<?php

namespace SilverStripe\Subsites\Extensions;

use Page;
use SilverStripe\CMS\Model\SiteTree;
use SilverStripe\Control\Controller;
use SilverStripe\Control\Director;
use SilverStripe\Control\HTTP;
use SilverStripe\Core\Config\Config;
use SilverStripe\Core\Convert;
use SilverStripe\Forms\CheckboxField;
use SilverStripe\Forms\DropdownField;
use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\FormAction;
use SilverStripe\Forms\ToggleCompositeField;
use SilverStripe\i18n\i18n;
use SilverStripe\ORM\DataExtension;
use SilverStripe\ORM\DataObject;
use SilverStripe\ORM\DataQuery;
use SilverStripe\ORM\Queries\SQLSelect;
use SilverStripe\Security\Security;
use SilverStripe\SiteConfig\SiteConfig;
use SilverStripe\Subsites\Model\Subsite;
use SilverStripe\Subsites\State\SubsiteState;
use SilverStripe\View\SSViewer;

/**
 * Extension for the SiteTree object to add subsites support
 */
class SiteTreeSubsites extends DataExtension
{
    private static $has_one = [
        'Subsite' => Subsite::class, // The subsite that this page belongs to
    ];

    private static $many_many = [
        'CrossSubsiteLinkTracking' => SiteTree::class // Stored separately, as the logic for URL rewriting is different
    ];

    private static $many_many_extraFields = [
        'CrossSubsiteLinkTracking' => ['FieldName' => 'Varchar']
    ];

    public function isMainSite()
    {
        return $this->owner->SubsiteID == 0;
    }

    /**
     * Update any requests to limit the results to the current site
     * @param SQLSelect $query
     * @param DataQuery $dataQuery
     */
    public function augmentSQL(SQLSelect $query, DataQuery $dataQuery = null)
    {
        if (Subsite::$disable_subsite_filter) {
            return;
        }
        if ($dataQuery && $dataQuery->getQueryParam('Subsite.filter') === false) {
            return;
        }

        // If you're querying by ID, ignore the sub-site - this is a bit ugly...
        // if(!$query->where || (strpos($query->where[0], ".\"ID\" = ") === false && strpos($query->where[0], ".`ID` = ") === false && strpos($query->where[0], ".ID = ") === false && strpos($query->where[0], "ID = ") !== 0)) {
        if ($query->filtersOnID()) {
            return;
        }

        $subsiteID = null;
        if (Subsite::$force_subsite) {
            $subsiteID = Subsite::$force_subsite;
        } else {
            $subsiteID = SubsiteState::singleton()->getSubsiteId();
        }

        if ($subsiteID === null) {
            return;
        }

        // The foreach is an ugly way of getting the first key :-)
        foreach ($query->getFrom() as $tableName => $info) {
            // The tableName should be SiteTree or SiteTree_Live...
            $siteTreeTableName = SiteTree::getSchema()->tableName(SiteTree::class);
            if (strpos($tableName, $siteTreeTableName) === false) {
                break;
            }
            $query->addWhere("\"$tableName\".\"SubsiteID\" IN ($subsiteID)");
            break;
        }
    }

    public function onBeforeWrite()
    {
        if (!$this->owner->ID && !$this->owner->SubsiteID) {
            $this->owner->SubsiteID = SubsiteState::singleton()->getSubsiteId();
        }

        parent::onBeforeWrite();
    }

    public function updateCMSFields(FieldList $fields)
    {
        $subsites = Subsite::accessible_sites('CMS_ACCESS_CMSMain');
        $subsitesMap = [];
        if ($subsites && $subsites->count()) {
            $subsitesToMap = $subsites->exclude('ID', $this->owner->SubsiteID);
            $subsitesMap = $subsitesToMap->map('ID', 'Title');
        }

