<?php

declare(strict_types=1);

namespace Infrastructure\Persistence;

// @responsibility: Semantik-Suche und Graph-Daten für Semantic Explorer

use Domain\Repository\SemanticSearchRepositoryInterface;
use PDO;

final class SemanticSearchRepository implements SemanticSearchRepositoryInterface
{
    private PDO $db;

    public function __construct(PDO $pdo)
    {
        $this->db = $pdo;
    }

    /**
     * {@inheritDoc}
     */
    public function getSemanticStats(): array
    {
        return $this->db->query(
            'SELECT
                (SELECT COUNT(*) FROM entities) as entities,
                (SELECT COUNT(*) FROM entity_relations) as relations,
                (SELECT COUNT(*) FROM taxonomy_terms) as taxonomy,
                (SELECT COUNT(*) FROM ontology_classes) as ontology,
                (SELECT COUNT(*) FROM chunk_semantics) as semantics'
        )->fetch();
    }

    /**
     * {@inheritDoc}
     */
    public function findEntitySemantics(string $search = '', string $type = '', int $limit = 50, int $offset = 0): array
    {
        // Deduplicated entities with aggregated chunk/document counts
        $sql = 'SELECT e.id, e.name, e.canonical_name, e.type, e.description, e.status,
                       COUNT(DISTINCT ce.chunk_id) as chunk_count,
                       COUNT(DISTINCT c.document_id) as document_count,
                       MIN(ce.chunk_id) as first_chunk_id,
                       MIN(d.filename) as first_filename,
                       MIN(d.id) as first_document_id
                FROM entities e
                LEFT JOIN chunk_entities ce ON e.id = ce.entity_id
                LEFT JOIN chunks c ON ce.chunk_id = c.id
                LEFT JOIN documents d ON c.document_id = d.id
                WHERE 1=1';

        $params = [];

        if ($search !== '') {
            $sql .= ' AND (e.name LIKE :search OR e.description LIKE :search2 OR e.canonical_name LIKE :search3)';
            $params['search'] = '%' . $search . '%';
            $params['search2'] = '%' . $search . '%';
            $params['search3'] = '%' . $search . '%';
        }

        if ($type !== '') {
            $sql .= ' AND e.type = :type';
            $params['type'] = $type;
        }

        $sql .= ' GROUP BY e.id, e.name, e.canonical_name, e.type, e.description, e.status';
        $sql .= ' ORDER BY e.name LIMIT ' . $limit . ' OFFSET ' . $offset;

        $stmt = $this->db->prepare($sql);
        $stmt->execute($params);

        return $stmt->fetchAll();
    }

    /**
     * {@inheritDoc}
     */
    public function countEntitySemantics(string $search = '', string $type = ''): int
    {
        $sql = 'SELECT COUNT(DISTINCT e.id) FROM entities e WHERE e.description IS NOT NULL';
        $params = [];

        if ($search !== '') {
            $sql .= ' AND (e.name LIKE :search OR e.description LIKE :search2)';
            $params['search'] = '%' . $search . '%';
            $params['search2'] = '%' . $search . '%';
        }

        if ($type !== '') {
            $sql .= ' AND e.type = :type';
            $params['type'] = $type;
        }

        $stmt = $this->db->prepare($sql);
        $stmt->execute($params);

        return (int) $stmt->fetchColumn();
    }

    /**
     * {@inheritDoc}
     */
    public function getGraphData(): array
    {
        // Get all entities
        $entities = $this->db->query(
            'SELECT id, name, type FROM entities ORDER BY name'
        )->fetchAll();

        // Get all relations
        $relations = $this->db->query(
            'SELECT source_entity_id, target_entity_id, relation_type, strength
             FROM entity_relations'
        )->fetchAll();

        // Build node index for link resolution
        $nodeIndex = [];
        $nodes = [];
        foreach ($entities as $i => $entity) {
            $nodeIndex[$entity['id']] = $i;
            $nodes[] = [
                'id' => 'entity_' . $entity['id'],
                'label' => $entity['name'],
                'type' => strtoupper($entity['type'] ?? 'OTHER'),
                'entityId' => (int) $entity['id'],
            ];
        }

        // Build links with index references
        $links = [];
        foreach ($relations as $relation) {
            $sourceId = $relation['source_entity_id'];
            $targetId = $relation['target_entity_id'];

            // Skip if entity not found
            if (!isset($nodeIndex[$sourceId]) || !isset($nodeIndex[$targetId])) {
                continue;
            }

            $links[] = [
                'source' => $nodeIndex[$sourceId],
                'target' => $nodeIndex[$targetId],
                'type' => $relation['relation_type'],
                'strength' => (float) ($relation['strength'] ?? 1.0),
            ];
        }

        // Get unique types for stats
        $entityTypes = array_unique(array_column($nodes, 'type'));
        $relationTypes = array_unique(array_column($links, 'type'));

        return [
            'nodes' => $nodes,
            'links' => $links,
            'stats' => [
                'nodes' => count($nodes),
                'links' => count($links),
                'entityTypes' => count($entityTypes),
                'relationTypes' => count($relationTypes),
            ],
        ];
    }
}