<?php


namespace ComboStrap;

use ModificationDate;

/**
 * The class that manage the replication
 * Class Replicate
 * @package ComboStrap
 *
 * The database can also be seen as a {@link MetadataStore}
 * and an {@link Index}
 */
class DatabasePageRow
{


    /**
     * The list of attributes that are set
     * at build time
     * used in the build functions such as {@link DatabasePageRow::getDatabaseRowFromPage()}
     * to build the sql
     */
    private const PAGE_BUILD_ATTRIBUTES =
        [
            self::ROWID,
            DokuwikiId::DOKUWIKI_ID_ATTRIBUTE,
            self::ANALYTICS_ATTRIBUTE,
            PageDescription::PROPERTY_NAME,
            Canonical::PROPERTY_NAME,
            ResourceName::PROPERTY_NAME,
            PageTitle::TITLE,
            PageH1::PROPERTY_NAME,
            PagePublicationDate::PROPERTY_NAME,
            ModificationDate::PROPERTY_NAME,
            PageCreationDate::PROPERTY_NAME,
            PagePath::PROPERTY_NAME,
            StartDate::PROPERTY_NAME,
            EndDate::PROPERTY_NAME,
            Region::PROPERTY_NAME,
            Lang::PROPERTY_NAME,
            PageType::PROPERTY_NAME,
            PageId::PROPERTY_NAME,
            PageId::PAGE_ID_ABBR_ATTRIBUTE,
            \ReplicationDate::PROPERTY_NAME,
            BacklinkCount::PROPERTY_NAME
        ];
    const ANALYTICS_ATTRIBUTE = "analytics";

    /**
     * For whatever reason, the row id is lowercase
     */
    const ROWID = "rowid";

    const CANONICAL = MetadataDbStore::CANONICAL;

    /**
     * @var Page
     */
    private $page;
    /**
     * @var Sqlite|null
     */
    private $sqlite;

    /**
     * @var array
     */
    private $row;

    /**
     * Replicate constructor.
     */
    public function __construct()
    {

        /**
         * Persist on the DB
         */
        $this->sqlite = Sqlite::createOrGetSqlite();


    }

    /**
     * Delete the cache,
     * Process the analytics
     * Save it in the Db
     * Delete from the page to refresh if any
     *
     * If you want the analytics:
     *   * from the cache use {@link self::getAnalyticsFromFs()}
     *   * from the db use {@link self::getAnalyticsFromDb()}
     *
     *
     * @throws ExceptionCombo
     */
    public function replicate(): DatabasePageRow
    {
        if ($this->sqlite === null) {
            throw new ExceptionCombo("Sqlite is mandatory for database replication");
        }

        if (!$this->page->exists()) {
            throw new ExceptionCombo("You can't replicate the non-existing page ($this->page) on the file system");
        }


        /**
         * Page Replication should appears
         */
        $this->replicatePage();

        /**
         * @var Metadata $tabularMetadataToSync
         */
        $tabularMetadataToSync = [
            (new References()),
            (new Aliases())
        ];
        $fsStore = MetadataDokuWikiStore::getOrCreateFromResource($this->page);
        $dbStore = MetadataDbStore::getOrCreateFromResource($this->page);
        foreach ($tabularMetadataToSync as $tabular) {
            $tabular
                ->setResource($this->page)
                ->setReadStore($fsStore)
                ->buildFromReadStore()
                ->setWriteStore($dbStore)
                ->persist();
        }

        /**
         * Analytics (derived)
         * Should appear at the end of the replication because it is based
         * on the previous replication (ie backlink count)
         */
        $this->replicateAnalytics();


        return $this;

    }

    /**
     * @throws ExceptionCombo
     */
    public function replicateAndRebuild()
    {
        $this->replicate();
        $this->rebuild();
        return $this;
    }

    private function addPageIdMeta(array &$metaRecord)
    {
        $metaRecord[PageId::PROPERTY_NAME] = $this->page->getPageId();
        $metaRecord[PageId::PAGE_ID_ABBR_ATTRIBUTE] = $this->page->getPageIdAbbr();
    }

    public static function createFromPageId(string $pageId): DatabasePageRow
    {
        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromPageId($pageId);
        if ($row != null) {
            $databasePage->setRow($row);
        }
        return $databasePage;
    }

    public static function createFromPageObject(Page $page): DatabasePageRow
    {

        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromPage($page);
        if ($row !== null) {
            $databasePage->setRow($row);
        }
        return $databasePage;
    }

    public static function createFromPageIdAbbr(string $pageIdAbbr): DatabasePageRow
    {
        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromAttribute(PageId::PAGE_ID_ABBR_ATTRIBUTE, $pageIdAbbr);
        if ($row != null) {
            $databasePage->setRow($row);
        }
        return $databasePage;