        // Master page edit field (only allowed from default subsite to avoid inconsistent relationships)
        $isDefaultSubsite = $this->owner->SubsiteID == 0 || $this->owner->Subsite()->DefaultSite;

        if ($isDefaultSubsite && $subsitesMap) {
            $fields->addFieldToTab(
                'Root.Main',
                ToggleCompositeField::create(
                    'SubsiteOperations',
                    _t(__CLASS__ . '.SubsiteOperations', 'Subsite Operations'),
                    [
                        new DropdownField('CopyToSubsiteID', _t(
                            __CLASS__ . '.CopyToSubsite',
                            'Copy page to subsite'
                        ), $subsitesMap),
                        new CheckboxField(
                            'CopyToSubsiteWithChildren',
                            _t(__CLASS__ . '.CopyToSubsiteWithChildren', 'Include children pages?')
                        ),
                        $copyAction = new FormAction(
                            'copytosubsite',
                            _t(__CLASS__ . '.CopyAction', 'Copy')
                        )
                    ]
                )->setHeadingLevel(4)
            );

            // @todo check if this needs re-implementation
//            $copyAction->includeDefaultJS(false);
        }

        // replace readonly link prefix
        $subsite = $this->owner->Subsite();
        $nested_urls_enabled = Config::inst()->get(SiteTree::class, 'nested_urls');
        if ($subsite && $subsite->exists()) {
            // Use baseurl from domain
            $baseLink = $subsite->absoluteBaseURL();

            // Add parent page if enabled
            if ($nested_urls_enabled && $this->owner->ParentID) {
                $baseLink = Controller::join_links(
                    $baseLink,
                    $this->owner->Parent()->RelativeLink(true)
                );
            }

            $urlsegment = $fields->dataFieldByName('URLSegment');
            $urlsegment->setURLPrefix($baseLink);
        }
    }

    /**
     * Does the basic duplication, but doesn't write anything
     * this means we can subclass this easier and do more complex
     * relation duplication.
     */
    public function duplicateToSubsitePrep($subsiteID)
    {
        if (is_object($subsiteID)) {
            $subsiteID = $subsiteID->ID;
        }

        $oldSubsite = SubsiteState::singleton()->getSubsiteId();
        if ($subsiteID) {
            Subsite::changeSubsite($subsiteID);
        } else {
            $subsiteID = $oldSubsite;
        }
        // doesn't write as we need to reset the SubsiteID, ParentID etc
        $clone = $this->owner->duplicate(false);
        $clone->CheckedPublicationDifferences = $clone->AddedToStage = true;
        $subsiteID = ($subsiteID ? $subsiteID : $oldSubsite);
        $clone->SubsiteID = $subsiteID;
        // We have no idea what the parentID should be, so as a workaround use the url-segment and subsite ID
        if ($this->owner->Parent()) {
            $parentSeg = $this->owner->Parent()->URLSegment;
            $newParentPage = Page::get()->filter('URLSegment', $parentSeg)->first();
            if ($newParentPage) {
                $clone->ParentID = $newParentPage->ID;
            } else {
                // reset it to the top level, so the user can decide where to put it
                $clone->ParentID = 0;
            }
        }
        // MasterPageID is here for legacy purposes, to satisfy the subsites_relatedpages module
        $clone->MasterPageID = $this->owner->ID;
        return $clone;
    }

    /**
     * Create a duplicate of this page and save it to another subsite
     * @param $subsiteID int|Subsite The Subsite to copy to, or its ID
     */
    public function duplicateToSubsite($subsiteID = null)
    {
        $clone = $this->owner->duplicateToSubsitePrep($subsiteID);
        $clone->invokeWithExtensions('onBeforeDuplicateToSubsite', $this->owner);
        $clone->write();
        $clone->duplicateSubsiteRelations($this->owner);
        // new extension hooks which happens after write,
        // onAfterDuplicate isn't reliable due to
        // https://github.com/silverstripe/silverstripe-cms/issues/1253
        $clone->invokeWithExtensions('onAfterDuplicateToSubsite', $this->owner);
        return $clone;
    }

