<?php

declare(strict_types=1);

namespace OCA\Memories\Db;

use OCP\DB\QueryBuilder\IQueryBuilder;
use OCP\IDBConnection;

trait TimelineQueryPeopleRecognize
{
    protected IDBConnection $connection;

    public function transformPeopleRecognitionFilter(IQueryBuilder $query, string $userId, string $faceStr, bool $isAggregate)
    {
        // Get name and uid of face user
        $faceNames = explode('/', $faceStr);
        if (2 !== \count($faceNames)) {
            throw new \Exception('Invalid face query');
        }

        // Starting with Recognize v3.6, the detections are duplicated for each user
        // So we don't need to use the user ID provided by the user, but retain
        // this here for backwards compatibility + API consistency with Face Recognition
        // $faceUid = $faceNames[0];

        $faceName = $faceNames[1];

        if (!$isAggregate) {
            // Multiple detections for the same image
            $query->addSelect('rfd.id AS faceid');
        }

        // Join with cluster
        $clusterQuery = null;
        if ('NULL' === $faceName) {
            $clusterQuery = $query->expr()->isNull('rfd.cluster_id');
        } else {
            $nameField = is_numeric($faceName) ? 'rfc.id' : 'rfc.title';
            $query->innerJoin('m', 'recognize_face_clusters', 'rfc', $query->expr()->andX(
                $query->expr()->eq('rfc.user_id', $query->createNamedParameter($userId)),
                $query->expr()->eq($nameField, $query->createNamedParameter($faceName)),
            ));
            $clusterQuery = $query->expr()->eq('rfd.cluster_id', 'rfc.id');
        }

        // Join with detections
        $query->innerJoin('m', 'recognize_face_detections', 'rfd', $query->expr()->andX(
            $query->expr()->eq('rfd.file_id', 'm.fileid'),
            $clusterQuery,
        ));
    }

    public function transformPeopleRecognizeRect(IQueryBuilder &$query, string $userId)
    {
        // Include detection params in response
        $query->addSelect(
            'rfd.width AS face_w',
            'rfd.height AS face_h',
            'rfd.x AS face_x',
            'rfd.y AS face_y',
        );
    }

    public function getPeopleRecognize(TimelineRoot &$root, string $uid)
    {
        $query = $this->connection->getQueryBuilder();

        // SELECT all face clusters
        $count = $query->func()->count($query->createFunction('DISTINCT m.fileid'), 'count');
        $query->select('rfc.id', 'rfc.user_id', 'rfc.title', $count)->from('recognize_face_clusters', 'rfc');

        // WHERE there are faces with this cluster
        $query->innerJoin('rfc', 'recognize_face_detections', 'rfd', $query->expr()->eq('rfc.id', 'rfd.cluster_id'));

        // WHERE these items are memories indexed photos
        $query->innerJoin('rfd', 'memories', 'm', $query->expr()->eq('m.fileid', 'rfd.file_id'));

        // WHERE these photos are in the user's requested folder recursively
        $query = $this->joinFilecache($query, $root, true, false);

        // WHERE this cluster belongs to the user
        $query->where($query->expr()->eq('rfc.user_id', $query->createNamedParameter($uid)));

        // GROUP by ID of face cluster
        $query->groupBy('rfc.id');

        // ORDER by number of faces in cluster
        $query->orderBy($query->createFunction("rfc.title <> ''"), 'DESC');
        $query->addOrderBy('count', 'DESC');
        $query->addOrderBy('rfc.id'); // tie-breaker

        // FETCH all faces
        $cursor = $this->executeQueryWithCTEs($query);
        $faces = $cursor->fetchAll();

        // Post process
        foreach ($faces as &$row) {
            $row['id'] = (int) $row['id'];
            $row['count'] = (int) $row['count'];
            $row['name'] = $row['title'];
            unset($row['title']);
        }

        return $faces;
    }

    public function getPeopleRecognizePhotos(int $id, TimelineRoot $root, ?int $limit): array
    {
        $query = $this->connection->getQueryBuilder();

        // SELECT face detections for ID
        $query->select(
            'rfd.file_id',              // Get actual file
            'rfd.x',                    // Image cropping
            'rfd.y',
            'rfd.width',
            'rfd.height',
            'm.w as image_width',       // Scoring
            'm.h as image_height',
            'm.fileid',
            'm.datetaken',              // Just in case, for postgres
        )->from('recognize_face_detections', 'rfd');

        // WHERE detection belongs to this cluster
        $query->where($query->expr()->eq('rfd.cluster_id', $query->createNamedParameter($id)));

        // WHERE these photos are memories indexed
        $query->innerJoin('rfd', 'memories', 'm', $query->expr()->eq('m.fileid', 'rfd.file_id'));

        // WHERE these photos are in the user's requested folder recursively
        $query = $this->joinFilecache($query, $root, true, false);

        // LIMIT results
        if (null !== $limit) {
            $query->setMaxResults($limit);
        }

        // Sort by date taken so we get recent photos
        $query->orderBy('m.datetaken', 'DESC');
        $query->addOrderBy('m.fileid', 'DESC'); // tie-breaker

        // FETCH face detections
        return $this->executeQueryWithCTEs($query)->fetchAll();
    }

    /** Convert face fields to object */
    private function processPeopleRecognizeDetection(&$row)
    {
        // Differentiate Recognize queries from Face Recognition
        if (!isset($row) || !isset($row['face_w'])) {
            return;
        }

        // Convert face rect to object
        $row['facerect'] = [
            'w' => (float) $row['face_w'],
            'h' => (float) $row['face_h'],
            'x' => (float) $row['face_x'],
            'y' => (float) $row['face_y'],
        ];

        unset($row['face_w'], $row['face_h'], $row['face_x'], $row['face_y']);
    }
}