<?php

declare(strict_types=1);

namespace App\Framework\Design\Analyzer;

use App\Framework\Design\Parser\ClassNameParser;
use App\Framework\Design\ValueObjects\ComponentPatternType;
use App\Framework\Design\ValueObjects\CssParseResult;

/**
 * Erkennt Component-Patterns in CSS
 */
final readonly class ComponentDetector
{
    public function __construct(
        private ClassNameParser $classNameParser = new ClassNameParser()
    ) {
    }

    /**
     * Erkennt alle Components im CSS
     */
    public function detectComponents(CssParseResult $parseResult): ComponentDetectionResult
    {
        $classNames = array_values($parseResult->classNames);

        if (empty($classNames)) {
            return new ComponentDetectionResult(
                totalComponents: 0,
                bemComponents: [],
                utilityComponents: [],
                traditionalComponents: [],
                patternStatistics: [],
                recommendations: ['No CSS classes found to analyze for component patterns.']
            );
        }

        // Pattern-Erkennung
        $patterns = $this->classNameParser->detectPatterns($classNames);

        // Gruppierung nach Pattern-Typ
        $bemComponents = [];
        $utilityComponents = [];
        $traditionalComponents = [];

        foreach ($patterns as $pattern) {
            switch ($pattern->type) {
                case ComponentPatternType::BEM:
                    $bemComponents[] = $pattern;

                    break;
                case ComponentPatternType::UTILITY:
                    $utilityComponents[] = $pattern;

                    break;
                case ComponentPatternType::COMPONENT:
                    $traditionalComponents[] = $pattern;

                    break;
            }
        }

        // Statistiken erstellen
        $statistics = $this->generatePatternStatistics($patterns, $classNames);

        // Empfehlungen generieren
        $recommendations = $this->generateRecommendations($bemComponents, $utilityComponents, $traditionalComponents, $classNames);

        return new ComponentDetectionResult(
            totalComponents: count($patterns),
            bemComponents: $bemComponents,
            utilityComponents: $utilityComponents,
            traditionalComponents: $traditionalComponents,
            patternStatistics: $statistics,
            recommendations: $recommendations
        );
    }

    /**
     * Analysiert spezifisch BEM-Patterns
     */
    public function analyzeBemPatterns(CssParseResult $parseResult): array
    {
        $bemClasses = $parseResult->getBemClasses();
        $analysis = [];

        foreach ($bemClasses as $className) {
            $block = $className->getBemBlock();

            if (! isset($analysis[$block])) {
                $analysis[$block] = [
                    'block' => $block,
                    'elements' => [],
                    'modifiers' => [],
                    'total_classes' => 0,
                    'completeness' => 'unknown',
                ];
            }

            $analysis[$block]['total_classes']++;

            if ($className->isBemElement()) {
                $element = $className->getBemElement();
                if ($element && ! in_array($element, $analysis[$block]['elements'])) {
                    $analysis[$block]['elements'][] = $element;
                }
            }

            if ($className->isBemModifier()) {
                $modifier = $className->getBemModifier();
                if ($modifier && ! in_array($modifier, $analysis[$block]['modifiers'])) {
                    $analysis[$block]['modifiers'][] = $modifier;
                }
            }
        }

        // Completeness-Bewertung
        foreach ($analysis as $block => &$data) {
            $hasElements = ! empty($data['elements']);
            $hasModifiers = ! empty($data['modifiers']);

            if (! $hasElements && ! $hasModifiers) {
                $data['completeness'] = 'block_only';
            } elseif ($hasElements && ! $hasModifiers) {
                $data['completeness'] = 'block_with_elements';
            } elseif (! $hasElements && $hasModifiers) {
                $data['completeness'] = 'block_with_modifiers';
            } else {
                $data['completeness'] = 'full_bem';
            }
        }

        return $analysis;
    }

    /**
     * Analysiert Utility-Class-Patterns
     */
    public function analyzeUtilityPatterns(CssParseResult $parseResult): array
    {
        $utilityClasses = $parseResult->getUtilityClasses();
        $analysis = [];

        foreach ($utilityClasses as $className) {
            $category = $className->getUtilityCategory();

            if (! $category) {
                continue;
            }

            if (! isset($analysis[$category])) {
                $analysis[$category] = [
                    'category' => $category,
                    'classes' => [],
                    'count' => 0,
                    'coverage' => 'unknown',
                ];
            }

