<?php

declare(strict_types=1);

namespace App\Framework\Mail\Commands;

use App\Framework\CommandBus\CommandHandler;
use App\Framework\Exception\ExceptionContext;
use App\Framework\Logging\Logger;
use App\Framework\Mail\Exceptions\SmtpException;
use App\Framework\Mail\TransportInterface;

final readonly class SendEmailBatchCommandHandler
{
    public function __construct(
        private TransportInterface $transport,
        private Logger $logger,
    ) {
    }

    #[CommandHandler]
    public function handle(SendEmailBatchCommand $command): void
    {
        $messageCount = $command->getMessageCount();
        $successCount = 0;
        $failureCount = 0;
        $errors = [];

        $this->logger->info('Starting batch email sending', [
            'message_count' => $messageCount,
            'transport' => $this->transport->getName(),
        ]);

        foreach ($command->messages as $index => $message) {
            try {
                $result = $this->transport->send($message);

                if ($result->isSuccess()) {
                    $successCount++;

                    $this->logger->debug('Batch email sent successfully', [
                        'batch_index' => $index,
                        'message_id' => $result->getMessageId(),
                        'to' => $message->to->toString(),
                        'subject' => $message->subject,
                    ]);
                } else {
                    $failureCount++;
                    $errorMessage = "Email {$index} failed: " . $result->getError();
                    $errors[] = $errorMessage;

                    $this->logger->warning('Batch email failed', [
                        'batch_index' => $index,
                        'error' => $result->getError(),
                        'metadata' => $result->getMetadata(),
                        'to' => $message->to->toString(),
                        'subject' => $message->subject,
                    ]);
                }

            } catch (\Exception $e) {
                $failureCount++;
                $errorMessage = "Email {$index} exception: " . $e->getMessage();
                $errors[] = $errorMessage;

                $this->logger->error('Batch email exception', [
                    'batch_index' => $index,
                    'exception_class' => get_class($e),
                    'exception_message' => $e->getMessage(),
                    'to' => $message->to->toString(),
                    'subject' => $message->subject,
                ]);
            }
        }

        $this->logger->info('Batch email sending completed', [
            'total_messages' => $messageCount,
            'successful' => $successCount,
            'failed' => $failureCount,
            'success_rate' => $messageCount > 0 ? round(($successCount / $messageCount) * 100, 2) : 0,
        ]);

        // If all emails failed, throw an exception to trigger retry
        if ($failureCount === $messageCount && $messageCount > 0) {
            throw new SmtpException(
                message: "All {$messageCount} emails in batch failed to send",
                context: ExceptionContext::forOperation('send_email_batch', 'mail')
                    ->withData([
                        'total_messages' => $messageCount,
                        'failed_messages' => $failureCount,
                        'errors' => $errors,
                        'transport' => $this->transport->getName(),
                    ])
            );
        }

        // If more than 50% failed, log a warning but don't throw (partial success)
        if ($failureCount > ($messageCount / 2)) {
            $this->logger->warning('High failure rate in batch email sending', [
                'total_messages' => $messageCount,
                'failed_messages' => $failureCount,
                'failure_rate' => round(($failureCount / $messageCount) * 100, 2),
                'errors' => $errors,
            ]);
        }
    }
}