<?php

namespace App\Services;

use App\Models\AIDecision;
use App\Models\Article;
use App\Models\Ticket;
use App\Repositories\Contracts\ArticleRepositoryInterface;

class SemanticSearchService
{
    public function __construct(
        private readonly EmbeddingService $embeddingService,
        private readonly ArticleRepositoryInterface $articleRepository,
        private readonly AIClassifierService $classifierService,
    ) {}

    public function findBestArticle(Ticket $ticket): array
    {
        $queryText = $ticket->normalized_message ?: $ticket->message;
        $language = (string) ($ticket->redaction_report['language'] ?? 'nl');
        $embeddingContext = $this->embeddingService->context();

        $ticketEmbeddingIsCurrent = $ticket->embedding !== null
            && $ticket->embedding_provider_instance_id === $embeddingContext['provider_instance_id']
            && $ticket->embedding_model === $embeddingContext['embedding_model'];

        $embedding = $ticketEmbeddingIsCurrent ? $ticket->embedding : $this->embeddingService->embed($queryText);
        if (! $ticketEmbeddingIsCurrent) {
            $ticket->embedding = $embedding;
            $ticket->embedding_provider_instance_id = $embeddingContext['provider_instance_id'];
            $ticket->embedding_model = $embeddingContext['embedding_model'];
            $ticket->embedded_at = now();
            $ticket->save();
        }

        $rawCandidates = $this->articleRepository->findSimilarByEmbedding($embedding, 12, $embeddingContext);
        $candidates = $this->prepareCandidates($queryText, $rawCandidates, 5);
        $classification = $this->classifierService->rank($queryText, $candidates, $language);

        $bestArticle = $classification->articleId ? Article::find($classification->articleId) : null;

        AIDecision::query()->create([
            'ticket_id' => $ticket->id,
            'article_id' => $bestArticle?->id,
            'confidence' => $classification->confidence,
            'explanation' => $classification->explanation,
            'raw_response' => $classification->rawResponse,
        ]);

        return [
            'best_article' => $bestArticle,
            'confidence' => $classification->confidence,
            'explanation' => $classification->explanation,
            'top_3_candidates' => collect($candidates)->take(3)->map(fn ($c) => $c->toArray())->values()->all(),
            'top_5_candidates' => collect($candidates)->map(fn ($c) => $c->toArray())->values()->all(),
            'retrieval_meta' => [
                'raw_candidates_count' => count($rawCandidates),
                'deduped_candidates_count' => count($candidates),
            ],
            'requested_tool_call' => $classification->toolCall,
            'classifier_raw_response' => $classification->rawResponse,
        ];
    }

    private function prepareCandidates(string $queryText, array $candidates, int $limit): array
    {
        $seen = [];
        $unique = [];

        foreach ($candidates as $candidate) {
            $dedupeKey = $candidate->sourceArticleId
                ? 'source_id:'.$candidate->sourceArticleId
                : ($candidate->sourceUrl ? 'source_url:'.$candidate->sourceUrl : 'article:'.$candidate->articleId);

            if (isset($seen[$dedupeKey])) {
                continue;
            }

            $seen[$dedupeKey] = true;
            $unique[] = $candidate;
        }

        $query = mb_strtolower($queryText);
        $isHowTo = str_contains($query, 'hoe') || str_contains($query, 'instel') || str_contains($query, 'stap');

        usort($unique, function ($a, $b) use ($isHowTo) {
            $scoreA = $this->candidateScore($a->title.' '.$a->content, $a->distance, $isHowTo);
            $scoreB = $this->candidateScore($b->title.' '.$b->content, $b->distance, $isHowTo);

            return $scoreB <=> $scoreA;
        });

        return array_values(array_slice($unique, 0, $limit));
    }

    private function candidateScore(string $text, float $distance, bool $isHowTo): float
    {
        $score = 1.0 - $distance;
        $haystack = mb_strtolower($text);

        if ($isHowTo) {
            $proceduralKeywords = ['hoe', 'stap', 'instellen', 'aanmaken', 'wijzigen', 'klik', 'menu', 'beheren', 'dns'];
            foreach ($proceduralKeywords as $keyword) {
                if (str_contains($haystack, $keyword)) {
                    $score += 0.03;
                }
            }
        }

        return $score;
    }
}