<?php

namespace App\Services\Mail;

use App\Models\Tenants\MailLog;
use App\Models\Tenants\TenantMailConfig;
use Illuminate\Mail\Mailable;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Mail;

class TenantMailService
{
    /**
     * 테넌트 설정을 적용하여 메일 발송
     */
    public function send(
        Mailable $mailable,
        string|array $to,
        ?int $tenantId = null,
        bool $sync = false
    ): MailLog {
        $tenantId = $tenantId ?? session('selected_tenant_id', 1);
        $config = $this->getConfig($tenantId);

        // 메일 로그 생성 (queued 상태)
        $mailLog = MailLog::create([
            'tenant_id' => $tenantId,
            'mailable_type' => class_basename($mailable),
            'to_address' => is_array($to) ? implode(', ', $to) : $to,
            'from_address' => $config ? $config->from_address : config('mail.from.address'),
            'subject' => $this->getSubject($mailable),
            'status' => 'queued',
            'options' => [
                'provider_used' => $config?->provider ?? 'platform',
            ],
        ]);

        // 쿼터 확인
        if ($config && ! $this->checkQuota($tenantId, $config)) {
            $mailLog->update([
                'status' => 'failed',
                'options' => array_merge($mailLog->options ?? [], [
                    'error_message' => '일일 발송 한도 초과',
                ]),
            ]);
            Log::warning("Mail quota exceeded for tenant {$tenantId}");

            return $mailLog;
        }

        try {
            $this->configureMail($config);
            $this->applyBranding($mailable, $config);

            if ($sync) {
                Mail::to($to)->send($mailable);
            } else {
                Mail::to($to)->queue($mailable);
            }

            $mailLog->update([
                'status' => 'sent',
                'sent_at' => now(),
            ]);
        } catch (\Exception $e) {
            Log::error("Mail send failed for tenant {$tenantId}: ".$e->getMessage());

            // Fallback: 플랫폼 기본 SMTP
            if ($config && $config->provider !== 'platform') {
                try {
                    $this->resetMailConfig();
                    Mail::to($to)->send($mailable);

                    $mailLog->update([
                        'status' => 'sent',
                        'sent_at' => now(),
                        'options' => array_merge($mailLog->options ?? [], [
                            'fallback_used' => true,
                            'original_error' => $e->getMessage(),
                        ]),
                    ]);

                    return $mailLog;
                } catch (\Exception $fallbackException) {
                    // Fallback도 실패
                }
            }

            $mailLog->update([
                'status' => 'failed',
                'options' => array_merge($mailLog->options ?? [], [
                    'error_message' => $e->getMessage(),
                    'retry_count' => ($mailLog->getOption('retry_count', 0)) + 1,
                ]),
            ]);
        }

        return $mailLog;
    }

    /**
     * 테넌트 메일 설정 조회
     */
    private function getConfig(int $tenantId): ?TenantMailConfig
    {
        return TenantMailConfig::withoutGlobalScopes()
            ->where('tenant_id', $tenantId)
            ->where('is_active', true)
            ->first();
    }

    /**
     * 일일 발송 쿼터 확인
     */
    private function checkQuota(int $tenantId, TenantMailConfig $config): bool
    {
        $todayCount = MailLog::withoutGlobalScopes()
            ->where('tenant_id', $tenantId)
            ->whereDate('created_at', today())
            ->whereIn('status', ['queued', 'sent'])
            ->count();

        return $todayCount < $config->daily_limit;
    }

    /**
     * SMTP 설정 동적 교체
     */
    private function configureMail(?TenantMailConfig $config): void
    {
        if (! $config || $config->provider === 'platform') {
            return;
        }

        if ($config->provider === 'smtp') {
            config([
                'mail.mailers.smtp.host' => $config->getSmtpHost(),
                'mail.mailers.smtp.port' => $config->getSmtpPort(),
                'mail.mailers.smtp.encryption' => $config->getSmtpEncryption(),
                'mail.mailers.smtp.username' => $config->getSmtpUsername(),
                'mail.mailers.smtp.password' => $config->getSmtpPassword(),
                'mail.from.address' => $config->from_address,
                'mail.from.name' => $config->from_name,
            ]);
        }
    }

    /**
     * 기본 메일 설정 복원
     */
    private function resetMailConfig(): void
    {
        config([
            'mail.mailers.smtp.host' => env('MAIL_HOST'),
            'mail.mailers.smtp.port' => env('MAIL_PORT'),
            'mail.mailers.smtp.encryption' => env('MAIL_ENCRYPTION'),
            'mail.mailers.smtp.username' => env('MAIL_USERNAME'),
            'mail.mailers.smtp.password' => env('MAIL_PASSWORD'),
            'mail.from.address' => env('MAIL_FROM_ADDRESS'),
            'mail.from.name' => env('MAIL_FROM_NAME'),
        ]);
    }

    /**
     * 브랜딩 데이터 적용
     */
    private function applyBranding(Mailable $mailable, ?TenantMailConfig $config): void
    {
        if (! $config) {
            return;
        }

        $mailable->from($config->from_address, $config->from_name);

        if ($config->reply_to) {
            $mailable->replyTo($config->reply_to);
        }
    }

    /**
     * Mailable 제목 추출
     */
    private function getSubject(Mailable $mailable): string
    {
        try {
            $reflection = new \ReflectionProperty($mailable, 'subject');
            $subject = $reflection->getValue($mailable);
            if ($subject) {
                return $subject;
            }
        } catch (\ReflectionException $e) {
            // subject 속성이 없는 경우
        }

        return class_basename($mailable);
    }

    /**
     * 오늘 발송 건수 조회
     */
    public function getTodayCount(int $tenantId): int
    {
        return MailLog::withoutGlobalScopes()
            ->where('tenant_id', $tenantId)
            ->whereDate('created_at', today())
            ->whereIn('status', ['queued', 'sent'])
            ->count();
    }

    /**
     * 이번 달 발송 건수 조회
     */
    public function getMonthCount(int $tenantId): int
    {
        return MailLog::withoutGlobalScopes()
            ->where('tenant_id', $tenantId)
            ->whereMonth('created_at', now()->month)
            ->whereYear('created_at', now()->year)
            ->whereIn('status', ['queued', 'sent'])
            ->count();
    }
}