<?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\Console\Helper;

use Symfony\Component\Console\Cursor;
use Symfony\Component\Console\Exception\MissingInputException;
use Symfony\Component\Console\Exception\RuntimeException;
use Symfony\Component\Console\Formatter\OutputFormatter;
use Symfony\Component\Console\Formatter\OutputFormatterStyle;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\StreamableInputInterface;
use Symfony\Component\Console\Output\ConsoleOutputInterface;
use Symfony\Component\Console\Output\ConsoleSectionOutput;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Console\Question\ChoiceQuestion;
use Symfony\Component\Console\Question\Question;
use Symfony\Component\Console\Terminal;

use function Symfony\Component\String\s;

/**
 * The QuestionHelper class provides helpers to interact with the user.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class QuestionHelper extends Helper
{
    /**
     * @var resource|null
     */
    private $inputStream;

    private static bool $stty = true;
    private static bool $stdinIsInteractive;

    /**
     * Asks a question to the user.
     *
     * @return mixed The user answer
     *
     * @throws RuntimeException If there is no data to read in the input stream
     */
    public function ask(InputInterface $input, OutputInterface $output, Question $question): mixed
    {
        if ($output instanceof ConsoleOutputInterface) {
            $output = $output->getErrorOutput();
        }

        if (!$input->isInteractive()) {
            return $this->getDefaultAnswer($question);
        }

        if ($input instanceof StreamableInputInterface && $stream = $input->getStream()) {
            $this->inputStream = $stream;
        }

        try {
            if (!$question->getValidator()) {
                return $this->doAsk($output, $question);
            }

            $interviewer = fn () => $this->doAsk($output, $question);

            return $this->validateAttempts($interviewer, $output, $question);
        } catch (MissingInputException $exception) {
            $input->setInteractive(false);

            if (null === $fallbackOutput = $this->getDefaultAnswer($question)) {
                throw $exception;
            }

            return $fallbackOutput;
        }
    }

    public function getName(): string
    {
        return 'question';
    }

    /**
     * Prevents usage of stty.
     *
     * @return void
     */
    public static function disableStty()
    {
        self::$stty = false;
    }

    /**
     * Asks the question to the user.
     *
     * @throws RuntimeException In case the fallback is deactivated and the response cannot be hidden
     */
    private function doAsk(OutputInterface $output, Question $question): mixed
    {
        $this->writePrompt($output, $question);

        $inputStream = $this->inputStream ?: \STDIN;
        $autocomplete = $question->getAutocompleterCallback();

        if (null === $autocomplete || !self::$stty || !Terminal::hasSttyAvailable()) {
            $ret = false;
            if ($question->isHidden()) {
                try {
                    $hiddenResponse = $this->getHiddenResponse($output, $inputStream, $question->isTrimmable());
                    $ret = $question->isTrimmable() ? trim($hiddenResponse) : $hiddenResponse;
                } catch (RuntimeException $e) {
                    if (!$question->isHiddenFallback()) {
                        throw $e;
                    }
                }
            }

            if (false === $ret) {
                $isBlocked = stream_get_meta_data($inputStream)['blocked'] ?? true;

                if (!$isBlocked) {
                    stream_set_blocking($inputStream, true);
                }

                $ret = $this->readInput($inputStream, $question);

                if (!$isBlocked) {
                    stream_set_blocking($inputStream, false);
                }

                if (false === $ret) {
                    throw new MissingInputException('Aborted.');
                }
                if ($question->isTrimmable()) {
                    $ret = trim($ret);
                }
            }
        } else {
            $autocomplete = $this->autocomplete($output, $question, $inputStream, $autocomplete);
            $ret = $question->isTrimmable() ? trim($autocomplete) : $autocomplete;
        }

        if ($output instanceof ConsoleSectionOutput) {
            $output->addContent(''); // add EOL to the question
            $output->addContent($ret);
        }

        $ret = \strlen($ret) > 0 ? $ret : $question->getDefault();

        if ($normalizer = $question->getNormalizer()) {
            return $normalizer($ret);
        }

        return $ret;
    }

    private function getDefaultAnswer(Question $question): mixed
    {
        $default = $question->getDefault();

        if (null === $default) {
            return $default;
        }

        if ($validator = $question->getValidator()) {
            return \call_user_func($validator, $default);
        } elseif ($question instanceof ChoiceQuestion) {
            $choices = $question->getChoices();

            if (!$question->isMultiselect()) {
                return $choices[$default] ?? $default;
            }

