<?php

if (!defined('ABSPATH')) {
    exit;
}

class AI_SEO_Article_Generator_AEO_Schema {
    
    private $plugin;
    
    public function __construct() {
        $this->plugin = ai_seo_article_generator();
        $this->init_hooks();
    }
    
    private function init_hooks() {
        add_action('wp_head', array($this, 'inject_aeo_schema'), 5);
        add_filter('ai_seo_article_generator_schema_types', array($this, 'get_available_schema_types'));
    }
    
    /**
     * Main method to inject AEO-optimized schema markup
     */
    public function inject_aeo_schema() {
        global $post;
        
        if (!is_single() || !$post || !get_post_meta($post->ID, 'ai_seo_article_generator_generated', true)) {
            return;
        }
        
        $content = get_post_field('post_content', $post->ID);
        $content_type = $this->detect_content_type($content);
        
        $schemas = array();
        
        switch ($content_type) {
            case 'howto':
                $schemas[] = $this->generate_howto_schema($post->ID, $content);
                break;
                
            case 'qa':
                $schemas[] = $this->generate_qapage_schema($post->ID, $content);
                break;
                
            case 'review':
                $schemas[] = $this->generate_review_schema($post->ID, $content);
                break;
                
            case 'video':
                $schemas[] = $this->generate_video_schema($post->ID, $content);
                break;
                
            default:
                $schemas[] = $this->generate_enhanced_article_schema($post->ID, $content);
                break;
        }
        
        // Always add FAQ schema if Q&A patterns detected
        $faq_schema = $this->generate_enhanced_faq_schema($post->ID, $content);
        if ($faq_schema) {
            $schemas[] = $faq_schema;
        }
        
        // Output all schemas
        foreach ($schemas as $schema) {
            if ($schema) {
                echo '<script type="application/ld+json">' . "\n";
                echo wp_json_encode($schema, JSON_UNESCAPED_UNICODE);
                echo "\n" . '</script>' . "\n";
            }
        }
    }
    
    /**
     * Auto-detect content type based on content analysis
     */
    public function detect_content_type($content) {
        $text = wp_strip_all_tags($content);
        
        // Hebrew and English patterns for different content types
        $patterns = array(
            'howto' => array(
                'hebrew' => '/(?:שלבים?|צעדים?|אופן|איך|כיצד|מדריך|הוראות|ביצוע)/ui',
                'english' => '/(?:steps?|how\s+to|guide|instructions|tutorial|process)/ui'
            ),
            'qa' => array(
                'hebrew' => '/(?:שאלות?\s+ותשובות?|ש[:\-]|ת[:\-]|שאלה|תשובה)/ui',
                'english' => '/(?:q[\s\:&]*a|question|answer|faq)/ui'
            ),
            'review' => array(
                'hebrew' => '/(?:ביקורת|סקירה|דירוג|הערכה|המלצה|כוכבים)/ui',
                'english' => '/(?:review|rating|stars?|recommendation|evaluation)/ui'
            ),
            'video' => array(
                'hebrew' => '/(?:וידאו|סרטון|צפייה|צפו|רצח)/ui',
                'english' => '/(?:video|watch|play|youtube|vimeo)/ui'
            )
        );
        
        $scores = array();
        
        foreach ($patterns as $type => $pattern_set) {
            $scores[$type] = 0;
            
            foreach ($pattern_set as $lang => $pattern) {
                $matches = preg_match_all($pattern, $text);
                if ($matches) {
                    $scores[$type] += $matches;
                }
            }
        }
        
        // Return the type with highest score, or 'article' as default
        $max_score = max($scores);
        if ($max_score >= 2) {
            return array_search($max_score, $scores);
        }
        
        return 'article';
    }
    
    /**
     * Generate HowTo schema for step-by-step content
     */
    public function generate_howto_schema($post_id, $content) {
        $post = get_post($post_id);
        
        // Extract steps from content
        $steps = $this->extract_steps($content);
        
        if (empty($steps)) {
            return false;
        }
        
        $schema = array(
            '@context' => 'https://schema.org',
            '@type' => 'HowTo',
            'name' => get_the_title($post_id),
            'description' => $this->get_post_excerpt($post_id),
            'image' => $this->get_post_image($post_id),
            'step' => array()
        );
        
        foreach ($steps as $index => $step) {
            $schema['step'][] = array(
                '@type' => 'HowToStep',
                'position' => $index + 1,
                'name' => $step['title'],
                'text' => $step['description']
            );
        }
        
