<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Mime\Tests\Encoder;

use PHPUnit\Framework\TestCase;
use Symfony\Component\Mime\Encoder\QpMimeHeaderEncoder;

class QpMimeHeaderEncoderTest extends TestCase
{
    public function testNameIsQ()
    {
        $encoder = new QpMimeHeaderEncoder();
        $this->assertEquals('Q', $encoder->getName());
    }

    public function testSpaceAndTabNeverAppear()
    {
        /* -- RFC 2047, 4.
         Only a subset of the printable ASCII characters may be used in
        'encoded-text'.  Space and tab characters are not allowed, so that
        the beginning and end of an 'encoded-word' are obvious.
        */

        $encoder = new QpMimeHeaderEncoder();
        $this->assertNotRegExp('~[ \t]~', $encoder->encodeString("a \t b"), 'encoded-words in headers cannot contain LWSP as per RFC 2047.');
    }

    public function testSpaceIsRepresentedByUnderscore()
    {
        /* -- RFC 2047, 4.2.
        (2) The 8-bit hexadecimal value 20 (e.g., ISO-8859-1 SPACE) may be
        represented as "_" (underscore, ASCII 95.).  (This character may
        not pass through some internetwork mail gateways, but its use
        will greatly enhance readability of "Q" encoded data with mail
        readers that do not support this encoding.)  Note that the "_"
        always represents hexadecimal 20, even if the SPACE character
        occupies a different code position in the character set in use.
        */
        $encoder = new QpMimeHeaderEncoder();
        $this->assertEquals('a_b', $encoder->encodeString('a b'), 'Spaces can be represented by more readable underscores as per RFC 2047.');
    }

    public function testEqualsAndQuestionAndUnderscoreAreEncoded()
    {
        /* -- RFC 2047, 4.2.
        (3) 8-bit values which correspond to printable ASCII characters other
        than "=", "?", and "_" (underscore), MAY be represented as those
        characters.  (But see section 5 for restrictions.)  In
        particular, SPACE and TAB MUST NOT be represented as themselves
        within encoded words.
        */
        $encoder = new QpMimeHeaderEncoder();
        $this->assertEquals('=3D=3F=5F', $encoder->encodeString('=?_'), 'Chars =, ? and _ (underscore) may not appear as per RFC 2047.');
    }

    public function testParensAndQuotesAreEncoded()
    {
        /* -- RFC 2047, 5 (2).
         A "Q"-encoded 'encoded-word' which appears in a 'comment' MUST NOT
        contain the characters "(", ")" or "
        */

        $encoder = new QpMimeHeaderEncoder();
        $this->assertEquals('=28=22=29', $encoder->encodeString('(")'), 'Chars (, " (DQUOTE) and ) may not appear as per RFC 2047.');
    }

    public function testOnlyCharactersAllowedInPhrasesAreUsed()
    {
        /* -- RFC 2047, 5.
        (3) As a replacement for a 'word' entity within a 'phrase', for example,
        one that precedes an address in a From, To, or Cc header.  The ABNF
        definition for 'phrase' from RFC 822 thus becomes:

        phrase = 1*( encoded-word / word )

        In this case the set of characters that may be used in a "Q"-encoded
        'encoded-word' is restricted to: <upper and lower case ASCII
        letters, decimal digits, "!", "*", "+", "-", "/", "=", and "_"
        (underscore, ASCII 95.)>.  An 'encoded-word' that appears within a
        'phrase' MUST be separated from any adjacent 'word', 'text' or
        'special' by 'linear-white-space'.
        */

        $allowedBytes = array_merge(
            range(\ord('a'), \ord('z')), range(\ord('A'), \ord('Z')),
            range(\ord('0'), \ord('9')),
            [\ord('!'), \ord('*'), \ord('+'), \ord('-'), \ord('/')]
        );
        $encoder = new QpMimeHeaderEncoder();
        foreach (range(0x00, 0xFF) as $byte) {
            $char = pack('C', $byte);
            $encodedChar = $encoder->encodeString($char, 'iso-8859-1');
            if (\in_array($byte, $allowedBytes)) {
                $this->assertEquals($char, $encodedChar, 'Character '.$char.' should not be encoded.');
            } elseif (0x20 == $byte) {
                // special case
                $this->assertEquals('_', $encodedChar, 'Space character should be replaced.');
            } else {
                $this->assertEquals(sprintf('=%02X', $byte), $encodedChar, 'Byte '.$byte.' should be encoded.');
            }
        }
    }

    public function testEqualsNeverAppearsAtEndOfLine()
    {
        /* -- RFC 2047, 5 (3).
        The 'encoded-text' in an 'encoded-word' must be self-contained;
        'encoded-text' MUST NOT be continued from one 'encoded-word' to
        another.  This implies that the 'encoded-text' portion of a "B"
        'encoded-word' will be a multiple of 4 characters long; for a "Q"
        'encoded-word', any "=" character that appears in the 'encoded-text'
        portion will be followed by two hexadecimal characters.
        */

        $input = str_repeat('a', 140);

        $output = '';
        $seq = 0;
        for (; $seq < 140; ++$seq) {
            // compute the end of line (multiple of 4 chars)
            if (18 * 4 === $seq) {
                $output .= "\r\n"; // =\r\n
            }
            $output .= 'a';
        }

        $encoder = new QpMimeHeaderEncoder();
        $this->assertEquals($output, $encoder->encodeString($input));
    }
}