<?php

declare(strict_types=1);

namespace app\miniapi\service;

use app\miniapi\auth\SmsCode;
use app\miniapi\exception\ApiException;
use app\miniapi\http\Fields;
use app\miniapi\model\MiniUser;

final class SmsLogin
{
    public function __construct(private readonly SmsSender $sender = new SmsbaoSender())
    {
    }

    /**
     * Always answers with the same payload whether or not the phone belongs to an account.
     * Distinguishing the two cases would let a caller enumerate registered numbers, so an
     * unbound phone silently consumes nothing and receives no message.
     */
    public function sendCode(array $input, string $ip): array
    {
        if (!SmsCode::enabled()) {
            throw new ApiException(50301, '短信登录未开启', 503);
        }
        Fields::only($input, ['phone']);
        $phone = self::mobile($input);
        SmsCode::assertSendAllowed($phone, $ip);
        if (!MiniUser::query()->where('phone', $phone)->where('status', 1)->exists()) {
            return ['sent' => true, 'expires_in' => SmsCode::ttl()];
        }
        $code = SmsCode::issue($phone, $ip);
        try {
            $this->sender->send($phone, sprintf('您的验证码是 %s，%d 分钟内有效。请勿转发给他人。', $code, intdiv(SmsCode::ttl(), 60)));
        } catch (ApiException $error) {
            // A code the caller never received must not remain verifiable.
            SmsCode::discard($phone, $code);

            throw $error;
        }

        return ['sent' => true, 'expires_in' => SmsCode::ttl()];
    }

    public function login(array $input): array
    {
        if (!SmsCode::enabled()) {
            throw new ApiException(50301, '短信登录未开启', 503);
        }
        Fields::only($input, ['phone', 'code']);
        $phone = self::mobile($input);
        SmsCode::consume($phone, Fields::text($input, 'code', 6));
        $user = MiniUser::query()->where('phone', $phone)->first();
        if (!$user || (int) $user->status !== 1) {
            throw new ApiException(40102, '验证码已失效，请重新获取', 401);
        }

        return (new AuthService())->issueForExisting($user);
    }

    /** SMS gateways only reach mainland mobile numbers; other formats never leave the server. */
    public static function mobile(array $input): string
    {
        $phone = Fields::phone($input);
        if (!preg_match('/^1[3-9][0-9]{9}$/D', $phone)) {
            throw new ApiException(42201, '请填写有效的中国大陆手机号码', 422, ['phone' => '须为1开头的11位手机号']);
        }

        return $phone;
    }
}