        // Add estimated time if detectable
        $estimated_time = $this->extract_estimated_time($content);
        if ($estimated_time) {
            $schema['totalTime'] = $estimated_time;
        }
        
        // Add tools/supplies if mentioned
        $tools = $this->extract_tools_supplies($content);
        if (!empty($tools)) {
            $schema['tool'] = array_map(function($tool) {
                return array(
                    '@type' => 'HowToTool',
                    'name' => $tool
                );
            }, $tools);
        }
        
        return $schema;
    }
    
    /**
     * Generate QAPage schema for Q&A content
     */
    public function generate_qapage_schema($post_id, $content) {
        $qa_pairs = $this->extract_qa_pairs($content);
        
        if (empty($qa_pairs)) {
            return false;
        }
        
        $schema = array(
            '@context' => 'https://schema.org',
            '@type' => 'QAPage',
            'mainEntity' => array()
        );
        
        foreach ($qa_pairs as $qa) {
            $schema['mainEntity'][] = array(
                '@type' => 'Question',
                'name' => $qa['question'],
                'acceptedAnswer' => array(
                    '@type' => 'Answer',
                    'text' => $qa['answer'],
                    'author' => array(
                        '@type' => 'Person',
                        'name' => get_the_author_meta('display_name', get_post($post_id)->post_author)
                    )
                )
            );
        }
        
        return $schema;
    }
    
    /**
     * Generate Review schema for review content
     */
    public function generate_review_schema($post_id, $content) {
        $review_data = $this->extract_review_data($content);
        
        if (!$review_data) {
            return false;
        }
        
        $schema = array(
            '@context' => 'https://schema.org',
            '@type' => 'Review',
            'itemReviewed' => array(
                '@type' => 'Thing',
                'name' => $review_data['item_name']
            ),
            'author' => array(
                '@type' => 'Person',
                'name' => get_the_author_meta('display_name', get_post($post_id)->post_author)
            ),
            'reviewBody' => $review_data['review_text'],
            'datePublished' => get_the_date('c', $post_id)
        );
        
        if (isset($review_data['rating'])) {
            $schema['reviewRating'] = array(
                '@type' => 'Rating',
                'ratingValue' => $review_data['rating'],
                'bestRating' => $review_data['max_rating'] ?? 5
            );
        }
        
        return $schema;
    }
    
    /**
     * Generate VideoObject schema for video content
     */
    public function generate_video_schema($post_id, $content) {
        $video_data = $this->extract_video_data($content);
        
        if (!$video_data) {
            return false;
        }
        
        $schema = array(
            '@context' => 'https://schema.org',
            '@type' => 'VideoObject',
            'name' => get_the_title($post_id),
            'description' => $this->get_post_excerpt($post_id),
            'thumbnailUrl' => $this->get_post_image($post_id),
            'uploadDate' => get_the_date('c', $post_id)
        );
        
        if (isset($video_data['url'])) {
            $schema['contentUrl'] = $video_data['url'];
        }
        
        if (isset($video_data['duration'])) {
            $schema['duration'] = $video_data['duration'];
        }
        
        return $schema;
    }
    
    /**
     * Generate enhanced article schema with AEO optimizations
     */
    public function generate_enhanced_article_schema($post_id, $content) {
        $post = get_post($post_id);
        $main_keyword = get_post_meta($post_id, 'ai_seo_article_generator_main_keyword', true);
        $sub_keywords = get_post_meta($post_id, 'ai_seo_article_generator_sub_keywords', true);
        $is_hebrew = get_post_meta($post_id, 'ai_seo_article_generator_is_hebrew', true);
        
        $schema = array(
            '@context' => 'https://schema.org',
            '@type' => 'Article',
            'headline' => get_the_title($post_id),
            'description' => $this->get_post_excerpt($post_id),
            'author' => array(
                '@type' => 'Person',
                'name' => get_the_author_meta('display_name', $post->post_author),
                'url' => get_author_posts_url($post->post_author)
            ),
            'publisher' => array(
                '@type' => 'Organization',
                'name' => get_bloginfo('name'),
                'url' => home_url(),
                'logo' => array(
                    '@type' => 'ImageObject',
                    'url' => get_site_icon_url(60)
                )
            ),
            'datePublished' => get_the_date('c', $post_id),
            'dateModified' => get_the_modified_date('c', $post_id),
            'mainEntityOfPage' => array(
                '@type' => 'WebPage',
                '@id' => get_permalink($post_id)
            ),
            'image' => $this->get_post_image($post_id)
        );
        