            $analysis[$category]['classes'][] = $className->name;
            $analysis[$category]['count']++;
        }

        // Coverage-Bewertung für verschiedene Kategorien
        foreach ($analysis as $category => &$data) {
            $data['coverage'] = $this->assessUtilityCoverage($category, $data['classes']);
        }

        return $analysis;
    }

    /**
     * Findet potenzielle Component-Candidates
     */
    public function findComponentCandidates(CssParseResult $parseResult): array
    {
        $candidates = [];
        $selectorFrequency = [];

        // Analysiere Selektor-Häufigkeiten
        foreach ($parseResult->rules as $rule) {
            foreach ($rule->selectors as $selector) {
                if ($selector->getType()->value === 'class') {
                    $classes = $selector->extractClasses();

                    foreach ($classes as $class) {
                        if (! isset($selectorFrequency[$class])) {
                            $selectorFrequency[$class] = 0;
                        }
                        $selectorFrequency[$class]++;
                    }
                }
            }
        }

        // Finde Klassen mit hoher Verwendung (potenzielle Components)
        foreach ($selectorFrequency as $className => $frequency) {
            if ($frequency >= 3) { // Threshold für Component-Candidate
                $candidates[] = [
                    'class' => $className,
                    'frequency' => $frequency,
                    'potential' => $this->assessComponentPotential($className, $frequency),
                    'suggestions' => $this->getComponentSuggestions($className, $frequency),
                ];
            }
        }

        // Sortiere nach Häufigkeit
        usort($candidates, fn ($a, $b) => $b['frequency'] <=> $a['frequency']);

        return $candidates;
    }

    /**
     * Generiert Pattern-Statistiken
     */
    private function generatePatternStatistics(array $patterns, array $classNames): array
    {
        $totalClasses = count($classNames);
        $statistics = [
            'total_patterns' => count($patterns),
            'total_classes' => $totalClasses,
            'pattern_distribution' => [],
            'complexity_analysis' => [],
        ];

        $patternTypes = [];
        foreach ($patterns as $pattern) {
            $type = $pattern->type->value;

            if (! isset($patternTypes[$type])) {
                $patternTypes[$type] = 0;
            }
            $patternTypes[$type]++;
        }

        foreach ($patternTypes as $type => $count) {
            $percentage = $totalClasses > 0 ? round(($count / $totalClasses) * 100, 1) : 0;
            $statistics['pattern_distribution'][$type] = [
                'count' => $count,
                'percentage' => $percentage,
            ];
        }

        // Complexity Analysis
        foreach ($patterns as $pattern) {
            $complexity = $pattern->getComplexity();

            if (! isset($statistics['complexity_analysis'][$complexity])) {
                $statistics['complexity_analysis'][$complexity] = 0;
            }
            $statistics['complexity_analysis'][$complexity]++;
        }

        return $statistics;
    }

    /**
     * Generiert Empfehlungen
     */
    private function generateRecommendations(array $bemComponents, array $utilityComponents, array $traditionalComponents, array $classNames): array
    {
        $recommendations = [];
        $totalClasses = count($classNames);

        // BEM-Empfehlungen
        if (empty($bemComponents) && $totalClasses > 10) {
            $recommendations[] = 'Consider adopting BEM methodology for better component organization and naming consistency.';
        } elseif (! empty($bemComponents)) {
            $blocksWithoutElements = 0;
            foreach ($bemComponents as $component) {
                if (empty($component->metadata['elements'])) {
                    $blocksWithoutElements++;
                }
            }

            if ($blocksWithoutElements > count($bemComponents) / 2) {
                $recommendations[] = 'Many BEM blocks lack elements. Consider breaking down components into smaller, reusable parts.';
            }
        }

