class DumpCompletionCommand

final class DumpCompletionCommand extends Command {
    private array $supportedShells;
    protected function configure() : void {
        $fullCommand = $_SERVER['PHP_SELF'];
        $commandName = basename($fullCommand);
        $fullCommand = @realpath($fullCommand) ?: $fullCommand;
        $shell = self::guessShell();
        [
            $rcFile,
            $completionFile,
        ] = match ($shell) {    'fish' => [
                '~/.config/fish/config.fish',
                "/etc/fish/completions/{$commandName}.fish",
            ],
            'zsh' => [
                '~/.zshrc',
                '$fpath[1]/_' . $commandName,
            ],
            default => [
                '~/.bashrc',
                "/etc/bash_completion.d/{$commandName}",
            ],
        
        };
        $supportedShells = implode(', ', $this->getSupportedShells());
        $this->setHelp(<<<EOH
The <info>%command.name%</> command dumps the shell completion script required
to use shell autocompletion (currently, {<span class="php-variable">$supportedShells</span>} completion are supported).

<comment>Static installation
-------------------</>

Dump the script to a global completion file and restart your shell:

    <info>%command.full_name% {<span class="php-variable">$shell</span>} | sudo tee {<span class="php-variable">$completionFile</span>}</>

Or dump the script to a local file and source it:

    <info>%command.full_name% {<span class="php-variable">$shell</span>} > completion.sh</>

    <comment># source the file whenever you use the project</>
    <info>source completion.sh</>

    <comment># or add this line at the end of your "{<span class="php-variable">$rcFile</span>}" file:</>
    <info>source /path/to/completion.sh</>

<comment>Dynamic installation
--------------------</>

Add this to the end of your shell configuration file (e.g. <info>"{<span class="php-variable">$rcFile</span>}"</>):

    <info>eval "\$({<span class="php-variable">$fullCommand</span>} completion {<span class="php-variable">$shell</span>})"</>
EOH
)
            ->addArgument('shell', InputArgument::OPTIONAL, 'The shell type (e.g. "bash"), the value of the "$SHELL" env var will be used if this is not given', null, $this->getSupportedShells(...))
            ->addOption('debug', null, InputOption::VALUE_NONE, 'Tail the completion debug log');
    }
    protected function execute(InputInterface $input, OutputInterface $output) : int {
        $commandName = basename($_SERVER['argv'][0]);
        if ($input->getOption('debug')) {
            $this->tailDebugLog($commandName, $output);
            return 0;
        }
        $shell = $input->getArgument('shell') ?? self::guessShell();
        $completionFile = __DIR__ . '/../Resources/completion.' . $shell;
        if (!file_exists($completionFile)) {
            $supportedShells = $this->getSupportedShells();
            if ($output instanceof ConsoleOutputInterface) {
                $output = $output->getErrorOutput();
            }
            if ($shell) {
                $output->writeln(\sprintf('<error>Detected shell "%s", which is not supported by Symfony shell completion (supported shells: "%s").</>', $shell, implode('", "', $supportedShells)));
            }
            else {
                $output->writeln(\sprintf('<error>Shell not detected, Symfony shell completion only supports "%s").</>', implode('", "', $supportedShells)));
            }
            return 2;
        }
        $output->write(str_replace([
            '{{ COMMAND_NAME }}',
            '{{ VERSION }}',
        ], [
            $commandName,
            CompleteCommand::COMPLETION_API_VERSION,
        ], file_get_contents($completionFile)));
        return 0;
    }
    private static function guessShell() : string {
        return basename($_SERVER['SHELL'] ?? '');
    }
    private function tailDebugLog(string $commandName, OutputInterface $output) : void {
        $debugFile = sys_get_temp_dir() . '/sf_' . $commandName . '.log';
        if (!file_exists($debugFile)) {
            touch($debugFile);
        }
        $process = new Process([
            'tail',
            '-f',
            $debugFile,
        ], null, null, null, 0);
        $process->run(function (string $type, string $line) use ($output) : void {
            $output->write($line);
        });
    }
    
    /**
     * @return string[]
     */
    private function getSupportedShells() : array {
        if (isset($this->supportedShells)) {
            return $this->supportedShells;
        }
        $shells = [];
        foreach (new \DirectoryIterator(__DIR__ . '/../Resources/') as $file) {
            if (str_starts_with($file->getBasename(), 'completion.') && $file->isFile()) {
                $shells[] = $file->getExtension();
            }
        }
        sort($shells);
        return $this->supportedShells = $shells;
    }

}