        // Add keywords
        if ($main_keyword && $sub_keywords) {
            $schema['keywords'] = $main_keyword . ', ' . $sub_keywords;
        }
        
        // Add language
        if ($is_hebrew) {
            $schema['inLanguage'] = 'he-IL';
        }
        
        // Add article sections for better structure
        $headings = $this->extract_headings($content);
        if (!empty($headings)) {
            $schema['articleSection'] = array_map(function($h) { 
                return $h['text']; 
            }, $headings);
        }
        
        // Add word count for AEO
        $word_count = str_word_count(wp_strip_all_tags($content));
        $schema['wordCount'] = $word_count;
        
        // Add citation-ready abstract
        $abstract = $this->generate_citation_abstract($content, $main_keyword);
        if ($abstract) {
            $schema['abstract'] = $abstract;
        }
        
        return $schema;
    }
    
    /**
     * Enhanced FAQ schema with better Hebrew pattern recognition
     */
    public function generate_enhanced_faq_schema($post_id, $content) {
        $text = wp_strip_all_tags($content);
        
        // Enhanced Hebrew Q&A patterns
        $hebrew_patterns = array(
            '/(?:^|\n)(?:שאלה\s*[\d\)\.]*\s*[\:\-]?\s*)(.+?)\n(?:תשובה\s*[\d\)\.]*\s*[\:\-]?\s*)(.+?)(?=\n(?:שאלה|$))/uis',
            '/(?:^|\n)(?:ש\s*[\d\)\.]*\s*[\:\-]\s*)(.+?)\n(?:ת\s*[\d\)\.]*\s*[\:\-]\s*)(.+?)(?=\n(?:ש\s*[\d\)\.]*\s*[\:\-]|$))/uis',
            '/(?:מהו|מה זה|איך|כיצד|למה|מתי|איפה|מדוע)\s+(.+?)\?\s*\n(.+?)(?=\n(?:מהו|מה זה|איך|כיצד|למה|מתי|איפה|מדוע)|$)/uis'
        );
        
        // English Q&A patterns
        $english_patterns = array(
            '/(?:^|\n)(?:Q\s*[\d\)\.]*\s*[\:\-]?\s*)(.+?)\n(?:A\s*[\d\)\.]*\s*[\:\-]?\s*)(.+?)(?=\n(?:Q\s*[\d\)\.]*\s*[\:\-]|$))/uis',
            '/(?:What|How|Why|When|Where|Which)\s+(.+?)\?\s*\n(.+?)(?=\n(?:What|How|Why|When|Where|Which)|$)/uis'
        );
        
        $faqs = array();
        
        // Process Hebrew patterns
        foreach ($hebrew_patterns as $pattern) {
            if (preg_match_all($pattern, $text, $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    $question = trim($match[1]);
                    $answer = trim($match[2]);
                    
                    if (strlen($question) > 10 && strlen($answer) > 20) {
                        $faqs[] = array(
                            '@type' => 'Question',
                            'name' => $this->clean_hebrew_text($question),
                            'acceptedAnswer' => array(
                                '@type' => 'Answer',
                                'text' => $this->clean_hebrew_text($answer),
                                'author' => array(
                                    '@type' => 'Person',
                                    'name' => get_the_author_meta('display_name', get_post($post_id)->post_author)
                                )
                            )
                        );
                    }
                }
            }
        }
        
        // Process English patterns
        foreach ($english_patterns as $pattern) {
            if (preg_match_all($pattern, $text, $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    $question = trim($match[1]);
                    $answer = trim($match[2]);
                    
                    if (strlen($question) > 10 && strlen($answer) > 20) {
                        $faqs[] = array(
                            '@type' => 'Question',
                            'name' => $question,
                            'acceptedAnswer' => array(
                                '@type' => 'Answer',
                                'text' => $answer,
                                'author' => array(
                                    '@type' => 'Person',
                                    'name' => get_the_author_meta('display_name', get_post($post_id)->post_author)
                                )
                            )
                        );
                    }
                }
            }
        }
        
        if (count($faqs) >= 2) {
            return array(
                '@context' => 'https://schema.org',
                '@type' => 'FAQPage',
                'mainEntity' => $faqs
            );
        }
        
        return false;
    }
    
    /**
     * Get available schema types for admin interface
     */
    public function get_available_schema_types() {
        return array(
            'article' => __('Article', 'ai-seo-article-generator'),
            'howto' => __('How-To Guide', 'ai-seo-article-generator'),
            'qa' => __('Q&A Page', 'ai-seo-article-generator'),
            'review' => __('Review', 'ai-seo-article-generator'),
            'video' => __('Video Content', 'ai-seo-article-generator'),
            'faq' => __('FAQ Page', 'ai-seo-article-generator')
        );
    }
    
