<?php

class RL_MailWarmer_DB_Helper {

    private static $conversations_table = 'rl_mailwarmer_conversations';
    private static $messages_table = 'rl_mailwarmer_messages';
    private static $backups_table = 'rl_mailwarmer_dns_backups';
    private static $health_reports_table = 'rl_mailwarmer_health_reports';

    /**
     * Create necessary database tables.
     */
    public static function create_tables() {
        global $wpdb;

        $charset_collate = $wpdb->get_charset_collate();

        // Conversation table
        $conversation_sql = "CREATE TABLE IF NOT EXISTS `{$wpdb->prefix}" . self::$conversations_table . "` (
            id BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
            campaign_id BIGINT(20) UNSIGNED NOT NULL,
            email_account_id BIGINT(20) UNSIGNED NOT NULL,
            created_at DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL,
            status VARCHAR(20) DEFAULT 'new' NOT NULL,
            first_message_timestamp DATETIME DEFAULT NULL,
            prompt LONGTEXT DEFAULT NULL,
            conversation_steps LONGTEXT DEFAULT NULL,
            ai_response LONGTEXT DEFAULT NULL,
            PRIMARY KEY (id),
            KEY campaign_id_idx (campaign_id),
            KEY status_idx (status),
            KEY first_message_timestamp_idx (first_message_timestamp),
            INDEX email_account_id_idx (email_account_id)
        ) $charset_collate;";

        // Message table
        $message_sql = "CREATE TABLE IF NOT EXISTS `{$wpdb->prefix}" . self::$messages_table . "` (
            id BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
            campaign_id BIGINT(20) UNSIGNED NOT NULL,
            conversation_id BIGINT(20) UNSIGNED NOT NULL,
            email_account_id BIGINT(20) UNSIGNED NOT NULL,
            scheduled_for_timestamp DATETIME NOT NULL,
            status ENUM('pending', 'in_progress', 'sent', 'failed') NOT NULL DEFAULT 'pending',
            from_email VARCHAR(255) NOT NULL,
            to_email TEXT NOT NULL,
            cc TEXT NULL,
            subject VARCHAR(255) NOT NULL,
            body LONGTEXT NOT NULL,
            PRIMARY KEY (id),
            INDEX scheduled_idx (scheduled_for_timestamp, status),
            INDEX conversation_id_idx (conversation_id),
            INDEX campaign_id_idx (campaign_id),
            INDEX email_account_id_idx (email_account_id)
        ) $charset_collate;";

        // Backup table
        $backup_sql = "CREATE TABLE IF NOT EXISTS `{$wpdb->prefix}" . self::$backups_table . "` (
            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            domain_id BIGINT UNSIGNED NOT NULL,
            record_name VARCHAR(255) NOT NULL,
            record_type VARCHAR(50) NOT NULL,
            record_content LONGTEXT NOT NULL,
            created_at DATETIME NOT NULL,
            INDEX (domain_id),
            INDEX (record_name),
            INDEX (record_type)
        ) $charset_collate;";

        // Backup table
        $health_report_sql = "CREATE TABLE IF NOT EXISTS `{$wpdb->prefix}" . self::$health_reports_table . "` (
            id BIGINT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            domain_id BIGINT UNSIGNED NOT NULL,
            report_content LONGTEXT NOT NULL,
            created_at DATETIME NOT NULL,
            last_checked DATETIME NOT NULL,
            INDEX (domain_id)
        ) $charset_collate;";

        // DNS Backup table

        require_once ABSPATH . 'wp-admin/includes/upgrade.php';
        dbDelta($conversation_sql);
        dbDelta($message_sql);
        dbDelta($backup_sql);
        dbDelta($health_report_sql);
    }

    /**
     * Insert a conversation record.
     */
    public static function insert_conversation($conversation_data) {
        global $wpdb;
        $wpdb->insert("{$wpdb->prefix}" . self::$conversations_table, $conversation_data);

        return $wpdb->insert_id;
    }

    /**
     * Update a conversation record.
     *
     * @param int   $conversation_id The ID of the conversation to update.
     * @param array $update_data     An associative array of columns and values to update.
     *
     * @return int|false The number of rows updated, or false on error.
     */
    public static function update_conversation($conversation_id, $update_data) {
        global $wpdb;
        
        // Ensure that $conversation_id is a valid integer
        if (!is_int($conversation_id) || $conversation_id <= 0) {
            return false;
        }
        
        // Update the table with the provided data
        $updated = $wpdb->update(
            "{$wpdb->prefix}" . self::$conversations_table,
            $update_data,
            ['id' => $conversation_id] // WHERE clause
        );

        return $updated !== false ? $updated : false;
    }

    /**
     * Insert a message record.
     */
    public static function insert_message($message_data) {
        global $wpdb;