    }

    /**
     * @param $canonical
     * @return DatabasePageRow
     */
    public static function createFromCanonical($canonical): DatabasePageRow
    {

        DokuPath::addRootSeparatorIfNotPresent($canonical);
        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromAttribute(Canonical::PROPERTY_NAME, $canonical);
        if ($row != null) {
            $databasePage->setRow($row);
        }
        return $databasePage;


    }

    public static function createFromAlias($alias): DatabasePageRow
    {

        DokuPath::addRootSeparatorIfNotPresent($alias);
        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromAlias($alias);
        if ($row != null) {
            $databasePage->setRow($row);
            $page = $databasePage->getPage();
            if ($page !== null) {
                // page may be null in production
                // PHP Fatal error:  Uncaught Error: Call to a member function setBuildAliasPath() on null in
                // /opt/www/bytle/farmer.bytle.net/lib/plugins/combo/ComboStrap/DatabasePageRow.php:220
                $page->setBuildAliasPath($alias);
            }
        }
        return $databasePage;

    }

    public static function createFromDokuWikiId($id): DatabasePageRow
    {
        $databasePage = new DatabasePageRow();
        $row = $databasePage->getDatabaseRowFromDokuWikiId($id);
        if ($row !== null) {
            $databasePage->setRow($row);
        }
        return $databasePage;
    }

    public function getPageId()
    {
        return $this->getFromRow(PageId::PROPERTY_NAME);
    }


    public
    function shouldReplicate(): bool
    {

        /**
         * When the file does not exist
         */
        $exist = FileSystems::exists($this->page->getAnalyticsDocument()->getCachePath());
        if (!$exist) {
            return true;
        }

        /**
         * When the file exists
         */
        $modifiedTime = FileSystems::getModifiedTime($this->page->getAnalyticsDocument()->getCachePath());
        $dateReplication = $this->getReplicationDate();
        if ($modifiedTime > $dateReplication) {
            return true;
        }

        /**
         * When the database version file is higher
         */
        $version = LocalPath::createFromPath(__DIR__ . "/../db/latest.version");
        $versionModifiedTime = FileSystems::getModifiedTime($version);
        if ($versionModifiedTime > $dateReplication) {
            return true;
        }

        /**
         * When the class date time is higher
         */
        $code = LocalPath::createFromPath(__DIR__ . "/DatabasePageRow.php");
        $codeModified = FileSystems::getModifiedTime($code);
        if ($codeModified > $dateReplication) {
            return true;
        }

        return false;

    }

    public
    function delete()
    {

        $request = Sqlite::createOrGetSqlite()
            ->createRequest()
            ->setQueryParametrized('delete from pages where id = ?', [$this->page->getDokuwikiId()]);
        try {
            $request->execute();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("Something went wrong when deleting the page ({$this->page}) from the database");
        } finally {
            $request->close();
        }
        $this->buildInitObjectFields();

    }

    /**
     * @return Json|null the analytics array or null if not in db
     */
    public
    function getAnalyticsData(): ?Json
    {

        $jsonString = $this->getFromRow(self::ANALYTICS_ATTRIBUTE);
        if ($jsonString === null) {
            return null;
        }
        try {
            return Json::createFromString($jsonString);
        } catch (ExceptionCombo $e) {
            LogUtility::msg("Error while building back the analytics JSON object. {$e->getMessage()}");
            return null;
        }

    }

    /**
     * Return the database row
     *
     *
     */
    private
    function getDatabaseRowFromPage(Page $page): ?array
    {

        $this->setPage($page);

        if ($this->sqlite === null) return null;

        // Do we have a page attached to this page id
        $pageId = $page->getPageId();
        if ($pageId !== null) {
            $row = $this->getDatabaseRowFromPageId($pageId);
            if ($row !== null) {
                return $row;
            }
        }

        // Do we have a page attached to the canonical
        $canonical = $page->getCanonical();
        if ($canonical != null) {
            $row = $this->getDatabaseRowFromCanonical($canonical);
            if ($row !== null) {
                return $row;
            }
        }

