<?php

namespace App\Services\Sms;

use App\Models\SmsVerification;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\RateLimiter;
use Illuminate\Validation\ValidationException;

class ParticipantSmsVerificationService
{
    public function sendLoginCode(string $mobile, SmsSender $sender): ParticipantSmsVerificationResult
    {
        $lock = Cache::lock(
            'sms-send-lock:'.hash('sha256', $mobile),
            max(30, (int) config('sms.timeout', 5) + 10)
        );

        if (! $lock->get()) {
            Log::warning('sms.send lock_contended', [
                'mobile_mask' => $this->maskMobile($mobile),
            ]);
            throw ValidationException::withMessages([
                'mobile' => ['请勿频繁发送'],
            ]);
        }

        try {
            return $this->sendWithinLock($mobile, $sender);
        } finally {
            $lock->release();
        }
    }

    private function sendWithinLock(string $mobile, SmsSender $sender): ParticipantSmsVerificationResult
    {
        $resendSec = (int) config('sms.resend_interval_seconds', 60);
        $rateKey = 'sms-send:'.hash('sha256', $mobile);
        if (RateLimiter::tooManyAttempts($rateKey, 1)) {
            Log::warning('sms.send rate_limited', [
                'mobile_mask' => $this->maskMobile($mobile),
                'rate_limiter_available_in' => RateLimiter::availableIn($rateKey),
                'resend_interval_seconds' => $resendSec,
            ]);
            throw ValidationException::withMessages([
                'mobile' => ['请勿频繁发送'],
            ]);
        }

        $lastAttempt = SmsVerification::query()
            ->where('scene', SmsVerification::SCENE_PARTICIPANT_LOGIN)
            ->where('mobile', $mobile)
            ->latest('id')
            ->first();

        if ($lastAttempt?->created_at !== null && $lastAttempt->created_at->gt(now()->subSeconds($resendSec))) {
            Log::warning('sms.send rate_limited', [
                'mobile_mask' => $this->maskMobile($mobile),
                'last_attempt_id' => $lastAttempt->id,
                'last_attempt_status' => $lastAttempt->status,
                'last_attempt_at' => $lastAttempt->created_at?->toDateTimeString(),
                'resend_interval_seconds' => $resendSec,
            ]);
            throw ValidationException::withMessages([
                'mobile' => ['请勿频繁发送'],
            ]);
        }
        RateLimiter::hit($rateKey, $resendSec);

        $code = (string) random_int(100000, 999999);
        $smsEnabled = (bool) config('sms.enabled');
        $ttlSeconds = (int) config('sms.code_ttl_seconds', 300);
        $ttlMinutes = (string) (int) ceil($ttlSeconds / 60);

        Log::info('sms.send branch', [
            'mobile_mask' => $this->maskMobile($mobile),
            'sms_enabled' => (bool) config('sms.enabled'),
        ]);

        $verification = SmsVerification::query()->create([
            'scene' => SmsVerification::SCENE_PARTICIPANT_LOGIN,
            'mobile' => $mobile,
            'code' => $code,
            'provider' => $smsEnabled
                ? SmsVerification::PROVIDER_TENCENTCLOUD
                : SmsVerification::PROVIDER_DISABLED,
            'status' => SmsVerification::STATUS_PENDING,
            'template_id' => (string) config('sms.tencentcloud.template_id'),
            'sign_name' => (string) config('sms.tencentcloud.sign_name'),
            'request_payload_json' => [
                'phone_number' => $this->maskMobile($mobile),
                'template_id' => (string) config('sms.tencentcloud.template_id'),
                'sign_name' => (string) config('sms.tencentcloud.sign_name'),
                'template_param_count' => (int) config('sms.tencentcloud.template_param_count', 2),
                'ttl_minutes' => $ttlMinutes,
            ],
            'expires_at' => now()->addSeconds($ttlSeconds),
        ]);

        try {
            $result = $sender->sendVerification($verification);
        } catch (\Throwable $e) {
            $verification->forceFill([
                'status' => SmsVerification::STATUS_FAILED,
                'failed_at' => now(),
                'provider_code' => 'SENDER_EXCEPTION',
                'provider_message' => $e->getMessage(),
                'response_json' => ['error' => 'sender_exception'],
            ])->save();

            Log::error('sms.send sender_exception', [
                'mobile_mask' => $this->maskMobile($mobile),
                'verification_id' => $verification->id,
                'error' => $e->getMessage(),
            ]);

            return new ParticipantSmsVerificationResult(false, $verification->refresh(), '发送失败');
        }

        if (! $result->success) {
            $verification->forceFill([
                'status' => SmsVerification::STATUS_FAILED,
                'failed_at' => now(),
                'provider_request_id' => $result->requestId,
                'provider_code' => $result->providerCode,
                'provider_message' => $result->providerMessage,
                'response_json' => $result->response,
            ])->save();

            Log::error('sms.send failed', [
                'mobile_mask' => $this->maskMobile($mobile),
                'verification_id' => $verification->id,
                'provider' => $result->provider,
                'provider_request_id' => $result->requestId,
                'provider_code' => $result->providerCode,
                'provider_message' => $result->providerMessage,
            ]);

            return new ParticipantSmsVerificationResult(
                false,
                $verification->refresh(),
                $result->providerCode === 'CONFIG_INCOMPLETE' ? '短信服务配置未完成' : '发送失败'
            );
        }

        DB::transaction(function () use ($verification, $result, $mobile) {
            $verification->forceFill([
                'status' => SmsVerification::STATUS_SENT,
                'sent_at' => now(),
                'provider_request_id' => $result->requestId,
                'provider_code' => $result->providerCode,
                'provider_message' => $result->providerMessage,
                'response_json' => $result->response,
            ])->save();

            $this->expirePreviousVerifications($mobile, $verification->id);
        });

        Log::info('sms.send sent', [
            'mobile_mask' => $this->maskMobile($mobile),
            'verification_id' => $verification->id,
            'provider' => $result->provider,
            'provider_request_id' => $result->requestId,
            'provider_code' => $result->providerCode,
        ]);

        return new ParticipantSmsVerificationResult(
            true,
            $verification->refresh(),
            '发送成功',
            // 临时：联调展示验证码；正式环境勿开 SMS_EXPOSE_DEBUG_CODE
            (bool) config('sms.expose_debug_code') ? $code : null
        );
    }

    private function expirePreviousVerifications(string $mobile, int $currentId): void
    {
        SmsVerification::query()
            ->where('scene', SmsVerification::SCENE_PARTICIPANT_LOGIN)
            ->where('mobile', $mobile)
            ->where('id', '<>', $currentId)
            ->whereIn('status', [
                SmsVerification::STATUS_PENDING,
                SmsVerification::STATUS_SENT,
            ])
            ->update(['status' => SmsVerification::STATUS_EXPIRED]);
    }

    private function maskMobile(string $mobile): string
    {
        if (strlen($mobile) < 11) {
            return '***';
        }

        return substr($mobile, 0, 3).'****'.substr($mobile, -4);
    }
}