<?php

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Fixer\ControlStructure;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\FixerDefinition\CodeSample;
use PhpCsFixer\FixerDefinition\FixerDefinition;
use PhpCsFixer\Tokenizer\Token;
use PhpCsFixer\Tokenizer\Tokens;

/**
 * @author Eddilbert Macharia <edd.cowan@gmail.com>
 */
final class NoAlternativeSyntaxFixer extends AbstractFixer
{
    /**
     * {@inheritdoc}
     */
    public function getDefinition()
    {
        return new FixerDefinition(
            'Replace control structure alternative syntax to use braces.',
            [
                new CodeSample(
                    "<?php\nif(true):echo 't';else:echo 'f';endif;\n"
                ),
                new CodeSample(
                    "<?php\nwhile(true):echo 'red';endwhile;\n"
                ),
                new CodeSample(
                    "<?php\nfor(;;):echo 'xc';endfor;\n"
                ),
                new CodeSample(
                    "<?php\nforeach(array('a') as \$item):echo 'xc';endforeach;\n"
                ),
            ]
        );
    }

    /**
     * {@inheritdoc}
     */
    public function isCandidate(Tokens $tokens)
    {
        return $tokens->isAnyTokenKindsFound(
            [
                T_ENDIF,
                T_ENDWHILE,
                T_ENDFOREACH,
                T_ENDFOR,
            ]
        );
    }

    /**
     * {@inheritdoc}
     */
    public function getPriority()
    {
        // Should run before BracesFixer and ElseifFixer
        return 1;
    }

    /**
     * {@inheritdoc}
     */
    protected function applyFix(\SplFileInfo $file, Tokens $tokens)
    {
        for ($index = \count($tokens) - 1; 0 <= $index; --$index) {
            $token = $tokens[$index];
            $this->fixElseif($index, $token, $tokens);
            $this->fixElse($index, $token, $tokens);
            $this->fixOpenCloseControls($index, $token, $tokens);
        }
    }

    private function findParenthesisEnd(Tokens $tokens, $structureTokenIndex)
    {
        $nextIndex = $tokens->getNextMeaningfulToken($structureTokenIndex);
        $nextToken = $tokens[$nextIndex];

        // return if next token is not opening parenthesis
        if (!$nextToken->equals('(')) {
            return $structureTokenIndex;
        }

        return $tokens->findBlockEnd(Tokens::BLOCK_TYPE_PARENTHESIS_BRACE, $nextIndex);
    }

    /**
     * Handle both extremes of the control structures.
     * e.g. if(): or endif;.
     *
     * @param int    $index  the index of the token being processed
     * @param Token  $token  the token being processed
     * @param Tokens $tokens the collection of tokens
     */
    private function fixOpenCloseControls($index, Token $token, Tokens $tokens)
    {
        if ($token->isGivenKind([T_IF, T_FOREACH, T_WHILE, T_FOR])) {
            $openIndex = $tokens->getNextTokenOfKind($index, ['(']);
            $closeIndex = $tokens->findBlockEnd(Tokens::BLOCK_TYPE_PARENTHESIS_BRACE, $openIndex);
            $afterParenthesisIndex = $tokens->getNextNonWhitespace($closeIndex);
            $afterParenthesis = $tokens[$afterParenthesisIndex];

            if (!$afterParenthesis->equals(':')) {
                return;
            }
            $items = [];
            if (!$tokens[$afterParenthesisIndex - 1]->isWhitespace()) {
                $items[] = new Token([T_WHITESPACE, ' ']);
            }
            $items[] = new Token('{');

            if (!$tokens[$afterParenthesisIndex + 1]->isWhitespace()) {
                $items[] = new Token([T_WHITESPACE, ' ']);
            }
            $tokens->clearAt($afterParenthesisIndex);
            $tokens->insertAt($afterParenthesisIndex, $items);
        }

        if (!$token->isGivenKind([T_ENDIF, T_ENDFOREACH, T_ENDWHILE, T_ENDFOR])) {
            return;
        }

        $nextTokenIndex = $tokens->getNextMeaningfulToken($index);
        $nextToken = $tokens[$nextTokenIndex];
        $tokens[$index] = new Token('}');
        if ($nextToken->equals(';')) {
            $tokens->clearAt($nextTokenIndex);
        }
    }

    /**
     * Handle the else:.
     *
     * @param int    $index  the index of the token being processed
     * @param Token  $token  the token being processed
     * @param Tokens $tokens the collection of tokens
     */
    private function fixElse($index, Token $token, Tokens $tokens)
    {
        if (!$token->isGivenKind(T_ELSE)) {
            return;
        }

        $tokenAfterElseIndex = $tokens->getNextMeaningfulToken($index);
        $tokenAfterElse = $tokens[$tokenAfterElseIndex];
        if (!$tokenAfterElse->equals(':')) {
            return;
        }

        $this->addBraces($tokens, new Token([T_ELSE, 'else']), $index, $tokenAfterElseIndex);
    }

    /**
     * Handle the elsif(): cases.
     *
     * @param int    $index  the index of the token being processed
     * @param Token  $token  the token being processed
     * @param Tokens $tokens the collection of tokens
     */
    private function fixElseif($index, Token $token, Tokens $tokens)
    {
        if (!$token->isGivenKind(T_ELSEIF)) {
            return;
        }
        $parenthesisEndIndex = $this->findParenthesisEnd($tokens, $index);
        $tokenAfterParenthesisIndex = $tokens->getNextMeaningfulToken($parenthesisEndIndex);
        $tokenAfterParenthesis = $tokens[$tokenAfterParenthesisIndex];
        if (!$tokenAfterParenthesis->equals(':')) {
            return;
        }

        $this->addBraces($tokens, new Token([T_ELSEIF, 'elseif']), $index, $tokenAfterParenthesisIndex);
    }

    /**
     * Add opening and closing braces to the else: and elseif: .
     *
     * @param Tokens $tokens     the tokens collection
     * @param Token  $token      the current token
     * @param int    $index      the current token index
     * @param int    $colonIndex the index of the colon
     */
    private function addBraces(Tokens $tokens, Token $token, $index, $colonIndex)
    {
        $items = [
            new Token('}'),
            new Token([T_WHITESPACE, ' ']),
            $token,
        ];
        if (!$tokens[$index + 1]->isWhitespace()) {
            $items[] = new Token([T_WHITESPACE, ' ']);
        }
        $tokens->clearAt($index);
        $tokens->insertAt(
            $index,
            $items
        );

        // increment the position of the colon by number of items inserted
        $colonIndex += \count($items);

        $items = [new Token('{')];
        if (!$tokens[$colonIndex + 1]->isWhitespace()) {
            $items[] = new Token([T_WHITESPACE, ' ']);
        }

        $tokens->clearAt($colonIndex);
        $tokens->insertAt(
            $colonIndex,
            $items
        );
    }
}
