<?php

declare(strict_types=1);

namespace App\Services\NovaCards;

use App\Models\NovaCard;
use Illuminate\Support\Arr;

/**
 * AI-assist hooks for Nova Cards v3.
 *
 * This service provides assistive suggestions — it does NOT auto-publish
 * or override the creator. All suggestions are optional and editable.
 *
 * Integration strategy: each suggest* method returns a plain array of
 * suggestions. If an AI/ML backend is configured (via config/nova_cards.php),
 * this service dispatches to it; otherwise it uses deterministic rule-based
 * fallbacks. This keeps the system functional without a live AI dependency.
 */
class NovaCardAiAssistService
{
    public function suggestTags(NovaCard $card): array
    {
        $text = implode(' ', array_filter([
            $card->quote_text,
            $card->quote_author,
            $card->title,
            $card->description,
        ]));

        // Rule-based: extract meaningful words as tag suggestions.
        // In production, replace/extend with an actual NLP/AI call.
        $words = preg_split('/[\s\-_,\.]+/u', strtolower($text));
        $stopWords = ['the', 'a', 'an', 'in', 'on', 'at', 'to', 'for', 'of', 'and', 'or', 'is', 'it', 'be', 'by', 'that', 'this', 'with', 'you', 'your', 'we', 'our', 'not'];
        $filtered = array_values(array_filter(
            array_unique($words ?? []),
            fn ($w) => is_string($w) && mb_strlen($w) >= 4 && ! in_array($w, $stopWords, true),
        ));

        return array_slice($filtered, 0, 6);
    }

    public function suggestMood(NovaCard $card): array
    {
        $text = strtolower((string) $card->quote_text . ' ' . (string) $card->title);
        $moods = [];

        $moodMap = [
            'love|heart|romance|kiss|tender' => 'romantic',
            'dark|shadow|night|alone|silence|void|lost' => 'dark-poetry',
            'inspire|hope|dream|believe|courage|strength|rise' => 'inspirational',
            'morning|sunrise|calm|peace|gentle|soft|breeze' => 'soft-morning',
            'minimal|simple|quiet|still|breath|moment' => 'minimal',
            'power|bold|fierce|fire|warrior|fight|hustle' => 'motivational',
            'cyber|neon|digital|code|matrix|tech|signal' => 'cyber-mood',
        ];

        foreach ($moodMap as $pattern => $mood) {
            if (preg_match('/(' . $pattern . ')/i', $text)) {
                $moods[] = $mood;
            }
        }

        return array_slice(array_unique($moods), 0, 3);
    }

    public function suggestLayout(NovaCard $card): array
    {
        $project = is_array($card->project_json) ? $card->project_json : [];
        $quoteLength = mb_strlen((string) $card->quote_text);
        $hasAuthor = ! empty($card->quote_author);

        // Heuristic layout suggestions based on text content.
        $suggestions = [];

        if ($quoteLength < 80) {
            $suggestions[] = [
                'layout' => 'quote_centered',
                'reason' => 'Short quotes work well centered with generous padding.',
            ];
        } elseif ($quoteLength < 200) {
            $suggestions[] = [
                'layout' => 'quote_heavy',
                'reason' => 'Medium quotes benefit from a focused heavy layout.',
            ];
        } else {
            $suggestions[] = [
                'layout' => 'editorial',
                'reason' => 'Longer quotes fit editorial multi-column layouts.',
            ];
        }

        if ($hasAuthor) {
            $suggestions[] = [
                'layout' => 'byline_bottom',
                'reason' => 'With an author, a bottom byline anchors attribution cleanly.',
            ];
        }

        return $suggestions;
    }

    public function suggestBackground(NovaCard $card): array
    {
        $moods = $this->suggestMood($card);
        $suggestions = [];

