<?php

namespace SilverStripe\Subsites\Extensions;

use SilverStripe\Control\Cookie;
use SilverStripe\Core\Convert;
use SilverStripe\Forms\CheckboxSetField;
use SilverStripe\Forms\FieldList;
use SilverStripe\Forms\OptionsetField;
use SilverStripe\Forms\ReadonlyField;
use SilverStripe\ORM\DataExtension;
use SilverStripe\ORM\DataQuery;
use SilverStripe\ORM\DB;
use SilverStripe\ORM\Queries\SQLSelect;
use SilverStripe\Security\Group;
use SilverStripe\Security\PermissionProvider;
use SilverStripe\Subsites\Model\Subsite;
use SilverStripe\Subsites\State\SubsiteState;

/**
 * Extension for the Group object to add subsites support
 *
 * @package subsites
 */
class GroupSubsites extends DataExtension implements PermissionProvider
{
    private static $db = [
        'AccessAllSubsites' => 'Boolean'
    ];

    private static $many_many = [
        'Subsites' => Subsite::class
    ];

    private static $defaults = [
        'AccessAllSubsites' => true
    ];

    /**
     * Migrations for GroupSubsites data.
     */
    public function requireDefaultRecords()
    {
        if (!$this->owner) {
            return;
        }
        // Migration for Group.SubsiteID data from when Groups only had a single subsite
        $ownerClass = get_class($this->owner);
        $schema = $ownerClass::getSchema();
        $groupFields = DB::field_list($schema->tableName(Group::class));

        // Detection of SubsiteID field is the trigger for old-style-subsiteID migration
        if (isset($groupFields['SubsiteID'])) {
            // Migrate subsite-specific data
            DB::query('INSERT INTO "Group_Subsites" ("GroupID", "SubsiteID")
				SELECT "ID", "SubsiteID" FROM "Group" WHERE "SubsiteID" > 0');

            // Migrate global-access data
            DB::query('UPDATE "Group" SET "AccessAllSubsites" = 1 WHERE "SubsiteID" = 0');

            // Move the field out of the way so that this migration doesn't get executed again
            DB::get_schema()->renameField(Group::class, 'SubsiteID', '_obsolete_SubsiteID');

            // No subsite access on anything means that we've just installed the subsites module.
            // Make all previous groups global-access groups
        } else {
            if (!DB::query('SELECT "Group"."ID" FROM "Group"
			LEFT JOIN "Group_Subsites" ON "Group_Subsites"."GroupID" = "Group"."ID" AND "Group_Subsites"."SubsiteID" > 0
			WHERE "AccessAllSubsites" = 1
			OR "Group_Subsites"."GroupID" IS NOT NULL ')->value()
            ) {
                DB::query('UPDATE "Group" SET "AccessAllSubsites" = 1');
            }
        }
    }

    public function updateCMSFields(FieldList $fields)
    {
        if ($this->owner->canEdit()) {
            // i18n tab
            $fields->findOrMakeTab('Root.Subsites', _t('GroupSubsites.SECURITYTABTITLE', 'Subsites'));

            $subsites = Subsite::accessible_sites(['ADMIN', 'SECURITY_SUBSITE_GROUP'], true);
            $subsiteMap = $subsites->map();

            // Prevent XSS injection
            $subsiteMap = Convert::raw2xml($subsiteMap->toArray());

            // Interface is different if you have the rights to modify subsite group values on
            // all subsites
            if (isset($subsiteMap[0])) {
                $fields->addFieldToTab('Root.Subsites', new OptionsetField(
                    'AccessAllSubsites',
                    _t('GroupSubsites.ACCESSRADIOTITLE', 'Give this group access to'),
                    [
                        1 => _t('GroupSubsites.ACCESSALL', 'All subsites'),
                        0 => _t('GroupSubsites.ACCESSONLY', 'Only these subsites'),
                    ]
                ));

                unset($subsiteMap[0]);
                $fields->addFieldToTab('Root.Subsites', new CheckboxSetField(
                    'Subsites',
                    '',
                    $subsiteMap
                ));
            } else {
                if (sizeof($subsiteMap) <= 1) {
                    $fields->addFieldToTab('Root.Subsites', new ReadonlyField(
                        'SubsitesHuman',
                        _t('GroupSubsites.ACCESSRADIOTITLE', 'Give this group access to'),
                        reset($subsiteMap)
                    ));
                } else {
                    $fields->addFieldToTab('Root.Subsites', new CheckboxSetField(
                        'Subsites',
                        _t('GroupSubsites.ACCESSRADIOTITLE', 'Give this group access to'),
                        $subsiteMap
                    ));
                }
            }
        }
    }

