<?php

namespace Amp\Test;

use Amp;
use Amp\Failure;
use Amp\Pause;
use Amp\Success;
use Amp\Loop;

class StreamTest extends \PHPUnit_Framework_TestCase {
    public function testSuccessfulPromises() {
        $results = [];
        Loop::run(function () use (&$results) {
            $stream = Amp\stream([new Success(1), new Success(2), new Success(3)]);

            $stream->listen(function ($value) use (&$results) {
                $results[] = $value;
            });
        });

        $this->assertSame([1, 2, 3], $results);
    }

    public function testFailedPromises() {
        $exception = new \Exception;
        Loop::run(function () use (&$reason, $exception) {
            $stream = Amp\stream([new Failure($exception), new Failure($exception)]);

            $callback = function ($exception, $value) use (&$reason) {
                $reason = $exception;
            };

            $stream->when($callback);
        });

        $this->assertSame($exception, $reason);
    }

    public function testMixedPromises() {
        $exception = new \Exception;
        $results = [];
        Loop::run(function () use (&$results, &$reason, $exception) {
            $stream = Amp\stream([new Success(1), new Success(2), new Failure($exception), new Success(4)]);

            $stream->listen(function ($value) use (&$results) {
                $results[] = $value;
            });

            $callback = function ($exception, $value) use (&$reason) {
                $reason = $exception;
            };

            $stream->when($callback);
        });

        $this->assertSame(\range(1, 2), $results);
        $this->assertSame($exception, $reason);
    }

    public function testPendingPromises() {
        $results = [];
        Loop::run(function () use (&$results) {
            $stream = Amp\stream([new Pause(30, 1), new Pause(10, 2), new Pause(20, 3), new Success(4)]);

            $stream->listen(function ($value) use (&$results) {
                $results[] = $value;
            });
        });

        $this->assertSame(\range(1, 4), $results);
    }

    public function testTraversable() {
        $results = [];
        Loop::run(function () use (&$results) {
            $generator = (function () {
                foreach (\range(1, 4) as $value) {
                    yield $value;
                }
            })();

            $stream = Amp\stream($generator);

            $stream->listen(function ($value) use (&$results) {
                $results[] = $value;
            });
        });

        $this->assertSame(\range(1, 4), $results);
    }

    /**
     * @expectedException \TypeError
     * @expectedExceptionMessage Must provide an array or instance of Traversable
     * @dataProvider provideInvalidStreamArguments
     */
    public function testInvalid($arg) {
        Amp\stream($arg);
    }

    public function provideInvalidStreamArguments() {
        return [
            [null],
            [new \stdClass],
            [32],
            [false],
            [true],
            ["string"],
        ];
    }
}