<?php

declare(strict_types=1);

namespace GuzzleHttp\Psr7;

use Psr\Http\Message\StreamInterface;

/**
 * Provides a read only stream that pumps data from a PHP callable.
 *
 * When invoking the provided callable, the PumpStream will pass the amount of
 * data requested to read to the callable. The callable can choose to ignore
 * this value and return fewer or more bytes than requested. Any extra data
 * returned by the provided callable is buffered internally until drained using
 * the read() function of the PumpStream. The provided callable MUST return
 * false when there is no more data to read.
 */
final class PumpStream implements StreamInterface
{
    /** @var callable(int): (string|false|null)|null */
    private $source;

    /** @var int|null */
    private $size;

    /** @var int */
    private $tellPos = 0;

    /** @var array */
    private $metadata;

    /** @var BufferStream */
    private $buffer;

    /**
     * @param callable(int): (string|false|null)  $source  Source of the stream data. The callable MAY
     *                                                     accept an integer argument used to control the
     *                                                     amount of data to return. The callable MUST
     *                                                     return a string when called, or false|null on error
     *                                                     or EOF.
     * @param array{size?: int, metadata?: array} $options Stream options:
     *                                                     - metadata: Hash of metadata to use with stream.
     *                                                     - size: Size of the stream, if known.
     */
    public function __construct(callable $source, array $options = [])
    {
        $this->source = $source;
        $this->size = $options['size'] ?? null;
        $this->metadata = $options['metadata'] ?? [];
        $this->buffer = new BufferStream();
    }

    public function __toString(): string
    {
        try {
            return Utils::copyToString($this);
        } catch (\Throwable $e) {
            if (\PHP_VERSION_ID >= 70400) {
                throw $e;
            }
            trigger_error(sprintf('%s::__toString exception: %s', self::class, (string) $e), E_USER_ERROR);

            return '';
        }
    }

    public function close(): void
    {
        $this->detach();
    }

    public function detach()
    {
        $this->tellPos = 0;
        $this->source = null;

        return null;
    }

    public function getSize(): ?int
    {
        return $this->size;
    }

    public function tell(): int
    {
        return $this->tellPos;
    }

    public function eof(): bool
    {
        return $this->source === null;
    }

    public function isSeekable(): bool
    {
        return false;
    }

    public function rewind(): void
    {
        $this->seek(0);
    }

    public function seek($offset, $whence = SEEK_SET): void
    {
        throw new \RuntimeException('Cannot seek a PumpStream');
    }

    public function isWritable(): bool
    {
        return false;
    }

    public function write($string): int
    {
        throw new \RuntimeException('Cannot write to a PumpStream');
    }

    public function isReadable(): bool
    {
        return true;
    }

    public function read($length): string
    {
        $data = $this->buffer->read($length);
        $readLen = strlen($data);
        $this->tellPos += $readLen;
        $remaining = $length - $readLen;

        if ($remaining) {
            $this->pump($remaining);
            $data .= $this->buffer->read($remaining);
            $this->tellPos += strlen($data) - $readLen;
        }

        return $data;
    }

    public function getContents(): string
    {
        $result = '';
        while (!$this->eof()) {
            $result .= $this->read(1000000);
        }

        return $result;
    }

    /**
     * @return mixed
     */
    public function getMetadata($key = null)
    {
        if (!$key) {
            return $this->metadata;
        }

        return $this->metadata[$key] ?? null;
    }

    private function pump(int $length): void
    {
        if ($this->source !== null) {
            do {
                $data = ($this->source)($length);
                if ($data === false || $data === null) {
                    $this->source = null;

                    return;
                }
                $this->buffer->write($data);
                $length -= strlen($data);
            } while ($length > 0);
        }
    }
}

• [D] Exception
• [F] AppendStream.php
  Delete
• [F] BufferStream.php
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• [F] CachingStream.php
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• [F] DroppingStream.php
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• [F] FnStream.php
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• [F] Header.php
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• [F] HttpFactory.php
  Delete
• [F] InflateStream.php
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• [F] LazyOpenStream.php
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• [F] LimitStream.php
  Delete
• [F] Message.php
  Delete
• [F] MessageTrait.php
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• [F] MimeType.php
  Delete
• [F] MultipartStream.php
  Delete
• [F] NoSeekStream.php
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• [F] PumpStream.php
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• [F] Query.php
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• [F] Request.php
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• [F] Response.php
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• [F] Rfc7230.php
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• [F] ServerRequest.php
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• [F] Stream.php
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• [F] StreamDecoratorTrait.php
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• [F] StreamWrapper.php
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• [F] UploadedFile.php
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• [F] Uri.php
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• [F] UriComparator.php
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• [F] UriNormalizer.php
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• [F] UriResolver.php
  Delete
• [F] Utils.php
  Delete

About Section

About NFC Pay: Our Story and Mission

NFC Pay was founded with a vision to transform the way people handle transactions. Our journey is defined by a commitment to innovation, security, and convenience. We strive to deliver seamless, user-friendly payment solutions that make everyday transactions effortless and secure. Our mission is to empower you to pay with ease and confidence, anytime, anywhere.

• Simplifying Payments, One Tap at a Time.
• Reinventing Your Wallet for Modern Convenience.
• Smart Payments for a Effortless Lifestyle.
• Experience the Ease of Tap and Pay.
• Innovative Solutions for Your Daily Transactions.

FAQ Section

Frequently Asked Questions About NFC Pay

Here are answers to some common questions about NFC Pay. We aim to provide clear and concise information to help you understand how our platform works and how it can benefit you. If you have any further inquiries, please don’t hesitate to contact our support team.

How do I register for NFC Pay?

Download the app and sign up using your email or phone number, then complete the verification process.

Is my payment information secure?

Yes, we use advanced encryption and security protocols to protect your payment details.

Can I add multiple cards to my NFC Pay wallet?

Absolutely, you can link multiple debit or credit cards to your wallet.

How do I transfer money to another user?

Go to the transfer section, select the recipient, enter the amount, and authorize the transfer.

What should I do if I forget my PIN?

Use the “Forgot PIN” feature in the app to reset it following the provided instructions.

How can I activate my merchant account?

Sign up for a merchant account through the app and follow the setup instructions to start accepting payments.

Can I track my payment status?

Yes, you can view and track your payment status in the account dashboard