            $default = explode(',', $default);
            foreach ($default as $k => $v) {
                $v = $question->isTrimmable() ? trim($v) : $v;
                $default[$k] = $choices[$v] ?? $v;
            }
        }

        return $default;
    }

    /**
     * Outputs the question prompt.
     *
     * @return void
     */
    protected function writePrompt(OutputInterface $output, Question $question)
    {
        $message = $question->getQuestion();

        if ($question instanceof ChoiceQuestion) {
            $output->writeln(array_merge([
                $question->getQuestion(),
            ], $this->formatChoiceQuestionChoices($question, 'info')));

            $message = $question->getPrompt();
        }

        $output->write($message);
    }

    /**
     * @return string[]
     */
    protected function formatChoiceQuestionChoices(ChoiceQuestion $question, string $tag): array
    {
        $messages = [];

        $maxWidth = max(array_map([__CLASS__, 'width'], array_keys($choices = $question->getChoices())));

        foreach ($choices as $key => $value) {
            $padding = str_repeat(' ', $maxWidth - self::width($key));

            $messages[] = \sprintf("  [<$tag>%s$padding</$tag>] %s", $key, $value);
        }

        return $messages;
    }

    /**
     * Outputs an error message.
     *
     * @return void
     */
    protected function writeError(OutputInterface $output, \Exception $error)
    {
        if (null !== $this->getHelperSet() && $this->getHelperSet()->has('formatter')) {
            $message = $this->getHelperSet()->get('formatter')->formatBlock($error->getMessage(), 'error');
        } else {
            $message = '<error>'.$error->getMessage().'</error>';
        }

        $output->writeln($message);
    }

    /**
     * Autocompletes a question.
     *
     * @param resource $inputStream
     */
    private function autocomplete(OutputInterface $output, Question $question, $inputStream, callable $autocomplete): string
    {
        $cursor = new Cursor($output, $inputStream);

        $fullChoice = '';
        $ret = '';

        $i = 0;
        $ofs = -1;
        $matches = $autocomplete($ret);
        $numMatches = \count($matches);
        $inputHelper = new TerminalInputHelper($inputStream);

        // Disable icanon (so we can fread each keypress) and echo (we'll do echoing here instead)
        shell_exec('stty -icanon -echo');

        // Add highlighted text style
        $output->getFormatter()->setStyle('hl', new OutputFormatterStyle('black', 'white'));

        // Read a keypress
        while (!feof($inputStream)) {
            $inputHelper->waitForInput();
            $c = fread($inputStream, 1);

            // as opposed to fgets(), fread() returns an empty string when the stream content is empty, not false.
            if (false === $c || ('' === $ret && '' === $c && null === $question->getDefault())) {
                // Restore the terminal so it behaves normally again
                $inputHelper->finish();
                throw new MissingInputException('Aborted.');
            } elseif ("\177" === $c) { // Backspace Character
                if (0 === $numMatches && 0 !== $i) {
                    --$i;
                    $cursor->moveLeft(s($fullChoice)->slice(-1)->width(false));

                    $fullChoice = self::substr($fullChoice, 0, $i);
                }

                if (0 === $i) {
                    $ofs = -1;
                    $matches = $autocomplete($ret);
                    $numMatches = \count($matches);
                } else {
                    $numMatches = 0;
                }

                // Pop the last character off the end of our string
                $ret = self::substr($ret, 0, $i);
            } elseif ("\033" === $c) {
                // Did we read an escape sequence?
                $c .= fread($inputStream, 2);

                // A = Up Arrow. B = Down Arrow
                if (isset($c[2]) && ('A' === $c[2] || 'B' === $c[2])) {
                    if ('A' === $c[2] && -1 === $ofs) {
                        $ofs = 0;
                    }

                    if (0 === $numMatches) {
                        continue;
                    }

                    $ofs += ('A' === $c[2]) ? -1 : 1;
                    $ofs = ($numMatches + $ofs) % $numMatches;
                }
            } elseif ('' === $c || \ord($c) < 32) {
                if ("\t" === $c || "\n" === $c) {
                    if ($numMatches > 0 && -1 !== $ofs) {
                        $ret = (string) $matches[$ofs];
                        // Echo out remaining chars for current match
                        $remainingCharacters = substr($ret, \strlen($this->mostRecentlyEnteredValue($fullChoice)));
                        $output->write($remainingCharacters);
                        $fullChoice .= $remainingCharacters;
                        $i = (false === $encoding = mb_detect_encoding($fullChoice, null, true)) ? \strlen($fullChoice) : mb_strlen($fullChoice, $encoding);