        // log_to_file("insert_message - Message body: $body");

        // $wpdb->insert(
        //     "{$wpdb->prefix}rl_mailwarmer_message",
        //     [
        //         'campaign_id' => $campaign_id,
        //         'conversation_id' => $conversation_id,
        //         'scheduled_for_timestamp' => $scheduled_for,
        //         'status' => 'pending',
        //         'from_email' => $from_email,
        //         'to_email' => $to_email,
        //         'cc' => $cc,
        //         'subject' => $subject,
        //         'body' => $body,
        //         'first_message' => $first_message ? 1 : 0,
        //     ],
        //     ['%d', '%d', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%d']
        // );
        $wpdb->insert("{$wpdb->prefix}" . self::$messages_table, $message_data);

        return $wpdb->insert_id;
    }

    /**
     * Delete all conversations and messages for a given campaign ID.
     *
     * @param int $campaign_id The ID of the campaign.
     */
    public static function delete_all_conversations_messages($campaign_id) {
        global $wpdb;

        // Ensure campaign_id is an integer
        $campaign_id = (int) $campaign_id;

        $conversations_table = $wpdb->prefix . self::$conversations_table;
        $messages_table = $wpdb->prefix . self::$messages_table;

        // Delete messages
        $delete_messages_result = $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $messages_table WHERE campaign_id = %d",
                $campaign_id
            )
        );
        log_to_file("delete_all_conversations_messages - delete_messages_result: ", $delete_messages_result);

        // Delete conversations
        $delete_conversations_result = $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $conversations_table WHERE campaign_id = %d",
                $campaign_id
            )
        );
        log_to_file("delete_all_conversations_messages - delete_conversations_result: ", $delete_conversations_result);
    }

    /**
     * Delete all future conversations and messages for a given campaign ID.
     *
     * @param int $campaign_id The ID of the campaign.
     */
    public static function delete_future_conversations_messages($campaign_id) {
        global $wpdb;

        $conversations_table = $wpdb->prefix . self::$conversations_table;
        $messages_table = $wpdb->prefix . self::$messages_table;
        $current_time = current_time('mysql');

        // Delete future messages
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $messages_table WHERE campaign_id = %d AND scheduled_for_timestamp > %s",
                $campaign_id,
                $current_time
            )
        );

        // Delete future conversations
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $conversations_table WHERE campaign_id = %d AND first_message_timestamp > %s",
                $campaign_id,
                $current_time
            )
        );
    }

    /**
     * Delete all conversations and messages older than X days.
     *
     * @param int $days The number of days.
     */
    public static function delete_old_conversations_messages($days) {
        global $wpdb;

        $conversations_table = $wpdb->prefix . self::$conversations_table;
        $messages_table = $wpdb->prefix . self::$messages_table;
        $threshold_date = date('Y-m-d H:i:s', strtotime("-$days days"));

        // Delete old messages
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $messages_table WHERE scheduled_for_timestamp < %s",
                $threshold_date
            )
        );

        // Delete old conversations
        $wpdb->query(
            $wpdb->prepare(
                "DELETE FROM $conversations_table WHERE first_message_timestamp < %s",
                $threshold_date
            )
        );
    }


    /**
     * Fetch pending messages.
     */
    public static function fetch_pending_messages($limit = 100) {
        global $wpdb;

        $sql = $wpdb->prepare(
            "SELECT * FROM `{$wpdb->prefix}" . self::$messages_table . "`
             WHERE scheduled_for_timestamp <= %s AND status = 'pending'
             LIMIT %d",
            current_time('mysql'),
            $limit
        );

        return $wpdb->get_results($sql, ARRAY_A);
    }

    // Get Message Counts
    public static function get_message_counts_by_date($campaign_id) {
        global $wpdb;
        $messages_table = $wpdb->prefix . self::$messages_table;

        $results = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT 
                    DATE(scheduled_for_timestamp) AS message_date, 
                    COUNT(*) AS message_count
                 FROM 
                    $messages_table
                 WHERE 
                    campaign_id = %d
                 GROUP BY 
                    DATE(scheduled_for_timestamp)
                 ORDER BY 
                    message_date ASC",
                $campaign_id
            ),
            ARRAY_A
        );

        return $results;
    }

    /**
     * Insert DNS backups into the database.
     *
     * @param mixed $domain The domain ID or post object.
     * @param array $records The DNS records to back up.
     * @return bool True on success, false on failure.
     */
    public static function insert_dns_backup($domain, $record) {
        global $wpdb;
        $backups_table = $wpdb->prefix . 'rl_mailwarmer_dns_backups';