        // Do we have a page attached to the path
        $path = $page->getPath();
        $row = $this->getDatabaseRowFromPath($path);
        if ($row !== null) { // the path may no yet updated in the db
            return $row;
        }

        /**
         * Do we have a page attached to this ID
         */
        $id = $page->getPath()->getDokuwikiId();
        return $this->getDatabaseRowFromDokuWikiId($id);


    }


    public function getReplicationDate(): ?\DateTime
    {
        $dateString = $this->getFromRow(\ReplicationDate::getPersistentName());
        if ($dateString === null) {
            return null;
        }
        try {
            return Iso8601Date::createFromString($dateString)->getDateTime();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("Error while reading the replication date in the database. {$e->getMessage()}");
            return null;
        }

    }

    /**
     * @return bool
     * @throws ExceptionCombo
     */
    public function replicatePage(): bool
    {

        if (!$this->page->exists()) {
            throw new ExceptionCombo("You can't replicate the page ($this->page) because it does not exists.");
        }

        /**
         * Replication Date
         */
        $replicationDate = \ReplicationDate::createFromPage($this->page)
            ->setWriteStore(MetadataDbStore::class)
            ->setValue(new \DateTime());

        /**
         * Convenient variable
         */
        $page = $this->page;


        /**
         * Same data as {@link Page::getMetadataForRendering()}
         */
        $record = $this->getMetaRecord();
        $record['IS_HOME'] = ($page->isHomePage() === true ? 1 : 0);
        $record[$replicationDate::getPersistentName()] = $replicationDate->toStoreValue();

        return $this->upsertAttributes($record);

    }


    /**
     * @return bool when an update as occurred
     *
     * Attribute that are scalar / modifiable in the database
     * (not aliases or json data for instance)
     */
    public function replicateMetaAttributes(): bool
    {

        return $this->upsertAttributes($this->getMetaRecord());

    }

    public function upsertAttributes(array $attributes): bool
    {

        if ($this->sqlite === null) {
            return false;
        }

        if (empty($attributes)) {
            LogUtility::msg("The page database attribute passed should not be empty");
            return false;
        }

        $values = [];
        $columnClauses = [];
        foreach ($attributes as $key => $value) {
            if (is_array($value)) {
                throw new ExceptionComboRuntime("The attribute ($key) has value that is an array (" . implode(", ", $value) . ")");
            }
            $columnClauses[] = "$key = ?";
            $values[$key] = $value;
        }

        /**
         * Primary key has moved during the time
         * It should be the UUID but not for older version
         *
         * If the primary key is null, no record was found
         */
        $rowId = $this->getRowId();
        if ($rowId !== null) {
            /**
             * We just add the primary key
             * otherwise as this is a associative
             * array, we will miss a value for the update statement
             */
            $values[] = $rowId;

            $updateStatement = "update PAGES SET " . implode(", ", $columnClauses) . " where ROWID = ?";
            $request = $this->sqlite
                ->createRequest()
                ->setQueryParametrized($updateStatement, $values);
            $countChanges = 0;
            try {
                $countChanges = $request
                    ->execute()
                    ->getChangeCount();
            } catch (ExceptionCombo $e) {
                LogUtility::msg("There was a problem during the page attribute updates. : {$e->getMessage()}");
                return false;
            } finally {
                $request->close();
            }
            if ($countChanges !== 1) {
                LogUtility::msg("The database replication has not updated exactly 1 record but ($countChanges) record", LogUtility::LVL_MSG_ERROR, \action_plugin_combo_fulldatabasereplication::CANONICAL);
            }

        } else {

            /**
             * Creation
             */
            if ($this->page === null) {
                LogUtility::msg("The page should be defined to create a page row");
                return false;
            }
            $values[DokuwikiId::DOKUWIKI_ID_ATTRIBUTE] = $this->page->getPath()->getDokuwikiId();
            $values[PagePath::PROPERTY_NAME] = $this->page->getPath()->toAbsolutePath()->toString();
            /**
             * Default implements the auto-canonical feature
             */
            $values[Canonical::PROPERTY_NAME] = $this->page->getCanonicalOrDefault();

            /**
             * Analytics
             */
            if (!isset($values[self::ANALYTICS_ATTRIBUTE])) {
                // otherwise we get an empty string
                // and a json function will not work
                $values[self::ANALYTICS_ATTRIBUTE] = Json::createEmpty()->toPrettyJsonString();
            }