                        $matches = array_filter(
                            $autocomplete($ret),
                            fn ($match) => '' === $ret || str_starts_with($match, $ret)
                        );
                        $numMatches = \count($matches);
                        $ofs = -1;
                    }

                    if ("\n" === $c) {
                        $output->write($c);
                        break;
                    }

                    $numMatches = 0;
                }

                continue;
            } else {
                if ("\x80" <= $c) {
                    $c .= fread($inputStream, ["\xC0" => 1, "\xD0" => 1, "\xE0" => 2, "\xF0" => 3][$c & "\xF0"]);
                }

                $output->write($c);
                $ret .= $c;
                $fullChoice .= $c;
                ++$i;

                $tempRet = $ret;

                if ($question instanceof ChoiceQuestion && $question->isMultiselect()) {
                    $tempRet = $this->mostRecentlyEnteredValue($fullChoice);
                }

                $numMatches = 0;
                $ofs = 0;

                foreach ($autocomplete($ret) as $value) {
                    // If typed characters match the beginning chunk of value (e.g. [AcmeDe]moBundle)
                    if (str_starts_with($value, $tempRet)) {
                        $matches[$numMatches++] = $value;
                    }
                }
            }

            $cursor->clearLineAfter();

            if ($numMatches > 0 && -1 !== $ofs) {
                $cursor->savePosition();
                // Write highlighted text, complete the partially entered response
                $charactersEntered = \strlen($this->mostRecentlyEnteredValue($fullChoice));
                $output->write('<hl>'.OutputFormatter::escapeTrailingBackslash(substr($matches[$ofs], $charactersEntered)).'</hl>');
                $cursor->restorePosition();
            }
        }

        // Restore the terminal so it behaves normally again
        $inputHelper->finish();

        return $fullChoice;
    }

    private function mostRecentlyEnteredValue(string $entered): string
    {
        // Determine the most recent value that the user entered
        if (!str_contains($entered, ',')) {
            return $entered;
        }

        $choices = explode(',', $entered);
        if ('' !== $lastChoice = trim($choices[\count($choices) - 1])) {
            return $lastChoice;
        }

        return $entered;
    }

    /**
     * Gets a hidden response from user.
     *
     * @param resource $inputStream The handler resource
     * @param bool     $trimmable   Is the answer trimmable
     *
     * @throws RuntimeException In case the fallback is deactivated and the response cannot be hidden
     */
    private function getHiddenResponse(OutputInterface $output, $inputStream, bool $trimmable = true): string
    {
        if ('\\' === \DIRECTORY_SEPARATOR) {
            $exe = __DIR__.'/../Resources/bin/hiddeninput.exe';

            // handle code running from a phar
            if (str_starts_with(__FILE__, 'phar:')) {
                $tmpExe = sys_get_temp_dir().'/hiddeninput.exe';
                copy($exe, $tmpExe);
                $exe = $tmpExe;
            }

            $sExec = shell_exec('"'.$exe.'"');
            $value = $trimmable ? rtrim($sExec) : $sExec;
            $output->writeln('');

            if (isset($tmpExe)) {
                unlink($tmpExe);
            }

            return $value;
        }

        $inputHelper = null;

        if (self::$stty && Terminal::hasSttyAvailable()) {
            $inputHelper = new TerminalInputHelper($inputStream);
            shell_exec('stty -echo');
        } elseif ($this->isInteractiveInput($inputStream)) {
            throw new RuntimeException('Unable to hide the response.');
        }

        $value = $this->doReadInput($inputStream, helper: $inputHelper);

        if (4095 === \strlen($value)) {
            $errOutput = $output instanceof ConsoleOutputInterface ? $output->getErrorOutput() : $output;
            $errOutput->warning('The value was possibly truncated by your shell or terminal emulator');
        }

