<?php

/**
 * Helper functions for the conversation messages
 */

use Symfony\Component\Mime\Email;
use Symfony\Component\Mailer\Mailer;
use Symfony\Component\Mailer\Transport\Transport;
use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
use PhpImap\Mailbox;


if (!defined('ABSPATH')) {
    exit;
}

class RL_MailWarmer_Message_Handler {

    /**
     * Process pending messages.
     */
    public static function process_pending_messages() {
        // log_to_file("process_pending_messages - Running");
        global $wpdb;

        // Fetch the next 100 pending messages with scheduled timestamps in the past
        $table_name = $wpdb->prefix . 'rl_mailwarmer_messages';
        $messages = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT * FROM $table_name WHERE status = %s AND scheduled_for_timestamp < %s ORDER BY scheduled_for_timestamp ASC LIMIT 1",
                'pending',
                current_time('mysql')
            ),
            ARRAY_A
        );

        if (empty($messages)) {
            // log_to_file("process_pending_messages - messages empty");
            return;
        }

        foreach ($messages as $message) {
            // log_to_file("==========================================================");
            try {
                if (!empty($message['first_message']) && $message['first_message']) {
                    // log_to_file("process_pending_messages - trying send_message");
                    $result = self::send_message($message);
                } else {
                    // log_to_file("process_pending_messages - trying reply_message");
                    $result = self::reply_message($message);
                }

                // Update message status to 'completed' on success
                if ($result) {
                    self::update_message_status($message['id'], 'completed');
                } else {
                    self::update_message_status($message['id'], 'failed');
                }
            } catch (Exception $e) {
                // Handle errors gracefully and log them
                log_to_file('Error processing message ID ' . $message['id'] . ': ' . $e->getMessage());
                self::update_message_status($message['id'], 'failed');
            }
            sleep(3);
        }
    }

    /**
     * Prepare email data and fetch connection info.
     *
     * @param array $message The message data.
     * @return array Prepared email data and connection info.
     * @throws Exception If required data is missing.
     */
    private static function prepare_email_data($message) {
        // log_to_file("prepare_email_data - Running");
        // log_to_file("prepare_email_data - Message: ", $message);

        // Ensure 'from' is valid and fetch connection info
        if (empty($message['from_email'])) {
            throw new Exception(__('Missing "from" address in the message.', 'rl-mailwarmer'));
        }

        // Find the email-account post matching the 'from' address
        $from_post_id = self::find_email_account_by_address($message['from_email']);
        if (!$from_post_id) {
            throw new Exception(__('No matching email account found for "from" address.', 'rl-mailwarmer'));
        }

        // Fetch connection details
        // log_to_file("prepare_email_data - Getting connection info");
        $mail_password = get_post_meta($from_post_id, 'mail_password', true);
        $email_provider_id = get_post_meta($from_post_id, 'email_provider', true);
        $connection_info = RL_MailWarmer_Email_Helper::get_provider_defaults($email_provider_id);
        $connection_info['username'] = $message['from_email'];
        $connection_info['mail_password'] = $mail_password;
        // log_to_file("prepare_email_data - Connection Info: ", $connection_info);

        // Override provider defaults with account-specific settings
        foreach (['smtp_server', 'smtp_port', 'smtp_password', 'imap_server', 'imap_port', 'imap_password'] as $key) {
            $meta_value = get_post_meta($from_post_id, $key, true);
            if (!empty($meta_value)) {
                $connection_info[$key] = $meta_value;
            }
        }

        // Handle recipients
        // log_to_file("prepare_email_data - Handling recipients");
        $to_emails = is_array($message['to_email']) ? $message['to_email'] : explode(',', $message['to_email']);
        $cc_emails = is_array($message['cc']) ? $message['cc'] : explode(',', $message['cc']);

        return [
            'connection_info' => $connection_info,
            'to'              => array_filter(array_map('trim', $to_emails)),
            'cc'              => array_filter(array_map('trim', $cc_emails)),
            'subject'         => $message['subject'],
            'body'            => $message['body'],
            'from'            => $message['from_email'],
        ];
    }

