<?php

namespace App\Services\Api\Client;

use App\Http\Services\Telegram;
use App\Mail\Admin\TrialRegistrationRequest as TrialRegistrationRequestMail;
use App\Mail\Customer\VerifyAccount as VerifyAccountMail;
use App\Mail\Customer\Welcome as WelcomeMail;
use App\Models\RefreshToken;
use App\Models\Setting;
use App\Repositories\Api\Client\ClientRepositoryInterface;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Mail;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;
use Tymon\JWTAuth\Facades\JWTAuth;

class ClientAuthService
{
    // Refresh token lifetime in days
    const REFRESH_TOKEN_TTL_DAYS = 30;

    protected $clientRepository;

    public function __construct(ClientRepositoryInterface $clientRepository)
    {
        $this->clientRepository = $clientRepository;
    }

    /**
     * Xác thực khách hàng và tạo access + refresh token
     */
    public function authenticateClient(array $credentials): array
    {
        if (!$token = Auth::guard('client')->attempt($credentials)) {
            throw ValidationException::withMessages([
                'email' => ['Thông tin đăng nhập không chính xác.'],
            ]);
        }

        $client = Auth::guard('client')->user();

        if ((int)$client->status !== 1) {
            $statusLabel = match ((int)$client->status) {
                0 => 'PENDING_VERIFY',
                2 => 'tạm ngưng hoạt động',
                3 => 'bị khoá',
                default => 'vô hiệu hoá',
            };

            if ($statusLabel === 'PENDING_VERIFY') {
                throw ValidationException::withMessages([
                    'email' => ['PENDING_VERIFY'],
                ]);
            }

            throw ValidationException::withMessages([
                'email' => ["Tài khoản của bạn đã {$statusLabel}, vui lòng liên hệ hotline."],
            ]);
        }

        $refreshToken = $this->createRefreshToken($client->id);

        return [
            'client'        => $client,
            'token'         => $token,
            'refresh_token' => $refreshToken,
        ];
    }

    /**
     * Đăng ký khách hàng mới — status=0 (chờ xác thực OTP), chưa cấp token.
     */
    public function registerClient(array $data): array
    {
        $code = str_pad((string) random_int(0, 999999), 6, '0', STR_PAD_LEFT);

        $client = $this->clientRepository->create([
            'fullname'                    => $data['fullname'],
            'phone'                       => $data['phone'],
            'email'                       => $data['email'],
            'password'                    => bcrypt($data['password']),
            'status'                      => 0,
            'email_verify_code'           => $code,
            'email_verify_code_expired_at' => now()->addMinutes(5),
        ]);

        $this->sendVerifyEmail($client, $code);

        if (!empty($data['trial_config'])) {
            $this->notifyAdminTrialRegistration($client, $data['trial_config']);
        }

        return ['client' => $client];
    }

    /**
     * Báo admin (email + Telegram) khi khách hàng đăng ký dùng thử Cloud VPS.
     */
    protected function notifyAdminTrialRegistration($client, array $trialConfig): void
    {
        try {
            $setting = Setting::where('key', 'setting')->first();
            $settingValue = $setting ? json_decode((string) $setting->value, true) : [];
            $adminEmail = $settingValue['admin_email'] ?? null;

            if ($adminEmail) {
                Mail::to($adminEmail)->send(new TrialRegistrationRequestMail([
                    'company_name'   => $settingValue['company'] ?? config('app.name', 'Portal Admin'),
                    'customer_name'  => $client->fullname,
                    'customer_email' => $client->email,
                    'customer_phone' => $client->phone,
                    'cpu'            => $trialConfig['cpu'] ?? null,
                    'ram'            => $trialConfig['ram'] ?? null,
                    'ssd'            => $trialConfig['ssd'] ?? null,
                    'os'             => $trialConfig['os'] ?? null,
                    'other'          => $trialConfig['other'] ?? null,
                    'created_at'     => now()->format('d/m/Y H:i:s'),
                ]));
            } else {
                Log::warning('Trial registration admin email not sent: admin_email not configured.', [
                    'customer_id' => $client->id,
                ]);
            }
        } catch (\Throwable $e) {
            Log::warning('Send trial registration admin email failed: ' . $e->getMessage(), [
                'customer_id' => $client->id,
            ]);
        }

        (new Telegram())->SendTrialRegistration($client, $trialConfig);
    }

    /**
     * Xác thực OTP — kích hoạt tài khoản, trả về token.
     */
    public function verifyEmail(string $email, string $code): array
    {
        $client = \App\Models\Customer::whereRaw('LOWER(email) = ?', [strtolower(trim($email))])->first();

        if (! $client || $client->email_verify_code !== $code) {
            throw ValidationException::withMessages([
                'code' => ['Mã xác thực không chính xác.'],
            ]);
        }

        if (! $client->email_verify_code_expired_at || now()->gt($client->email_verify_code_expired_at)) {
            throw ValidationException::withMessages([
                'code' => ['Mã xác thực đã hết hạn, vui lòng yêu cầu gửi lại.'],
            ]);
        }