    /**
     * Duplicate relations using a static property to define
     * which ones we want to duplicate
     *
     * It may be that some relations are not diostinct to sub site so can stay
     * whereas others may need to be duplicated
     *
     */
    public function duplicateSubsiteRelations($originalPage)
    {
        $thisClass = $originalPage->ClassName;
        $relations = Config::inst()->get($thisClass, 'duplicate_to_subsite_relations');

        if ($relations && !empty($relations)) {
            foreach ($relations as $relation) {
                $items = $originalPage->$relation();
                foreach ($items as $item) {
                    $duplicateItem = $item->duplicate(false);
                    $duplicateItem->{$thisClass.'ID'} = $this->owner->ID;
                    $duplicateItem->write();
                }
            }
        }
    }

    /**
     * @return SiteConfig
     */
    public function alternateSiteConfig()
    {
        if (!$this->owner->SubsiteID) {
            return false;
        }
        $sc = DataObject::get_one(SiteConfig::class, '"SubsiteID" = ' . $this->owner->SubsiteID);
        if (!$sc) {
            $sc = new SiteConfig();
            $sc->SubsiteID = $this->owner->SubsiteID;
            $sc->Title = _t('SilverStripe\\Subsites\\Model\\Subsite.SiteConfigTitle', 'Your Site Name');
            $sc->Tagline = _t('SilverStripe\\Subsites\\Model\\Subsite.SiteConfigSubtitle', 'Your tagline here');
            $sc->write();
        }
        return $sc;
    }

    /**
     * Only allow editing of a page if the member satisfies one of the following conditions:
     * - Is in a group which has access to the subsite this page belongs to
     * - Is in a group with edit permissions on the "main site"
     *
     * @param null $member
     * @return bool
     */
    public function canEdit($member = null)
    {
        if (!$member) {
            $member = Security::getCurrentUser();
        }

        // Find the sites that this user has access to
        $goodSites = Subsite::accessible_sites('CMS_ACCESS_CMSMain', true, 'all', $member)->column('ID');

        if (!is_null($this->owner->SubsiteID)) {
            $subsiteID = $this->owner->SubsiteID;
        } else {
            // The relationships might not be available during the record creation when using a GridField.
            // In this case the related objects will have empty fields, and SubsiteID will not be available.
            //
            // We do the second best: fetch the likely SubsiteID from the session. The drawback is this might
            // make it possible to force relations to point to other (forbidden) subsites.
            $subsiteID = SubsiteState::singleton()->getSubsiteId();
        }

        // Return true if they have access to this object's site
        if (!(in_array(0, $goodSites) || in_array($subsiteID, $goodSites))) {
            return false;
        }
    }

    /**
     * @param null $member
     * @return bool
     */
    public function canDelete($member = null)
    {
        if (!$member && $member !== false) {
            $member = Security::getCurrentUser();
        }

        return $this->canEdit($member);
    }

    /**
     * @param null $member
     * @return bool
     */
    public function canAddChildren($member = null)
    {
        if (!$member && $member !== false) {
            $member = Security::getCurrentUser();
        }

        return $this->canEdit($member);
    }

    /**
     * @param null $member
     * @return bool
     */
    public function canPublish($member = null)
    {
        if (!$member && $member !== false) {
            $member = Security::getCurrentUser();
        }

        return $this->canEdit($member);
    }

    /**
     * Called by ContentController::init();
     * @param $controller
     */
    public static function contentcontrollerInit($controller)
    {
        $subsite = Subsite::currentSubsite();

        if ($subsite && $subsite->Theme) {
            SSViewer::add_themes([$subsite->Theme]);
        }

        if ($subsite && i18n::getData()->validate($subsite->Language)) {
            i18n::set_locale($subsite->Language);
        }
    }

    /**
     * @param null $action
     * @return string
     */
    public function alternateAbsoluteLink($action = null)
    {
        // Generate the existing absolute URL and replace the domain with the subsite domain.
        // This helps deal with Link() returning an absolute URL.
        $url = Director::absoluteURL($this->owner->Link($action));
        if ($this->owner->SubsiteID) {
            $url = preg_replace('/\/\/[^\/]+\//', '//' . $this->owner->Subsite()->domain() . '/', $url);
        }
        return $url;
    }

