<?php

namespace App\Repositories;

use App\DTOs\ArticleCandidateDTO;
use App\Models\Article;
use App\Models\ArticleChunk;
use App\Repositories\Contracts\ArticleRepositoryInterface;

class ArticleRepository implements ArticleRepositoryInterface
{
    public function findSimilarByEmbedding(array $embedding, int $limit = 5, array $embeddingContext = [], array $filters = []): array
    {
        $vector = '['.implode(',', array_map(static fn ($value) => (float) $value, $embedding)).']';

        $chunkDistances = ArticleChunk::query()
            ->selectRaw('article_id, MIN(embedding <=> ?::vector) as distance', [$vector])
            ->whereNotNull('embedding')
            ->when((bool) ($filters['published_only'] ?? false), function ($query) {
                $query->whereHas('article', function ($articleQuery) {
                    $articleQuery
                        ->where('status', 'published')
                        ->where('is_ai_draft', false);
                });
            })
            ->when($embeddingContext !== [], function ($query) use ($embeddingContext) {
                $query
                    ->where('embedding_provider_instance_id', $embeddingContext['provider_instance_id'] ?? null)
                    ->where('embedding_model', $embeddingContext['embedding_model'] ?? null);
            })
            ->groupBy('article_id')
            ->orderByRaw('MIN(embedding <=> ?::vector)', [$vector])
            ->limit($limit)
            ->get();

        if ($chunkDistances->isEmpty()) {
            return [];
        }

        $distanceByArticleId = $chunkDistances->pluck('distance', 'article_id');
        $articleIds = $chunkDistances->pluck('article_id')->all();

        $articles = Article::query()
            ->whereIn('id', $articleIds)
            ->get()
            ->sortBy(fn (Article $a) => (float) ($distanceByArticleId[$a->id] ?? 1))
            ->values();

        return $articles
            ->map(fn (Article $article) => ArticleCandidateDTO::fromArticle($article, (float) ($distanceByArticleId[$article->id] ?? 1)))
            ->all();
    }
}