if (!$clientData) return response()->json(["error" => "Invalid clientData"], 400);
        if (!hash_equals($clientData['challenge'], $storedChallenge)) return response()->json(["error" => "Invalid challenge"], 403);
        if ($clientData['origin'] !== 'https://' . $this->rpId) return response()->json(["error" => "Invalid origin"], 403);
        if ($clientData['type'] !== 'webauthn.create') return response()->json(["error" => "Invalid type"], 403);

        Webauth::create([
            "name"          => $request->input("name", "دستگاه " . $customer->name),
            "customer_id"   => $customer->id,
            "credential_id" => $data["id"],
            "public_key"    => $data["response"]["publicKey"],
            "attestation"   => json_encode($data["response"]["attestationObject"]),
            "transports"    => null,
            "sign_count"    => 0,
            "last_used_at"  => now(),
        ]);

        return response()->json(["message" => "اثر انگشت با موفقیت ثبت شد"]);
    }

    /** تولید challenge برای ورود */
    public function generateLoginOptions()
    {
        $challenge = $this->b64e(random_bytes(32));
        Cache::put("login_challenge_global", $challenge, 120);

        return response()->json([
            "publicKey" => [
                "challenge" => $challenge,
                "rpId" => $this->rpId,
                "userVerification" => "required",
                "timeout" => 60000,
            ]
        ]);
    }


    /** تایید ورود */
    public function verifyLogin(Request $request)
    {
        $data = $request->all();

        $credentialId = $data['id'] ?? null;
        if (!$credentialId) {
            return response()->json(["message" => "credential_id missing"], 400);
        }

        $credential = Webauth::where("credential_id", $credentialId)->first();
        if (!$credential) {
            return response()->json(["message" => "اثر انگشت شناخته نشد"], 404);
        }

        $customer = User::find($credential->customer_id);
        if (!$customer) {
            return response()->json(["message" => "کاربر حذف شده"], 404);
        }

        $storedChallenge = Cache::pull("login_challenge_global");
        if (!$storedChallenge) {
            return response()->json(["message" => "Challenge منقضی شد"], 403);
        }

        // clientData
        $clientDataJSON = base64_decode(strtr($data['response']['clientDataJSON'], '-_', '+/'));
        $clientData = json_decode($clientDataJSON, true);

        if ($clientData['challenge'] !== $storedChallenge) {
            return response()->json(["message" => "Invalid challenge"], 403);
        }

        if ($clientData['origin'] !== 'https://' . $this->rpId) {
            return response()->json(["message" => "Invalid origin"], 403);
        }

        // authenticatorData
        $authData = base64_decode(strtr($data['response']['authenticatorData'], '-_', '+/'));

        $signature = base64_decode(strtr($data['response']['signature'], '-_', '+/'));
        $clientDataHash = hash('sha256', $clientDataJSON, true);
        $signedData = $authData . $clientDataHash;

        $ok = openssl_verify($signedData, $signature, $credential->public_key, OPENSSL_ALGO_SHA256);
        if ($ok !== 1) {
            return response()->json(["message" => "Invalid signature"], 403);
        }

        // لاگین
        $token = auth('customer')->login($customer);
        auth('customer')->setUser($customer);

        return response()->json([
            "message" => "ورود موفق",
            "token" => $token,
            "user_id" => $customer->id
        ]);
    }

    private function b64e($v)
    {
        return rtrim(strtr(base64_encode($v),'+/','-_'),'=');
    }
}