<?php
/**
 * Logging wrapper for AI Content by Parallax.
 *
 * @package AIContentByParallax
 */

namespace AIContentByParallax\Core;

defined( 'ABSPATH' ) || exit;

use WC_Log_Handler_File;

/**
 * Write and read plugin log entries.
 */
class Logger {

	/**
	 * This becomes the log "source" and therefore the log file prefix.
	 * You will see it in WooCommerce > Status/Tools > Logs dropdown.
	 */
	private const SOURCE = 'ai-content-by-parallax';

	/**
	 * Retrieve WooCommerce logger instance if available.
	 *
	 * @return \WC_Logger|null
	 */
	private static function wc_logger() {
		// Plugin depends on WC, but guard anyway to avoid fatal during bootstrap.
		if ( function_exists( 'wc_get_logger' ) ) {
			return wc_get_logger();
		}

		return null;
	}

	/**
	 * Build log context array.
	 *
	 * @param array $extra Additional context entries.
	 * @return array
	 */
	private static function context( array $extra = array() ): array {
		return array_merge(
			array( 'source' => self::SOURCE ),
			$extra
		);
	}

	/**
	 * Write a log entry.
	 *
	 * @param string $level   emergency|alert|critical|error|warning|notice|info|debug.
	 * @param string $message Log message.
	 * @param mixed  $payload Optional payload; will be appended as pretty JSON.
	 */
	public static function write_log( string $level, string $message, $payload = null ): void {
		$logger = self::wc_logger();

		// If WC isn't available for some reason, fail soft.
		if ( ! $logger ) {
			return;
		}

		// if is info level and enable_debug_support is false, do not log.
		if ( 'info' === $level && ! Settings::get( 'enable_debug_support' ) ) {
			return;
		}

		if ( null !== $payload ) {
			$pretty = wp_json_encode(
				$payload,
				JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE
			);

			$message .= "\nBEGIN_PAYLOAD\n" . ( false !== $pretty ? $pretty : '[payload_encode_failed]' ) . "\nEND_PAYLOAD";
		}

		// Prefer WC's logger methods. log() is fine too.
		$logger->log( $level, $message, self::context() );
	}

	/**
	 * Read the most recent log file contents for this source (today’s file).
	 * Note: WC logs are per-day and include a hash in the filename.
	 *
	 * @return string
	 */
	public static function read_log(): string {
		if ( ! class_exists( WC_Log_Handler_File::class ) ) {
			return '';
		}

		$path = WC_Log_Handler_File::get_log_file_path( self::SOURCE );
		if ( ! $path ) {
			return '';
		}

		$normalized = wp_normalize_path( $path );
		$real_path  = realpath( $normalized );

		if ( false === $real_path ) {
			return '';
		}

		$real_path = wp_normalize_path( $real_path );
		$base_dir  = defined( 'WC_LOG_DIR' ) ? (string) WC_LOG_DIR : dirname( $real_path );
		$base_dir  = wp_normalize_path( $base_dir );
		$base_real = realpath( $base_dir );
		if ( false !== $base_real ) {
			$base_dir = wp_normalize_path( $base_real );
		}
		$base_dir = trailingslashit( $base_dir );

		// Ensure the resolved log file stays within the WooCommerce log directory.
		if ( 0 !== strpos( $real_path, $base_dir ) ) {
			return '';
		}

		if ( ! is_file( $real_path ) || ! is_readable( $real_path ) ) {
			return '';
		}

		// Cap output size to avoid memory issues.
		$max_bytes = 262144; // 256KB.

		if ( ! is_admin() ) {
			return '';
		}

		// AdminIncludes is responsible for loading WP_Filesystem classes on admin screens.
		if ( ! class_exists( 'WP_Filesystem_Direct', false ) ) {
			return '';
		}

		$fs = new \WP_Filesystem_Direct( null );
		if ( ! $fs || ! method_exists( $fs, 'get_contents' ) ) {
			return '';
		}

		$contents = $fs->get_contents( $real_path );
		if ( ! is_string( $contents ) || '' === $contents ) {
			return '';
		}

		// Enforce max bytes even if FS returns more.
		if ( strlen( $contents ) > $max_bytes ) {
			$contents = substr( $contents, 0, $max_bytes );
		}

		return esc_html( $contents );
	}
}