            /**
             * Page Id / Abbr are mandatory for url redirection
             */
            $this->addPageIdAttributeIfNeeded($values);

            $request = $this->sqlite
                ->createRequest()
                ->setTableRow('PAGES', $values);
            try {
                /**
                 * rowid is used in {@link DatabasePageRow::exists()}
                 * to check if the page exists in the database
                 * We update it
                 */
                $this->row[self::ROWID] = $request
                    ->execute()
                    ->getInsertId();
                $this->row = array_merge($values, $this->row);
            } catch (ExceptionCombo $e) {
                LogUtility::msg("There was a problem during the updateAttributes insert. : {$e->getMessage()}");
                return false;
            } finally {
                $request->close();
            }

        }
        return true;

    }

    public
    function getDescription()
    {
        return $this->getFromRow(PageDescription::DESCRIPTION_PROPERTY);
    }


    public
    function getPageName()
    {
        return $this->getFromRow(ResourceName::PROPERTY_NAME);
    }

    public
    function exists(): bool
    {
        return $this->getFromRow(self::ROWID) !== null;
    }

    /**
     * Called when a page is moved
     * @param $targetId
     */
    public
    function updatePathAndDokuwikiId($targetId)
    {
        if (!$this->exists()) {
            LogUtility::msg("The `database` page ($this) does not exist and cannot be moved to ($targetId)", LogUtility::LVL_MSG_ERROR);
        }

        $path = $targetId;
        DokuPath::addRootSeparatorIfNotPresent($path);
        $attributes = [
            DokuwikiId::DOKUWIKI_ID_ATTRIBUTE => $targetId,
            PagePath::PROPERTY_NAME => $path
        ];

        $this->upsertAttributes($attributes);

    }

    public
    function __toString()
    {
        return $this->page->__toString();
    }


    /**
     * Redirect are now added during a move
     * Not when a duplicate is found.
     * With the advent of the page id, it should never occurs anymore
     * @param Page $page
     * @deprecated 2012-10-28
     */
    private
    function deleteIfExistsAndAddRedirectAlias(Page $page): void
    {

        if ($this->page != null) {
            $page->getDatabasePage()->deleteIfExist();
            $this->addRedirectAliasWhileBuildingRow($page);
        }

    }

    public
    function getCanonical()
    {
        return $this->getFromRow(Canonical::PROPERTY_NAME);
    }

    /**
     * Set the field to their values
     * @param $row
     */
    public
    function setRow($row)
    {
        if ($row === null) {
            LogUtility::msg("A row should not be null");
            return;
        }
        if (!is_array($row)) {
            LogUtility::msg("A row should be an array");
            return;
        }

        /**
         * All get function lookup the row
         */
        $this->row = $row;


    }

    private
    function buildInitObjectFields()
    {
        $this->row = null;

    }

    public
    function rebuild(): DatabasePageRow
    {

        if ($this->page != null) {
            $this->page->rebuild();
            $row = $this->getDatabaseRowFromPage($this->page);
            if ($row !== null) {
                $this->setRow($row);
            }
        }
        return $this;

    }

    /**
     * @return array - an array of the fix page metadata (ie not derived)
     * Therefore quick to insert/update
     *
     */
    private
    function getMetaRecord(): array
    {
        $sourceStore = MetadataDokuWikiStore::getOrCreateFromResource($this->page);
        $targetStore = MetadataDbStore::getOrCreateFromResource($this->page);

        $record = array(
            Canonical::PROPERTY_NAME,
            PagePath::PROPERTY_NAME,
            ResourceName::PROPERTY_NAME,
            PageTitle::TITLE,
            PageH1::PROPERTY_NAME,
            PageDescription::PROPERTY_NAME,
            PageCreationDate::PROPERTY_NAME,
            ModificationDate::PROPERTY_NAME,
            PagePublicationDate::PROPERTY_NAME,
            StartDate::PROPERTY_NAME,
            EndDate::PROPERTY_NAME,
            Region::PROPERTY_NAME,
            Lang::PROPERTY_NAME,
            PageType::PROPERTY_NAME,
            DokuwikiId::DOKUWIKI_ID_ATTRIBUTE,
        );
        $metaRecord = [];
        foreach ($record as $name) {
            $metadata = Metadata::getForName($name);
            if ($metadata === null) {
                throw new ExceptionComboRuntime("The metadata ($name) is unknown");
            }
            $metaRecord[$name] = $metadata
                ->setResource($this->page)
                ->setReadStore($sourceStore)
                ->buildFromReadStore()
                ->setWriteStore($targetStore)
                ->toStoreValueOrDefault(); // used by the template, the value is or default
        }

