<?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\String;

use Symfony\Component\String\Exception\ExceptionInterface;
use Symfony\Component\String\Exception\InvalidArgumentException;
use Symfony\Component\String\Exception\RuntimeException;

/**
 * Represents a binary-safe string of bytes.
 *
 * @author Nicolas Grekas <p@tchwork.com>
 * @author Hugo Hamon <hugohamon@neuf.fr>
 *
 * @throws ExceptionInterface
 */
class ByteString extends AbstractString
{
    private const ALPHABET_ALPHANUMERIC = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';

    public function __construct(string $string = '')
    {
        $this->string = $string;
    }

    /*
     * The following method was derived from code of the Hack Standard Library (v4.40 - 2020-05-03)
     *
     * https://github.com/hhvm/hsl/blob/80a42c02f036f72a42f0415e80d6b847f4bf62d5/src/random/private.php#L16
     *
     * Code subject to the MIT license (https://github.com/hhvm/hsl/blob/master/LICENSE).
     *
     * Copyright (c) 2004-2020, Facebook, Inc. (https://www.facebook.com/)
     */

    public static function fromRandom(int $length = 16, string $alphabet = null): self
    {
        if ($length <= 0) {
            throw new InvalidArgumentException(sprintf('A strictly positive length is expected, "%d" given.', $length));
        }

        $alphabet = $alphabet ?? self::ALPHABET_ALPHANUMERIC;
        $alphabetSize = \strlen($alphabet);
        $bits = (int) ceil(log($alphabetSize, 2.0));
        if ($bits <= 0 || $bits > 56) {
            throw new InvalidArgumentException('The length of the alphabet must in the [2^1, 2^56] range.');
        }

        $ret = '';
        while ($length > 0) {
            $urandomLength = (int) ceil(2 * $length * $bits / 8.0);
            $data = random_bytes($urandomLength);
            $unpackedData = 0;
            $unpackedBits = 0;
            for ($i = 0; $i < $urandomLength && $length > 0; ++$i) {
                // Unpack 8 bits
                $unpackedData = ($unpackedData << 8) | \ord($data[$i]);
                $unpackedBits += 8;

                // While we have enough bits to select a character from the alphabet, keep
                // consuming the random data
                for (; $unpackedBits >= $bits && $length > 0; $unpackedBits -= $bits) {
                    $index = ($unpackedData & ((1 << $bits) - 1));
                    $unpackedData >>= $bits;
                    // Unfortunately, the alphabet size is not necessarily a power of two.
                    // Worst case, it is 2^k + 1, which means we need (k+1) bits and we
                    // have around a 50% chance of missing as k gets larger
                    if ($index < $alphabetSize) {
                        $ret .= $alphabet[$index];
                        --$length;
                    }
                }
            }
        }

        return new static($ret);
    }

    public function bytesAt(int $offset): array
    {
        $str = $this->string[$offset] ?? '';

        return '' === $str ? [] : [\ord($str)];
    }

    public function append(string ...$suffix): static
    {
        $str = clone $this;
        $str->string .= 1 >= \count($suffix) ? ($suffix[0] ?? '') : implode('', $suffix);

        return $str;
    }

    public function camel(): static
    {
        $str = clone $this;
        $str->string = lcfirst(str_replace(' ', '', ucwords(preg_replace('/[^a-zA-Z0-9\x7f-\xff]++/', ' ', $this->string))));

        return $str;
    }

    public function chunk(int $length = 1): array
    {
        if (1 > $length) {
            throw new InvalidArgumentException('The chunk length must be greater than zero.');
        }

        if ('' === $this->string) {
            return [];
        }

        $str = clone $this;
        $chunks = [];

        foreach (str_split($this->string, $length) as $chunk) {
            $str->string = $chunk;
            $chunks[] = clone $str;
        }

        return $chunks;
    }

    public function endsWith(string|iterable|AbstractString $suffix): bool
    {
        if ($suffix instanceof AbstractString) {
            $suffix = $suffix->string;
        } elseif (!\is_string($suffix)) {
            return parent::endsWith($suffix);
        }

        return '' !== $suffix && \strlen($this->string) >= \strlen($suffix) && 0 === substr_compare($this->string, $suffix, -\strlen($suffix), null, $this->ignoreCase);
    }

    public function equalsTo(string|iterable|AbstractString $string): bool
    {
        if ($string instanceof AbstractString) {
            $string = $string->string;
        } elseif (!\is_string($string)) {
            return parent::equalsTo($string);
        }

        if ('' !== $string && $this->ignoreCase) {
            return 0 === strcasecmp($string, $this->string);
        }