        // Restore the terminal so it behaves normally again
        $inputHelper?->finish();

        if ($trimmable) {
            $value = trim($value);
        }
        $output->writeln('');

        return $value;
    }

    /**
     * Validates an attempt.
     *
     * @param callable $interviewer A callable that will ask for a question and return the result
     *
     * @throws \Exception In case the max number of attempts has been reached and no valid response has been given
     */
    private function validateAttempts(callable $interviewer, OutputInterface $output, Question $question): mixed
    {
        $error = null;
        $attempts = $question->getMaxAttempts();

        while (null === $attempts || $attempts--) {
            if (null !== $error) {
                $this->writeError($output, $error);
            }

            try {
                return $question->getValidator()($interviewer());
            } catch (RuntimeException $e) {
                throw $e;
            } catch (\Exception $error) {
            }
        }

        throw $error;
    }

    private function isInteractiveInput($inputStream): bool
    {
        if ('php://stdin' !== (stream_get_meta_data($inputStream)['uri'] ?? null)) {
            return false;
        }

        if (isset(self::$stdinIsInteractive)) {
            return self::$stdinIsInteractive;
        }

        return self::$stdinIsInteractive = @stream_isatty(fopen('php://stdin', 'r'));
    }

    /**
     * Reads one or more lines of input and returns what is read.
     *
     * @param resource $inputStream The handler resource
     * @param Question $question    The question being asked
     */
    private function readInput($inputStream, Question $question): string|false
    {
        if (!$question->isMultiline()) {
            $cp = $this->setIOCodepage();
            $ret = $this->doReadInput($inputStream);

            return $this->resetIOCodepage($cp, $ret);
        }

        $multiLineStreamReader = $this->cloneInputStream($inputStream);
        if (null === $multiLineStreamReader) {
            return false;
        }

        $cp = $this->setIOCodepage();
        $ret = $this->doReadInput($multiLineStreamReader, "\x4");

        if (stream_get_meta_data($inputStream)['seekable']) {
            fseek($inputStream, ftell($multiLineStreamReader));
        }

        return $this->resetIOCodepage($cp, $ret);
    }

    private function setIOCodepage(): int
    {
        if (\function_exists('sapi_windows_cp_set')) {
            $cp = sapi_windows_cp_get();
            sapi_windows_cp_set(sapi_windows_cp_get('oem'));

            return $cp;
        }

        return 0;
    }

    /**
     * Sets console I/O to the specified code page and converts the user input.
     */
    private function resetIOCodepage(int $cp, string|false $input): string|false
    {
        if (0 !== $cp) {
            sapi_windows_cp_set($cp);

            if (false !== $input && '' !== $input) {
                $input = sapi_windows_cp_conv(sapi_windows_cp_get('oem'), $cp, $input);
            }
        }

        return $input;
    }

    /**
     * Clones an input stream in order to act on one instance of the same
     * stream without affecting the other instance.
     *
     * @param resource $inputStream The handler resource
     *
     * @return resource|null The cloned resource, null in case it could not be cloned
     */
    private function cloneInputStream($inputStream)
    {
        $streamMetaData = stream_get_meta_data($inputStream);
        $seekable = $streamMetaData['seekable'] ?? false;
        $mode = $streamMetaData['mode'] ?? 'rb';
        $uri = $streamMetaData['uri'] ?? null;

        if (null === $uri) {
            return null;
        }

        $cloneStream = fopen($uri, $mode);

        // For seekable and writable streams, add all the same data to the
        // cloned stream and then seek to the same offset.
        if (true === $seekable && !\in_array($mode, ['r', 'rb', 'rt'])) {
            $offset = ftell($inputStream);
            rewind($inputStream);
            stream_copy_to_stream($inputStream, $cloneStream);
            fseek($inputStream, $offset);
            fseek($cloneStream, $offset);
        }

        return $cloneStream;
    }

    /**
     * @param resource $inputStream
     */
    private function doReadInput($inputStream, ?string $exitChar = null, ?TerminalInputHelper $helper = null): string
    {
        $ret = '';
        $helper ??= new TerminalInputHelper($inputStream, false);

        while (!feof($inputStream)) {
            $helper->waitForInput();
            $char = fread($inputStream, 1);

            // as opposed to fgets(), fread() returns an empty string when the stream content is empty, not false.
            if (false === $char || ('' === $ret && '' === $char)) {
                throw new MissingInputException('Aborted.');
            }

            if (\PHP_EOL === "{$ret}{$char}" || $exitChar === $char) {
                break;
            }

            $ret .= $char;

            if (null === $exitChar && "\n" === $char) {
                break;
            }
        }

        return $ret;
    }
}