        if ($this->page->getPageId() !== null) {
            $this->addPageIdMeta($metaRecord);
        }
        return $metaRecord;
    }

    public
    function deleteIfExist(): DatabasePageRow
    {
        if ($this->exists()) {
            $this->delete();
        }
        return $this;
    }

    public
    function getRowId()
    {
        return $this->getFromRow(self::ROWID);
    }

    private
    function getDatabaseRowFromPageId(string $pageId)
    {

        if ($this->sqlite === null) {
            return null;
        }

        $pageIdAttribute = PageId::PROPERTY_NAME;
        $query = $this->getParametrizedLookupQuery($pageIdAttribute);
        $request = Sqlite::createOrGetSqlite()
            ->createRequest()
            ->setQueryParametrized($query, [$pageId]);
        $rows = [];
        try {
            $rows = $request
                ->execute()
                ->getRows();
        } catch (ExceptionCombo $e) {
            LogUtility::msg($e->getMessage(), LogUtility::LVL_MSG_ERROR, $e->getCanonical());
            return null;
        } finally {
            $request->close();
        }

        switch (sizeof($rows)) {
            case 0:
                return null;
            case 1:
                $id = $rows[0][DokuwikiId::DOKUWIKI_ID_ATTRIBUTE];
                /**
                 * Page Id Collision detection
                 */
                if ($this->page != null && $id !== $this->page->getDokuwikiId()) {
                    $duplicatePage = Page::createPageFromId($id);
                    if (!$duplicatePage->exists()) {
                        // Move
                        LogUtility::msg("The non-existing duplicate page ($id) has been added as redirect alias for the page ($this->page)", LogUtility::LVL_MSG_INFO);
                        $this->addRedirectAliasWhileBuildingRow($duplicatePage);
                    } else {
                        // This can happens if two page were created not on the same website
                        // of if the sqlite database was deleted and rebuilt.
                        // The chance is really, really low
                        $errorMessage = "The page ($this->page) and the page ($id) have the same page id ($pageId)";
                        LogUtility::msg($errorMessage, LogUtility::LVL_MSG_ERROR, self::CANONICAL);
                        // What to do ?
                        // The database does not allow two page id with the same value
                        // If it happens, ugh, ugh, ..., a replication process between website may be.
                        return null;
                    }
                }
                return $rows[0];
            default:
                $existingPages = implode(", ", $rows);
                LogUtility::msg("The pages ($existingPages) have all the same page id ($pageId)", LogUtility::LVL_MSG_ERROR);
                return null;
        }

    }


    private
    function getParametrizedLookupQuery(string $pageIdAttribute): string
    {
        $select = Sqlite::createSelectFromTableAndColumns("pages", self::PAGE_BUILD_ATTRIBUTES);
        return "$select where $pageIdAttribute = ?";
    }


    public function setPage(Page $page)
    {
        $this->page = $page;
        return $this;
    }

    private
    function getDatabaseRowFromCanonical($canonical)
    {
        $query = $this->getParametrizedLookupQuery(Canonical::PROPERTY_NAME);
        $request = $this->sqlite
            ->createRequest()
            ->setQueryParametrized($query, [$canonical]);
        $rows = [];
        try {
            $rows = $request
                ->execute()
                ->getRows();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("An exception has occurred with the page search from CANONICAL. " . $e->getMessage());
            return null;
        } finally {
            $request->close();
        }

        switch (sizeof($rows)) {
            case 0:
                return null;
            case 1:
                $id = $rows[0][DokuwikiId::DOKUWIKI_ID_ATTRIBUTE];
                if ($this->page !== null && $id !== $this->page->getDokuwikiId()) {
                    $duplicatePage = Page::createPageFromId($id);
                    if (!$duplicatePage->exists()) {
                        $this->addRedirectAliasWhileBuildingRow($duplicatePage);
                        LogUtility::msg("The non-existing duplicate page ($id) has been added as redirect alias for the page ($this->page)", LogUtility::LVL_MSG_INFO);
                    } else {
                        LogUtility::msg("The page ($this->page) and the page ($id) have the same canonical ($canonical)", LogUtility::LVL_MSG_ERROR);
                    }
                }
                return $rows[0];
            default:
                $existingPages = [];
                foreach ($rows as $row) {
                    $id = $row[DokuwikiId::DOKUWIKI_ID_ATTRIBUTE];
                    $duplicatePage = Page::createPageFromId($id);
                    if (!$duplicatePage->exists()) {

