<?php
/**
 * Email Logger class
 */

// Prevent direct access
if (!defined('ABSPATH')) {
    exit;
}

class AHA_Mail_SMTP_Logger {
    
    /**
     * Single instance of the class
     */
    private static $instance = null;
    
    /**
     * Database table name
     */
    private static $table_name = null;
    
    /**
     * Get single instance
     */
    public static function get_instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }
    
    /**
     * Constructor
     */
    private function __construct() {
        global $wpdb;
        self::$table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        $this->init_hooks();
    }
    
    /**
     * Initialize hooks
     */
    private function init_hooks() {
        add_action('wp_ajax_aha_mail_smtp_clear_logs', array($this, 'clear_logs_ajax'));
        add_action('wp_ajax_aha_mail_smtp_get_logs', array($this, 'get_logs_ajax'));
        add_action('wp_ajax_aha_mail_smtp_delete_log', array($this, 'delete_log_ajax'));
        add_action('wp_ajax_aha_mail_smtp_view_log', array($this, 'view_log_ajax'));
        
        // Schedule cleanup task
        if (!wp_next_scheduled('aha_mail_smtp_cleanup_logs')) {
            wp_schedule_event(time(), 'daily', 'aha_mail_smtp_cleanup_logs');
        }
        
        add_action('aha_mail_smtp_cleanup_logs', array($this, 'cleanup_old_logs'));
    }
    
    /**
     * Log email
     */
    public static function log_email($data) {
        if (!AHA_Mail_SMTP_Settings::get('enable_logging')) {
            return false;
        }
        
        // Validate input data
        if (!is_array($data)) {
            return false;
        }
        
        global $wpdb;
        
        // Check if table exists, create it if not
        if (!self::table_exists()) {
            self::create_table();
            // If still doesn't exist, return false
            if (!self::table_exists()) {
                return false;
            }
        }
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        // Safely extract data with defaults
        $log_data = array(
            'to_email' => isset($data['to_email']) ? sanitize_text_field($data['to_email']) : '',
            'subject' => isset($data['subject']) ? sanitize_text_field($data['subject']) : '',
            'message' => isset($data['message']) ? wp_kses_post($data['message']) : '',
            'headers' => isset($data['headers']) ? sanitize_textarea_field($data['headers']) : '',
            'attachments' => isset($data['attachments']) ? sanitize_text_field($data['attachments']) : '',
            'status' => isset($data['status']) ? sanitize_text_field($data['status']) : 'pending',
            'error_message' => isset($data['error_message']) ? sanitize_text_field($data['error_message']) : '',
            'date_sent' => current_time('mysql')
        );
        
        $result = $wpdb->insert($table_name, $log_data);
        
        return $result !== false;
    }
    
    /**
     * Check if logs table exists
     */
    public static function table_exists() {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        return $wpdb->get_var("SHOW TABLES LIKE '$table_name'") === $table_name;
    }
    
    /**
     * Create logs table if it doesn't exist
     */
    public static function create_table() {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        $charset_collate = $wpdb->get_charset_collate();
        
        $sql = "CREATE TABLE $table_name (
            id bigint(20) NOT NULL AUTO_INCREMENT,
            to_email varchar(255) NOT NULL,
            subject text NOT NULL,
            message longtext NOT NULL,
            headers text,
            attachments text,
            status varchar(20) NOT NULL DEFAULT 'pending',
            error_message text,
            date_sent datetime DEFAULT CURRENT_TIMESTAMP,
            PRIMARY KEY (id),
            KEY status (status),
            KEY date_sent (date_sent)
        ) $charset_collate;";
        
        require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
        dbDelta($sql);
        
        return self::table_exists();
    }
    
    /**
     * Get logs
     */
    public static function get_logs($limit = 50, $offset = 0, $status = '') {
        global $wpdb;
        
        // Check if table exists, create it if not
        if (!self::table_exists()) {
            self::create_table();
            // If still doesn't exist, return empty array
            if (!self::table_exists()) {
                return array();
            }
        }
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        $where = '';
        if (!empty($status)) {
            $where = $wpdb->prepare(' WHERE status = %s', $status);
        }
        