        return $string === $this->string;
    }

    public function folded(): static
    {
        $str = clone $this;
        $str->string = strtolower($str->string);

        return $str;
    }

    public function indexOf(string|iterable|AbstractString $needle, int $offset = 0): ?int
    {
        if ($needle instanceof AbstractString) {
            $needle = $needle->string;
        } elseif (!\is_string($needle)) {
            return parent::indexOf($needle, $offset);
        }

        if ('' === $needle) {
            return null;
        }

        $i = $this->ignoreCase ? stripos($this->string, $needle, $offset) : strpos($this->string, $needle, $offset);

        return false === $i ? null : $i;
    }

    public function indexOfLast(string|iterable|AbstractString $needle, int $offset = 0): ?int
    {
        if ($needle instanceof AbstractString) {
            $needle = $needle->string;
        } elseif (!\is_string($needle)) {
            return parent::indexOfLast($needle, $offset);
        }

        if ('' === $needle) {
            return null;
        }

        $i = $this->ignoreCase ? strripos($this->string, $needle, $offset) : strrpos($this->string, $needle, $offset);

        return false === $i ? null : $i;
    }

    public function isUtf8(): bool
    {
        return '' === $this->string || preg_match('//u', $this->string);
    }

    public function join(array $strings, string $lastGlue = null): static
    {
        $str = clone $this;

        $tail = null !== $lastGlue && 1 < \count($strings) ? $lastGlue.array_pop($strings) : '';
        $str->string = implode($this->string, $strings).$tail;

        return $str;
    }

    public function length(): int
    {
        return \strlen($this->string);
    }

    public function lower(): static
    {
        $str = clone $this;
        $str->string = strtolower($str->string);

        return $str;
    }

    public function match(string $regexp, int $flags = 0, int $offset = 0): array
    {
        $match = ((\PREG_PATTERN_ORDER | \PREG_SET_ORDER) & $flags) ? 'preg_match_all' : 'preg_match';

        if ($this->ignoreCase) {
            $regexp .= 'i';
        }

        set_error_handler(static function ($t, $m) { throw new InvalidArgumentException($m); });

        try {
            if (false === $match($regexp, $this->string, $matches, $flags | \PREG_UNMATCHED_AS_NULL, $offset)) {
                $lastError = preg_last_error();

                foreach (get_defined_constants(true)['pcre'] as $k => $v) {
                    if ($lastError === $v && '_ERROR' === substr($k, -6)) {
                        throw new RuntimeException('Matching failed with '.$k.'.');
                    }
                }

                throw new RuntimeException('Matching failed with unknown error code.');
            }
        } finally {
            restore_error_handler();
        }

        return $matches;
    }

    public function padBoth(int $length, string $padStr = ' '): static
    {
        $str = clone $this;
        $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_BOTH);

        return $str;
    }

    public function padEnd(int $length, string $padStr = ' '): static
    {
        $str = clone $this;
        $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_RIGHT);

        return $str;
    }

    public function padStart(int $length, string $padStr = ' '): static
    {
        $str = clone $this;
        $str->string = str_pad($this->string, $length, $padStr, \STR_PAD_LEFT);

        return $str;
    }

    public function prepend(string ...$prefix): static
    {
        $str = clone $this;
        $str->string = (1 >= \count($prefix) ? ($prefix[0] ?? '') : implode('', $prefix)).$str->string;

        return $str;
    }

    public function replace(string $from, string $to): static
    {
        $str = clone $this;

        if ('' !== $from) {
            $str->string = $this->ignoreCase ? str_ireplace($from, $to, $this->string) : str_replace($from, $to, $this->string);
        }

        return $str;
    }

    public function replaceMatches(string $fromRegexp, string|callable $to): static
    {
        if ($this->ignoreCase) {
            $fromRegexp .= 'i';
        }

        $replace = \is_array($to) || $to instanceof \Closure ? 'preg_replace_callback' : 'preg_replace';

        set_error_handler(static function ($t, $m) { throw new InvalidArgumentException($m); });

        try {
            if (null === $string = $replace($fromRegexp, $to, $this->string)) {
                $lastError = preg_last_error();

                foreach (get_defined_constants(true)['pcre'] as $k => $v) {
                    if ($lastError === $v && '_ERROR' === substr($k, -6)) {
                        throw new RuntimeException('Matching failed with '.$k.'.');
                    }
                }

                throw new RuntimeException('Matching failed with unknown error code.');
            }
        } finally {
            restore_error_handler();
        }