    /**
     * If this group belongs to a subsite,
     * append the subsites title to the group title
     * to make it easy to distinguish in the tree-view
     * of the security admin interface.
     */
    public function alternateTreeTitle()
    {
        if ($this->owner->AccessAllSubsites) {
            $title = _t('GroupSubsites.GlobalGroup', 'global group');
            return htmlspecialchars($this->owner->Title, ENT_QUOTES) . ' <i>(' . $title . ')</i>';
        }

        $subsites = Convert::raw2xml(implode(', ', $this->owner->Subsites()->column('Title')));
        return htmlspecialchars($this->owner->Title) . " <i>($subsites)</i>";
    }

    /**
     * Update any requests to limit the results to the current site
     * @param SQLSelect $query
     * @param DataQuery|null $dataQuery
     */
    public function augmentSQL(SQLSelect $query, DataQuery $dataQuery = null)
    {
        if (Subsite::$disable_subsite_filter) {
            return;
        }
        if (Cookie::get('noSubsiteFilter') == 'true') {
            return;
        }

        // If you're querying by ID, ignore the sub-site - this is a bit ugly...
        if (!$query->filtersOnID()) {
            $subsiteID = SubsiteState::singleton()->getSubsiteId();
            if ($subsiteID === null) {
                return;
            }

            // Don't filter by Group_Subsites if we've already done that
            $hasGroupSubsites = false;
            foreach ($query->getFrom() as $item) {
                if ((is_array($item) && strpos(
                    $item['table'],
                    'Group_Subsites'
                ) !== false) || (!is_array($item) && strpos(
                    $item,
                    'Group_Subsites'
                ) !== false)
                ) {
                    $hasGroupSubsites = true;
                    break;
                }
            }

            if (!$hasGroupSubsites) {
                if ($subsiteID) {
                    $query->addLeftJoin('Group_Subsites', "\"Group_Subsites\".\"GroupID\"
                        = \"Group\".\"ID\" AND \"Group_Subsites\".\"SubsiteID\" = $subsiteID");
                    $query->addWhere('("Group_Subsites"."SubsiteID" IS NOT NULL OR
                        "Group"."AccessAllSubsites" = 1)');
                } else {
                    $query->addWhere('"Group"."AccessAllSubsites" = 1');
                }
            }

            // WORKAROUND for databases that complain about an ORDER BY when the column wasn't selected (e.g. SQL Server)
            $select = $query->getSelect();
            if (isset($select[0]) && !$select[0] == 'COUNT(*)') {
                $query->addOrderBy('AccessAllSubsites', 'DESC');
            }
        }
    }

    public function onBeforeWrite()
    {
        // New record test approximated by checking whether the ID has changed.
        // Note also that the after write test is only used when we're *not* on a subsite
        if ($this->owner->isChanged('ID') && !SubsiteState::singleton()->getSubsiteId()) {
            $this->owner->AccessAllSubsites = 1;
        }
    }

    public function onAfterWrite()
    {
        // New record test approximated by checking whether the ID has changed.
        // Note also that the after write test is only used when we're on a subsite
        if ($this->owner->isChanged('ID') && $currentSubsiteID = SubsiteState::singleton()->getSubsiteId()) {
            $subsites = $this->owner->Subsites();
            $subsites->add($currentSubsiteID);
        }
    }

    public function alternateCanEdit()
    {
        // Find the sites that this group belongs to and the sites where we have appropriate perm.
        $accessibleSites = Subsite::accessible_sites('CMS_ACCESS_SecurityAdmin')->column('ID');
        $linkedSites = $this->owner->Subsites()->column('ID');

        // We are allowed to access this site if at we have CMS_ACCESS_SecurityAdmin permission on
        // at least one of the sites
        return (bool)array_intersect($accessibleSites, $linkedSites);
    }

    public function providePermissions()
    {
        return [
            'SECURITY_SUBSITE_GROUP' => [
                'name' => _t('GroupSubsites.MANAGE_SUBSITES', 'Manage subsites for groups'),
                'category' => _t('Permissions.PERMISSIONS_CATEGORY', 'Roles and access permissions'),
                'help' => _t(
                    'GroupSubsites.MANAGE_SUBSITES_HELP',
                    'Ability to limit the permissions for a group to one or more subsites.'
                ),
                'sort' => 200
            ]
        ];
    }
}