Chris@14: <?php declare(strict_types=1);
Chris@14: /*
Chris@14:  * This file is part of sebastian/diff.
Chris@14:  *
Chris@14:  * (c) Sebastian Bergmann <sebastian@phpunit.de>
Chris@14:  *
Chris@14:  * For the full copyright and license information, please view the LICENSE
Chris@14:  * file that was distributed with this source code.
Chris@14:  */
Chris@14: 
Chris@14: namespace SebastianBergmann\Diff\Output;
Chris@14: 
Chris@14: /**
Chris@14:  * Builds a diff string representation in unified diff format in chunks.
Chris@14:  */
Chris@14: final class UnifiedDiffOutputBuilder extends AbstractChunkOutputBuilder
Chris@14: {
Chris@14:     /**
Chris@14:      * @var string
Chris@14:      */
Chris@14:     private $header;
Chris@14: 
Chris@14:     /**
Chris@14:      * @var bool
Chris@14:      */
Chris@14:     private $addLineNumbers;
Chris@14: 
Chris@14:     public function __construct(string $header = "--- Original\n+++ New\n", bool $addLineNumbers = false)
Chris@14:     {
Chris@14:         $this->header         = $header;
Chris@14:         $this->addLineNumbers = $addLineNumbers;
Chris@14:     }
Chris@14: 
Chris@14:     public function getDiff(array $diff): string
Chris@14:     {
Chris@14:         $buffer = \fopen('php://memory', 'r+b');
Chris@14: 
Chris@14:         if ('' !== $this->header) {
Chris@14:             \fwrite($buffer, $this->header);
Chris@14:             if ("\n" !== \substr($this->header, -1, 1)) {
Chris@14:                 \fwrite($buffer, "\n");
Chris@14:             }
Chris@14:         }
Chris@14: 
Chris@14:         $this->writeDiffChunked($buffer, $diff, $this->getCommonChunks($diff));
Chris@14: 
Chris@14:         $diff = \stream_get_contents($buffer, -1, 0);
Chris@14: 
Chris@14:         \fclose($buffer);
Chris@14: 
Chris@14:         return $diff;
Chris@14:     }
Chris@14: 
Chris@14:     // `old` is an array with key => value pairs . Each pair represents a start and end index of `diff`
Chris@14:     // of a list of elements all containing `same` (0) entries.
Chris@14:     private function writeDiffChunked($output, array $diff, array $old)
Chris@14:     {
Chris@14:         $upperLimit = \count($diff);
Chris@14:         $start      = 0;
Chris@14:         $fromStart  = 0;
Chris@14:         $toStart    = 0;
Chris@14: 
Chris@14:         if (\count($old)) { // no common parts, list all diff entries
Chris@14:             \reset($old);
Chris@14: 
Chris@14:             // iterate the diff, go from chunk to chunk skipping common chunk of lines between those
Chris@14:             do {
Chris@14:                 $commonStart = \key($old);
Chris@14:                 $commonEnd   = \current($old);
Chris@14: 
Chris@14:                 if ($commonStart !== $start) {
Chris@14:                     list($fromRange, $toRange) = $this->getChunkRange($diff, $start, $commonStart);
Chris@14:                     $this->writeChunk($output, $diff, $start, $commonStart, $fromStart, $fromRange, $toStart, $toRange);
Chris@14: 
Chris@14:                     $fromStart += $fromRange;
Chris@14:                     $toStart += $toRange;
Chris@14:                 }
Chris@14: 
Chris@14:                 $start        = $commonEnd + 1;
Chris@14:                 $commonLength = $commonEnd - $commonStart + 1; // calculate number of non-change lines in the common part
Chris@14:                 $fromStart += $commonLength;
Chris@14:                 $toStart += $commonLength;
Chris@14:             } while (false !== \next($old));
Chris@14: 
Chris@14:             \end($old); // short cut for finding possible last `change entry`
Chris@14:             $tmp = \key($old);
Chris@14:             \reset($old);
Chris@14:             if ($old[$tmp] === $upperLimit - 1) {
Chris@14:                 $upperLimit = $tmp;
Chris@14:             }
Chris@14:         }
Chris@14: 
Chris@14:         if ($start < $upperLimit - 1) { // check for trailing (non) diff entries
Chris@14:             do {
Chris@14:                 --$upperLimit;
Chris@14:             } while (isset($diff[$upperLimit][1]) && $diff[$upperLimit][1] === 0);
Chris@14:             ++$upperLimit;
Chris@14: 
Chris@14:             list($fromRange, $toRange) = $this->getChunkRange($diff, $start, $upperLimit);
Chris@14:             $this->writeChunk($output, $diff, $start, $upperLimit, $fromStart, $fromRange, $toStart, $toRange);
Chris@14:         }
Chris@14:     }
Chris@14: 
Chris@14:     private function writeChunk(
Chris@14:         $output,
Chris@14:         array $diff,
Chris@14:         int $diffStartIndex,
Chris@14:         int $diffEndIndex,
Chris@14:         int $fromStart,
Chris@14:         int $fromRange,
Chris@14:         int $toStart,
Chris@14:         int $toRange
Chris@14:     ) {
Chris@14:         if ($this->addLineNumbers) {
Chris@14:             \fwrite($output, '@@ -' . (1 + $fromStart));
Chris@14: 
Chris@14:             if ($fromRange > 1) {
Chris@14:                 \fwrite($output, ',' . $fromRange);
Chris@14:             }
Chris@14: 
Chris@14:             \fwrite($output, ' +' . (1 + $toStart));
Chris@14:             if ($toRange > 1) {
Chris@14:                 \fwrite($output, ',' . $toRange);
Chris@14:             }
Chris@14: 
Chris@14:             \fwrite($output, " @@\n");
Chris@14:         } else {
Chris@14:             \fwrite($output, "@@ @@\n");
Chris@14:         }
Chris@14: 
Chris@14:         for ($i = $diffStartIndex; $i < $diffEndIndex; ++$i) {
Chris@14:             if ($diff[$i][1] === 1 /* ADDED */) {
Chris@14:                 \fwrite($output, '+' . $diff[$i][0]);
Chris@14:             } elseif ($diff[$i][1] === 2 /* REMOVED */) {
Chris@14:                 \fwrite($output, '-' . $diff[$i][0]);
Chris@14:             } else { /* Not changed (old) 0 or Warning 3 */
Chris@14:                 \fwrite($output, ' ' . $diff[$i][0]);
Chris@14:             }
Chris@14: 
Chris@14:             $lc = \substr($diff[$i][0], -1);
Chris@14:             if ($lc !== "\n" && $lc !== "\r") {
Chris@14:                 \fwrite($output, "\n"); // \No newline at end of file
Chris@14:             }
Chris@14:         }
Chris@14:     }
Chris@14: 
Chris@14:     private function getChunkRange(array $diff, int $diffStartIndex, int $diffEndIndex): array
Chris@14:     {
Chris@14:         $toRange   = 0;
Chris@14:         $fromRange = 0;
Chris@14: 
Chris@14:         for ($i = $diffStartIndex; $i < $diffEndIndex; ++$i) {
Chris@14:             if ($diff[$i][1] === 1) { // added
Chris@14:                 ++$toRange;
Chris@14:             } elseif ($diff[$i][1] === 2) { // removed
Chris@14:                 ++$fromRange;
Chris@14:             } elseif ($diff[$i][1] === 0) { // same
Chris@14:                 ++$fromRange;
Chris@14:                 ++$toRange;
Chris@14:             }
Chris@14:         }
Chris@14: 
Chris@14:         return [$fromRange, $toRange];
Chris@14:     }
Chris@14: }