<?php

declare(strict_types=1);

namespace TFGraphics\SmartImport\Integration;

use TFGraphics\SmartImport\Domain\DTO\AttributeDTO;
use TFGraphics\SmartImport\Domain\Search\MediaType;
use TFGraphics\SmartImport\ProductIntelligence\MergeDecision;
use TFGraphics\SmartImport\ProductIntelligence\ProductScore;

final class PreviewIntelligenceService
{
    private float $lowConfidenceThreshold;

    public function __construct(float $lowConfidenceThreshold = 0.50)
    {
        $this->lowConfidenceThreshold = max(0.0, min(1.0, $lowConfidenceThreshold));
    }

    public function analyze(IntegrationResult $result): PreviewAnalysis
    {
        if (! $result->isEnabled()) {
            return new PreviewAnalysis($result);
        }

        $productScore = $result->getProductScore();
        $confidence = $result->getConfidenceReport();
        $quality = $result->getQualityReport();
        $qualitySummary = $quality !== null
            ? new PreviewQualitySummary(
                $quality->getOverallGrade(),
                $quality->getOverallScore(),
                $quality->getStrengths(),
                $quality->getWeaknesses(),
                $quality->getMissingInformation()
            )
            : null;

        return new PreviewAnalysis(
            $result,
            $productScore !== null ? $productScore->getConfidenceScore() : null,
            $confidence !== null ? $confidence->getOverallScore() : null,
            $qualitySummary,
            $this->mergeSummary($productScore),
            $this->recommendations($result)
        );
    }

    public function getAiSuggestions(IntegrationResult $result): array
    {
        return [];
    }

    public function getSeoSuggestions(IntegrationResult $result): array
    {
        return [];
    }

    public function getMetadataSuggestions(IntegrationResult $result): array
    {
        return [];
    }

    private function mergeSummary(?ProductScore $productScore): array
    {
        if ($productScore === null || $productScore->getMergeTrace() === null) {
            return [];
        }

        $summary = [];
        foreach ($productScore->getMergeTrace()->getDecisions() as $field => $decision) {
            if (! $decision instanceof MergeDecision) {
                continue;
            }
            $summary[$field] = [
                'selected_provider' => $decision->getSelectedProvider(),
                'rejected_providers' => $decision->getRejectedProviders(),
                'reason' => $decision->getReason(),
                'score' => $decision->getScore(),
                'timestamp' => $decision->getTimestamp(),
            ];
        }

        return $summary;
    }

    private function recommendations(IntegrationResult $result): array
    {
        $recommendations = [];
        $productScore = $result->getProductScore();
        $confidence = $result->getConfidenceReport();
        $quality = $result->getQualityReport();

        if ($this->isMissing($productScore, 'description')) {
            $recommendations[] = new PreviewRecommendation(
                'missing_description',
                'Descrizione mancante',
                PreviewRecommendation::TYPE_DATA,
                'description',
                'high'
            );
        }
        if ($quality !== null && in_array('image_quality', $quality->getWeaknesses(), true)) {
            $recommendations[] = new PreviewRecommendation(
                'low_quality_images',
                'Immagini di bassa qualità',
                PreviewRecommendation::TYPE_QUALITY,
                'images',
                'high'
            );
        }
        if ($confidence !== null && in_array('publisher', $confidence->getConflictingFields(), true)) {
            $recommendations[] = new PreviewRecommendation(
                'conflicting_publisher',
                'Editore in conflitto',
                PreviewRecommendation::TYPE_CONFLICT,
                'publisher',
                'medium'
            );
        }
        if ($this->requiresIsbn($productScore) && ! $this->hasIsbn($productScore)) {
            $recommendations[] = new PreviewRecommendation(
                'missing_isbn',
                'ISBN mancante',
                PreviewRecommendation::TYPE_DATA,
                'identifiers',
                'medium'
            );
        }
        if ($quality !== null && in_array('metadata_richness', $quality->getWeaknesses(), true)) {
            $recommendations[] = new PreviewRecommendation(
                'weak_metadata',
                'Metadati poco completi',
                PreviewRecommendation::TYPE_METADATA,
                null,
                'medium'
            );
        }
        if ($confidence !== null && $confidence->getOverallScore() < $this->lowConfidenceThreshold) {
            $recommendations[] = new PreviewRecommendation(
                'low_confidence',
                'Affidabilità bassa',
                PreviewRecommendation::TYPE_QUALITY,
                null,
                'high'
            );
        }

        return $recommendations;
    }

    private function requiresIsbn(?ProductScore $productScore): bool
    {
        if ($productScore === null) {
            return false;
        }

        $attributesField = $productScore->getField('attributes');
        if ($attributesField === null || ! is_array($attributesField->getValue())) {
            return false;
        }

        foreach ($attributesField->getValue() as $attribute) {
            if (! $attribute instanceof AttributeDTO || strtolower(trim($attribute->getName())) !== 'media_type') {
                continue;
            }

            return MediaType::normalize($attribute->getValue()) === MediaType::BOOK;
        }

        return false;
    }

    private function isMissing(?ProductScore $productScore, string $field): bool
    {
        return $productScore === null || $productScore->getField($field) === null;
    }

    private function hasIsbn(?ProductScore $productScore): bool
    {
        if ($productScore === null || $productScore->getField('identifiers') === null) {
            return false;
        }

        $identifiers = $productScore->getField('identifiers')->getValue();
        if (! is_array($identifiers)) {
            return false;
        }

        return ! empty($identifiers['isbn']) || ! empty($identifiers['isbn10']) || ! empty($identifiers['isbn13']);
    }
}