<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

namespace ExpressionEngine\Service\Updater\Downloader;

use ExpressionEngine\Service\Updater\UpdaterException;
use ExpressionEngine\Service\License\ExpressionEngineLicense;
use ExpressionEngine\Library\Filesystem\Filesystem;
use ExpressionEngine\Service\Updater\Logger;
use ExpressionEngine\Service\Config\File;

/**
 * Updater preflight checker
 *
 * Runs all preflight operations to check for any potential errors that may
 * occur during upgrade so that they are fixed up front
 */
class Preflight
{
    use UpdaterPaths;

    protected $filesystem;
    protected $logger;
    protected $config;
    protected $theme_paths;

    /**
     * Constructor
     *
     * @param	Filesystem $filesystem Filesystem service object
     * @param	Logger $logger Updater logger object
     * @param	Config\File $config File config service object
     * @param	array $sites Array of unique theme paths
     */
    public function __construct(Filesystem $filesystem, Logger $logger, File $config, array $theme_paths)
    {
        $this->filesystem = $filesystem;
        $this->logger = $logger;
        $this->config = $config;
        $this->theme_paths = $theme_paths;
    }

    /**
     * Cleans up download and extract locations of any previous update artifacts
     */
    public function cleanUpOldUpgrades()
    {
        $this->logger->log('Cleaning up upgrade working directory');

        // Delete any old zip archives
        if ($this->filesystem->isFile($this->getArchiveFilePath())) {
            $this->logger->log('Old zip archives found, deleting');
            $this->filesystem->delete($this->getArchiveFilePath());
        }

        // Delete old extracted archives
        if ($this->filesystem->isDir($this->getExtractedArchivePath())) {
            $this->logger->log('Old extracted archives found, deleting');
            $this->filesystem->delete($this->getExtractedArchivePath());
        }

        // Delete any old SQL backups
        $sql_path = $this->path() . 'database.sql';
        if ($this->filesystem->isFile($sql_path)) {
            $this->logger->log('Old SQL backup found, deleting');
            $this->filesystem->delete($sql_path);
        }

        // Delete old extracted archives
        $backup_path = $this->path() . 'backups';
        if ($this->filesystem->isDir($backup_path)) {
            $this->logger->log('Old file backup folders found, deleting');
            $this->filesystem->delete($backup_path);
        }
    }

    /**
     * Verifies we have enough disk space to download and extract the package
     */
    public function checkDiskSpace()
    {
        $this->logger->log('Checking free disk space');
        $free_space = $this->filesystem->getFreeDiskSpace($this->path());
        $this->logger->log('Free disk space (bytes): ' . $free_space);

        // Try to maintain at least 50MB free disk space
        if ($free_space < 52428800) {
            throw new UpdaterException('Not enough disk space available to complete the update (' . $free_space . ' free bytes reported). Please free up some space and try the upgrade again.', 11);
        }
    }

    /**
     * Verifies we have permission to write to the folders we need to to complete
     * the upgrade
     */
    public function checkPermissions()
    {
        $this->logger->log('Checking file permissions needed to complete the update');

        $theme_paths = array_map(function ($path) {
            return preg_replace("#/+#", "/", rtrim($path, DIRECTORY_SEPARATOR) . '/ee/');
        }, $this->getThemePaths());

        $paths = array_merge(
            [
                $this->path(),
                SYSPATH . 'ee',
                PATH_CACHE,
                SYSPATH . 'user/config/config.php'
            ],
            $this->filesystem->getDirectoryContents(SYSPATH . 'ee/'),
            $theme_paths
        );

        foreach ($theme_paths as $path) {
            $paths = array_merge(
                $paths,
                $this->filesystem->getDirectoryContents($path)
            );
        }

        $paths = array_filter($paths, function ($path) {
            return ! $this->filesystem->isWritable($path);
        });

        if (! empty($paths)) {
            // This bit of code before the exception truncates the full server
            // path from the path strings and shortens them to just their parent
            // theme or system folder
            $search = array_map(function ($theme_path) {
                $real_path = realpath($theme_path . '../../');

                return $real_path ? $real_path . '/' : $theme_path;
            }, $theme_paths);

            $syspath = realpath(SYSPATH . '../');
            $search[] = $syspath ? $syspath . '/' : SYSPATH;
            $search = array_unique($search);

            $paths = array_map(function ($path) use ($search) {
                return str_replace($search, '', $path);
            }, $paths);

            throw new UpdaterException(sprintf(
                lang('files_not_writable'),
                implode("\n", $paths),
                DOC_URL . 'installation/update.html'
            ), 1);
        }
    }

    /**
     * Here, we need to gather all the information the updater microapp might need,
     * such as file paths. We may not be able to access these things easily from
     * within the microapp because they may be stored in any manner of places, so
     * we'll grab them early and put them in our working directory for the update.
     */
    public function stashConfig()
    {
        $config = [
            'update_path' => $this->path(),
            'archive_path' => $this->getExtractedArchivePath(),
            'theme_paths' => $this->getThemePaths()
        ];

        foreach ($config['theme_paths'] as $theme_path) {
            $this->validateThemePath($theme_path);
        }

        $this->filesystem->write(
            $this->path() . 'configs.json',
            json_encode($config),
            true
        );
    }

    /**
     * Creates an array of theme paths for all sites
     *
     * @return	array	Theme server paths
     */
    protected function getThemePaths()
    {
        // Is there a config file override for the theme path? Use that instead
        // and hope that the other sites' paths aren't conditionally set in the
        // file because we'll only get the one
        if ($this->config->get('theme_folder_path') !== null) {
            return [$this->config->get('theme_folder_path')];
        }

        return $this->theme_paths;
    }

    /**
     * Checks whether themes path are existent and are valid ones
     *
     * @return	void
     */
    private function validateThemePath($theme_path)
    {
        if (!$this->filesystem->exists(rtrim(rtrim($theme_path, '/'), DIRECTORY_SEPARATOR) . '/ee/cp')) {
            throw new UpdaterException(sprintf(
                lang('theme_folder_path_invalid'),
                $theme_path,
                DOC_URL . 'control-panel/settings/urls.html#themes-path'
            ), 1);
        }
    }
}

// EOF