    /**
     * Use the CMS domain for iframed CMS previews to prevent single-origin violations
     * and SSL cert problems.
     * @param null $action
     * @return string
     */
    public function alternatePreviewLink($action = null)
    {
        $url = Director::absoluteURL($this->owner->Link());
        if ($this->owner->SubsiteID) {
            $url = HTTP::setGetVar('SubsiteID', $this->owner->SubsiteID, $url);
        }
        return $url;
    }

    /**
     * Inject the subsite ID into the content so it can be used by frontend scripts.
     * @param $tags
     * @return string
     */
    public function MetaTags(&$tags)
    {
        if ($this->owner->SubsiteID) {
            $tags .= '<meta name="x-subsite-id" content="' . $this->owner->SubsiteID . "\" />\n";
        }

        return $tags;
    }

    public function augmentSyncLinkTracking()
    {
        // Set LinkTracking appropriately
        $links = HTTP::getLinksIn($this->owner->Content);
        $linkedPages = [];

        if ($links) {
            foreach ($links as $link) {
                if (substr($link, 0, strlen('http://')) == 'http://') {
                    $withoutHttp = substr($link, strlen('http://'));
                    if (strpos($withoutHttp, '/') && strpos($withoutHttp, '/') < strlen($withoutHttp)) {
                        $domain = substr($withoutHttp, 0, strpos($withoutHttp, '/'));
                        $rest = substr($withoutHttp, strpos($withoutHttp, '/') + 1);

                        $subsiteID = Subsite::getSubsiteIDForDomain($domain);
                        if ($subsiteID == 0) {
                            continue;
                        } // We have no idea what the domain for the main site is, so cant track links to it

                        $origDisableSubsiteFilter = Subsite::$disable_subsite_filter;
                        Subsite::disable_subsite_filter(true);
                        $candidatePage = DataObject::get_one(
                            SiteTree::class,
                            "\"URLSegment\" = '" . Convert::raw2sql(urldecode($rest)) . "' AND \"SubsiteID\" = " . $subsiteID,
                            false
                        );
                        Subsite::disable_subsite_filter($origDisableSubsiteFilter);

                        if ($candidatePage) {
                            $linkedPages[] = $candidatePage->ID;
                        } else {
                            $this->owner->HasBrokenLink = true;
                        }
                    }
                }
            }
        }

        $this->owner->CrossSubsiteLinkTracking()->setByIDList($linkedPages);
    }

    /**
     * Ensure that valid url segments are checked within the correct subsite of the owner object,
     * even if the current subsiteID is set to some other subsite.
     *
     * @return null|bool Either true or false, or null to not influence result
     */
    public function augmentValidURLSegment()
    {
        // If this page is being filtered in the current subsite, then no custom validation query is required.
        $subsite = Subsite::$force_subsite ?: SubsiteState::singleton()->getSubsiteId();
        if (empty($this->owner->SubsiteID) || $subsite == $this->owner->SubsiteID) {
            return null;
        }

        // Backup forced subsite
        $prevForceSubsite = Subsite::$force_subsite;
        Subsite::$force_subsite = $this->owner->SubsiteID;

        // Repeat validation in the correct subsite
        $isValid = $this->owner->validURLSegment();

        // Restore
        Subsite::$force_subsite = $prevForceSubsite;

        return (bool)$isValid;
    }

    /**
     * Return a piece of text to keep DataObject cache keys appropriately specific
     */
    public function cacheKeyComponent()
    {
        return 'subsite-' . SubsiteState::singleton()->getSubsiteId();
    }

    /**
     * @param Member
     * @return boolean|null
     */
    public function canCreate($member = null)
    {
        // Typically called on a singleton, so we're not using the Subsite() relation
        $subsite = Subsite::currentSubsite();
        if ($subsite && $subsite->exists() && $subsite->PageTypeBlacklist) {
            $blacklisted = explode(',', $subsite->PageTypeBlacklist);
            // All subclasses need to be listed explicitly
            if (in_array(get_class($this->owner), $blacklisted)) {
                return false;
            }
        }
    }
}