        $moodGradientMap = [
            'romantic' => ['gradient_preset' => 'rose-poetry', 'reason' => 'Warm rose tones suit romantic content.'],
            'dark-poetry' => ['gradient_preset' => 'midnight-nova', 'reason' => 'Deep dark gradients amplify dark poetry vibes.'],
            'inspirational' => ['gradient_preset' => 'golden-hour', 'reason' => 'Warm golden tones elevate inspirational messages.'],
            'soft-morning' => ['gradient_preset' => 'soft-dawn', 'reason' => 'Gentle pastels suit morning or calm content.'],
            'minimal' => ['gradient_preset' => 'carbon-minimal', 'reason' => 'Clean dark or light neutrals suit minimal style.'],
            'motivational' => ['gradient_preset' => 'bold-fire', 'reason' => 'Bold warm gradients energise motivational content.'],
            'cyber-mood' => ['gradient_preset' => 'cyber-pulse', 'reason' => 'Electric neon gradients suit cyber aesthetic.'],
        ];

        foreach ($moods as $mood) {
            if (isset($moodGradientMap[$mood])) {
                $suggestions[] = $moodGradientMap[$mood];
            }
        }

        // Default if no match.
        if (empty($suggestions)) {
            $suggestions[] = ['gradient_preset' => 'midnight-nova', 'reason' => 'A versatile dark gradient that works for most content.'];
        }

        return $suggestions;
    }

    public function suggestFontPairing(NovaCard $card): array
    {
        $moods = $this->suggestMood($card);

        $moodFontMap = [
            'romantic' => ['font_preset' => 'romantic-serif', 'reason' => 'Elegant serif pairs beautifully with romantic content.'],
            'dark-poetry' => ['font_preset' => 'dark-poetic', 'reason' => 'Strong contrast serif pairs with dark poetry style.'],
            'inspirational' => ['font_preset' => 'modern-sans', 'reason' => 'Clean modern sans feels energising and clear.'],
            'soft-morning' => ['font_preset' => 'soft-rounded', 'reason' => 'Rounded type has warmth and approachability.'],
            'minimal' => ['font_preset' => 'minimal-mono', 'reason' => 'Monospaced type enforces a minimalist aesthetic.'],
            'cyber-mood' => ['font_preset' => 'cyber-display', 'reason' => 'Tech display fonts suit cyber and digital themes.'],
        ];

        foreach ($moods as $mood) {
            if (isset($moodFontMap[$mood])) {
                return [$moodFontMap[$mood]];
            }
        }

        return [['font_preset' => 'modern-sans', 'reason' => 'A clean, versatile sans-serif for most content.']];
    }

    public function suggestReadabilityFixes(NovaCard $card): array
    {
        $issues = [];
        $project = is_array($card->project_json) ? $card->project_json : [];

        $textColor = Arr::get($project, 'typography.text_color', '#ffffff');
        $bgType = Arr::get($project, 'background.type', 'gradient');
        $overlayStyle = Arr::get($project, 'background.overlay_style', 'dark-soft');
        $quoteSize = (int) Arr::get($project, 'typography.quote_size', 72);
        $lineHeight = (float) Arr::get($project, 'typography.line_height', 1.2);

        // Detect light text without overlay on upload background.
        if ($bgType === 'upload' && in_array($overlayStyle, ['none', 'minimal'], true)) {
            $issues[] = [
                'field' => 'background.overlay_style',
                'message' => 'Adding a dark overlay improves text legibility on photo backgrounds.',
                'suggestion' => 'dark-soft',
            ];
        }

        // Detect very small quote text.
        if ($quoteSize < 40) {
            $issues[] = [
                'field' => 'typography.quote_size',
                'message' => 'Quote text may be too small to read on mobile.',
                'suggestion' => 52,
            ];
        }

        // Detect very tight line height on long text.
        if ($lineHeight < 1.1 && mb_strlen((string) $card->quote_text) > 100) {
            $issues[] = [
                'field' => 'typography.line_height',
                'message' => 'Increasing line height improves readability for longer quotes.',
                'suggestion' => 1.3,
            ];
        }

        return $issues;
    }

    /**
     * Return all suggestions in one call, for the AI assist panel.
     */
    public function allSuggestions(NovaCard $card): array
    {
        return [
            'tags' => $this->suggestTags($card),
            'moods' => $this->suggestMood($card),
            'layouts' => $this->suggestLayout($card),
            'backgrounds' => $this->suggestBackground($card),
            'font_pairings' => $this->suggestFontPairing($card),
            'readability_fixes' => $this->suggestReadabilityFixes($card),
        ];
    }
}