<?php

/**
 * Class Kanji
 *
 * @created      25.11.2015
 * @author       Smiley <smiley@chillerlan.net>
 * @copyright    2015 Smiley
 * @license      MIT
 */
namespace WCPOS\Vendor\chillerlan\QRCode\Data;

use WCPOS\Vendor\chillerlan\QRCode\Common\BitBuffer;
use WCPOS\Vendor\chillerlan\QRCode\Common\Mode;
use Throwable;
use function chr, implode, intdiv, is_string, mb_convert_encoding, mb_detect_encoding, mb_internal_encoding, mb_strlen, ord, sprintf, strlen;
/**
 * Kanji mode: 13-bit double-byte characters from the Shift-JIS character set
 *
 * ISO/IEC 18004:2000 Section 8.3.5
 * ISO/IEC 18004:2000 Section 8.4.5
 *
 * @see https://en.wikipedia.org/wiki/Shift_JIS#As_defined_in_JIS_X_0208:1997
 * @see http://www.rikai.com/library/kanjitables/kanji_codes.sjis.shtml
 * @see https://gist.github.com/codemasher/d07d3e6e9346c08e7a41b8b978784952
 */
final class Kanji extends QRDataModeAbstract
{
    /**
     * possible values: SJIS, SJIS-2004
     *
     * SJIS-2004 may produce errors in PHP < 8
     *
     * @var string
     */
    public const ENCODING = 'SJIS';
    /**
     * @inheritDoc
     */
    public const DATAMODE = Mode::KANJI;
    /**
     * @inheritDoc
     */
    protected function getCharCount() : int
    {
        return mb_strlen($this->data, self::ENCODING);
    }
    /**
     * @inheritDoc
     */
    public function getLengthInBits() : int
    {
        return $this->getCharCount() * 13;
    }
    /**
     * @inheritDoc
     * @throws \chillerlan\QRCode\Data\QRCodeDataException
     */
    public static function convertEncoding(string $string) : string
    {
        $detected = mb_detect_encoding($string, [mb_internal_encoding(), 'UTF-8', 'SJIS', 'SJIS-2004'], \true);
        if ($detected === \false) {
            throw new QRCodeDataException('mb_detect_encoding error');
        }
        if ($detected === self::ENCODING) {
            return $string;
        }
        $string = mb_convert_encoding($string, self::ENCODING, $detected);
        if (!is_string($string)) {
            throw new QRCodeDataException(sprintf('invalid encoding: %s', $detected));
        }
        return $string;
    }
    /**
     * checks if a string qualifies as SJIS Kanji
     */
    public static function validateString(string $string) : bool
    {
        try {
            $string = self::convertEncoding($string);
        } catch (Throwable $e) {
            return \false;
        }
        $len = strlen($string);
        if ($len < 2 || $len % 2 !== 0) {
            return \false;
        }
        for ($i = 0; $i < $len; $i += 2) {
            $byte1 = ord($string[$i]);
            $byte2 = ord($string[$i + 1]);
            // byte 1 unused and vendor ranges
            if ($byte1 < 0x81 || $byte1 > 0x84 && $byte1 < 0x88 || $byte1 > 0x9f && $byte1 < 0xe0 || $byte1 > 0xea) {
                return \false;
            }
            // byte 2 unused ranges
            if ($byte2 < 0x40 || $byte2 === 0x7f || $byte2 > 0xfc) {
                return \false;
            }
        }
        return \true;
    }
    /**
     * @inheritDoc
     *
     * @throws \chillerlan\QRCode\Data\QRCodeDataException on an illegal character occurence
     */
    public function write(BitBuffer $bitBuffer, int $versionNumber) : QRDataModeInterface
    {
        $bitBuffer->put(self::DATAMODE, 4)->put($this->getCharCount(), $this::getLengthBits($versionNumber));
        $len = strlen($this->data);
        for ($i = 0; $i + 1 < $len; $i += 2) {
            $c = (0xff & ord($this->data[$i])) << 8 | 0xff & ord($this->data[$i + 1]);
            if ($c >= 0x8140 && $c <= 0x9ffc) {
                $c -= 0x8140;
            } elseif ($c >= 0xe040 && $c <= 0xebbf) {
                $c -= 0xc140;
            } else {
                throw new QRCodeDataException(sprintf('illegal char at %d [%d]', $i + 1, $c));
            }
            $bitBuffer->put(($c >> 8 & 0xff) * 0xc0 + ($c & 0xff), 13);
        }
        if ($i < $len) {
            throw new QRCodeDataException(sprintf('illegal char at %d', $i + 1));
        }
        return $this;
    }
    /**
     * @inheritDoc
     *
     * @throws \chillerlan\QRCode\Data\QRCodeDataException
     */
    public static function decodeSegment(BitBuffer $bitBuffer, int $versionNumber) : string
    {
        $length = $bitBuffer->read(self::getLengthBits($versionNumber));
        if ($bitBuffer->available() < $length * 13) {
            throw new QRCodeDataException('not enough bits available');
            // @codeCoverageIgnore
        }
        // Each character will require 2 bytes. Read the characters as 2-byte pairs and decode as SJIS afterwards
        $buffer = [];
        $offset = 0;
        while ($length > 0) {
            // Each 13 bits encodes a 2-byte character
            $twoBytes = $bitBuffer->read(13);
            $assembledTwoBytes = intdiv($twoBytes, 0xc0) << 8 | $twoBytes % 0xc0;
            $assembledTwoBytes += $assembledTwoBytes < 0x1f00 ? 0x8140 : 0xc140;
            // In the 0xE040 to 0xEBBF range
            $buffer[$offset] = chr(0xff & $assembledTwoBytes >> 8);
            $buffer[$offset + 1] = chr(0xff & $assembledTwoBytes);
            $offset += 2;
            $length--;
        }
        return mb_convert_encoding(implode('', $buffer), mb_internal_encoding(), self::ENCODING);
    }
}