<?php
/** PHP_CodeSniffer with the PHPCompatibility rules, run inside the WordPress request: no exec() needed, works on hosts that disable it. */

namespace Leaplens;

use PHP_CodeSniffer\Config;
use PHP_CodeSniffer\Files\LocalFile;
use PHP_CodeSniffer\Ruleset;

defined( 'ABSPATH' ) || exit;

final class Engine {

	/** Memory the rule set takes once loaded. */
	const BOOT_BYTES = 16 * MB_IN_BYTES;

	/** PHP_CodeSniffer's own notes about a file, not compatibility findings. */
	const IGNORED_INTERNAL = array( 'Internal.LineEndings.Mixed', 'Internal.NoCodeFound' );

	private $target;
	private $config;
	private $ruleset;

	public function __construct( $target ) {
		$this->target = $target;
	}

	public static function unavailable_reason() {
		if ( ! is_readable( self::vendor_dir() . 'php_codesniffer/autoload.php' ) ) {
			return __( 'The bundled PHP_CodeSniffer files are missing. Reinstall the plugin.', 'leaplens' );
		}
		if ( ! function_exists( 'token_get_all' ) ) {
			return __( 'The PHP tokenizer extension is disabled on this server.', 'leaplens' );
		}
		foreach ( array( 'PHP_CodeSniffer\Autoload', 'PHP_CodeSniffer\Config' ) as $class ) {
			if ( class_exists( $class, false ) ) {
				$file = (string) ( new \ReflectionClass( $class ) )->getFileName();
				if ( 0 !== strpos( wp_normalize_path( $file ), self::vendor_dir() ) ) {
					/* translators: %s: file path of the other copy. */
					return sprintf( __( 'Another plugin already loaded its own copy of PHP_CodeSniffer (%s).', 'leaplens' ), $file );
				}
			}
		}
		// On the command line PHP_CodeSniffer probes STDIN, which needs posix_isatty() or shell_exec().
		if ( defined( 'STDIN' ) && ! function_exists( 'posix_isatty' ) && ! function_exists( 'shell_exec' ) ) {
			return __( 'Scanning from the command line needs the PHP posix extension. Continue the scan from the admin screen.', 'leaplens' );
		}
		return '';
	}

	public function booted() {
		return null !== $this->ruleset;
	}

	private static function vendor_dir() {
		return wp_normalize_path( LEAPLENS_DIR . 'vendor/' );
	}

	private function boot() {
		if ( $this->ruleset ) {
			return;
		}
		$reason = self::unavailable_reason();
		if ( '' !== $reason ) {
			throw new \RuntimeException( esc_html( $reason ) );
		}
		$vendor = self::vendor_dir();
		if ( ! defined( 'PHP_CODESNIFFER_VERBOSITY' ) ) {
			define( 'PHP_CODESNIFFER_VERBOSITY', 0 );
		}
		if ( ! defined( 'PHP_CODESNIFFER_CBF' ) ) {
			define( 'PHP_CODESNIFFER_CBF', false );
		}
		require_once $vendor . 'php_codesniffer/autoload.php';
		require_once $vendor . 'phpcsutils/phpcsutils-autoload.php';
		// Defines the T_* token constants the tokenizer relies on.
		class_exists( 'PHP_CodeSniffer\Util\Tokens' );

		// Annotations are ignored: a "phpcs:ignore" in a plugin must not hide a removed function from this scan.
		$this->config  = new Config( array( '--standard=' . $vendor . 'phpcompatibility/PHPCompatibility', '--runtime-set', 'testVersion', $this->target, '--ignore-annotations', '--no-cache', '-q' ), false );
		$this->ruleset = new Ruleset( $this->config );
	}

	/** Findings for one file as [line, type, code, message, guarded], sorted by line; one per line and rule, guarded only when every hit on the line is. Throws when the file cannot be analysed. */
	public function check_file( $path ) {
		$this->boot();
		$file = new LocalFile( $path, $this->ruleset, $this->config );
		try {
			$file->process();
			$out    = array();
			$guards = null;
			foreach ( array( 'error' => $file->getErrors(), 'warning' => $file->getWarnings() ) as $type => $lines ) {
				foreach ( $lines as $line => $columns ) {
					foreach ( $columns as $column => $messages ) {
						foreach ( $messages as $m ) {
							$code = (string) $m['source'];
							if ( 0 === strpos( $code, 'Internal.' ) ) {
								if ( in_array( $code, self::IGNORED_INTERNAL, true ) ) {
									continue;
								}
								throw new \RuntimeException( esc_html( wp_strip_all_tags( (string) $m['message'] ) ) );
							}
							if ( null === $guards ) {
								$guards = new Guards( $file->getTokens(), $this->target );
							}
							$key         = $line . "\0" . $code;
							$guarded     = $guards->skips( $line, $column, $type, $code ) && ( ! isset( $out[ $key ] ) || $out[ $key ][4] );
							$out[ $key ] = array( (int) $line, $type, $code, (string) $m['message'], $guarded );
						}
					}
				}
			}
			ksort( $out, SORT_NATURAL );
			return array_values( $out );
		} finally {
			$file->cleanUp();
			// PHPCSUtils keeps per-file results in static caches meant for one CLI run; across hundreds of files they exhaust memory.
			\PHPCSUtils\Internal\Cache::clear();
			\PHPCSUtils\Internal\NoFileCache::clear();
		}
	}
}