    // Helper methods
    
    private function extract_steps($content) {
        $text = wp_strip_all_tags($content);
        $steps = array();
        
        // Hebrew step patterns
        $hebrew_patterns = array(
            '/(?:שלב\s*[\d\)\.]+\s*[\:\-]?\s*)(.+?)(?:\n(.+?))?(?=\n(?:שלב\s*[\d\)\.]+|$))/uis',
            '/(?:צעד\s*[\d\)\.]+\s*[\:\-]?\s*)(.+?)(?:\n(.+?))?(?=\n(?:צעד\s*[\d\)\.]+|$))/uis'
        );
        
        // English step patterns
        $english_patterns = array(
            '/(?:step\s*[\d\)\.]+\s*[\:\-]?\s*)(.+?)(?:\n(.+?))?(?=\n(?:step\s*[\d\)\.]+|$))/uis',
            '/(?:^\d+\.\s*)(.+?)(?:\n(.+?))?(?=\n(?:\d+\.|$))/uis'
        );
        
        $all_patterns = array_merge($hebrew_patterns, $english_patterns);
        
        foreach ($all_patterns as $pattern) {
            if (preg_match_all($pattern, $text, $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    $title = trim($match[1]);
                    $description = isset($match[2]) ? trim($match[2]) : '';
                    
                    if (strlen($title) > 5) {
                        $steps[] = array(
                            'title' => $title,
                            'description' => $description ?: $title
                        );
                    }
                }
                break; // Use first matching pattern
            }
        }
        
        return $steps;
    }
    
    private function extract_qa_pairs($content) {
        $text = wp_strip_all_tags($content);
        $qa_pairs = array();
        
        // Use enhanced FAQ extraction logic
        $temp_schema = $this->generate_enhanced_faq_schema(0, $content);
        if ($temp_schema && isset($temp_schema['mainEntity'])) {
            foreach ($temp_schema['mainEntity'] as $item) {
                $qa_pairs[] = array(
                    'question' => $item['name'],
                    'answer' => $item['acceptedAnswer']['text']
                );
            }
        }
        
        return $qa_pairs;
    }
    
    private function extract_review_data($content) {
        $text = wp_strip_all_tags($content);
        
        // Look for rating patterns
        $rating_patterns = array(
            '/(?:דירוג|ציון|כוכבים?)\s*[\:\-]?\s*(\d+(?:\.\d+)?)\s*(?:מתוך|\/)\s*(\d+)/ui',
            '/(?:rating|score|stars?)\s*[\:\-]?\s*(\d+(?:\.\d+)?)\s*(?:out\s+of|\/)\s*(\d+)/ui',
            '/(\d+(?:\.\d+)?)\s*(?:כוכבים?|stars?)/ui'
        );
        
        $rating = null;
        $max_rating = 5;
        
        foreach ($rating_patterns as $pattern) {
            if (preg_match($pattern, $text, $matches)) {
                $rating = floatval($matches[1]);
                if (isset($matches[2])) {
                    $max_rating = intval($matches[2]);
                }
                break;
            }
        }
        
        if ($rating === null) {
            return false;
        }
        
        // Extract item name (usually from title or first heading)
        $item_name = get_the_title();
        
        return array(
            'rating' => $rating,
            'max_rating' => $max_rating,
            'item_name' => $item_name,
            'review_text' => substr($text, 0, 500) // First 500 chars as review excerpt
        );
    }
    
    private function extract_video_data($content) {
        // Look for video URLs or embeds
        if (preg_match('/(?:youtube\.com\/watch\?v=|youtu\.be\/|vimeo\.com\/)([^\s&]+)/i', $content, $matches)) {
            return array(
                'url' => $matches[0],
                'duration' => null // Could be enhanced to extract duration
            );
        }
        
        return false;
    }
    
    private function extract_estimated_time($content) {
        $text = wp_strip_all_tags($content);
        