    /**
     * Find the email-account post ID by email address.
     *
     * @param string $email_address The email address to search for.
     * @return int|null The post ID if found, or null.
     */
    private static function find_email_account_by_address($email_address) {
        // log_to_file("find_email_account_by_address - Searching for: $email_address");
        $query = new WP_Query([
            'post_type'   => 'email-account',
            'post_status' => 'publish',
            'title'       => $email_address,
            'fields'      => 'ids',
        ]);

        if (!empty($query->posts)) {
            return $query->posts[0];
        } else {
            return new WP_Error('find_email_account_by_address - Unable to find a matching email address');
        }
    }

    /**
     * Update the status of a message.
     *
     * @param int    $message_id The ID of the message to update.
     * @param string $status     The new status ('completed', 'failed', etc.).
     * @return void
     */
    private static function update_message_status($message_id, $status) {
        global $wpdb;

        $table_name = $wpdb->prefix . 'rl_mailwarmer_messages';

        $wpdb->update(
            $table_name,
            ['status' => $status],
            ['id' => $message_id],
            ['%s'],
            ['%d']
        );
    }


    /**
     * Send the first message in a conversation.
     *
     * @param array $message The message details.
     * @return bool True if the message is sent successfully, false otherwise.
     * @throws Exception If required fields are missing or an error occurs during sending.
     */
    public static function send_message($message) {
        // log_to_file("send_message - Running");
        // log_to_file("send_message - Message: ", $message);

        // Prepare email data and connection info
        $email_data = self::prepare_email_data($message);

        // log_to_file("send_message - Email Data: ", $email_data);

        // Extract connection info
        $connection_info = $email_data['connection_info'];

        // Check required fields
        if (empty($email_data['to']) || empty($email_data['from']) || empty($email_data['subject']) || empty($email_data['body'])) {
            throw new Exception(__('Missing required fields for sending the email.', 'rl-mailwarmer'));
        }

        // Create the SMTP transport
        // log_to_file("send_message - Creating Transport");
        $transport = new Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport(
            $connection_info['smtp_server'],
            $connection_info['smtp_port']
        );

        // Set authentication details
        $transport->setUsername($connection_info['username']);
        $transport->setPassword($connection_info['mail_password']);

        // Create the mailer
        $mailer = new Symfony\Component\Mailer\Mailer($transport);

        // Build the email
        // log_to_file("send_message - Building Mail");
        $email = (new Email())
            ->from($email_data['from'])
            ->to(...$email_data['to'])
            ->subject($email_data['subject'])
            ->html($email_data['body']);

        // Add CCs if present
        if (!empty($email_data['cc'])) {
            $email->cc(...$email_data['cc']);
        }

        // Attempt to send the email
        // log_to_file("send_message - Trying to send");
        try {
            $mailer->send($email);
            log_to_file("send_message - Successfully sent SMTP mail from ", $email_data['from']);
            return true; // Email sent successfully
        } catch (TransportExceptionInterface $e) {
            error_log('Error sending email: ' . $e->getMessage());
            return false; // Sending failed
        }
    }


    /**
     * Reply to an email message.
     *
     * @param array $message The message details.
     * @return bool True if the message is replied to successfully, false otherwise.
     * @throws Exception If required fields are missing or an error occurs.
     */
    public static function reply_message($message) {
        // Prepare email data and connection info
        $email_data = self::prepare_email_data($message);
        // log_to_file("reply_message - Email Data: ", $email_data);

        // Extract connection info
        $connection_info = $email_data['connection_info'];

        // Validate required fields
        if (empty($email_data['to']) || empty($email_data['from']) || empty($email_data['subject']) || empty($email_data['body'])) {
            throw new Exception(__('Missing required fields for replying to the email.', 'rl-mailwarmer'));
        }

        // Attempt to find the original email via IMAP


// // Attempt to find the original email and reply via IMAP
// try {
//     $imap = new \PhpImap\Mailbox(
//         sprintf('{%s:%d/imap/ssl}', $connection_info['imap_server'], $connection_info['imap_port']),
//         $connection_info['imap_username'],
//         $connection_info['imap_password'],
//         null,
//         'UTF-8'
//     );

//     // Search for the email with the matching subject
//     $emails = $imap->searchMailbox('SUBJECT "' . addslashes($email_data['subject']) . '"');
//     if (!empty($emails)) {
//         // Fetch the email data
//         $original_email = $imap->getMail($emails[0]);

//         // Prepare and send the reply via IMAP
//         $imap->reply(
//             $emails[0],
//             $email_data['body'],
//             ['from' => $email_data['from'], 'cc' => $email_data['cc']]
//         );

