<?php
/**
 * PHPCompatibility, an external standard for PHP_CodeSniffer.
 *
 * @package   PHPCompatibility
 * @copyright 2012-2019 PHPCompatibility Contributors
 * @license   https://opensource.org/licenses/LGPL-3.0 LGPL3
 * @link      https://github.com/PHPCompatibility/PHPCompatibility
 */

namespace PHPCompatibility\Sniffs\FunctionNameRestrictions;

use PHPCompatibility\Sniff;
use PHP_CodeSniffer_File as File;
use PHP_CodeSniffer_Tokens as Tokens;

/**
 * Detect declarations of PHP 4 style constructors which are deprecated as of PHP 7.0.0.
 *
 * PHP 4 style constructors - methods that have the same name as the class they are defined in -
 * are deprecated as of PHP 7.0.0, and will be removed in the future.
 * PHP 7 will emit `E_DEPRECATED` if a PHP 4 constructor is the only constructor defined
 * within a class. Classes that implement a `__construct()` method are unaffected.
 *
 * Note: Methods with the same name as the class they are defined in _within a namespace_
 * are not recognized as constructors anyway and therefore outside the scope of this sniff.
 *
 * PHP version 7.0
 *
 * @link https://www.php.net/manual/en/migration70.deprecated.php#migration70.deprecated.php4-constructors
 * @link https://wiki.php.net/rfc/remove_php4_constructors
 * @link https://www.php.net/manual/en/language.oop5.decon.php
 *
 * @since 7.0.0
 * @since 7.0.8 This sniff now throws a warning instead of an error as the functionality is
 *              only deprecated (for now).
 * @since 9.0.0 Renamed from `DeprecatedPHP4StyleConstructorsSniff` to `RemovedPHP4StyleConstructorsSniff`.
 */
class RemovedPHP4StyleConstructorsSniff extends Sniff {


	/**
	 * Returns an array of tokens this test wants to listen for.
	 *
	 * @since 7.0.0
	 *
	 * @return array
	 */
	public function register() {
		return array(
			\T_CLASS,
		);
	}

	/**
	 * Processes this test, when one of its tokens is encountered.
	 *
	 * @since 7.0.0
	 * @since 7.0.8 The message is downgraded from error to warning as - for now - support
	 *              for PHP4-style constructors is just deprecated, not yet removed.
	 *
	 * @param \PHP_CodeSniffer_File $phpcsFile The file being scanned.
	 * @param int                   $stackPtr  The position of the current token in the
	 *                                         stack passed in $tokens.
	 *
	 * @return void
	 */
	public function process( File $phpcsFile, $stackPtr ) {
		if ( $this->supportsAbove( '7.0' ) === false ) {
			return;
		}

		if ( $this->determineNamespace( $phpcsFile, $stackPtr ) !== '' ) {
			/*
			 * Namespaced methods with the same name as the class are treated as
			 * regular methods, so we can bow out if we're in a namespace.
			 *
			 * Note: the exception to this is PHP 5.3.0-5.3.2. This is currently
			 * not dealt with.
			 */
			return;
		}

		$tokens = $phpcsFile->getTokens();

		$class = $tokens[ $stackPtr ];

		if ( isset( $class['scope_closer'] ) === false ) {
			return;
		}

		$nextNonEmpty = $phpcsFile->findNext( Tokens::$emptyTokens, ( $stackPtr + 1 ), null, true );
		if ( $nextNonEmpty === false || $tokens[ $nextNonEmpty ]['code'] !== \T_STRING ) {
			// Anonymous class in combination with PHPCS 2.3.x.
			return;
		}

		$scopeCloser = $class['scope_closer'];
		$className   = $tokens[ $nextNonEmpty ]['content'];

		if ( empty( $className ) || \is_string( $className ) === false ) {
			return;
		}

		$nextFunc            = $stackPtr;
		$classNameLc         = strtolower( $className );
		$newConstructorFound = false;
		$oldConstructorFound = false;
		$oldConstructorPos   = -1;
		while ( ( $nextFunc = $phpcsFile->findNext( array( \T_FUNCTION, \T_DOC_COMMENT_OPEN_TAG ), ( $nextFunc + 1 ), $scopeCloser ) ) !== false ) {
			// Skip over docblocks.
			if ( $tokens[ $nextFunc ]['code'] === \T_DOC_COMMENT_OPEN_TAG ) {
				$nextFunc = $tokens[ $nextFunc ]['comment_closer'];
				continue;
			}

			$functionScopeCloser = $nextFunc;
			if ( isset( $tokens[ $nextFunc ]['scope_closer'] ) ) {
				// Normal (non-interface, non-abstract) method.
				$functionScopeCloser = $tokens[ $nextFunc ]['scope_closer'];
			}

			$funcName = $phpcsFile->getDeclarationName( $nextFunc );
			if ( empty( $funcName ) || \is_string( $funcName ) === false ) {
				$nextFunc = $functionScopeCloser;
				continue;
			}

			$funcNameLc = strtolower( $funcName );

			if ( $funcNameLc === '__construct' ) {
				$newConstructorFound = true;
			}

			if ( $funcNameLc === $classNameLc ) {
				$oldConstructorFound = true;
				$oldConstructorPos   = $nextFunc;
			}

			// If both have been found, no need to continue looping through the functions.
			if ( $newConstructorFound === true && $oldConstructorFound === true ) {
				break;
			}

			$nextFunc = $functionScopeCloser;
		}

		if ( $newConstructorFound === false && $oldConstructorFound === true ) {
			$phpcsFile->addWarning(
				'Use of deprecated PHP4 style class constructor is not supported since PHP 7.',
				$oldConstructorPos,
				'Found'
			);
		}
	}
}
