<?php
/*
* This file is part of PHPUnit.
*
* (c) Sebastian Bergmann <sebastian@phpunit.de>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace PHPUnit\Framework\Constraint;

use Countable;
use Generator;
use Iterator;
use IteratorAggregate;
use Traversable;

class Count extends Constraint
{
/**
* @var int
*/
protected $expectedCount = 0;

/**
* @param int $expected
*/
public function __construct($expected)
{
parent::__construct();
$this->expectedCount = $expected;
}

/**
* Evaluates the constraint for parameter $other. Returns true if the
* constraint is met, false otherwise.
*
* @param mixed $other
*
* @return bool
*/
protected function matches($other)
{
return $this->expectedCount === $this->getCountOf($other);
}

/**
* @param \Countable|\Traversable|array $other
*
* @return int|null
*/
protected function getCountOf($other)
{
if ($other instanceof Countable || \is_array($other)) {
return \count($other);
}

if ($other instanceof Traversable) {
while ($other instanceof IteratorAggregate) {
$other = $other->getIterator();
}

$iterator = $other;

if ($iterator instanceof Generator) {
return $this->getCountOfGenerator($iterator);
}

if (!$iterator instanceof Iterator) {
return \iterator_count($iterator);
}

$key = $iterator->key();
$count = \iterator_count($iterator);

// Manually rewind $iterator to previous key, since iterator_count
// moves pointer.
if ($key !== null) {
$iterator->rewind();
while ($iterator->valid() && $key !== $iterator->key()) {
$iterator->next();
}
}

return $count;
}
}

/**
* Returns the total number of iterations from a generator.
* This will fully exhaust the generator.
*
* @param Generator $generator
*
* @return int
*/
protected function getCountOfGenerator(Generator $generator)
{
for ($count = 0; $generator->valid(); $generator->next()) {
++$count;
}

return $count;
}

/**
* Returns the description of the failure.
*
* The beginning of failure messages is "Failed asserting that" in most
* cases. This method should return the second part of that sentence.
*
* @param mixed $other Evaluated value or object.
*
* @return string
*/
protected function failureDescription($other)
{
return \sprintf(
'actual size %d matches expected size %d',
$this->getCountOf($other),
$this->expectedCount
);
}

/**
* @return string
*/
public function toString()
{
return \sprintf(
'count matches %d',
$this->expectedCount
);
}
}