        $domain_post = is_object($domain) ? $domain : RL_MailWarmer_Domain_Helper::get_domain_post($domain);
        if (!$domain_post) {
            throw new Exception(__('Invalid domain specified.', 'rl-mailwarmer'));
        }

        // log_to_file("insert_dns_backup - Attemting to backup record: ", $record);

        $existing = $wpdb->get_row(
            $wpdb->prepare(
                "SELECT * FROM $backups_table WHERE domain_id = %d AND record_name = %s AND record_type = %s ORDER BY created_at DESC LIMIT 1",
                $domain_post->ID,
                $record['name'],
                $record['type']
            ),
            ARRAY_A
        );

        if ($existing && $existing['record_content'] === $record['content']) {
            // log_to_file("insert_dns_backup - New & Old content are the same. Skipping insert and returning TRUE");
            // return true;
            return $existing['id'];
            // continue; // Skip unchanged records
        }

        try {
            $wpdb->insert($backups_table, [
                'domain_id' => $domain_post->ID,
                'record_name' => $record['name'],
                'record_type' => $record['type'],
                'record_content' => $record['content'],
                'created_at' => current_time('mysql'),
            ]);
        } catch (Exception $e) {
            error_log(__('insert_dns_backup - Failed to insert new DNS backup record: ', 'rl-mailwarmer') . $e->getMessage());
        }
            

        return $wpdb->insert_id;
        // return true;
    }

    /**
     * Insert health report backups into the database.
     *
     * @param mixed $domain The domain ID or post object.
     * @param array $records The DNS records to back up.
     * @return bool True on success, false on failure.
     */
    public static function insert_health_report_backup($domain, $report) {
        global $wpdb;
        $health_reports_table = $wpdb->prefix . 'rl_mailwarmer_health_reports';

        $domain_post = is_object($domain) ? $domain : RL_MailWarmer_Domain_Helper::get_domain_post($domain);
        if (!$domain_post) {
            throw new Exception(__('Invalid domain specified.', 'rl-mailwarmer'));
        }

        // log_to_file("insert_health_report_backup - Attempting to save health report for {$domain_post->post_title}: ");

        try {
            // log_to_file("insert_health_report_backup - Fetching existing rows.");
            $existing = $wpdb->get_row(
                $wpdb->prepare(
                    "SELECT * FROM $health_reports_table WHERE domain_id = %d ORDER BY created_at DESC LIMIT 1",
                    $domain_post->ID
                ),
                ARRAY_A
            );
            // log_to_file("insert_health_report_backup - Done fetching existing rows.");
            if ($existing && $existing['report_content'] === $report) {
                // log_to_file("insert_health_report_backup - New & Old content are the same. Skipping insert and returning ID of existing record");
                // Prepare the data
                $data = [
                    'last_checked' => current_time('mysql'), // Save the JSON response as a string
                ];
                $where = [
                    'id' => $existing['id'],
                ];

                // Update the database
                try {
                    $result = $wpdb->update(
                        $health_reports_table,
                        $data,
                        $where,
                        ['%s'],
                        ['%d']
                    );
                } catch (Exception $e) {
                    log_to_file("insert_health_report_backup - Error updating existing database entry.");
                    throw new Exception(__('insert_health_report_backup - Error updating existing database entry: ', 'rl-mailwarmer') . $e->getMessage());
                }
                return $existing['id'];
                // continue; // Skip unchanged records
            }
        } catch (Exception $e) {
            log_to_file("insert_health_report_backup - Error fetching existing rows.");
            throw new Exception(__('insert_health_report_backup - Unable to fetch existing records: ', 'rl-mailwarmer') . $e->getMessage());
            
        }
        
        try {
            $current_time = current_time('mysql');
            $data = [
                'domain_id' => $domain_post->ID,
                'report_content' => $report,
                'created_at' => $current_time,
                'last_checked' => $current_time,
            ];
            $result = $wpdb->insert(
                $health_reports_table,
                $data
            );
            if ($result === false) {
                return new WP_Error('db_update_failed', __('Failed to update the conversation steps.', 'rl-mailwarmer'));
            }
            return $result;
        } catch (Exception $e) {
            throw new Exception(__('insert_health_report_backup - Failed to insert new health report record: ', 'rl-mailwarmer') . $e->getMessage());
            // error_log(__('insert_dns_backup - Failed to insert new health report record: ', 'rl-mailwarmer') . $e->getMessage());
        }
            

        return false;
    }
}