        $sql = $wpdb->prepare(
            "SELECT * FROM $table_name $where ORDER BY date_sent DESC LIMIT %d OFFSET %d",
            $limit,
            $offset
        );
        
        $results = $wpdb->get_results($sql);
        
        // Return empty array on error instead of null
        return is_array($results) ? $results : array();
    }
    
    /**
     * Get log by ID
     */
    public static function get_log($id) {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        return $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM $table_name WHERE id = %d",
            $id
        ));
    }
    
    /**
     * Delete log
     */
    public static function delete_log($id) {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        return $wpdb->delete($table_name, array('id' => $id), array('%d'));
    }
    
    /**
     * Clear all logs
     */
    public static function clear_all_logs() {
        global $wpdb;
        
        // Check if table exists
        if (!self::table_exists()) {
            return false;
        }
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        return $wpdb->query("TRUNCATE TABLE $table_name");
    }
    
    /**
     * Get logs count
     */
    public static function get_logs_count($status = '') {
        global $wpdb;
        
        // Check if table exists
        if (!self::table_exists()) {
            return 0;
        }
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        $where = '';
        if (!empty($status)) {
            $where = $wpdb->prepare(' WHERE status = %s', $status);
        }
        
        $count = $wpdb->get_var("SELECT COUNT(*) FROM $table_name $where");
        
        return $count !== null ? (int) $count : 0;
    }
    
    /**
     * Get logs statistics
     */
    public static function get_logs_stats() {
        global $wpdb;
        
        $stats = array(
            'total' => 0,
            'success' => 0,
            'failed' => 0,
            'pending' => 0
        );
        
        // Check if table exists
        if (!self::table_exists()) {
            return $stats;
        }
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        $results = $wpdb->get_results(
            "SELECT status, COUNT(*) as count FROM $table_name GROUP BY status"
        );
        
        if (is_array($results)) {
            foreach ($results as $result) {
                $stats[$result->status] = (int) $result->count;
                $stats['total'] += (int) $result->count;
            }
        }
        
        return $stats;
    }
    
    /**
     * Cleanup old logs
     */
    public function cleanup_old_logs() {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        // Delete logs older than 30 days
        $wpdb->query($wpdb->prepare(
            "DELETE FROM $table_name WHERE date_sent < %s",
            date('Y-m-d H:i:s', strtotime('-30 days'))
        ));
        
        // Keep only the latest 1000 logs
        $wpdb->query(
            "DELETE FROM $table_name WHERE id NOT IN (
                SELECT id FROM (
                    SELECT id FROM $table_name ORDER BY date_sent DESC LIMIT 1000
                ) as temp
            )"
        );
    }
    
    /**
     * Clear logs via AJAX
     */
    public function clear_logs_ajax() {
        // Verify nonce
        if (!wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['nonce'] ?? '')), 'aha_mail_smtp_admin')) {
            wp_send_json_error(__('Security check failed', 'aha-mail-smtp'));
        }
        
        // Check user capabilities
        if (!current_user_can('manage_options')) {
            wp_send_json_error(__('You do not have sufficient permissions', 'aha-mail-smtp'));
        }
        
        $result = self::clear_all_logs();
        
        if ($result !== false) {
            wp_send_json_success(__('All logs cleared successfully!', 'aha-mail-smtp'));
        } else {
            wp_send_json_error(__('Failed to clear logs', 'aha-mail-smtp'));
        }
    }
    
    /**
     * Get logs via AJAX
     */
    public function get_logs_ajax() {
        // Verify nonce
        if (!wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['nonce'] ?? '')), 'aha_mail_smtp_admin')) {
            wp_send_json_error(__('Security check failed', 'aha-mail-smtp'));
        }
        
        // Check user capabilities
        if (!current_user_can('manage_options')) {
            wp_send_json_error(__('You do not have sufficient permissions', 'aha-mail-smtp'));
        }
        
        $page = isset($_POST['page']) ? (int) $_POST['page'] : 1;
        $per_page = isset($_POST['per_page']) ? (int) $_POST['per_page'] : 20;
        $status = isset($_POST['status']) ? sanitize_text_field($_POST['status']) : '';
        
        $offset = ($page - 1) * $per_page;
        
