<?php
/**
 * A short, safe log of AI Advisor requests.
 *
 * @package TurtleReport
 */

namespace TurtleReport\Advisor;

use TurtleReport\Support\Text;
use TurtleReport\Support\OptionUpdate;

defined( 'ABSPATH' ) || exit;

/**
 * Keeps the last few AI requests for Settings → AI Advisor, to explain a
 * failure without guessing: when it ran, the result, HTTP status, the
 * provider's error code and request ID, retries, time taken and token counts.
 *
 * It only stores those fields. Never the API key, the question, the answer,
 * client names or any report data. One option, not autoloaded. With
 * WP_DEBUG_LOG on, failures also go to the PHP error log in the same form.
 */
final class Diagnostics {

	/** Option. */
	const OPTION = 'turtlereport_ai_log';

	/** Entries kept. */
	const KEEP = 20;

	/** Fields allowed in an entry, and their type. */
	const FIELDS = array(
		'time'       => 'int',
		'ok'         => 'bool',
		'kind'       => 'word',
		'http'       => 'int',
		'code'       => 'word',
		'model'      => 'word',
		'scope'      => 'word',
		'attempts'   => 'int',
		'waited'     => 'float',
		'ms'         => 'int',
		'in'         => 'int',
		'out'        => 'int',
		'chars'      => 'int',
		'request_id' => 'word',
	);

	/**
	 * Adds an entry; unknown fields are dropped.
	 *
	 * @param array $entry Entry.
	 * @return array The entry as stored.
	 */
	public function add( array $entry ) {
		$clean = array( 'time' => time() );
		foreach ( self::FIELDS as $key => $type ) {
			if ( ! array_key_exists( $key, $entry ) || null === $entry[ $key ] ) {
				continue;
			}
			$v = $entry[ $key ];
			if ( ! is_scalar( $v ) ) {
				continue;
			}
			switch ( $type ) {
				case 'int':
					$clean[ $key ] = (int) $v;
					break;
				case 'float':
					$clean[ $key ] = round( (float) $v, 1 );
					break;
				case 'bool':
					$clean[ $key ] = (bool) $v;
					break;
				default:
					// Short identifiers only (model IDs, error codes, request IDs); never free text.
					$clean[ $key ] = Text::substr( (string) preg_replace( '/[^A-Za-z0-9_\.\-:\/]/', '', HttpProvider::clean( (string) $v ) ), 0, 64 );
			}
		}
		OptionUpdate::change(
			self::OPTION,
			static function ( array $log ) use ( $clean ) {
				$log[] = $clean;
				return array_slice( $log, -self::KEEP );
			}
		);

		if ( empty( $clean['ok'] ) && defined( 'WP_DEBUG' ) && WP_DEBUG && defined( 'WP_DEBUG_LOG' ) && WP_DEBUG_LOG ) {
			$parts = array();
			foreach ( $clean as $k => $v ) {
				$parts[] = $k . '=' . ( is_bool( $v ) ? ( $v ? '1' : '0' ) : $v );
			}
			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- Only with WP_DEBUG_LOG on; the entry holds codes and counts, never keys or client data.
			error_log( '[TurtleReport AI] ' . implode( ' ', $parts ) );
		}
		return $clean;
	}

	/**
	 * Entries, oldest first.
	 *
	 * @return array[]
	 */
	public function recent() {
		$log = get_option( self::OPTION, array() );
		return is_array( $log ) ? array_values( array_filter( $log, 'is_array' ) ) : array();
	}

	/**
	 * Removes all entries.
	 *
	 * @return void
	 */
	public function clear() {
		delete_option( self::OPTION );
	}
}