class HgDownloader

class HgDownloader extends VcsDownloader {
    
    /**
     * @inheritDoc
     */
    protected function doDownload(PackageInterface $package, string $path, string $url, ?PackageInterface $prevPackage = null) : PromiseInterface {
        if (null === HgUtils::getVersion($this->process)) {
            throw new \RuntimeException('hg was not found in your PATH, skipping source download');
        }
        return \React\Promise\resolve(null);
    }
    
    /**
     * @inheritDoc
     */
    protected function doInstall(PackageInterface $package, string $path, string $url) : PromiseInterface {
        $hgUtils = new HgUtils($this->io, $this->config, $this->process);
        $cloneCommand = static function (string $url) use ($path) : array {
            return [
                'hg',
                'clone',
                '--',
                $url,
                $path,
            ];
        };
        $hgUtils->runCommand($cloneCommand, $url, $path);
        $command = [
            'hg',
            'up',
            '--',
            (string) $package->getSourceReference(),
        ];
        if (0 !== $this->process
            ->execute($command, $ignoredOutput, realpath($path))) {
            throw new \RuntimeException('Failed to execute ' . implode(' ', $command) . "\n\n" . $this->process
                ->getErrorOutput());
        }
        return \React\Promise\resolve(null);
    }
    
    /**
     * @inheritDoc
     */
    protected function doUpdate(PackageInterface $initial, PackageInterface $target, string $path, string $url) : PromiseInterface {
        $hgUtils = new HgUtils($this->io, $this->config, $this->process);
        $ref = $target->getSourceReference();
        $this->io
            ->writeError(" Updating to " . $target->getSourceReference());
        if (!$this->hasMetadataRepository($path)) {
            throw new \RuntimeException('The .hg directory is missing from ' . $path . ', see https://getcomposer.org/commit-deps for more information');
        }
        $command = static function ($url) : array {
            return [
                'hg',
                'pull',
                '--',
                $url,
            ];
        };
        $hgUtils->runCommand($command, $url, $path);
        $command = static function () use ($ref) : array {
            return [
                'hg',
                'up',
                '--',
                $ref,
            ];
        };
        $hgUtils->runCommand($command, $url, $path);
        return \React\Promise\resolve(null);
    }
    
    /**
     * @inheritDoc
     */
    public function getLocalChanges(PackageInterface $package, string $path) : ?string {
        if (!is_dir($path . '/.hg')) {
            return null;
        }
        $this->process
            ->execute([
            'hg',
            'st',
        ], $output, realpath($path));
        $output = trim($output);
        return strlen($output) > 0 ? $output : null;
    }
    
    /**
     * @inheritDoc
     */
    protected function getCommitLogs(string $fromReference, string $toReference, string $path) : string {
        $command = [
            'hg',
            'log',
            '-r',
            $fromReference . ':' . $toReference,
            '--style',
            'compact',
        ];
        if (0 !== $this->process
            ->execute($command, $output, realpath($path))) {
            throw new \RuntimeException('Failed to execute ' . implode(' ', $command) . "\n\n" . $this->process
                ->getErrorOutput());
        }
        return $output;
    }
    
    /**
     * @inheritDoc
     */
    protected function hasMetadataRepository(string $path) : bool {
        return is_dir($path . '/.hg');
    }

}