//         return true; // Reply sent successfully via IMAP
//     }


        try {
            // log_to_file("reply_message - Trying to reply via IMAP");
            $imap = new \PhpImap\Mailbox(
                sprintf('{%s:%d/imap/ssl}', $connection_info['imap_server'], $connection_info['imap_port']),
                $connection_info['username'],
                $connection_info['mail_password'],
                null,
                'UTF-8'
            );

            // Search for the email with the matching subject
            // log_to_file("reply_message - Searching for message");
            $emails = $imap->searchMailbox('SUBJECT "' . addslashes($email_data['subject']) . '"');
            if (!empty($emails)) {


                // Fetch the email data
                $original_email = $imap->getMail($emails[0]);
                // log_to_file("reply_message - Message found!");
                // log_to_file("reply_message - IMAP Message: ", $original_email);

                // Step 2: Send the reply via SMTP
                $transport = new Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport(
                    $connection_info['smtp_server'],
                    $connection_info['smtp_port']
                );

                // Set authentication details
                $transport->setUsername($connection_info['username']);
                $transport->setPassword($connection_info['mail_password']);

                $mailer = new Mailer($transport);

                $reply_email = (new Email())
                    ->from($email_data['from'])
                    ->to(...$email_data['to'])
                    ->subject('Re: ' . $original_email->subject)
                    ->html($email_data['body']);

                // Add headers for threading
                $headers = $reply_email->getHeaders();
                $headers->addTextHeader('In-Reply-To', $original_email->messageId);
                $headers->addTextHeader('References', trim($original_email->headers->references . ' ' . $original_email->messageId));

                    // ->addHeader('In-Reply-To', $original_email->messageId)
                    // ->addHeader('References', trim($original_email->headers->references . ' ' . $original_email->messageId));

                if (!empty($email_data['cc'])) {
                    $reply_email->cc(...$email_data['cc']);
                }

                $mailer->send($reply_email);

                log_to_file("reply_message - Successfully sent IMAP/SMTP reply from ", $email_data['from']);

                // Step 3: Upload the reply to the Sent folder
                $imap_stream = imap_open(
                    sprintf('{%s:%d/imap/ssl}', $connection_info['imap_server'], $connection_info['imap_port']),
                    $connection_info['username'],
                    $connection_info['mail_password']
                );

                $raw_message = $reply_email->toString(); // Convert the Email object to raw MIME format
                imap_append($imap_stream, sprintf('{%s}/Sent', $connection_info['imap_server']), $raw_message);

                imap_close($imap_stream);

                // Create the reply headers
                // $reply_headers = [
                //     'In-Reply-To' => $original_email->messageId,
                //     'References'  => trim($original_email->headers->references . ' ' . $original_email->messageId),
                // ];

                // // Construct the reply body
                // $reply_body = $email_data['body'] . "\n\n" .
                //     'On ' . $original_email->date . ', ' . $original_email->fromName . ' <' . $original_email->fromAddress . '> wrote:' . "\n" .
                //     $original_email->textPlain;

                // // Send the reply via IMAP
                // log_to_file("reply_message - Sending message via IMAP");
                // $imap->addMessageToSentFolder(
                //     'To: ' . implode(', ', $email_data['to']) . "\r\n" .
                //     'Cc: ' . implode(', ', $email_data['cc']) . "\r\n" .
                //     'Subject: Re: ' . $original_email->subject . "\r\n" .
                //     'From: ' . $email_data['from'] . "\r\n" .
                //     'In-Reply-To: ' . $reply_headers['In-Reply-To'] . "\r\n" .
                //     'References: ' . $reply_headers['References'] . "\r\n" .
                //     "\r\n" .
                //     $reply_body
                // );
                // log_to_file("reply_message - Done message via IMAP");

                // $mailer = new Mailer($transport);
                // $mailer->send($reply);

                return true; // Reply sent successfully
            }
        } catch (Exception $e) {
            log_to_file('IMAP Error: ' . $e->getMessage());
        }

        // Fallback to SMTP if IMAP fails
        try {
            // log_to_file("reply_message - Falling back to SMTP");
            $smtp_reply = (new Email())
                ->from($email_data['from'])
                ->to(...$email_data['to'])
                ->subject($email_data['subject'])
                ->html($email_data['body']);

