class ProjectSecurityRequirement

final class ProjectSecurityRequirement {
    use StringTranslationTrait;
    
    /**
     * The project title.
     *
     * @var string|null
     */
    protected $projectTitle;
    
    /**
     * Security coverage information for the project.
     *
     * @var array
     *
     * @see \Drupal\update\ProjectSecurityData::getCoverageInfo()
     */
    private $securityCoverageInfo;
    
    /**
     * The next version after the installed version in the format [MAJOR].[MINOR].
     *
     * @var string|null
     */
    private $nextMajorMinorVersion;
    
    /**
     * The existing (currently installed) version in the format [MAJOR].[MINOR].
     *
     * @var string|null
     */
    private $existingMajorMinorVersion;
    
    /**
     * Constructs a ProjectSecurityRequirement object.
     *
     * @param string|null $project_title
     *   The project title.
     * @param array $security_coverage_info
     *   Security coverage information as set by
     *   \Drupal\update\ProjectSecurityData::getCoverageInfo().
     * @param string|null $existing_major_minor_version
     *   The existing (currently installed) version in the format [MAJOR].[MINOR].
     * @param string|null $next_major_minor_version
     *   The next version after the installed version in the format
     *   [MAJOR].[MINOR].
     */
    private function __construct($project_title = NULL, array $security_coverage_info = [], $existing_major_minor_version = NULL, $next_major_minor_version = NULL) {
        $this->projectTitle = $project_title;
        $this->securityCoverageInfo = $security_coverage_info;
        $this->existingMajorMinorVersion = $existing_major_minor_version;
        $this->nextMajorMinorVersion = $next_major_minor_version;
    }
    
    /**
     * Creates a ProjectSecurityRequirement object from project data.
     *
     * @param array $project_data
     *   Project data from Drupal\update\UpdateManagerInterface::getProjects().
     *   The 'security_coverage_info' key should be set by
     *   calling \Drupal\update\ProjectSecurityData::getCoverageInfo() before
     *   calling this method. The following keys are used in this method:
     *   - existing_version (string): The version of the project that is installed
     *     on the site.
     *   - project_type (string): The type of project.
     *   - name (string): The project machine name.
     *   - title (string): The project title.
     * @param array $security_coverage_info
     *   The security coverage information as returned by
     *   \Drupal\update\ProjectSecurityData::getCoverageInfo().
     *
     * @return static
     *
     * @see \Drupal\update\UpdateManagerInterface::getProjects()
     * @see \Drupal\update\ProjectSecurityData::getCoverageInfo()
     * @see update_process_project_info()
     */
    public static function createFromProjectDataAndSecurityCoverageInfo(array $project_data, array $security_coverage_info) {
        if ($project_data['project_type'] !== 'core' || $project_data['name'] !== 'drupal' || empty($security_coverage_info)) {
            return new static();
        }
        if (isset($project_data['existing_version'])) {
            [
                $major,
                $minor,
            ] = explode('.', $project_data['existing_version']);
            $existing_version = "{$major}.{$minor}";
            $next_version = "{$major}." . ((int) $minor + 1);
            return new static($project_data['title'], $security_coverage_info, $existing_version, $next_version);
        }
        return new static($project_data['title'], $security_coverage_info);
    }
    
    /**
     * Gets the security coverage requirement, if any.
     *
     * @return array
     *   Requirements array as specified by hook_requirements(), or an empty array
     *   if no requirements can be determined.
     */
    public function getRequirement() {
        if (isset($this->securityCoverageInfo['security_coverage_end_version'])) {
            $requirement = $this->getVersionEndRequirement();
        }
        elseif (isset($this->securityCoverageInfo['security_coverage_end_date'])) {
            $requirement = $this->getDateEndRequirement();
        }
        else {
            return [];
        }
        $requirement['title'] = $this->t('Drupal core security coverage');
        return $requirement;
    }
    
    /**
     * Gets the requirements based on security coverage until a specific version.
     *
     * @return array
     *   Requirements array as specified by hook_requirements().
     */
    private function getVersionEndRequirement() {
        $requirement = [];
        if ($security_coverage_message = $this->getVersionEndCoverageMessage()) {
            $requirement['description'] = $security_coverage_message;
            if ($this->securityCoverageInfo['additional_minors_coverage'] > 0) {
                $requirement['value'] = $this->t('Covered until @end_version', [
                    '@end_version' => $this->securityCoverageInfo['security_coverage_end_version'],
                ]);
                $requirement['severity'] = $this->securityCoverageInfo['additional_minors_coverage'] > 1 ? REQUIREMENT_INFO : REQUIREMENT_WARNING;
            }
            else {
                $requirement['value'] = $this->t('Coverage has ended');
                $requirement['severity'] = REQUIREMENT_ERROR;
            }
        }
        return $requirement;
    }
    