        // Utility-Empfehlungen
        if (! empty($utilityComponents)) {
            $utilityCount = array_sum(array_map(fn ($comp) => $comp->metadata['class_count'], $utilityComponents));
            $utilityPercentage = round(($utilityCount / $totalClasses) * 100, 1);

            if ($utilityPercentage > 70) {
                $recommendations[] = 'High percentage of utility classes detected. Consider consolidating repetitive patterns into components.';
            } elseif ($utilityPercentage < 10 && $totalClasses > 20) {
                $recommendations[] = 'Low usage of utility classes. Consider adding utility classes for common spacing, colors, and typography.';
            }
        }

        // Mixed Pattern Empfehlungen
        $hasMultiplePatterns = (! empty($bemComponents) ? 1 : 0) +
                              (! empty($utilityComponents) ? 1 : 0) +
                              (! empty($traditionalComponents) ? 1 : 0);

        if ($hasMultiplePatterns >= 3) {
            $recommendations[] = 'Multiple CSS methodologies detected. Consider standardizing on one primary approach for consistency.';
        }

        // Spezifische Pattern-Empfehlungen
        if (! empty($traditionalComponents)) {
            $componentTypes = array_unique(array_map(fn ($comp) => $comp->metadata['component_type'], $traditionalComponents));

            if (in_array('button', $componentTypes) && in_array('form', $componentTypes)) {
                $recommendations[] = 'Consider creating a design system with consistent button and form component patterns.';
            }
        }

        if (empty($recommendations)) {
            $recommendations[] = 'Component patterns look well organized. Consider documenting the design system for team consistency.';
        }

        return $recommendations;
    }

    /**
     * Bewertet Utility-Coverage
     */
    private function assessUtilityCoverage(string $category, array $classes): string
    {
        $expectedCoverage = [
            'spacing' => ['xs', 'sm', 'md', 'lg', 'xl'],
            'color' => ['primary', 'secondary', 'success', 'warning', 'error'],
            'typography' => ['xs', 'sm', 'base', 'lg', 'xl'],
            'sizing' => ['sm', 'md', 'lg', 'full'],
        ];

        if (! isset($expectedCoverage[$category])) {
            return 'unknown';
        }

        $expected = $expectedCoverage[$category];
        $hasExpected = 0;

        foreach ($expected as $expectedClass) {
            foreach ($classes as $actualClass) {
                if (str_contains($actualClass, $expectedClass)) {
                    $hasExpected++;

                    break;
                }
            }
        }

        $percentage = count($expected) > 0 ? ($hasExpected / count($expected)) : 0;

        if ($percentage >= 0.8) {
            return 'excellent';
        } elseif ($percentage >= 0.6) {
            return 'good';
        } elseif ($percentage >= 0.4) {
            return 'fair';
        } else {
            return 'poor';
        }
    }

    /**
     * Bewertet Component-Potenzial
     */
    private function assessComponentPotential(string $className, int $frequency): string
    {
        if ($frequency >= 10) {
            return 'high';
        } elseif ($frequency >= 6) {
            return 'medium';
        } else {
            return 'low';
        }
    }

    /**
     * Gibt Component-Verbesserungsvorschläge
     */
    private function getComponentSuggestions(string $className, int $frequency): array
    {
        $suggestions = [];

        if ($frequency >= 8) {
            $suggestions[] = 'Consider extracting into a reusable component or design token.';
        }

        if (str_contains($className, 'btn') || str_contains($className, 'button')) {
            $suggestions[] = 'Consider creating button variants (primary, secondary, outline).';
        }

        if (str_contains($className, 'card')) {
            $suggestions[] = 'Consider standardizing card padding, borders, and shadows.';
        }

        return $suggestions;
    }
}