            // Add CCs if present
            if (!empty($email_data['cc'])) {
                $smtp_reply->cc(...$email_data['cc']);
            }

            // Create the SMTP transport
            $transport = new Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport(
                $connection_info['smtp_server'],
                $connection_info['smtp_port']
            );

            // Set authentication details
            $transport->setUsername($connection_info['username']);
            $transport->setPassword($connection_info['mail_password']);

            // Create the mailer
            $mailer = new Symfony\Component\Mailer\Mailer($transport);
            $mailer->send($smtp_reply);
            log_to_file("reply_message - Sent reply via fallback SMTP from ", $email_data['from']);
            // log_to_file('reply_message - SMTP Send Success (?)');

            return true; // Fallback SMTP reply sent successfully
        } catch (Exception $e) {
            log_to_file('reply_message - SMTP Error: ' . $e->getMessage());
            return false; // Reply failed
        }
    }
}

/**
 * Add a metabox to the WP dashboard for monitoring and processing the message queue.
 */
add_action('wp_dashboard_setup', function () {
    wp_add_dashboard_widget(
        'rl_mailwarmer_message_queue',
        __('Message Queue', 'rl-mailwarmer'),
        'rl_mailwarmer_render_message_queue_widget'
    );
});

/**
 * Render the Message Queue dashboard widget.
 */
function rl_mailwarmer_render_message_queue_widget() {
    global $wpdb;

    // Count past-due messages
    $table_name = $wpdb->prefix . 'rl_mailwarmer_messages';
    $past_due_count = $wpdb->get_var(
        $wpdb->prepare(
            "SELECT COUNT(*) FROM $table_name WHERE status = %s AND scheduled_for_timestamp < %s",
            'pending',
            current_time('mysql')
        )
    );

    ?>
    <div id="rl-mailwarmer-queue">
        <p><strong><?php esc_html_e('Past-Due Messages:', 'rl-mailwarmer'); ?></strong> <?php echo esc_html($past_due_count); ?></p>
        <button id="process-message-queue" class="button button-primary">
            <?php esc_html_e('Process Message Queue', 'rl-mailwarmer'); ?>
        </button>
        <div id="message-queue-result" style="margin-top: 10px;"></div>
    </div>

    <script>
        document.addEventListener('DOMContentLoaded', function () {
            const button = document.getElementById('process-message-queue');
            const resultDiv = document.getElementById('message-queue-result');

            button.addEventListener('click', function () {
                button.disabled = true;
                resultDiv.textContent = '<?php esc_html_e('Processing...', 'rl-mailwarmer'); ?>';

                jQuery.post(ajaxurl, {
                    action: 'rl_mailwarmer_process_message_queue',
                    security: '<?php echo esc_js(wp_create_nonce('rl_mailwarmer_queue_nonce')); ?>'
                }, function (response) {
                    button.disabled = false;

                    if (response.success) {
                        console.log("Success");
                        resultDiv.textContent = '<?php esc_html_e('Messages processed:', 'rl-mailwarmer'); ?> ' + response.data.processed_count;
                    } else {
                        console.log("Failure");
                        resultDiv.textContent = '<?php esc_html_e('Error:', 'rl-mailwarmer'); ?> ' + response.data.message;
                    }
                });
            });
        });
    </script>
    <?php
}

/**
 * AJAX handler to process the message queue.
 */
add_action('wp_ajax_rl_mailwarmer_process_message_queue', function () {
    // log_to_file("wp_ajax_rl_mailwarmer_process_message_queue - Running");
    // Verify nonce
    if (!check_ajax_referer('rl_mailwarmer_queue_nonce', 'security', false)) {
        wp_send_json_error(['message' => __('Invalid nonce.', 'rl-mailwarmer')]);
    }

    // Ensure the user has permission
    if (!current_user_can('manage_options')) {
        wp_send_json_error(['message' => __('Permission denied.', 'rl-mailwarmer')]);
    }

    try {
        // Process pending messages
        // log_to_file("wp_ajax_rl_mailwarmer_process_message_queue - Trying process_pending_messages()");
        $processed_count = RL_MailWarmer_Message_Handler::process_pending_messages();

        wp_send_json_success(['processed_count' => $processed_count]);
    } catch (Exception $e) {
        wp_send_json_error(['message' => $e->getMessage()]);
    }
});