                        $this->deleteIfExistsAndAddRedirectAlias($duplicatePage);

                    } else {

                        /**
                         * Check if the error may come from the auto-canonical
                         * (Never ever save generated data)
                         */
                        $canonicalLastNamesCount = PluginUtility::getConfValue(Canonical::CONF_CANONICAL_LAST_NAMES_COUNT, 0);
                        if ($canonicalLastNamesCount > 0) {
                            $this->page->unsetMetadata(Canonical::PROPERTY_NAME);
                            $duplicatePage->unsetMetadata(Canonical::PROPERTY_NAME);
                        }

                        $existingPages[] = $row;
                    }
                }
                if (sizeof($existingPages) === 1) {
                    return $existingPages[0];
                } else {
                    $existingPages = implode(", ", $existingPages);
                    LogUtility::msg("The existing pages ($existingPages) have all the same canonical ($canonical)", LogUtility::LVL_MSG_ERROR);
                    return null;
                }
        }
    }

    private
    function getDatabaseRowFromPath(string $path): ?array
    {
        DokuPath::addRootSeparatorIfNotPresent($path);
        return $this->getDatabaseRowFromAttribute(PagePath::PROPERTY_NAME, $path);
    }

    private
    function getDatabaseRowFromDokuWikiId(string $id): ?array
    {
        return $this->getDatabaseRowFromAttribute(DokuwikiId::DOKUWIKI_ID_ATTRIBUTE, $id);
    }

    public
    function getDatabaseRowFromAttribute(string $attribute, string $value)
    {
        $query = $this->getParametrizedLookupQuery($attribute);
        $request = $this->sqlite
            ->createRequest()
            ->setQueryParametrized($query, [$value]);
        $rows = [];
        try {
            $rows = $request
                ->execute()
                ->getRows();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("An exception has occurred with the page search from a PATH: " . $e->getMessage());
            return null;
        } finally {
            $request->close();
        }

        switch (sizeof($rows)) {
            case 0:
                return null;
            case 1:
                $value = $rows[0][DokuwikiId::DOKUWIKI_ID_ATTRIBUTE];
                if ($this->page != null && $value !== $this->page->getDokuwikiId()) {
                    $duplicatePage = Page::createPageFromId($value);
                    if (!$duplicatePage->exists()) {
                        $this->addRedirectAliasWhileBuildingRow($duplicatePage);
                    } else {
                        LogUtility::msg("The page ($this->page) and the page ($value) have the same $attribute ($value)", LogUtility::LVL_MSG_ERROR);
                    }
                }
                return $rows[0];
            default:
                $existingPages = [];
                foreach ($rows as $row) {
                    $value = $row[DokuwikiId::DOKUWIKI_ID_ATTRIBUTE];
                    $duplicatePage = Page::createPageFromId($value);
                    if (!$duplicatePage->exists()) {

                        $this->deleteIfExistsAndAddRedirectAlias($duplicatePage);

                    } else {
                        $existingPages[] = $row;
                    }
                }
                if (sizeof($existingPages) === 1) {
                    return $existingPages[0];
                } else {
                    $existingPages = implode(", ", $existingPages);
                    LogUtility::msg("The existing pages ($existingPages) have all the same $attribute ($value)", LogUtility::LVL_MSG_ERROR);
                    return null;
                }
        }
    }

    public
    function getPage(): ?Page
    {
        if (
            $this->page === null
            && $this->row[DokuwikiId::DOKUWIKI_ID_ATTRIBUTE] !== null
        ) {
            $this->page = Page::createPageFromId($this->row[DokuwikiId::DOKUWIKI_ID_ATTRIBUTE]);
        }
        return $this->page;
    }