        $str = clone $this;
        $str->string = $string;

        return $str;
    }

    public function reverse(): static
    {
        $str = clone $this;
        $str->string = strrev($str->string);

        return $str;
    }

    public function slice(int $start = 0, int $length = null): static
    {
        $str = clone $this;
        $str->string = (string) substr($this->string, $start, $length ?? \PHP_INT_MAX);

        return $str;
    }

    public function snake(): static
    {
        $str = $this->camel()->title();
        $str->string = strtolower(preg_replace(['/([A-Z]+)([A-Z][a-z])/', '/([a-z\d])([A-Z])/'], '\1_\2', $str->string));

        return $str;
    }

    public function splice(string $replacement, int $start = 0, int $length = null): static
    {
        $str = clone $this;
        $str->string = substr_replace($this->string, $replacement, $start, $length ?? \PHP_INT_MAX);

        return $str;
    }

    public function split(string $delimiter, int $limit = null, int $flags = null): array
    {
        if (1 > $limit = $limit ?? \PHP_INT_MAX) {
            throw new InvalidArgumentException('Split limit must be a positive integer.');
        }

        if ('' === $delimiter) {
            throw new InvalidArgumentException('Split delimiter is empty.');
        }

        if (null !== $flags) {
            return parent::split($delimiter, $limit, $flags);
        }

        $str = clone $this;
        $chunks = $this->ignoreCase
            ? preg_split('{'.preg_quote($delimiter).'}iD', $this->string, $limit)
            : explode($delimiter, $this->string, $limit);

        foreach ($chunks as &$chunk) {
            $str->string = $chunk;
            $chunk = clone $str;
        }

        return $chunks;
    }

    public function startsWith(string|iterable|AbstractString $prefix): bool
    {
        if ($prefix instanceof AbstractString) {
            $prefix = $prefix->string;
        } elseif (!\is_string($prefix)) {
            return parent::startsWith($prefix);
        }

        return '' !== $prefix && 0 === ($this->ignoreCase ? strncasecmp($this->string, $prefix, \strlen($prefix)) : strncmp($this->string, $prefix, \strlen($prefix)));
    }

    public function title(bool $allWords = false): static
    {
        $str = clone $this;
        $str->string = $allWords ? ucwords($str->string) : ucfirst($str->string);

        return $str;
    }

    public function toUnicodeString(string $fromEncoding = null): UnicodeString
    {
        return new UnicodeString($this->toCodePointString($fromEncoding)->string);
    }

    public function toCodePointString(string $fromEncoding = null): CodePointString
    {
        $u = new CodePointString();

        if (\in_array($fromEncoding, [null, 'utf8', 'utf-8', 'UTF8', 'UTF-8'], true) && preg_match('//u', $this->string)) {
            $u->string = $this->string;

            return $u;
        }

        set_error_handler(static function ($t, $m) { throw new InvalidArgumentException($m); });

        try {
            try {
                $validEncoding = false !== mb_detect_encoding($this->string, $fromEncoding ?? 'Windows-1252', true);
            } catch (InvalidArgumentException $e) {
                if (!\function_exists('iconv')) {
                    throw $e;
                }

                $u->string = iconv($fromEncoding ?? 'Windows-1252', 'UTF-8', $this->string);

                return $u;
            }
        } finally {
            restore_error_handler();
        }

        if (!$validEncoding) {
            throw new InvalidArgumentException(sprintf('Invalid "%s" string.', $fromEncoding ?? 'Windows-1252'));
        }

        $u->string = mb_convert_encoding($this->string, 'UTF-8', $fromEncoding ?? 'Windows-1252');

        return $u;
    }

    public function trim(string $chars = " \t\n\r\0\x0B\x0C"): static
    {
        $str = clone $this;
        $str->string = trim($str->string, $chars);

        return $str;
    }

    public function trimEnd(string $chars = " \t\n\r\0\x0B\x0C"): static
    {
        $str = clone $this;
        $str->string = rtrim($str->string, $chars);

        return $str;
    }

    public function trimStart(string $chars = " \t\n\r\0\x0B\x0C"): static
    {
        $str = clone $this;
        $str->string = ltrim($str->string, $chars);

        return $str;
    }

    public function upper(): static
    {
        $str = clone $this;
        $str->string = strtoupper($str->string);

        return $str;
    }

    public function width(bool $ignoreAnsiDecoration = true): int
    {
        $string = preg_match('//u', $this->string) ? $this->string : preg_replace('/[\x80-\xFF]/', '?', $this->string);

        return (new CodePointString($string))->width($ignoreAnsiDecoration);
    }
}