<?php

namespace App\Services;

use App\Models\Memory;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Pgvector\Laravel\Distance;
use Pgvector\Laravel\Vector;

class MemoryService
{
    public function __construct(
        protected ?string $ollamaUrl = null,
        protected ?string $embedModel = null,
    ) {
        $this->ollamaUrl ??= config('services.ollama.url');
        $this->embedModel ??= config('services.ollama.embedding_model');
    }

    /**
     * Erstellt ein Embedding via Ollama und persistiert die Memory.
     */
    public function remember(string $content, array $metadata = []): Memory
    {
        $embedding = $this->embed($content);

        return Memory::create([
            'content' => $content,
            'metadata' => $metadata,
            'embedding' => $embedding ? new Vector($embedding) : null,
        ]);
    }

    /**
     * @return array<int, Memory>
     */
    public function recall(string $query, int $limit = 5): array
    {
        $embedding = $this->embed($query);
        if ($embedding === null) {
            return Memory::latest()->limit($limit)->get()->all();
        }

        return Memory::query()
            ->nearestNeighbors('embedding', new Vector($embedding), Distance::Cosine)
            ->limit($limit)
            ->get()
            ->all();
    }

    /**
     * Erzeugt ein Embedding über die Ollama /api/embeddings Schnittstelle.
     *
     * @return array<int, float>|null
     */
    public function embed(string $text): ?array
    {
        try {
            $response = Http::timeout(30)
                ->post(rtrim($this->ollamaUrl, '/').'/api/embeddings', [
                    'model' => $this->embedModel,
                    'prompt' => $text,
                ]);

            if (! $response->successful()) {
                Log::warning('Embedding-Request fehlgeschlagen', ['status' => $response->status()]);

                return null;
            }

            return $response->json('embedding');
        } catch (\Throwable $e) {
            Log::error('Embedding-Fehler', ['exception' => $e->getMessage()]);

            return null;
        }
    }

    public function summarizeRecent(int $limit = 10): string
    {
        $memories = Memory::latest()->limit($limit)->get();

        return $memories
            ->map(fn (Memory $m) => '- '.str($m->content)->limit(160))
            ->implode("\n");
    }
}