    private
    function getDatabaseRowFromAlias($alias): ?array
    {

        $pageIdAttribute = PageId::PROPERTY_NAME;
        $buildFields = self::PAGE_BUILD_ATTRIBUTES;
        $fields = array_reduce($buildFields, function ($carry, $element) {
            if ($carry !== null) {
                return "$carry, p.{$element}";
            } else {
                return "p.{$element}";
            }
        }, null);
        $query = "select {$fields} from PAGES p, PAGE_ALIASES pa where p.{$pageIdAttribute} = pa.{$pageIdAttribute} and pa.PATH = ? ";
        $request = $this->sqlite
            ->createRequest()
            ->setQueryParametrized($query, [$alias]);
        $rows = [];
        try {
            $rows = $request
                ->execute()
                ->getRows();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("An exception has occurred with the alias selection query. {$e->getMessage()}");
            return null;
        } finally {
            $request->close();
        }
        switch (sizeof($rows)) {
            case 0:
                return null;
            case 1:
                return $rows[0];
            default:
                $id = $rows[0]['ID'];
                $pages = implode(",",
                    array_map(
                        function ($row) {
                            return $row['ID'];
                        },
                        $rows
                    )
                );
                LogUtility::msg("For the alias $alias, there is more than one page defined ($pages), the first one ($id) was used", LogUtility::LVL_MSG_ERROR, Aliases::PROPERTY_NAME);
                return $rows[0];
        }
    }


    /**
     * Utility function
     * @param Page $pageAlias
     */
    private
    function addRedirectAliasWhileBuildingRow(Page $pageAlias)
    {

        $aliasPath = $pageAlias->getPath()->toString();
        try {
            Aliases::createForPage($this->page)
                ->addAlias($aliasPath)
                ->sendToWriteStore();
        } catch (ExceptionCombo $e) {
            // we don't throw while getting
            LogUtility::msg("Unable to add the alias ($aliasPath) for the page ($this->page)");
        }

    }

    private
    function addPageIdAttributeIfNeeded(array &$values)
    {
        if (!isset($values[PageId::getPersistentName()])) {
            $values[PageId::getPersistentName()] = $this->page->getPageId();
        }
        if (!isset($values[PageId::PAGE_ID_ABBR_ATTRIBUTE])) {
            $values[PageId::PAGE_ID_ABBR_ATTRIBUTE] = $this->page->getPageIdAbbr();
        }
    }

    public
    function getFromRow(string $attribute)
    {
        if ($this->row === null) {
            return null;
        }

        if (!array_key_exists($attribute, $this->row)) {
            /**
             * An attribute should be added to {@link DatabasePageRow::PAGE_BUILD_ATTRIBUTES}
             * or in the table
             */
            throw new ExceptionComboRuntime("The metadata ($attribute) was not found in the returned database row.", $this->getCanonical());
        }

        $value = $this->row[$attribute];

        if ($value !== null) {
            return $value;
        }

        // don't know why but the sqlite plugin returns them uppercase
        // rowid is returned lowercase from the sqlite plugin
        $upperAttribute = strtoupper($attribute);
        return $this->row[$upperAttribute];

    }


    public function replicateAnalytics()
    {

        try {
            $analyticsJson = $this->page->getAnalyticsDocument()->getOrProcessJson();
        } catch (ExceptionCombo $e) {
            LogUtility::msg("Unable to replicate the analytics: " . $e->getMessage());
            return;
        }

        /**
         * Replication Date
         */
        $replicationDateMeta = \ReplicationDate::createFromPage($this->page)
            ->setWriteStore(MetadataDbStore::class)
            ->setValue(new \DateTime());

        /**
         * Analytics
         */
        $analyticsJsonAsString = $analyticsJson->toPrettyJsonString();
        $analyticsJsonAsArray = $analyticsJson->toArray();

        /**
         * Record
         */
        $record[self::ANALYTICS_ATTRIBUTE] = $analyticsJsonAsString;
        $record['IS_LOW_QUALITY'] = ($this->page->isLowQualityPage() === true ? 1 : 0);
        $record['WORD_COUNT'] = $analyticsJsonAsArray[AnalyticsDocument::STATISTICS][AnalyticsDocument::WORD_COUNT];
        $record[BacklinkCount::getPersistentName()] = $analyticsJsonAsArray[AnalyticsDocument::STATISTICS][BacklinkCount::getPersistentName()];
        $record[$replicationDateMeta::getPersistentName()] = $replicationDateMeta->toStoreValue();
        $this->upsertAttributes($record);
    }


}