<?php

namespace App\Services;

use App\Exceptions\OllamaUnavailableException;
use App\Models\EmbeddingCache;
use App\Services\Llm\LlmClientInterface;

class EmbeddingService
{
    public function __construct(
        private readonly LlmClientInterface $llmClient,
        private readonly AppSettingsService $settings,
    ) {}

    public function embed(string $text): array
    {
        $hash = hash('sha256', $text);
        $context = $this->context();
        $cached = EmbeddingCache::query()
            ->where('provider_instance_id', $context['provider_instance_id'])
            ->where('embedding_model', $context['embedding_model'])
            ->where('text_hash', $hash)
            ->first();

        if ($cached !== null) {
            return $cached->embedding;
        }

        $embedding = $this->llmClient->embed($text);
        if (! is_array($embedding) || $embedding === []) {
            throw new OllamaUnavailableException('LLM embedding response did not include a valid embedding');
        }

        EmbeddingCache::query()->updateOrCreate(
            [
                'provider_instance_id' => $context['provider_instance_id'],
                'embedding_model' => $context['embedding_model'],
                'text_hash' => $hash,
            ],
            ['text' => $text, 'embedding' => $embedding]
        );

        return $embedding;
    }

    public function context(): array
    {
        $instance = $this->settings->activeProviderInstance();
        $instanceId = (string) ($instance['id'] ?? $this->settings->activeProviderInstanceId());
        $model = trim((string) $this->settings->get('llm.models.embedding', ''));

        if ($model === '') {
            $model = (string) ($instance['embedding_model'] ?? '');
        }

        return [
            'provider_instance_id' => $instanceId,
            'embedding_model' => $model,
        ];
    }
}