    /**
     * Gets the message for additional minor version security coverage.
     *
     * @return array[]
     *   A render array containing security coverage message.
     *
     * @see \Drupal\update\ProjectSecurityData::getCoverageInfo()
     */
    private function getVersionEndCoverageMessage() {
        if ($this->securityCoverageInfo['additional_minors_coverage'] > 0) {
            // If the installed minor version will receive security coverage until
            // newer minor versions are released, inform the user.
            if ($this->securityCoverageInfo['additional_minors_coverage'] === 1) {
                // If the installed minor version will only receive security coverage
                // for 1 newer minor core version, encourage the site owner to update
                // soon.
                $message['coverage_message'] = [
                    '#markup' => $this->t('<a href=":update_status_report">Update to @next_minor or higher</a> soon to continue receiving security updates.', [
                        ':update_status_report' => Url::fromRoute('update.status')->toString(),
                        '@next_minor' => $this->nextMajorMinorVersion,
                    ]),
                    '#suffix' => ' ',
                ];
            }
        }
        else {
            // Because the current minor version no longer has security coverage,
            // advise the site owner to update.
            $message['coverage_message'] = [
                '#markup' => $this->getVersionNoSecurityCoverageMessage(),
                '#suffix' => ' ',
            ];
        }
        $message['release_cycle_link'] = [
            '#markup' => $this->getReleaseCycleLink(),
        ];
        return $message;
    }
    
    /**
     * Gets the security coverage requirement based on an end date.
     *
     * @return array
     *   Requirements array as specified by hook_requirements().
     */
    private function getDateEndRequirement() {
        $requirement = [];
        
        /** @var \Drupal\Component\Datetime\Time $time */
        $time = \Drupal::service('datetime.time');
        
        /** @var \Drupal\Core\Datetime\DateFormatterInterface $date_formatter */
        $date_formatter = \Drupal::service('date.formatter');
        // 'security_coverage_end_date' will either be in format 'Y-m-d' or 'Y-m'.
        if (substr_count($this->securityCoverageInfo['security_coverage_end_date'], '-') === 2) {
            $date_format = 'Y-m-d';
            $full_security_coverage_end_date = $this->securityCoverageInfo['security_coverage_end_date'];
        }
        else {
            $date_format = 'Y-m';
            // If the date does not include a day, use '15'. When calling
            // \DateTime::createFromFormat() the current day will be used if one is
            // not provided. This may cause the month to be wrong at the beginning or
            // end of the month. '15' will never be displayed because we are using the
            // 'Y-m' format.
            $full_security_coverage_end_date = $this->securityCoverageInfo['security_coverage_end_date'] . '-15';
        }
        $comparable_request_date = $date_formatter->format($time->getRequestTime(), 'custom', $date_format);
        if ($this->securityCoverageInfo['security_coverage_end_date'] <= $comparable_request_date) {
            // Security coverage is over.
            $requirement['value'] = $this->t('Coverage has ended');
            $requirement['severity'] = REQUIREMENT_ERROR;
            $requirement['description']['coverage_message'] = [
                '#markup' => $this->getVersionNoSecurityCoverageMessage(),
                '#suffix' => ' ',
            ];
        }
        else {
            $security_coverage_end_timestamp = \DateTime::createFromFormat('Y-m-d', $full_security_coverage_end_date)->getTimestamp();
            $output_date_format = $date_format === 'Y-m-d' ? 'Y-M-d' : 'Y-M';
            $formatted_end_date = $date_formatter->format($security_coverage_end_timestamp, 'custom', $output_date_format);
            $translation_arguments = [
                '@date' => $formatted_end_date,
            ];
            $requirement['value'] = $this->t('Covered until @date', $translation_arguments);
            $requirement['severity'] = REQUIREMENT_INFO;
            // 'security_coverage_ending_warn_date' will always be in the format
            // 'Y-m-d'.
            $request_date = $date_formatter->format($time->getRequestTime(), 'custom', 'Y-m-d');
            if (!empty($this->securityCoverageInfo['security_coverage_ending_warn_date']) && $this->securityCoverageInfo['security_coverage_ending_warn_date'] <= $request_date) {
                $requirement['description']['coverage_message'] = [
                    '#markup' => $this->t('Update to a supported minor version soon to continue receiving security updates.'),
                    '#suffix' => ' ',
                ];
                $requirement['severity'] = REQUIREMENT_WARNING;
            }
        }
        $requirement['description']['release_cycle_link'] = [
            '#markup' => $this->getReleaseCycleLink(),
        ];
        return $requirement;
    }
    
    /**
     * Gets the formatted message for a project with no security coverage.
     *
     * @return string
     *   The message for a version with no security coverage.
     */
    private function getVersionNoSecurityCoverageMessage() {
        return $this->t('<a href=":update_status_report">Update to a supported minor</a> as soon as possible to continue receiving security updates.', [
            ':update_status_report' => Url::fromRoute('update.status')->toString(),
        ]);
    }
    
    /**
     * Gets a link the release cycle page on drupal.org.
     *
     * @return string
     *   A link to the release cycle page on drupal.org.
     */
    private function getReleaseCycleLink() {
        return $this->t('Visit the <a href=":url">release cycle overview</a> for more information on supported releases.', [
            ':url' => 'https://www.drupal.org/core/release-cycle-overview',
        ]);
    }

}