peptide-news-plugin/includes/class-peptide-news-logger.php

<?php
/**
 * Plugin Logger.
 *
 * Provides structured logging to a custom database table with levels,
 * contexts, and an admin-facing viewer with AJAX pagination and clear.
 *
 * @since 2.1.0
 */
class Peptide_News_Logger {

    /** Log level constants. */
    const LEVEL_INFO    = 'info';
    const LEVEL_WARNING = 'warning';
    const LEVEL_ERROR   = 'error';
    const LEVEL_DEBUG   = 'debug';

    /** Maximum rows kept in the log table (auto-pruned on write). */
    const MAX_ROWS = 2000;

    /**
     * Return the log table name.
     */
    public static function table() {
        global $wpdb;
        return $wpdb->prefix . 'peptide_news_log';
    }

    /* ------------------------------------------------------------------
     * Writing
     * ----------------------------------------------------------------*/

    /**
     * Write a log entry.
     *
     * @param string $level   One of the LEVEL_* constants.
     * @param string $message Human-readable message.
     * @param string $context Category tag (fetch, llm, admin, cron, general).
     */
    public static function log( $level, $message, $context = 'general' ) {
        global $wpdb;

        $wpdb->insert(
            self::table(),
            array(
                'level'      => $level,
                'context'    => $context,
                'message'    => $message,
                'created_at' => current_time( 'mysql' ),
            ),
            array( '%s', '%s', '%s', '%s' )
        );

        // Auto-prune old entries.
        self::maybe_prune();
    }

    /** Convenience: info level. */
    public static function info( $message, $context = 'general' ) {
        self::log( self::LEVEL_INFO, $message, $context );
    }

    /** Convenience: warning level. */
    public static function warning( $message, $context = 'general' ) {
        self::log( self::LEVEL_WARNING, $message, $context );
    }

    /** Convenience: error level. */
    public static function error( $message, $context = 'general' ) {
        self::log( self::LEVEL_ERROR, $message, $context );
    }

    /** Convenience: debug level (only writes when WP_DEBUG is on). */
    public static function debug( $message, $context = 'general' ) {
        if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
            self::log( self::LEVEL_DEBUG, $message, $context );
        }
    }

    /* ------------------------------------------------------------------
     * Reading
     * ----------------------------------------------------------------*/

    /**
     * Retrieve log entries.
     *
     * @param array $args {
     *     Optional. Query arguments.
     *
     *     @type string $level   Filter by level.
     *     @type string $context Filter by context.
     *     @type int    $limit   Number of rows.
     *     @type int    $offset  Pagination offset.
     * }
     * @return array { 'rows' => array, 'total' => int }
     */
    public static function get_logs( $args = array() ) {
        global $wpdb;

        $defaults = array(
            'level'   => '',
            'context' => '',
            'limit'   => 50,
            'offset'  => 0,
        );
        $args = wp_parse_args( $args, $defaults );

        $table = self::table();
        $where = array( '1=1' );
        $vals  = array();

        if ( ! empty( $args['level'] ) ) {
            $where[] = 'level = %s';
            $vals[]  = $args['level'];
        }
        if ( ! empty( $args['context'] ) ) {
            $where[] = 'context = %s';
            $vals[]  = $args['context'];
        }

        $where_sql = implode( ' AND ', $where );

        // Total count.
        $count_sql = "SELECT COUNT(*) FROM {$table} WHERE {$where_sql}";
        $total     = empty( $vals )
            ? (int) $wpdb->get_var( $count_sql )
            : (int) $wpdb->get_var( $wpdb->prepare( $count_sql, $vals ) );

        // Rows.
        $order_sql = "SELECT * FROM {$table} WHERE {$where_sql} ORDER BY id DESC LIMIT %d OFFSET %d";
        $vals[]    = absint( $args['limit'] );
        $vals[]    = absint( $args['offset'] );
        $rows      = $wpdb->get_results( $wpdb->prepare( $order_sql, $vals ) );

        return array(
            'rows'  => $rows ? $rows : array(),
            'total' => $total,
        );
    }

    /* ------------------------------------------------------------------
     * Maintenance
     * ----------------------------------------------------------------*/

    /**
     * Remove rows beyond the MAX_ROWS cap.
     */
    private static function maybe_prune() {
        global $wpdb;
        $table = self::table();

        // Only prune every ~50 writes (probabilistic).
        if ( wp_rand( 1, 50 ) !== 1 ) {
            return;
        }

        $count = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$table}" );

        if ( $count > self::MAX_ROWS ) {
            $delete_count = $count - self::MAX_ROWS;
            $wpdb->query( $wpdb->prepare(
                "DELETE FROM {$table} ORDER BY id ASC LIMIT %d",
                $delete_count
            ) );
        }
    }

    /**
     * Clear all log entries.
     */
    public static function clear() {
        global $wpdb;
        $wpdb->query( "TRUNCATE TABLE " . self::table() );
    }

    /* ------------------------------------------------------------------
     * AJAX handlers
     * ----------------------------------------------------------------*/

    /**
     * AJAX: fetch paginated log entries.
     */
    public static function ajax_get_logs() {
        check_ajax_referer( 'peptide_news_admin', 'nonce' );

        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error( 'Unauthorized', 403 );
        }

        $page    = isset( $_POST['page'] ) ? absint( $_POST['page'] ) : 1;
        $level   = isset( $_POST['level'] ) ? sanitize_text_field( $_POST['level'] ) : '';
        $context = isset( $_POST['context'] ) ? sanitize_text_field( $_POST['context'] ) : '';
        $per_page = 50;

        $result = self::get_logs( array(
            'level'   => $level,
            'context' => $context,
            'limit'   => $per_page,
            'offset'  => ( $page - 1 ) * $per_page,
        ) );

        wp_send_json_success( array(
            'rows'       => $result['rows'],
            'total'      => $result['total'],
            'page'       => $page,
            'total_pages' => ceil( $result['total'] / $per_page ),
        ) );
    }

    /**
     * AJAX: clear all log entries.
     */
    public static function ajax_clear_logs() {
        check_ajax_referer( 'peptide_news_admin', 'nonce' );

        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error( 'Unauthorized', 403 );
        }

        self::clear();
        self::info( 'Log cleared by admin.', 'admin' );

        wp_send_json_success( array( 'message' => 'Log cleared.' ) );
    }

    /* ------------------------------------------------------------------
     * Schema
     * ----------------------------------------------------------------*/

    /**
     * Create the log table (called from activator / upgrade check).
     */
    public static function create_table() {
        global $wpdb;

        $table           = self::table();
        $charset_collate = $wpdb->get_charset_collate();

        $sql = "CREATE TABLE {$table} (
            id BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
            level VARCHAR(10) NOT NULL DEFAULT 'info',
            context VARCHAR(30) NOT NULL DEFAULT 'general',
            message TEXT NOT NULL,
            created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
            PRIMARY KEY (id),
            KEY idx_level (level),
            KEY idx_context (context),
            KEY idx_created (created_at)
        ) {$charset_collate};";

        require_once ABSPATH . 'wp-admin/includes/upgrade.php';
        dbDelta( $sql );
    }
}