        // Time patterns in Hebrew and English
        $time_patterns = array(
            '/(?:זמן\s+ביצוע|משך\s+זמן|לוקח)\s*[\:\-]?\s*(\d+)\s*(?:דקות?|שעות?)/ui',
            '/(?:takes?|duration|time)\s*[\:\-]?\s*(\d+)\s*(?:minutes?|hours?|mins?)/ui'
        );
        
        foreach ($time_patterns as $pattern) {
            if (preg_match($pattern, $text, $matches)) {
                $time = intval($matches[1]);
                $unit = 'M'; // Default to minutes
                
                if (strpos(strtolower($matches[0]), 'hour') !== false || 
                    strpos($matches[0], 'שעה') !== false) {
                    $unit = 'H';
                }
                
                return 'PT' . $time . $unit;
            }
        }
        
        return null;
    }
    
    private function extract_tools_supplies($content) {
        $text = wp_strip_all_tags($content);
        $tools = array();
        
        // Look for tool/supply lists
        $tool_patterns = array(
            '/(?:כלים|ציוד|חומרים)\s*[\:\-]?\s*(.+?)(?=\n\n|\n[א-ת]|\n[A-Z]|$)/uis',
            '/(?:tools?|supplies|materials?|equipment)\s*[\:\-]?\s*(.+?)(?=\n\n|\n[A-Z]|$)/uis'
        );
        
        foreach ($tool_patterns as $pattern) {
            if (preg_match($pattern, $text, $matches)) {
                $tool_text = $matches[1];
                // Split by common separators
                $items = preg_split('/[\n\-\*\d\.\)]+/', $tool_text);
                
                foreach ($items as $item) {
                    $item = trim($item);
                    if (strlen($item) > 3 && strlen($item) < 100) {
                        $tools[] = $item;
                    }
                }
                break;
            }
        }
        
        return array_slice($tools, 0, 10); // Limit to 10 tools
    }
    
    private function extract_headings($content) {
        $headings = array();
        
        if (preg_match_all('/<h([1-6])[^>]*>(.+?)<\/h[1-6]>/i', $content, $matches, PREG_SET_ORDER)) {
            foreach ($matches as $match) {
                $headings[] = array(
                    'level' => intval($match[1]),
                    'text' => wp_strip_all_tags($match[2])
                );
            }
        }
        
        return $headings;
    }
    
    private function generate_citation_abstract($content, $main_keyword) {
        $text = wp_strip_all_tags($content);
        $sentences = preg_split('/[.!?]+/', $text);
        
        // Find sentences containing the main keyword
        $relevant_sentences = array();
        
        foreach ($sentences as $sentence) {
            $sentence = trim($sentence);
            if (strlen($sentence) > 20 && strlen($sentence) < 200) {
                if (stripos($sentence, $main_keyword) !== false) {
                    $relevant_sentences[] = $sentence;
                }
            }
        }
        
        if (!empty($relevant_sentences)) {
            // Return the first relevant sentence as abstract (40-60 words ideal for AI citation)
            $abstract = $relevant_sentences[0];
            $word_count = str_word_count($abstract);
            
            if ($word_count > 60) {
                $words = explode(' ', $abstract);
                $abstract = implode(' ', array_slice($words, 0, 55)) . '...';
            }
            
            return $abstract;
        }
        
        return null;
    }
    
    private function get_post_excerpt($post_id) {
        $excerpt = get_the_excerpt($post_id);
        if (!$excerpt) {
            $content = get_post_field('post_content', $post_id);
            $excerpt = wp_trim_words(wp_strip_all_tags($content), 30);
        }
        return $excerpt;
    }
    
    private function get_post_image($post_id) {
        $image_url = get_the_post_thumbnail_url($post_id, 'large');
        
        if ($image_url) {
            return array(
                '@type' => 'ImageObject',
                'url' => $image_url,
                'width' => 1200,
                'height' => 630
            );
        }
        
        // Fallback to site icon
        $site_icon = get_site_icon_url(512);
        if ($site_icon) {
            return array(
                '@type' => 'ImageObject',
                'url' => $site_icon,
                'width' => 512,
                'height' => 512
            );
        }
        
        return null;
    }
    
    private function clean_hebrew_text($text) {
        if (!$text) return '';
        
        // Remove multiple backslashes and fix encoding issues
        $cleaned = $text;
        $cleaned = preg_replace('/```html\s*/', '', $cleaned);
        $cleaned = preg_replace('/```\s*/', '', $cleaned);
        $cleaned = preg_replace('/\\\\+\'/', "'", $cleaned);
        $cleaned = preg_replace('/\\\\+"/', '"', $cleaned);
        $cleaned = html_entity_decode($cleaned, ENT_QUOTES | ENT_HTML5, 'UTF-8');
        $cleaned = stripslashes($cleaned);
        $cleaned = preg_replace('/\s+/', ' ', $cleaned);
        
        return trim($cleaned);
    }
}