<?php
/** Private, bounded conversion logs. */
if (!defined('ABSPATH')) { exit; }

class IWAC_Logs {
    const OPTION_NAME = 'iwac_private_logs';
    const MAX_ENTRIES = 200;
    private static $registered = false;

    public function __construct() {
        if (!self::$registered) {
            self::$registered = true;
            add_action('admin_init', array($this, 'migrate_legacy_logs'));
            add_action('admin_notices', array($this, 'migration_notice'));
        }
    }

    public function log($message, $type = 'INFO') {
        $entries = $this->get_recent_logs(self::MAX_ENTRIES);
        array_unshift($entries, array(
            'timestamp' => current_time('Y-m-d H:i:s'),
            'type' => in_array($type, array('INFO', 'SUCCESS', 'ERROR', 'WARNING'), true) ? $type : 'INFO',
            'message' => substr(sanitize_text_field($message), 0, 2000),
        ));
        update_option(self::OPTION_NAME, array_slice($entries, 0, self::MAX_ENTRIES), false);
    }

    public function log_conversion_success($id, $format, $saved) {
        $attachment = get_post($id);
        $this->log(sprintf('Converted %s to %s. Transfer savings: %s KB',
            $attachment ? $attachment->post_title : '#' . absint($id), strtoupper($format), $saved), 'SUCCESS');
    }

    public function log_conversion_error($id, $format, $error) {
        $attachment = get_post($id);
        $this->log(sprintf('Failed to convert %s to %s. Error: %s',
            $attachment ? $attachment->post_title : '#' . absint($id), strtoupper($format), $error), 'ERROR');
    }

    public function get_recent_logs($limit = 50) {
        $entries = get_option(self::OPTION_NAME, array());
        return array_slice(is_array($entries) ? $entries : array(), 0, max(0, min(self::MAX_ENTRIES, (int) $limit)));
    }

    public function clear_logs() {
        return delete_option(self::OPTION_NAME);
    }

    public function export_logs() {
        $lines = array();
        foreach (array_reverse($this->get_recent_logs(self::MAX_ENTRIES)) as $entry) {
            $lines[] = sprintf('[%s] [%s] %s', $entry['timestamp'], $entry['type'], $entry['message']);
        }
        return implode("\n", $lines);
    }

    public function migrate_legacy_logs() {
        if (!current_user_can('manage_options') || get_option('iwac_private_logs_migrated')) { return; }
        $base = realpath(wp_upload_dir()['basedir']);
        if (!$base) { return; }
        $failed = false;
        foreach ((array) glob($base . '/iwac-conversion.log*') as $file) {
            if (!preg_match('/^iwac-conversion\\.log(?:\\.\\d{4}-\\d{2}-\\d{2}-\\d{2}-\\d{2}-\\d{2})?$/', basename($file))
                || is_link($file) || !is_file($file) || realpath(dirname($file)) !== $base) { continue; }
            if (!is_readable($file)) { $failed = true; continue; }
            $legacy = array();
            try {
                $reader = new SplFileObject($file, 'r');
                while (!$reader->eof()) {
                    $line = $reader->fgets();
                    if (preg_match('/^\\[(.*?)\\]\\s\\[(.*?)\\]\\s(.*)$/', trim($line), $match)) {
                        $legacy[] = array('timestamp' => sanitize_text_field($match[1]),
                            'type' => in_array($match[2], array('INFO', 'SUCCESS', 'ERROR', 'WARNING'), true) ? $match[2] : 'INFO',
                            'message' => substr(sanitize_text_field($match[3]), 0, 2000));
                        if (count($legacy) > self::MAX_ENTRIES) { array_shift($legacy); }
                    }
                }
                unset($reader);
            } catch (Throwable $error) { $failed = true; continue; }
            $merged = array_merge($this->get_recent_logs(self::MAX_ENTRIES), $legacy);
            $unique = array();
            foreach ($merged as $entry) { $unique[md5(wp_json_encode($entry))] = $entry; }
            $merged = array_values($unique);
            usort($merged, static function ($a, $b) { return strcmp($b['timestamp'], $a['timestamp']); });
            $merged = array_slice($merged, 0, self::MAX_ENTRIES);
            update_option(self::OPTION_NAME, $merged, false);
            if (get_option(self::OPTION_NAME, array()) !== $merged) { $failed = true; continue; }
            // Delete only the plugin's known legacy log names after private storage is verified.
            wp_delete_file($file);
            clearstatcache(true, $file);
            if (file_exists($file)) { $failed = true; }
        }
        update_option('iwac_legacy_logs_cleanup_failed', $failed, false);
        if (!$failed) { update_option('iwac_private_logs_migrated', 1, false); }
    }

    public function migration_notice() {
        if (current_user_can('manage_options') && get_option('iwac_legacy_logs_cleanup_failed')) {
            echo '<div class="notice notice-error"><p>' . esc_html__('Infinico Image Optimizer could not remove old public conversion logs. Check upload-directory permissions and remove iwac-conversion.log and its dated backups after keeping a private copy.', 'infinico-image-optimizer') . '</p></div>';
        }
    }
}