<?php

namespace App\Infrastructure\PostgreSQL\Repository\EmbeddingRepository;

use Doctrine\DBAL\Connection;
use App\Domain\Repository\EmbeddingRepository;
use App\Domain\Model\Embedding\Embedding;
use App\Domain\Model\Embedding\LargeEmbeddingVector;
use App\Domain\Model\Embedding\SmallEmbeddingVector;
use App\Domain\Model\EmbeddingCollection;
use App\Domain\Model\Value\Vector;
use App\Domain\Model\Id\EmbeddingId;
use App\Domain\Model\Id\EmbeddingIdCollection;

final class SqlEmbeddingRepository implements EmbeddingRepository
{
    public function __construct(
        private readonly Connection $connection,
    ) {}

    public function save(Embedding $embedding): void
    {
        $this->connection->executeStatement(
            'INSERT INTO embeddings (id, phrase_hash, phrase, large_embedding_vector, small_embedding_vector) VALUES (?, ?, ?, ?, ?) ON CONFLICT DO NOTHING',
            [
                $embedding->embeddingId->value,
                $embedding->phraseHash(),
                $embedding->phrase,
                $embedding->largeEmbeddingVector !== null 
                    ? '[' . implode(',', $embedding->largeEmbeddingVector->vector->values) . ']' 
                    : null,
                $embedding->smallEmbeddingVector !== null 
                    ? '[' . implode(',', $embedding->smallEmbeddingVector->vector->values) . ']' 
                    : null,
            ]
        );
    }

    public function saveAll(EmbeddingCollection $embeddingCollection): void
    {
        foreach ($embeddingCollection->array() as $embedding) {    
            $this->save($embedding);
        }
    }

    public function delete(Embedding $embedding): void
    {
        $this->connection->executeStatement(
            'DELETE FROM embeddings WHERE id = ?',
            [$embedding->embeddingId->value]
        );
    }

    public function findByPhrase(string $phrase): ?Embedding
    {
        $result = $this->connection->executeQuery(
            'SELECT * FROM embeddings WHERE phrase = ?',
            [$phrase]
        );

        $row = $result->fetchAssociative();
        if ($row === false) {
            return null;
        }

        return $this->mapRowToEmbedding($row);
    }

    public function searchByLargeEmbeddingVector(LargeEmbeddingVector $embeddingVector, int $limit = 20): EmbeddingCollection
    {
        $result = $this->connection->executeQuery(
            'SELECT *, large_embedding_vector <=> :embeddingVector AS distance
             FROM embeddings 
             WHERE large_embedding_vector IS NOT NULL
             ORDER BY large_embedding_vector <=> :embeddingVector
             LIMIT :limit',
            [
                'embeddingVector' => '[' . implode(',', $embeddingVector->vector->values) . ']',
                'limit' => $limit,
            ]
        );

        $embeddings = [];
        foreach ($result->fetchAllAssociative() as $row) {
            $embeddings[] = $this->mapRowToEmbedding($row);
        }

        return new EmbeddingCollection($embeddings);
    }

    public function searchBySmallEmbeddingVector(SmallEmbeddingVector $smallEmbeddingVector, int $limit = 20): EmbeddingCollection
    {
        $result = $this->connection->executeQuery(
            'SELECT *
             FROM embeddings 
             WHERE small_embedding_vector IS NOT NULL 
             ORDER BY small_embedding_vector <=> ? 
             LIMIT ?',
            [
                '[' . implode(',', $smallEmbeddingVector->vector->values) . ']',
                $limit,
            ]
        );

        $embeddings = [];
        foreach ($result->fetchAllAssociative() as $row) {
            $embeddings[] = $this->mapRowToEmbedding($row);
        }

        return new EmbeddingCollection($embeddings);
    }

    public function findByEmbeddingIdCollection(EmbeddingIdCollection $embeddingIdCollection): EmbeddingCollection
    {
        $ids = implode(',', array_map(fn(EmbeddingId $id) => $id->value, $embeddingIdCollection->array()));

        $result = $this->connection->executeQuery(
            "SELECT * FROM embeddings WHERE id IN ($ids)",
        );

        $embeddings = [];
        foreach ($result->fetchAllAssociative() as $row) {
            $embeddings[] = $this->mapRowToEmbedding($row);
        }

        return new EmbeddingCollection($embeddings);
    }

    public function deleteAll(): void
    {
        $this->connection->executeStatement('DELETE FROM embeddings');
    }

    /**
     * @param array<string, mixed> $row
     */
    private function mapRowToEmbedding(array $row): Embedding
    {
        $largeEmbeddingVector = null;
        if (is_string($row['large_embedding_vector'] ?? null)) {
            $largeValues = json_decode($row['large_embedding_vector'], true);
            if (is_array($largeValues)) {
                $floatValues = [];
                foreach ($largeValues as $value) {
                    if (is_numeric($value)) {
                        $floatValues[] = (float) $value;
                    }
                }
                if (count($floatValues) === count($largeValues)) {
                    $largeEmbeddingVector = new LargeEmbeddingVector(new Vector($floatValues));
                }
            }
        }

        $smallEmbeddingVector = null;
        if (is_string($row['small_embedding_vector'] ?? null)) {
            $smallValues = json_decode($row['small_embedding_vector'], true);
            if (is_array($smallValues)) {
                $floatValues = [];
                foreach ($smallValues as $value) {
                    if (is_numeric($value)) {
                        $floatValues[] = (float) $value;
                    }
                }
                if (count($floatValues) === count($smallValues)) {
                    $smallEmbeddingVector = new SmallEmbeddingVector(new Vector($floatValues));
                }
            }
        }

        return new Embedding(
            embeddingId: new EmbeddingId(is_string($row['id'] ?? null) ? $row['id'] : throw new \InvalidArgumentException('Embedding ID is required')),
            phrase: is_string($row['phrase'] ?? null) ? $row['phrase'] : throw new \InvalidArgumentException('Phrase is required'),
            largeEmbeddingVector: $largeEmbeddingVector,
            smallEmbeddingVector: $smallEmbeddingVector,
        );
    }
}