<?php declare(strict_types=1);

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\Repository\Vcs;

use Composer\Cache;
use Composer\Config;
use Composer\Pcre\Preg;
use Composer\Util\ProcessExecutor;
use Composer\Util\Filesystem;
use Composer\IO\IOInterface;

/**
 * @author BohwaZ <http://bohwaz.net/>
 */
class FossilDriver extends VcsDriver
{
    /** @var array<int|string, string> Map of tag name to identifier */
    protected $tags;
    /** @var array<int|string, string> Map of branch name to identifier */
    protected $branches;
    /** @var ?string */
    protected $rootIdentifier = null;
    /** @var ?string */
    protected $repoFile = null;
    /** @var string */
    protected $checkoutDir;

    /**
     * @inheritDoc
     */
    public function initialize(): void
    {
        // Make sure fossil is installed and reachable.
        $this->checkFossil();

        // Ensure we are allowed to use this URL by config.
        $this->config->prohibitUrlByConfig($this->url, $this->io);

        // Only if url points to a locally accessible directory, assume it's the checkout directory.
        // Otherwise, it should be something fossil can clone from.
        if (Filesystem::isLocalPath($this->url) && is_dir($this->url)) {
            $this->checkoutDir = $this->url;
        } else {
            if (!Cache::isUsable($this->config->get('cache-repo-dir')) || !Cache::isUsable($this->config->get('cache-vcs-dir'))) {
                throw new \RuntimeException('FossilDriver requires a usable cache directory, and it looks like you set it to be disabled');
            }

            $localName = Preg::replace('{[^a-z0-9]}i', '-', $this->url);
            $this->repoFile = $this->config->get('cache-repo-dir') . '/' . $localName . '.fossil';
            $this->checkoutDir = $this->config->get('cache-vcs-dir') . '/' . $localName . '/';

            $this->updateLocalRepo();
        }

        $this->getTags();
        $this->getBranches();
    }

    /**
     * Check that fossil can be invoked via command line.
     */
    protected function checkFossil(): void
    {
        if (0 !== $this->process->execute(['fossil', 'version'], $ignoredOutput)) {
            throw new \RuntimeException("fossil was not found, check that it is installed and in your PATH env.\n\n" . $this->process->getErrorOutput());
        }
    }

    /**
     * Clone or update existing local fossil repository.
     */
    protected function updateLocalRepo(): void
    {
        assert($this->repoFile !== null);

        $fs = new Filesystem();
        $fs->ensureDirectoryExists($this->checkoutDir);

        if (!is_writable(dirname($this->checkoutDir))) {
            throw new \RuntimeException('Can not clone '.$this->url.' to access package information. The "'.$this->checkoutDir.'" directory is not writable by the current user.');
        }

        // update the repo if it is a valid fossil repository
        if (is_file($this->repoFile) && is_dir($this->checkoutDir) && 0 === $this->process->execute(['fossil', 'info'], $output, $this->checkoutDir)) {
            if (0 !== $this->process->execute(['fossil', 'pull'], $output, $this->checkoutDir)) {
                $this->io->writeError('<error>Failed to update '.$this->url.', package information from this repository may be outdated ('.$this->process->getErrorOutput().')</error>');
            }
        } else {
            // clean up directory and do a fresh clone into it
            $fs->removeDirectory($this->checkoutDir);
            $fs->remove($this->repoFile);

            $fs->ensureDirectoryExists($this->checkoutDir);

            if (0 !== $this->process->execute(['fossil', 'clone', '--', $this->url, $this->repoFile], $output)) {
                $output = $this->process->getErrorOutput();

                throw new \RuntimeException('Failed to clone '.$this->url.' to repository ' . $this->repoFile . "\n\n" .$output);
            }

            if (0 !== $this->process->execute(['fossil', 'open', '--nested', '--', $this->repoFile], $output, $this->checkoutDir)) {
                $output = $this->process->getErrorOutput();

                throw new \RuntimeException('Failed to open repository '.$this->repoFile.' in ' . $this->checkoutDir . "\n\n" .$output);
            }
        }
    }

    /**
     * @inheritDoc
     */
    public function getRootIdentifier(): string
    {
        if (null === $this->rootIdentifier) {
            $this->rootIdentifier = 'trunk';
        }

        return $this->rootIdentifier;
    }

    /**
     * @inheritDoc
     */
    public function getUrl(): string
    {
        return $this->url;
    }

    /**
     * @inheritDoc
     */
    public function getSource(string $identifier): array
    {
        return ['type' => 'fossil', 'url' => $this->getUrl(), 'reference' => $identifier];
    }

    /**
     * @inheritDoc
     */
    public function getDist(string $identifier): ?array
    {
        return null;
    }

    /**
     * @inheritDoc
     */
    public function getFileContent(string $file, string $identifier): ?string
    {
        if (isset($identifier[0]) && $identifier[0] === '-') {
            throw new \RuntimeException('Invalid fossil identifier detected. Identifier must not start with a -, given: ' . $identifier);
        }

        $this->process->execute(['fossil', 'cat', '-r', $identifier, '--', $file], $content, $this->checkoutDir);

        if ('' === trim($content)) {
            return null;
        }

        return $content;
    }

    /**
     * @inheritDoc
     */
    public function getChangeDate(string $identifier): ?\DateTimeImmutable
    {
        $this->process->execute(['fossil', 'finfo', '-b', '-n', '1', 'composer.json'], $output, $this->checkoutDir);
        [, $date] = explode(' ', trim($output), 3);

        return new \DateTimeImmutable($date, new \DateTimeZone('UTC'));
    }

    /**
     * @inheritDoc
     */
    public function getTags(): array
    {
        if (null === $this->tags) {
            $tags = [];

            $this->process->execute(['fossil', 'tag', 'list'], $output, $this->checkoutDir);
            foreach ($this->process->splitLines($output) as $tag) {
                $tags[$tag] = $tag;
            }

            $this->tags = $tags;
        }

        return $this->tags;
    }

    /**
     * @inheritDoc
     */
    public function getBranches(): array
    {
        if (null === $this->branches) {
            $branches = [];

            $this->process->execute(['fossil', 'branch', 'list'], $output, $this->checkoutDir);
            foreach ($this->process->splitLines($output) as $branch) {
                $branch = trim(Preg::replace('/^\*/', '', trim($branch)));
                $branches[$branch] = $branch;
            }

            $this->branches = $branches;
        }

        return $this->branches;
    }

    /**
     * @inheritDoc
     */
    public static function supports(IOInterface $io, Config $config, string $url, bool $deep = false): bool
    {
        if (Preg::isMatch('#(^(?:https?|ssh)://(?:[^@]@)?(?:chiselapp\.com|fossil\.))#i', $url)) {
            return true;
        }

        if (Preg::isMatch('!/fossil/|\.fossil!', $url)) {
            return true;
        }

        // local filesystem
        if (Filesystem::isLocalPath($url)) {
            $url = Filesystem::getPlatformPath($url);
            if (!is_dir($url)) {
                return false;
            }

            $process = new ProcessExecutor($io);
            // check whether there is a fossil repo in that path
            if ($process->execute(['fossil', 'info'], $output, $url) === 0) {
                return true;
            }
        }

        return false;
    }
}
