oxirs-vec 0.2.4

Vector index abstractions for semantic similarity and AI-augmented querying
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
//! Cross-Language Vector Alignment - Version 1.2 Feature
//!
//! This module implements comprehensive cross-language vector alignment capabilities
//! that enable semantic search and similarity computation across different languages.
//! It supports multilingual embeddings, translation-based alignment, and cross-lingual
//! similarity scoring for knowledge graphs with multilingual content.

use crate::{embeddings::EmbeddingGenerator, similarity::SimilarityMetric, