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ThinkRank AI SEO – AI SEO Plugin for WordPress: Schema, XML Sitemaps, Meta Tags, Search Console & Local SEO / 1.1.0
ThinkRank AI SEO – AI SEO Plugin for WordPress: Schema, XML Sitemaps, Meta Tags, Search Console & Local SEO v1.1.0
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thinkrank / includes / seo / class-ai-content-analyzer.php

class-ai-content-analyzer.php in ThinkRank AI SEO – AI SEO Plugin for WordPress: Schema, XML Sitemaps, Meta Tags, Search Console & Local SEO 1.1.0, at includes/seo/class-ai-content-analyzer.php

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1 <?php
2 /**
3 * AI Content Analyzer Class
4 *
5 * Comprehensive AI-powered content analysis with real algorithms for readability,
6 * keyword density, semantic analysis, and content optimization. Implements 2025
7 * SEO best practices with industry-standard calculations and recommendations.
8 *
9 * @package ThinkRank
10 * @subpackage SEO
11 * @since 1.0.0
12 */
13
14 declare(strict_types=1);
15
16 namespace ThinkRank\SEO;
17
18 /**
19 * AI Content Analyzer Class
20 *
21 * Provides comprehensive content analysis using real AI algorithms including
22 * readability scoring, keyword analysis, semantic content analysis, and
23 * structure optimization with actionable recommendations.
24 *
25 * @since 1.0.0
26 */
27 class AI_Content_Analyzer extends Abstract_SEO_Manager {
28
29 /**
30 * Content analysis algorithms with their specifications
31 *
32 * @since 1.0.0
33 * @var array
34 */
35 private array $analysis_algorithms = [
36 'readability' => [
37 'flesch_reading_ease' => [
38 'name' => 'Flesch Reading Ease',
39 'formula' => '206.835 - (1.015 × ASL) - (84.6 × ASW)',
40 'scale' => [90 => 'Very Easy', 80 => 'Easy', 70 => 'Fairly Easy', 60 => 'Standard', 50 => 'Fairly Difficult', 30 => 'Difficult', 0 => 'Very Difficult'],
41 'weight' => 40
42 ],
43 'flesch_kincaid_grade' => [
44 'name' => 'Flesch-Kincaid Grade Level',
45 'formula' => '(0.39 × ASL) + (11.8 × ASW) - 15.59',
46 'target_range' => [6, 8],
47 'weight' => 30
48 ],
49 'automated_readability_index' => [
50 'name' => 'Automated Readability Index',
51 'formula' => '(4.71 × CPW) + (0.5 × SPW) - 21.43',
52 'target_range' => [6, 10],
53 'weight' => 30
54 ]
55 ],
56 'keyword_analysis' => [
57 'density_calculation' => [
58 'optimal_range' => [1.0, 3.0], // 1-3% keyword density
59 'warning_threshold' => 5.0, // Above 5% is keyword stuffing
60 'minimum_threshold' => 0.5 // Below 0.5% is under-optimized
61 ],
62 'proximity_analysis' => [
63 'ideal_distance' => 100, // Words between keyword occurrences
64 'clustering_threshold' => 50 // Words indicating keyword clustering
65 ],
66 'semantic_variations' => [
67 'synonym_weight' => 0.7,
68 'related_terms_weight' => 0.5,
69 'lsi_keywords_weight' => 0.8
70 ]
71 ],
72 'content_structure' => [
73 'heading_hierarchy' => [
74 'h1_count' => ['min' => 1, 'max' => 1],
75 'h2_count' => ['min' => 2, 'max' => 10],
76 'h3_count' => ['min' => 0, 'max' => 20],
77 'proper_nesting' => true
78 ],
79 'paragraph_analysis' => [
80 'ideal_length' => [50, 150], // Words per paragraph
81 'max_sentences' => 4,
82 'transition_words_ratio' => 0.3
83 ],
84 'content_length' => [
85 'blog_post' => ['min' => 300, 'optimal' => 1500, 'max' => 3000],
86 'product_page' => ['min' => 200, 'optimal' => 800, 'max' => 1500],
87 'landing_page' => ['min' => 500, 'optimal' => 2000, 'max' => 4000]
88 ]
89 ]
90 ];
91
92 /**
93 * Semantic analysis capabilities
94 *
95 * @since 1.0.0
96 * @var array
97 */
98 private array $semantic_capabilities = [
99 'topic_modeling' => [
100 'enabled' => true,
101 'min_topics' => 3,
102 'max_topics' => 10,
103 'coherence_threshold' => 0.7
104 ],
105 'entity_recognition' => [
106 'enabled' => true,
107 'entity_types' => ['PERSON', 'ORGANIZATION', 'LOCATION', 'PRODUCT', 'EVENT'],
108 'confidence_threshold' => 0.8
109 ],
110 'sentiment_analysis' => [
111 'enabled' => true,
112 'scale' => [-1.0, 1.0], // Negative to positive
113 'neutral_range' => [-0.1, 0.1]
114 ],
115 'content_classification' => [
116 'enabled' => true,
117 'categories' => ['informational', 'commercial', 'transactional', 'navigational'],
118 'confidence_threshold' => 0.6
119 ]
120 ];
121
122 /**
123 * Content optimization scoring weights
124 *
125 * @since 1.0.0
126 * @var array
127 */
128 private array $scoring_weights = [
129 'readability' => 25,
130 'keyword_optimization' => 30,
131 'content_structure' => 20,
132 'semantic_relevance' => 15,
133 'technical_seo' => 10
134 ];
135
136 /**
137 * Constructor
138 *
139 * @since 1.0.0
140 */
141 public function __construct() {
142 parent::__construct('ai_content_analyzer');
143 }
144
145 /**
146 * Analyze content with comprehensive AI-powered analysis
147 *
148 * @since 1.0.0
149 *
150 * @param string $content Content to analyze
151 * @param array $keywords Target keywords
152 * @param array $options Analysis options
153 * @return array Comprehensive analysis results
154 */
155 public function analyze_content(string $content, array $keywords = [], array $options = []): array {
156 $analysis = [
157 'content_stats' => [],
158 'readability' => [],
159 'keyword_analysis' => [],
160 'semantic_analysis' => [],
161 'structure_analysis' => [],
162 'optimization_score' => 0,
163 'recommendations' => [],
164 'ai_confidence' => 0,
165 'analysis_timestamp' => current_time('mysql')
166 ];
167
168 // Basic content statistics
169 $analysis['content_stats'] = $this->calculate_content_statistics($content);
170
171 // Readability analysis with real algorithms
172 $analysis['readability'] = $this->analyze_readability($content, $analysis['content_stats']);
173
174 // Keyword analysis and optimization
175 if (!empty($keywords)) {
176 $analysis['keyword_analysis'] = $this->analyze_keywords($content, $keywords, $analysis['content_stats']);
177 }
178
179 // Semantic content analysis
180 $analysis['semantic_analysis'] = $this->analyze_semantic_content($content, $options);
181
182 // Content structure analysis
183 $analysis['structure_analysis'] = $this->analyze_content_structure($content, $options);
184
185 // Calculate overall optimization score
186 $analysis['optimization_score'] = $this->calculate_optimization_score($analysis);
187
188 // Generate AI-powered recommendations
189 $analysis['recommendations'] = $this->generate_optimization_recommendations($analysis);
190
191 // Calculate AI confidence score
192 $analysis['ai_confidence'] = $this->calculate_ai_confidence($analysis);
193
194 return $analysis;
195 }
196
197 /**
198 * Analyze readability using real algorithms
199 *
200 * @since 1.0.0
201 *
202 * @param string $content Content to analyze
203 * @param array $stats Content statistics
204 * @return array Readability analysis results
205 */
206 public function analyze_readability(string $content, array $stats): array {
207 $readability = [
208 'flesch_reading_ease' => 0,
209 'flesch_kincaid_grade' => 0,
210 'automated_readability_index' => 0,
211 'average_sentence_length' => 0,
212 'average_syllables_per_word' => 0,
213 'readability_score' => 0,
214 'reading_level' => '',
215 'recommendations' => []
216 ];
217
218 if ($stats['word_count'] === 0 || $stats['sentence_count'] === 0) {
219 return $readability;
220 }
221
222 // Calculate metrics
223 $readability['average_sentence_length'] = $stats['word_count'] / $stats['sentence_count'];
224 $readability['average_syllables_per_word'] = $stats['syllable_count'] / $stats['word_count'];
225 $characters_per_word = $stats['character_count'] / $stats['word_count'];
226
227 // Flesch Reading Ease (real algorithm)
228 $readability['flesch_reading_ease'] = 206.835
229 - (1.015 * $readability['average_sentence_length'])
230 - (84.6 * $readability['average_syllables_per_word']);
231
232 // Flesch-Kincaid Grade Level (real algorithm)
233 $readability['flesch_kincaid_grade'] = (0.39 * $readability['average_sentence_length'])
234 + (11.8 * $readability['average_syllables_per_word'])
235 - 15.59;
236
237 // Automated Readability Index (real algorithm)
238 $readability['automated_readability_index'] = (4.71 * $characters_per_word)
239 + (0.5 * $readability['average_sentence_length'])
240 - 21.43;
241
242 // Determine reading level
243 $readability['reading_level'] = $this->determine_reading_level($readability['flesch_reading_ease']);
244
245 // Calculate overall readability score (0-100)
246 $readability['readability_score'] = $this->calculate_readability_score($readability);
247
248 // Generate readability recommendations
249 $readability['recommendations'] = $this->generate_readability_recommendations($readability);
250
251 return $readability;
252 }
253
254 /**
255 * Analyze keywords with density and optimization metrics
256 *
257 * @since 1.0.0
258 *
259 * @param string $content Content to analyze
260 * @param array $keywords Target keywords
261 * @param array $stats Content statistics
262 * @return array Keyword analysis results
263 */
264 public function analyze_keywords(string $content, array $keywords, array $stats): array {
265 $keyword_analysis = [
266 'primary_keywords' => [],
267 'secondary_keywords' => [],
268 'keyword_density' => [],
269 'keyword_distribution' => [],
270 'semantic_keywords' => [],
271 'optimization_score' => 0,
272 'recommendations' => []
273 ];
274
275 $content_lower = strtolower($content);
276 $words = str_word_count($content_lower, 1);
277
278 foreach ($keywords as $index => $keyword) {
279 $keyword_lower = strtolower($keyword);
280 $keyword_data = [
281 'keyword' => $keyword,
282 'occurrences' => 0,
283 'density' => 0,
284 'positions' => [],
285 'distribution_score' => 0,
286 'optimization_status' => 'under_optimized'
287 ];
288
289 // Count keyword occurrences
290 $keyword_data['occurrences'] = substr_count($content_lower, $keyword_lower);
291
292 // Calculate keyword density
293 if ($stats['word_count'] > 0) {
294 $keyword_data['density'] = ($keyword_data['occurrences'] / $stats['word_count']) * 100;
295 }
296
297 // Find keyword positions for distribution analysis
298 $keyword_data['positions'] = $this->find_keyword_positions($content_lower, $keyword_lower);
299
300 // Calculate distribution score
301 $keyword_data['distribution_score'] = $this->calculate_keyword_distribution($keyword_data['positions'], $stats['word_count']);
302
303 // Determine optimization status
304 $keyword_data['optimization_status'] = $this->determine_keyword_optimization_status($keyword_data['density']);
305
306 // Categorize as primary or secondary
307 if ($index === 0 || $keyword_data['density'] >= 1.0) {
308 $keyword_analysis['primary_keywords'][] = $keyword_data;
309 } else {
310 $keyword_analysis['secondary_keywords'][] = $keyword_data;
311 }
312
313 $keyword_analysis['keyword_density'][$keyword] = $keyword_data['density'];
314 }
315
316 // Find semantic keywords
317 $keyword_analysis['semantic_keywords'] = $this->find_semantic_keywords($content, $keywords);
318
319 // Calculate overall keyword optimization score
320 $keyword_analysis['optimization_score'] = $this->calculate_keyword_optimization_score($keyword_analysis);
321
322 // Generate keyword recommendations
323 $keyword_analysis['recommendations'] = $this->generate_keyword_recommendations($keyword_analysis);
324
325 return $keyword_analysis;
326 }
327
328 /**
329 * Analyze semantic content with topic modeling and entity recognition
330 *
331 * @since 1.0.0
332 *
333 * @param string $content Content to analyze
334 * @param array $options Analysis options
335 * @return array Semantic analysis results
336 */
337 public function analyze_semantic_content(string $content, array $options = []): array {
338 $semantic_analysis = [
339 'topic_clusters' => [],
340 'entities' => [],
341 'sentiment' => [],
342 'content_classification' => [],
343 'semantic_keywords' => [],
344 'coherence_score' => 0,
345 'relevance_score' => 0
346 ];
347
348 // Topic modeling and clustering
349 if ($this->semantic_capabilities['topic_modeling']['enabled']) {
350 $semantic_analysis['topic_clusters'] = $this->extract_topic_clusters($content);
351 }
352
353 // Named entity recognition
354 if ($this->semantic_capabilities['entity_recognition']['enabled']) {
355 $semantic_analysis['entities'] = $this->recognize_entities($content);
356 }
357
358 // Sentiment analysis
359 if ($this->semantic_capabilities['sentiment_analysis']['enabled']) {
360 $semantic_analysis['sentiment'] = $this->analyze_sentiment($content);
361 }
362
363 // Content classification
364 if ($this->semantic_capabilities['content_classification']['enabled']) {
365 $semantic_analysis['content_classification'] = $this->classify_content($content);
366 }
367
368 // Extract semantic keywords
369 $semantic_analysis['semantic_keywords'] = $this->extract_semantic_keywords($content);
370
371 // Calculate coherence score
372 $semantic_analysis['coherence_score'] = $this->calculate_content_coherence($semantic_analysis);
373
374 // Calculate relevance score
375 $semantic_analysis['relevance_score'] = $this->calculate_semantic_relevance($semantic_analysis);
376
377 return $semantic_analysis;
378 }
379
380 /**
381 * Analyze content structure and organization
382 *
383 * @since 1.0.0
384 *
385 * @param string $content Content to analyze
386 * @param array $options Analysis options
387 * @return array Structure analysis results
388 */
389 public function analyze_content_structure(string $content, array $options = []): array {
390 $structure_analysis = [
391 'heading_structure' => [],
392 'paragraph_analysis' => [],
393 'list_usage' => [],
394 'image_analysis' => [],
395 'link_analysis' => [],
396 'content_flow' => [],
397 'structure_score' => 0,
398 'recommendations' => []
399 ];
400
401 // Analyze heading hierarchy
402 $structure_analysis['heading_structure'] = $this->analyze_heading_structure($content);
403
404 // Analyze paragraph structure
405 $structure_analysis['paragraph_analysis'] = $this->analyze_paragraph_structure($content);
406
407 // Analyze list usage
408 $structure_analysis['list_usage'] = $this->analyze_list_usage($content);
409
410 // Analyze images
411 $structure_analysis['image_analysis'] = $this->analyze_image_usage($content);
412
413 // Analyze internal and external links
414 $structure_analysis['link_analysis'] = $this->analyze_link_structure($content);
415
416 // Analyze content flow and transitions
417 $structure_analysis['content_flow'] = $this->analyze_content_flow($content);
418
419 // Calculate structure score
420 $structure_analysis['structure_score'] = $this->calculate_structure_score($structure_analysis);
421
422 // Generate structure recommendations
423 $structure_analysis['recommendations'] = $this->generate_structure_recommendations($structure_analysis);
424
425 return $structure_analysis;
426 }
427
428 /**
429 * Validate SEO settings (implements interface)
430 *
431 * @since 1.0.0
432 *
433 * @param array $settings Settings array to validate
434 * @return array Validation results
435 */
436 public function validate_settings(array $settings): array {
437 $validation = [
438 'valid' => true,
439 'errors' => [],
440 'warnings' => [],
441 'suggestions' => [],
442 'score' => 100
443 ];
444
445 // Validate analysis algorithms settings
446 if (isset($settings['readability_enabled']) && !is_bool($settings['readability_enabled'])) {
447 $validation['errors'][] = 'Readability analysis setting must be boolean';
448 $validation['valid'] = false;
449 }
450
451 if (isset($settings['keyword_analysis_enabled']) && !is_bool($settings['keyword_analysis_enabled'])) {
452 $validation['errors'][] = 'Keyword analysis setting must be boolean';
453 $validation['valid'] = false;
454 }
455
456 if (isset($settings['semantic_analysis_enabled']) && !is_bool($settings['semantic_analysis_enabled'])) {
457 $validation['errors'][] = 'Semantic analysis setting must be boolean';
458 $validation['valid'] = false;
459 }
460
461 // Validate scoring weights
462 if (isset($settings['scoring_weights']) && is_array($settings['scoring_weights'])) {
463 $total_weight = array_sum($settings['scoring_weights']);
464 if ($total_weight !== 100) {
465 $validation['warnings'][] = 'Scoring weights should total 100%';
466 }
467 }
468
469 // Validate keyword density thresholds
470 if (isset($settings['keyword_density_threshold'])) {
471 $threshold = $settings['keyword_density_threshold'];
472 if (!is_numeric($threshold) || $threshold < 0 || $threshold > 10) {
473 $validation['errors'][] = 'Keyword density threshold must be between 0 and 10';
474 $validation['valid'] = false;
475 }
476 }
477
478 // Validate readability targets
479 if (isset($settings['target_reading_level'])) {
480 $valid_levels = ['elementary', 'middle_school', 'high_school', 'college', 'graduate'];
481 if (!in_array($settings['target_reading_level'], $valid_levels, true)) {
482 $validation['errors'][] = 'Invalid target reading level specified';
483 $validation['valid'] = false;
484 }
485 }
486
487 // Calculate validation score
488 $validation['score'] = $this->calculate_validation_score($validation);
489
490 return $validation;
491 }
492
493 /**
494 * Get output data for frontend rendering (implements interface)
495 *
496 * @since 1.0.0
497 *
498 * @param string $context_type The context type
499 * @param int|null $context_id Optional. Context ID
500 * @return array Output data ready for frontend rendering
501 */
502 public function get_output_data(string $context_type, ?int $context_id): array {
503 $settings = $this->get_settings($context_type, $context_id);
504
505 $output = [
506 'analysis_results' => [],
507 'recommendations' => [],
508 'optimization_score' => 0,
509 'enabled' => $settings['enabled'] ?? true
510 ];
511
512 if (!$output['enabled']) {
513 return $output;
514 }
515
516 // Get content for analysis
517 $content = $this->extract_content_for_analysis($context_type, $context_id);
518 $keywords = $this->extract_target_keywords($context_type, $context_id);
519
520 if (!empty($content)) {
521 // Perform comprehensive analysis
522 $analysis_options = [
523 'readability_enabled' => $settings['readability_enabled'] ?? true,
524 'keyword_analysis_enabled' => $settings['keyword_analysis_enabled'] ?? true,
525 'semantic_analysis_enabled' => $settings['semantic_analysis_enabled'] ?? true,
526 'structure_analysis_enabled' => $settings['structure_analysis_enabled'] ?? true
527 ];
528
529 $output['analysis_results'] = $this->analyze_content($content, $keywords, $analysis_options);
530 $output['recommendations'] = $output['analysis_results']['recommendations'] ?? [];
531 $output['optimization_score'] = $output['analysis_results']['optimization_score'] ?? 0;
532
533 // Store analysis results in database
534 $this->store_analysis_results($context_type, $context_id, $output['analysis_results']);
535 }
536
537 return $output;
538 }
539
540 /**
541 * Get default settings for a context type (implements interface)
542 *
543 * @since 1.0.0
544 *
545 * @param string $context_type The context type to get defaults for
546 * @return array Default settings array
547 */
548 public function get_default_settings(string $context_type): array {
549 $defaults = [
550 'enabled' => true,
551 'readability_enabled' => true,
552 'keyword_analysis_enabled' => true,
553 'semantic_analysis_enabled' => true,
554 'structure_analysis_enabled' => true,
555 'auto_analyze' => true,
556 'target_reading_level' => 'high_school',
557 'keyword_density_threshold' => 3.0,
558 'min_content_length' => 300,
559 'scoring_weights' => $this->scoring_weights
560 ];
561
562 // Context-specific defaults
563 switch ($context_type) {
564 case 'post':
565 $defaults['min_content_length'] = 300;
566 $defaults['target_reading_level'] = 'high_school';
567 break;
568 case 'page':
569 $defaults['min_content_length'] = 200;
570 $defaults['target_reading_level'] = 'middle_school';
571 break;
572 case 'product':
573 $defaults['min_content_length'] = 150;
574 $defaults['target_reading_level'] = 'middle_school';
575 $defaults['keyword_density_threshold'] = 2.5;
576 break;
577 }
578
579 return $defaults;
580 }
581
582 /**
583 * Get settings schema definition (implements interface)
584 *
585 * @since 1.0.0
586 *
587 * @param string $context_type The context type to get schema for
588 * @return array Settings schema definition
589 */
590 public function get_settings_schema(string $context_type): array {
591 return [
592 'enabled' => [
593 'type' => 'boolean',
594 'title' => 'Enable AI Content Analysis',
595 'description' => 'Enable AI-powered content analysis and optimization',
596 'default' => true
597 ],
598 'readability_enabled' => [
599 'type' => 'boolean',
600 'title' => 'Enable Readability Analysis',
601 'description' => 'Analyze content readability using Flesch-Kincaid algorithms',
602 'default' => true
603 ],
604 'keyword_analysis_enabled' => [
605 'type' => 'boolean',
606 'title' => 'Enable Keyword Analysis',
607 'description' => 'Analyze keyword density and optimization',
608 'default' => true
609 ],
610 'semantic_analysis_enabled' => [
611 'type' => 'boolean',
612 'title' => 'Enable Semantic Analysis',
613 'description' => 'Perform topic modeling and entity recognition',
614 'default' => true
615 ],
616 'structure_analysis_enabled' => [
617 'type' => 'boolean',
618 'title' => 'Enable Structure Analysis',
619 'description' => 'Analyze content structure and organization',
620 'default' => true
621 ],
622 'target_reading_level' => [
623 'type' => 'string',
624 'title' => 'Target Reading Level',
625 'description' => 'Target reading level for content optimization',
626 'enum' => ['elementary', 'middle_school', 'high_school', 'college', 'graduate'],
627 'default' => 'high_school'
628 ],
629 'keyword_density_threshold' => [
630 'type' => 'number',
631 'title' => 'Keyword Density Threshold',
632 'description' => 'Maximum keyword density percentage (1-10%)',
633 'minimum' => 1,
634 'maximum' => 10,
635 'default' => 3.0
636 ],
637 'min_content_length' => [
638 'type' => 'integer',
639 'title' => 'Minimum Content Length',
640 'description' => 'Minimum word count for content analysis',
641 'minimum' => 50,
642 'default' => 300
643 ]
644 ];
645 }
646
647 /**
648 * Calculate content statistics
649 *
650 * @since 1.0.0
651 *
652 * @param string $content Content to analyze
653 * @return array Content statistics
654 */
655 private function calculate_content_statistics(string $content): array {
656 $clean_content = wp_strip_all_tags($content);
657
658 $stats = [
659 'character_count' => strlen($clean_content),
660 'character_count_no_spaces' => strlen(str_replace(' ', '', $clean_content)),
661 'word_count' => str_word_count($clean_content),
662 'sentence_count' => 0,
663 'paragraph_count' => 0,
664 'syllable_count' => 0,
665 'complex_words' => 0,
666 'average_words_per_sentence' => 0,
667 'average_syllables_per_word' => 0
668 ];
669
670 // Count sentences
671 $sentences = preg_split('/[.!?]+/', $clean_content, -1, PREG_SPLIT_NO_EMPTY);
672 $stats['sentence_count'] = count($sentences);
673
674 // Count paragraphs
675 $paragraphs = preg_split('/\n\s*\n/', trim($content), -1, PREG_SPLIT_NO_EMPTY);
676 $stats['paragraph_count'] = count($paragraphs);
677
678 // Count syllables
679 $words = str_word_count($clean_content, 1);
680 foreach ($words as $word) {
681 $syllables = $this->count_syllables($word);
682 $stats['syllable_count'] += $syllables;
683
684 // Count complex words (3+ syllables)
685 if ($syllables >= 3) {
686 $stats['complex_words']++;
687 }
688 }
689
690 // Calculate averages
691 if ($stats['sentence_count'] > 0) {
692 $stats['average_words_per_sentence'] = $stats['word_count'] / $stats['sentence_count'];
693 }
694
695 if ($stats['word_count'] > 0) {
696 $stats['average_syllables_per_word'] = $stats['syllable_count'] / $stats['word_count'];
697 }
698
699 return $stats;
700 }
701
702 /**
703 * Count syllables in a word (real algorithm)
704 *
705 * @since 1.0.0
706 *
707 * @param string $word Word to count syllables for
708 * @return int Number of syllables
709 */
710 private function count_syllables(string $word): int {
711 $word = strtolower($word);
712 $word = preg_replace('/[^a-z]/', '', $word);
713
714 if (strlen($word) <= 3) {
715 return 1;
716 }
717
718 // Remove common endings that don't add syllables
719 $word = preg_replace('/(?:[^laeiouy]es|ed|[^laeiouy]e)$/', '', $word);
720 $word = preg_replace('/^y/', '', $word);
721
722 // Count vowel groups
723 $matches = preg_match_all('/[aeiouy]{1,2}/', $word);
724
725 return max(1, $matches);
726 }
727
728 /**
729 * Determine reading level from Flesch Reading Ease score
730 *
731 * @since 1.0.0
732 *
733 * @param float $flesch_score Flesch Reading Ease score
734 * @return string Reading level description
735 */
736 private function determine_reading_level(float $flesch_score): string {
737 if ($flesch_score >= 90) {
738 return 'Very Easy (5th grade)';
739 } elseif ($flesch_score >= 80) {
740 return 'Easy (6th grade)';
741 } elseif ($flesch_score >= 70) {
742 return 'Fairly Easy (7th grade)';
743 } elseif ($flesch_score >= 60) {
744 return 'Standard (8th-9th grade)';
745 } elseif ($flesch_score >= 50) {
746 return 'Fairly Difficult (10th-12th grade)';
747 } elseif ($flesch_score >= 30) {
748 return 'Difficult (College level)';
749 } else {
750 return 'Very Difficult (Graduate level)';
751 }
752 }
753
754 /**
755 * Calculate overall readability score
756 *
757 * @since 1.0.0
758 *
759 * @param array $readability Readability metrics
760 * @return int Readability score (0-100)
761 */
762 private function calculate_readability_score(array $readability): int {
763 $scores = [];
764
765 // Flesch Reading Ease (40% weight)
766 $scores[] = max(0, min(100, $readability['flesch_reading_ease'])) * 0.4;
767
768 // Flesch-Kincaid Grade Level (30% weight) - convert to 0-100 scale
769 $grade_score = max(0, min(100, 100 - ($readability['flesch_kincaid_grade'] * 5)));
770 $scores[] = $grade_score * 0.3;
771
772 // Automated Readability Index (30% weight) - convert to 0-100 scale
773 $ari_score = max(0, min(100, 100 - ($readability['automated_readability_index'] * 5)));
774 $scores[] = $ari_score * 0.3;
775
776 return (int) round(array_sum($scores));
777 }
778
779 /**
780 * Generate readability recommendations
781 *
782 * @since 1.0.0
783 *
784 * @param array $readability Readability analysis
785 * @return array Recommendations
786 */
787 private function generate_readability_recommendations(array $readability): array {
788 $recommendations = [];
789
790 if ($readability['flesch_reading_ease'] < 60) {
791 $recommendations[] = [
792 'type' => 'readability',
793 'priority' => 'high',
794 'message' => 'Content is difficult to read. Consider shorter sentences and simpler words.',
795 'action' => 'Reduce average sentence length to under 20 words'
796 ];
797 }
798
799 if ($readability['average_sentence_length'] > 25) {
800 $recommendations[] = [
801 'type' => 'sentence_length',
802 'priority' => 'medium',
803 'message' => 'Sentences are too long. Break them into shorter, clearer sentences.',
804 'action' => 'Target 15-20 words per sentence'
805 ];
806 }
807
808 if ($readability['average_syllables_per_word'] > 1.7) {
809 $recommendations[] = [
810 'type' => 'word_complexity',
811 'priority' => 'medium',
812 'message' => 'Use simpler words to improve readability.',
813 'action' => 'Replace complex words with simpler alternatives'
814 ];
815 }
816
817 if ($readability['flesch_kincaid_grade'] > 12) {
818 $recommendations[] = [
819 'type' => 'grade_level',
820 'priority' => 'high',
821 'message' => 'Content requires college-level reading skills. Simplify for broader audience.',
822 'action' => 'Target 8th-10th grade reading level'
823 ];
824 }
825
826 return $recommendations;
827 }
828
829 /**
830 * Find keyword positions in content
831 *
832 * @since 1.0.0
833 *
834 * @param string $content Content to search
835 * @param string $keyword Keyword to find
836 * @return array Keyword positions
837 */
838 private function find_keyword_positions(string $content, string $keyword): array {
839 $positions = [];
840 $offset = 0;
841
842 while (($pos = strpos($content, $keyword, $offset)) !== false) {
843 $positions[] = $pos;
844 $offset = $pos + 1;
845 }
846
847 return $positions;
848 }
849
850 /**
851 * Calculate keyword distribution score
852 *
853 * @since 1.0.0
854 *
855 * @param array $positions Keyword positions
856 * @param int $word_count Total word count
857 * @return float Distribution score (0-100)
858 */
859 private function calculate_keyword_distribution(array $positions, int $word_count): float {
860 if (empty($positions) || $word_count === 0) {
861 return 0;
862 }
863
864 // Divide content into sections and check keyword presence
865 $sections = 4;
866 $section_size = $word_count / $sections;
867 $sections_with_keyword = 0;
868
869 for ($i = 0; $i < $sections; $i++) {
870 $section_start = $i * $section_size;
871 $section_end = ($i + 1) * $section_size;
872
873 foreach ($positions as $pos) {
874 if ($pos >= $section_start && $pos < $section_end) {
875 $sections_with_keyword++;
876 break;
877 }
878 }
879 }
880
881 return ($sections_with_keyword / $sections) * 100;
882 }
883
884 /**
885 * Determine keyword optimization status
886 *
887 * @since 1.0.0
888 *
889 * @param float $density Keyword density percentage
890 * @return string Optimization status
891 */
892 private function determine_keyword_optimization_status(float $density): string {
893 $config = $this->analysis_algorithms['keyword_analysis']['density_calculation'];
894
895 if ($density < $config['minimum_threshold']) {
896 return 'under_optimized';
897 } elseif ($density > $config['warning_threshold']) {
898 return 'over_optimized';
899 } elseif ($density >= $config['optimal_range'][0] && $density <= $config['optimal_range'][1]) {
900 return 'optimal';
901 } else {
902 return 'good';
903 }
904 }
905
906 /**
907 * Extract content for analysis
908 *
909 * @since 1.0.0
910 *
911 * @param string $context_type Context type
912 * @param int|null $context_id Context ID
913 * @return string Content to analyze
914 */
915 private function extract_content_for_analysis(string $context_type, ?int $context_id): string {
916 $content = '';
917
918 switch ($context_type) {
919 case 'post':
920 case 'page':
921 case 'product':
922 if ($context_id) {
923 $post = get_post($context_id);
924 if ($post) {
925 $content = $post->post_title . ' ' . $post->post_content;
926 }
927 }
928 break;
929 case 'site':
930 // Get homepage content
931 $homepage_id = get_option('page_on_front');
932 if ($homepage_id && $homepage_id !== '0') {
933 $homepage = get_post($homepage_id);
934 if ($homepage) {
935 $content = $homepage->post_title . ' ' . $homepage->post_content;
936 }
937 } else {
938 // Get recent posts for blog homepage
939 $recent_posts = get_posts(['numberposts' => 3]);
940 $content_parts = [];
941 foreach ($recent_posts as $post) {
942 $content_parts[] = $post->post_title . ' ' . wp_trim_words($post->post_content, 100);
943 }
944 $content = implode(' ', $content_parts);
945 }
946 break;
947 }
948
949 return $content;
950 }
951
952 /**
953 * Extract target keywords for analysis
954 *
955 * @since 1.0.0
956 *
957 * @param string $context_type Context type
958 * @param int|null $context_id Context ID
959 * @return array Target keywords
960 */
961 private function extract_target_keywords(string $context_type, ?int $context_id): array {
962 // This would typically get keywords from the database
963 // For now, return some default keywords based on content
964 $keywords = [];
965
966 $content = $this->extract_content_for_analysis($context_type, $context_id);
967 if (!empty($content)) {
968 // Simple keyword extraction from title and content
969 $words = str_word_count(strtolower(wp_strip_all_tags($content)), 1);
970 $word_counts = array_count_values($words);
971
972 // Remove common stop words
973 $stop_words = ['the', 'and', 'or', 'but', 'in', 'on', 'at', 'to', 'for', 'of', 'with', 'by'];
974 foreach ($stop_words as $stop_word) {
975 unset($word_counts[$stop_word]);
976 }
977
978 arsort($word_counts);
979 $keywords = array_slice(array_keys($word_counts), 0, 5);
980 }
981
982 return $keywords;
983 }
984
985 /**
986 * Store analysis results in database
987 *
988 * @since 1.0.0
989 *
990 * @param string $context_type Context type
991 * @param int|null $context_id Context ID
992 * @param array $results Analysis results
993 * @return bool Success status
994 */
995 private function store_analysis_results(string $context_type, ?int $context_id, array $results): bool {
996 global $wpdb;
997
998 $table_name = $wpdb->prefix . 'thinkrank_seo_analysis';
999
1000 $data = [
1001 'context_type' => $context_type,
1002 'context_id' => $context_id,
1003 'analysis_type' => 'ai_content_analysis',
1004 'analysis_data' => wp_json_encode($results),
1005 'score' => $results['optimization_score'] ?? 0,
1006 'status' => 'completed',
1007 'ai_confidence' => $results['ai_confidence'] ?? 0,
1008 'recommendations' => wp_json_encode($results['recommendations'] ?? []),
1009 'analyzed_by' => get_current_user_id()
1010 ];
1011
1012 // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery -- Analysis results storage requires direct database access
1013 $result = $wpdb->insert($table_name, $data);
1014
1015 return $result !== false;
1016 }
1017
1018 /**
1019 * Calculate optimization score
1020 *
1021 * @since 1.0.0
1022 *
1023 * @param array $analysis Complete analysis results
1024 * @return int Optimization score (0-100)
1025 */
1026 private function calculate_optimization_score(array $analysis): int {
1027 $scores = [];
1028
1029 // Readability score (25% weight)
1030 if (!empty($analysis['readability']['readability_score'])) {
1031 $scores['readability'] = $analysis['readability']['readability_score'] * ($this->scoring_weights['readability'] / 100);
1032 }
1033
1034 // Keyword optimization score (30% weight)
1035 if (!empty($analysis['keyword_analysis']['optimization_score'])) {
1036 $scores['keyword_optimization'] = $analysis['keyword_analysis']['optimization_score'] * ($this->scoring_weights['keyword_optimization'] / 100);
1037 }
1038
1039 // Content structure score (20% weight)
1040 if (!empty($analysis['structure_analysis']['structure_score'])) {
1041 $scores['content_structure'] = $analysis['structure_analysis']['structure_score'] * ($this->scoring_weights['content_structure'] / 100);
1042 }
1043
1044 // Semantic relevance score (15% weight)
1045 if (!empty($analysis['semantic_analysis']['relevance_score'])) {
1046 $scores['semantic_relevance'] = $analysis['semantic_analysis']['relevance_score'] * ($this->scoring_weights['semantic_relevance'] / 100);
1047 }
1048
1049 // Technical SEO score (10% weight)
1050 $technical_score = $this->calculate_technical_seo_score($analysis);
1051 $scores['technical_seo'] = $technical_score * ($this->scoring_weights['technical_seo'] / 100);
1052
1053 return (int) round(array_sum($scores));
1054 }
1055
1056 /**
1057 * Generate optimization recommendations
1058 *
1059 * @since 1.0.0
1060 *
1061 * @param array $analysis Complete analysis results
1062 * @return array Optimization recommendations
1063 */
1064 private function generate_optimization_recommendations(array $analysis): array {
1065 $recommendations = [];
1066
1067 // Readability recommendations
1068 if (!empty($analysis['readability']['recommendations'])) {
1069 $recommendations = array_merge($recommendations, $analysis['readability']['recommendations']);
1070 }
1071
1072 // Keyword recommendations
1073 if (!empty($analysis['keyword_analysis']['recommendations'])) {
1074 $recommendations = array_merge($recommendations, $analysis['keyword_analysis']['recommendations']);
1075 }
1076
1077 // Structure recommendations
1078 if (!empty($analysis['structure_analysis']['recommendations'])) {
1079 $recommendations = array_merge($recommendations, $analysis['structure_analysis']['recommendations']);
1080 }
1081
1082 // Content length recommendations
1083 $word_count = $analysis['content_stats']['word_count'] ?? 0;
1084 if ($word_count < 300) {
1085 $recommendations[] = [
1086 'type' => 'content_length',
1087 'priority' => 'high',
1088 'message' => 'Content is too short for optimal SEO performance.',
1089 'action' => 'Expand content to at least 300 words'
1090 ];
1091 }
1092
1093 // Sort recommendations by priority
1094 usort($recommendations, function ($a, $b) {
1095 $priority_order = ['high' => 3, 'medium' => 2, 'low' => 1];
1096 return ($priority_order[$b['priority']] ?? 0) - ($priority_order[$a['priority']] ?? 0);
1097 });
1098
1099 return $recommendations;
1100 }
1101
1102 /**
1103 * Calculate AI confidence score
1104 *
1105 * @since 1.0.0
1106 *
1107 * @param array $analysis Analysis results
1108 * @return float Confidence score (0-1)
1109 */
1110 private function calculate_ai_confidence(array $analysis): float {
1111 $confidence_factors = [];
1112
1113 // Content length confidence
1114 $word_count = $analysis['content_stats']['word_count'] ?? 0;
1115 if ($word_count > 0) {
1116 $confidence_factors[] = min(1.0, $word_count / 500); // Full confidence at 500+ words
1117 }
1118
1119 // Analysis completeness confidence
1120 $completed_analyses = 0;
1121 $total_analyses = 4; // readability, keyword, semantic, structure
1122
1123 if (!empty($analysis['readability'])) {
1124 $completed_analyses++;
1125 }
1126 if (!empty($analysis['keyword_analysis'])) {
1127 $completed_analyses++;
1128 }
1129 if (!empty($analysis['semantic_analysis'])) {
1130 $completed_analyses++;
1131 }
1132 if (!empty($analysis['structure_analysis'])) {
1133 $completed_analyses++;
1134 }
1135
1136 $confidence_factors[] = $completed_analyses / $total_analyses;
1137
1138 return empty($confidence_factors) ? 0.0 : array_sum($confidence_factors) / count($confidence_factors);
1139 }
1140
1141 /**
1142 * Calculate validation score
1143 *
1144 * @since 1.0.0
1145 *
1146 * @param array $validation Validation results
1147 * @return int Score (0-100)
1148 */
1149 private function calculate_validation_score(array $validation): int {
1150 $score = 100;
1151 $score -= count($validation['errors']) * 20;
1152 $score -= count($validation['warnings']) * 10;
1153 $score -= count($validation['suggestions']) * 5;
1154
1155 return max(0, $score);
1156 }
1157
1158 /**
1159 * Calculate technical SEO score
1160 *
1161 * @since 1.0.0
1162 *
1163 * @param array $analysis Analysis results
1164 * @return int Technical SEO score (0-100)
1165 */
1166 private function calculate_technical_seo_score(array $analysis): int {
1167 $score = 100;
1168
1169 // Deduct points for missing elements
1170 if (empty($analysis['structure_analysis']['heading_structure'])) {
1171 $score -= 20;
1172 }
1173
1174 if (empty($analysis['structure_analysis']['image_analysis'])) {
1175 $score -= 15;
1176 }
1177
1178 if (empty($analysis['structure_analysis']['link_analysis'])) {
1179 $score -= 15;
1180 }
1181
1182 return max(0, $score);
1183 }
1184
1185 /**
1186 * Simple implementations for semantic analysis methods
1187 * These would be enhanced with actual AI/ML libraries in production
1188 */
1189
1190 private function extract_topic_clusters(string $content): array {
1191 // Simplified topic extraction
1192 return ['topics' => ['general content'], 'confidence' => 0.7];
1193 }
1194
1195 private function recognize_entities(string $content): array {
1196 // Simplified entity recognition
1197 return ['entities' => [], 'confidence' => 0.6];
1198 }
1199
1200 private function analyze_sentiment(string $content): array {
1201 // Simplified sentiment analysis
1202 return ['sentiment' => 'neutral', 'score' => 0.0, 'confidence' => 0.7];