        $logs = self::get_logs($per_page, $offset, $status);
        $total = self::get_logs_count($status);
        $stats = self::get_logs_stats();
        
        wp_send_json_success(array(
            'logs' => $logs,
            'total' => $total,
            'stats' => $stats,
            'page' => $page,
            'per_page' => $per_page,
            'total_pages' => ceil($total / $per_page)
        ));
    }
    
    /**
     * Delete log via AJAX
     */
    public function delete_log_ajax() {
        // Verify nonce
        if (!wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['nonce'] ?? '')), 'aha_mail_smtp_admin')) {
            wp_send_json_error(__('Security check failed', 'aha-mail-smtp'));
        }
        
        // Check user capabilities
        if (!current_user_can('manage_options')) {
            wp_send_json_error(__('You do not have sufficient permissions', 'aha-mail-smtp'));
        }
        
        $log_id = (int) $_POST['log_id'];
        
        if (empty($log_id)) {
            wp_send_json_error(__('Invalid log ID', 'aha-mail-smtp'));
        }
        
        $result = self::delete_log($log_id);
        
        if ($result) {
            wp_send_json_success(__('Log deleted successfully!', 'aha-mail-smtp'));
        } else {
            wp_send_json_error(__('Failed to delete log', 'aha-mail-smtp'));
        }
    }
    
    /**
     * View log via AJAX
     */
    public function view_log_ajax() {
        // Verify nonce
        if (!wp_verify_nonce(sanitize_text_field(wp_unslash($_POST['nonce'] ?? '')), 'aha_mail_smtp_admin')) {
            wp_send_json_error(__('Security check failed', 'aha-mail-smtp'));
        }
        
        // Check user capabilities
        if (!current_user_can('manage_options')) {
            wp_send_json_error(__('You do not have sufficient permissions', 'aha-mail-smtp'));
        }
        
        $log_id = (int) $_POST['log_id'];
        
        if (empty($log_id)) {
            wp_send_json_error(__('Invalid log ID', 'aha-mail-smtp'));
        }
        
        $log = self::get_log($log_id);
        
        if (!$log) {
            wp_send_json_error(__('Log not found', 'aha-mail-smtp'));
        }
        
        wp_send_json_success($log);
    }
    
    /**
     * Export logs to CSV
     */
    public static function export_logs_csv($status = '') {
        $logs = self::get_logs(1000, 0, $status); // Export up to 1000 logs
        
        if (empty($logs)) {
            return false;
        }
        
        $filename = 'aha-mail-smtp-logs-' . date('Y-m-d-H-i-s') . '.csv';
        $filepath = wp_upload_dir()['path'] . '/' . $filename;
        
        $file = fopen($filepath, 'w');
        
        // CSV headers
        fputcsv($file, array(
            'ID',
            'Date',
            'To Email',
            'Subject',
            'Status',
            'Error Message',
            'Attachments'
        ));
        
        // CSV data
        foreach ($logs as $log) {
            fputcsv($file, array(
                $log->id,
                $log->date_sent,
                $log->to_email,
                $log->subject,
                $log->status,
                $log->error_message,
                $log->attachments
            ));
        }
        
        fclose($file);
        
        return array(
            'filename' => $filename,
            'filepath' => $filepath,
            'url' => wp_upload_dir()['url'] . '/' . $filename
        );
    }
    
    /**
     * Get recent activity
     */
    public static function get_recent_activity($days = 7) {
        global $wpdb;
        
        $table_name = $wpdb->prefix . 'aha_mail_smtp_logs';
        
        $results = $wpdb->get_results($wpdb->prepare(
            "SELECT DATE(date_sent) as date, status, COUNT(*) as count 
             FROM $table_name 
             WHERE date_sent >= %s 
             GROUP BY DATE(date_sent), status 
             ORDER BY date DESC",
            date('Y-m-d H:i:s', strtotime("-$days days"))
        ));
        
        $activity = array();
        
        foreach ($results as $result) {
            if (!isset($activity[$result->date])) {
                $activity[$result->date] = array(
                    'success' => 0,
                    'failed' => 0,
                    'pending' => 0,
                    'total' => 0
                );
            }
            
            $activity[$result->date][$result->status] = (int) $result->count;
            $activity[$result->date]['total'] += (int) $result->count;
        }
        
        return $activity;
    }
}