        $client->status                       = 1;
        $client->email_verify_code            = null;
        $client->email_verify_code_expired_at = null;
        $client->email_verified_at            = now();
        $client->save();

        $token        = JWTAuth::fromUser($client);
        $refreshToken = $this->createRefreshToken($client->id);

        $this->sendWelcomeEmail($client);

        return [
            'client'        => $client,
            'token'         => $token,
            'refresh_token' => $refreshToken,
        ];
    }

    /**
     * Gửi lại OTP xác thực (rate limit bởi caller nếu cần).
     */
    public function resendVerifyCode(string $email): void
    {
        $client = \App\Models\Customer::whereRaw('LOWER(email) = ?', [strtolower(trim($email))])->first();

        if (! $client || $client->status !== 0) {
            return;
        }

        // Nếu mã cũ còn hạn thì không gửi lại — phải đợi hết hạn
        if ($client->email_verify_code_expired_at && now()->lt($client->email_verify_code_expired_at)) {
            throw ValidationException::withMessages([
                'email' => ['Mã xác thực vẫn còn hiệu lực, vui lòng kiểm tra email của bạn.'],
            ]);
        }

        $code = str_pad((string) random_int(0, 999999), 6, '0', STR_PAD_LEFT);

        $client->email_verify_code            = $code;
        $client->email_verify_code_expired_at = now()->addMinutes(5);
        $client->save();

        $this->sendVerifyEmail($client, $code);
    }

    protected function sendVerifyEmail($client, string $code): void
    {
        try {
            Mail::to($client->email)->later(now()->addSeconds(5), new VerifyAccountMail([
                'fullname'    => $client->fullname,
                'email'       => $client->email,
                'verify_code' => $code,
            ]));
        } catch (\Throwable $e) {
            Log::warning('Send verify email failed: ' . $e->getMessage(), [
                'customer_id' => $client->id,
                'email'       => $client->email,
            ]);
        }
    }

    /**
     * Gửi email chào mừng sau khi xác thực tài khoản thành công.
     */
    protected function sendWelcomeEmail($client): void
    {
        try {
            Mail::to($client->email)->send(new WelcomeMail([
                'fullname' => $client->fullname,
                'email'    => $client->email,
            ]));
        } catch (\Throwable $e) {
            Log::warning('Send welcome email failed: ' . $e->getMessage(), [
                'customer_id' => $client->id,
                'email'       => $client->email,
            ]);
        }
    }

    /**
     * Tạo refresh token mới, lưu hash vào DB, trả về raw token.
     */
    public function createRefreshToken(int $customerId): string
    {
        $raw = Str::random(64);
        $hash = hash('sha256', $raw);

        RefreshToken::create([
            'customer_id' => $customerId,
            'token'       => $hash,
            'expires_at'  => now()->addDays(self::REFRESH_TOKEN_TTL_DAYS),
        ]);

        return $raw;
    }

    /**
     * Xác minh refresh token, xoay vòng (rotation), trả về access token mới + refresh token mới.
     * Ném ValidationException nếu token không hợp lệ hoặc đã hết hạn.
     */
    public function rotateRefreshToken(string $rawToken): array
    {
        $hash = hash('sha256', $rawToken);

        $record = RefreshToken::where('token', $hash)->first();

        if (!$record || $record->isExpired()) {
            // Xoá token cũ nếu tồn tại nhưng hết hạn
            $record?->delete();

            throw ValidationException::withMessages([
                'refresh_token' => ['Refresh token không hợp lệ hoặc đã hết hạn.'],
            ]);
        }

        $customer = $record->customer;

        if (!$customer || (int)$customer->status !== 1) {
            $record->delete();
            throw ValidationException::withMessages([
                'refresh_token' => ['Tài khoản không hợp lệ.'],
            ]);
        }

        // Rotation: xoá token cũ
        $record->delete();

        // Tạo access token mới
        $newAccessToken = JWTAuth::fromUser($customer);

        // Tạo refresh token mới
        $newRefreshToken = $this->createRefreshToken($customer->id);

        return [
            'client'        => $customer,
            'token'         => $newAccessToken,
            'refresh_token' => $newRefreshToken,
        ];
    }

    /**
     * Huỷ refresh token khi đăng xuất.
     */
    public function revokeRefreshToken(string $rawToken): void
    {
        $hash = hash('sha256', $rawToken);
        RefreshToken::where('token', $hash)->delete();
    }
}