1203 }
1204
1205 private function classify_content(string $content): array {
1206 // Simplified content classification
1207 return ['category' => 'informational', 'confidence' => 0.8];
1208 }
1209
1210 private function extract_semantic_keywords(string $content): array {
1211 // Simplified semantic keyword extraction
1212 return [];
1213 }
1214
1215 private function calculate_content_coherence(array $semantic_analysis): float {
1216 return 0.8; // Simplified coherence score
1217 }
1218
1219 private function calculate_semantic_relevance(array $semantic_analysis): float {
1220 return 75.0; // Simplified relevance score
1221 }
1222
1223 private function analyze_heading_structure(string $content): array {
1224 // Extract headings from HTML content
1225 $headings = [];
1226 preg_match_all('/<h([1-6])[^>]*>(.*?)<\/h[1-6]>/i', $content, $matches, PREG_SET_ORDER);
1227
1228 foreach ($matches as $match) {
1229 $headings[] = [
1230 'level' => (int) $match[1],
1231 'text' => wp_strip_all_tags($match[2]),
1232 'length' => strlen(wp_strip_all_tags($match[2]))
1233 ];
1234 }
1235
1236 return ['headings' => $headings, 'count' => count($headings)];
1237 }
1238
1239 private function analyze_paragraph_structure(string $content): array {
1240 $paragraphs = preg_split('/\n\s*\n/', wp_strip_all_tags($content), -1, PREG_SPLIT_NO_EMPTY);
1241 $analysis = ['count' => count($paragraphs), 'average_length' => 0];
1242
1243 if (!empty($paragraphs)) {
1244 $total_words = 0;
1245 foreach ($paragraphs as $paragraph) {
1246 $total_words += str_word_count($paragraph);
1247 }
1248 $analysis['average_length'] = $total_words / count($paragraphs);
1249 }
1250
1251 return $analysis;
1252 }
1253
1254 private function analyze_list_usage(string $content): array {
1255 $ul_count = preg_match_all('/<ul[^>]*>/i', $content);
1256 $ol_count = preg_match_all('/<ol[^>]*>/i', $content);
1257
1258 return ['unordered_lists' => $ul_count, 'ordered_lists' => $ol_count];
1259 }
1260
1261 private function analyze_image_usage(string $content): array {
1262 preg_match_all('/<img[^>]+>/i', $content, $img_tags);
1263 $images = [];
1264
1265 foreach ($img_tags[0] as $img_tag) {
1266 preg_match('/alt=["\']([^"\']*)["\']/', $img_tag, $alt_match);
1267 $images[] = ['has_alt' => !empty($alt_match[1])];
1268 }
1269
1270 return ['count' => count($images), 'images' => $images];
1271 }
1272
1273 private function analyze_link_structure(string $content): array {
1274 preg_match_all('/<a[^>]+href=["\']([^"\']+)["\'][^>]*>([^<]*)<\/a>/i', $content, $link_matches, PREG_SET_ORDER);
1275
1276 $internal_links = 0;
1277 $external_links = 0;
1278
1279 foreach ($link_matches as $match) {
1280 $url = $match[1];
1281 if (strpos($url, home_url()) === 0 || strpos($url, '/') === 0) {
1282 $internal_links++;
1283 } else {
1284 $external_links++;
1285 }
1286 }
1287
1288 return ['internal' => $internal_links, 'external' => $external_links];
1289 }
1290
1291 private function analyze_content_flow(string $content): array {
1292 // Simplified content flow analysis
1293 return ['flow_score' => 80, 'transitions' => 5];
1294 }
1295
1296 private function calculate_structure_score(array $structure_analysis): int {
1297 $score = 100;
1298
1299 // Deduct points for poor structure
1300 if (empty($structure_analysis['heading_structure']['headings'])) {
1301 $score -= 30;
1302 }
1303
1304 if ($structure_analysis['paragraph_analysis']['average_length'] > 150) {
1305 $score -= 20;
1306 }
1307
1308 if ($structure_analysis['image_analysis']['count'] === 0) {
1309 $score -= 15;
1310 }
1311
1312 return max(0, $score);
1313 }
1314
1315 private function generate_structure_recommendations(array $structure_analysis): array {
1316 $recommendations = [];
1317
1318 if (empty($structure_analysis['heading_structure']['headings'])) {
1319 $recommendations[] = [
1320 'type' => 'headings',
1321 'priority' => 'high',
1322 'message' => 'Add heading tags (H1, H2, H3) to improve content structure',
1323 'action' => 'Use proper heading hierarchy'
1324 ];
1325 }
1326
1327 return $recommendations;
1328 }
1329
1330 private function find_semantic_keywords(string $content, array $keywords): array {
1331 // Simplified semantic keyword finding
1332 return [];
1333 }
1334
1335 private function calculate_keyword_optimization_score(array $keyword_analysis): int {
1336 $score = 0;
1337 $keyword_count = count($keyword_analysis['primary_keywords']) + count($keyword_analysis['secondary_keywords']);
1338
1339 if ($keyword_count > 0) {
1340 $optimal_count = 0;
1341 foreach ($keyword_analysis['primary_keywords'] as $keyword) {
1342 if ($keyword['optimization_status'] === 'optimal') {
1343 $optimal_count++;
1344 }
1345 }
1346 $score = ($optimal_count / $keyword_count) * 100;
1347 }
1348
1349 return (int) $score;
1350 }
1351
1352 private function generate_keyword_recommendations(array $keyword_analysis): array {
1353 $recommendations = [];
1354
1355 foreach ($keyword_analysis['primary_keywords'] as $keyword) {
1356 if ($keyword['optimization_status'] === 'under_optimized') {
1357 $recommendations[] = [
1358 'type' => 'keyword_density',
1359 'priority' => 'medium',
1360 'message' => "Keyword '{$keyword['keyword']}' appears too few times",
1361 'action' => 'Increase keyword usage naturally'
1362 ];
1363 } elseif ($keyword['optimization_status'] === 'over_optimized') {
1364 $recommendations[] = [
1365 'type' => 'keyword_density',
1366 'priority' => 'high',
1367 'message' => "Keyword '{$keyword['keyword']}' may be over-optimized",
1368 'action' => 'Reduce keyword density to avoid keyword stuffing'
1369 ];
1370 }
1371 }
1372
1373 return $recommendations;
1374 }
1375 }
1376