<?php declare(strict_types=1);
/*
 * 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 DatePeriod;
use EmptyIterator;
use Iterator;
use IteratorAggregate;
use PHPUnit\Framework\ExpectationFailedException;
use PHPUnit\Framework\TestFailure;
use PHPUnit\TestFixture\TestGeneratorMaker;
use PHPUnit\TestFixture\TestIterator;
use PHPUnit\TestFixture\TestIterator2;
use PHPUnit\TestFixture\TestIteratorAggregate;
use PHPUnit\TestFixture\TestIteratorAggregate2;
use Traversable;

/**
 * @small
 */
final class CountTest extends ConstraintTestCase
{
    public function testCount(): void
    {
        $countConstraint = new Count(3);
        $this->assertTrue($countConstraint->evaluate([1, 2, 3], '', true));

        $countConstraint = new Count(0);
        $this->assertTrue($countConstraint->evaluate([], '', true));

        $countConstraint = new Count(2);
        $it              = new TestIterator([1, 2]);
        $ia              = new TestIteratorAggregate($it);
        $ia2             = new TestIteratorAggregate2($ia);

        $this->assertTrue($countConstraint->evaluate($it, '', true));
        $this->assertTrue($countConstraint->evaluate($ia, '', true));
        $this->assertTrue($countConstraint->evaluate($ia2, '', true));
    }

    public function testCountDoesNotChangeIteratorKey(): void
    {
        $countConstraint = new Count(2);

        // test with 1st implementation of Iterator
        $it = new TestIterator([1, 2]);

        $countConstraint->evaluate($it, '', true);
        $this->assertEquals(1, $it->current());

        $it->next();
        $countConstraint->evaluate($it, '', true);
        $this->assertEquals(2, $it->current());

        $it->next();
        $countConstraint->evaluate($it, '', true);
        $this->assertFalse($it->valid());

        // test with 2nd implementation of Iterator
        $it = new TestIterator2([1, 2]);

        $countConstraint = new Count(2);
        $countConstraint->evaluate($it, '', true);
        $this->assertEquals(1, $it->current());

        $it->next();
        $countConstraint->evaluate($it, '', true);
        $this->assertEquals(2, $it->current());

        $it->next();
        $countConstraint->evaluate($it, '', true);
        $this->assertFalse($it->valid());

        // test with IteratorAggregate
        $it = new TestIterator([1, 2]);
        $ia = new TestIteratorAggregate($it);

        $countConstraint = new Count(2);
        $countConstraint->evaluate($ia, '', true);
        $this->assertEquals(1, $it->current());

        $it->next();
        $countConstraint->evaluate($ia, '', true);
        $this->assertEquals(2, $it->current());

        $it->next();
        $countConstraint->evaluate($ia, '', true);
        $this->assertFalse($it->valid());

        // test with nested IteratorAggregate
        $it  = new TestIterator([1, 2]);
        $ia  = new TestIteratorAggregate($it);
        $ia2 = new TestIteratorAggregate2($ia);

        $countConstraint = new Count(2);
        $countConstraint->evaluate($ia2, '', true);
        $this->assertEquals(1, $it->current());

        $it->next();
        $countConstraint->evaluate($ia2, '', true);
        $this->assertEquals(2, $it->current());

        $it->next();
        $countConstraint->evaluate($ia2, '', true);
        $this->assertFalse($it->valid());
    }

    public function testCountGeneratorsDoNotRewind(): void
    {
        $generatorMaker = new TestGeneratorMaker;

        $countConstraint = new Count(3);

        $generator = $generatorMaker->create([1, 2, 3]);
        $this->assertEquals(1, $generator->current());
        $countConstraint->evaluate($generator, '', true);
        $this->assertEquals(null, $generator->current());

        $countConstraint = new Count(2);

        $generator = $generatorMaker->create([1, 2, 3]);
        $this->assertEquals(1, $generator->current());
        $generator->next();
        $this->assertEquals(2, $generator->current());
        $countConstraint->evaluate($generator, '', true);
        $this->assertEquals(null, $generator->current());

        $countConstraint = new Count(1);

        $generator = $generatorMaker->create([1, 2, 3]);
        $this->assertEquals(1, $generator->current());
        $generator->next();
        $this->assertEquals(2, $generator->current());
        $generator->next();
        $this->assertEquals(3, $generator->current());
        $countConstraint->evaluate($generator, '', true);
        $this->assertEquals(null, $generator->current());
    }

    /**
     * Since PHP8, Traversable cannot be implemented directly.
     *
     * @requires PHP < 8.0
     */
    public function testCountTraversable(): void
    {
        $countConstraint = new Count(5);

        // DatePeriod is used as an object that is Traversable but does not
        // implement Iterator or IteratorAggregate. The following ISO 8601
        // recurring time interval will yield five total DateTime objects.
        $datePeriod = new DatePeriod('R4/2017-05-01T00:00:00Z/P1D');

        $this->assertInstanceOf(Traversable::class, $datePeriod);
        $this->assertNotInstanceOf(Iterator::class, $datePeriod);
        $this->assertNotInstanceOf(IteratorAggregate::class, $datePeriod);
        $this->assertTrue($countConstraint->evaluate($datePeriod, '', true));
    }

    public function testCountCanBeExportedToString(): void
    {
        $countConstraint = new Count(1);

        $this->assertEquals('count matches 1', $countConstraint->toString());
    }

    public function testCountEvaluateReturnsNullWithNonCountableAndNonTraversableOther(): void
    {
        $countConstraint = new Count(1);

        try {
            $this->assertNull($countConstraint->evaluate(1));
        } catch (ExpectationFailedException  $e) {
            $this->assertEquals(
                <<<'EOF'
Failed asserting that actual size 0 matches expected size 1.

EOF
                ,
                TestFailure::exceptionToString($e)
            );
        }
    }

    /**
     * @ticket https://github.com/sebastianbergmann/phpunit/issues/3743
     */
    public function test_EmptyIterator_is_handled_correctly(): void
    {
        $constraint = new Count(0);

        $this->assertTrue($constraint->evaluate(new EmptyIterator, '', true));
    }
}
