<?php
/**
 * Checks for unneeded whitespace.
 *
 * Checks that no whitespace precedes the first content of the file, exists
 * after the last content of the file, resides after content on any line, or
 * are two empty lines in functions.
 *
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @copyright 2006-2023 Squiz Pty Ltd (ABN 77 084 670 600)
 * @copyright 2023 PHPCSStandards and contributors
 * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/HEAD/licence.txt BSD Licence
 */

namespace PHP_CodeSniffer\Standards\Squiz\Sniffs\WhiteSpace;

use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Sniffs\Sniff;

class SuperfluousWhitespaceSniff implements Sniff
{

    /**
     * If TRUE, whitespace rules are not checked for blank lines.
     *
     * Blank lines are those that contain only whitespace.
     *
     * @var boolean
     */
    public $ignoreBlankLines = false;


    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register()
    {
        return [
            T_OPEN_TAG,
            T_OPEN_TAG_WITH_ECHO,
            T_CLOSE_TAG,
            T_WHITESPACE,
            T_COMMENT,
            T_DOC_COMMENT_WHITESPACE,
            T_CLOSURE,
        ];
    }


    /**
     * Processes this sniff, when one of its tokens is encountered.
     *
     * @param \PHP_CodeSniffer\Files\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, int $stackPtr)
    {
        $tokens = $phpcsFile->getTokens();

        if ($tokens[$stackPtr]['code'] === T_OPEN_TAG) {
            /*
                Check for start of file whitespace.
            */

            // If it's the first token, then there is no space.
            if ($stackPtr === 0) {
                return;
            }

            $beforeOpen = '';

            for ($i = ($stackPtr - 1); $i >= 0; $i--) {
                // If we find something that isn't inline html then there is something previous in the file.
                if ($tokens[$i]['type'] !== 'T_INLINE_HTML') {
                    return;
                }

                $beforeOpen .= $tokens[$i]['content'];
            }

            // If we have ended up with inline html make sure it isn't just whitespace.
            if (preg_match('`^[\pZ\s]+$`u', $beforeOpen) !== 1) {
                return;
            }

            $fix = $phpcsFile->addFixableError('Additional whitespace found at start of file', $stackPtr, 'StartFile');
            if ($fix === true) {
                $phpcsFile->fixer->beginChangeset();
                for ($i = 0; $i < $stackPtr; $i++) {
                    $phpcsFile->fixer->replaceToken($i, '');
                }

                $phpcsFile->fixer->endChangeset();
            }
        } elseif ($tokens[$stackPtr]['code'] === T_CLOSE_TAG) {
            /*
                Check for end of file whitespace.
            */

            if (isset($tokens[($stackPtr + 1)]) === false) {
                // The close PHP token is the last in the file.
                return;
            }

            $afterClose = '';

            for ($i = ($stackPtr + 1); $i < $phpcsFile->numTokens; $i++) {
                // If we find something that isn't inline HTML then there
                // is more to the file.
                if ($tokens[$i]['type'] !== 'T_INLINE_HTML') {
                    return;
                }

                $afterClose .= $tokens[$i]['content'];
            }

            // If we have ended up with inline html make sure it isn't just whitespace.
            if (preg_match('`^[\pZ\s]+$`u', $afterClose) !== 1) {
                return;
            }

            $fix = $phpcsFile->addFixableError('Additional whitespace found at end of file', $stackPtr, 'EndFile');
            if ($fix === true) {
                $phpcsFile->fixer->beginChangeset();
                for ($i = ($stackPtr + 1); $i < $phpcsFile->numTokens; $i++) {
                    $phpcsFile->fixer->replaceToken($i, '');
                }

                $phpcsFile->fixer->endChangeset();
            }
        } else {
            /*
                Check for end of line whitespace.
            */

            // Ignore whitespace that is not at the end of a line.
            if (isset($tokens[($stackPtr + 1)]['line']) === true
                && $tokens[($stackPtr + 1)]['line'] === $tokens[$stackPtr]['line']
            ) {
                return;
            }

            // Ignore blank lines if required.
            if ($this->ignoreBlankLines === true
                && $tokens[$stackPtr]['code'] === T_WHITESPACE
                && $tokens[($stackPtr - 1)]['line'] !== $tokens[$stackPtr]['line']
            ) {
                return;
            }

            $tokenContent = rtrim($tokens[$stackPtr]['content'], $phpcsFile->eolChar);
            if (empty($tokenContent) === false) {
                if ($tokenContent !== rtrim($tokenContent)) {
                    $fix = $phpcsFile->addFixableError('Whitespace found at end of line', $stackPtr, 'EndLine');
                    if ($fix === true) {
                        $phpcsFile->fixer->replaceToken($stackPtr, rtrim($tokenContent) . $phpcsFile->eolChar);
                    }
                }
            } elseif ($tokens[($stackPtr - 1)]['content'] !== rtrim($tokens[($stackPtr - 1)]['content'])
                && $tokens[($stackPtr - 1)]['line'] === $tokens[$stackPtr]['line']
            ) {
                $fix = $phpcsFile->addFixableError('Whitespace found at end of line', ($stackPtr - 1), 'EndLine');
                if ($fix === true) {
                    $phpcsFile->fixer->replaceToken(($stackPtr - 1), rtrim($tokens[($stackPtr - 1)]['content']));
                }
            }

            /*
                Check for multiple blank lines in a function.
            */

            if (($phpcsFile->hasCondition($stackPtr, [T_FUNCTION, T_CLOSURE]) === true)
                && $tokens[($stackPtr - 1)]['line'] < $tokens[$stackPtr]['line']
                && $tokens[($stackPtr - 2)]['line'] === $tokens[($stackPtr - 1)]['line']
            ) {
                // Properties and functions in nested classes have their own rules for spacing.
                $conditions   = $tokens[$stackPtr]['conditions'];
                $deepestScope = end($conditions);
                if ($deepestScope === T_ANON_CLASS) {
                    return;
                }

                // This is an empty line and the line before this one is not
                // empty, so this could be the start of a multiple empty
                // line block.
                $next  = $phpcsFile->findNext(T_WHITESPACE, $stackPtr, null, true);
                $lines = ($tokens[$next]['line'] - $tokens[$stackPtr]['line']);
                if ($lines > 1) {
                    $error = 'Functions must not contain multiple empty lines in a row; found %s empty lines';
                    $fix   = $phpcsFile->addFixableError($error, $stackPtr, 'EmptyLines', [$lines]);
                    if ($fix === true) {
                        $phpcsFile->fixer->beginChangeset();
                        $i = $stackPtr;
                        while ($tokens[$i]['line'] !== $tokens[$next]['line']) {
                            $phpcsFile->fixer->replaceToken($i, '');
                            $i++;
                        }

                        $phpcsFile->fixer->addNewlineBefore($i);
                        $phpcsFile->fixer->endChangeset();
                    }
                }
            }
        }
    }
}
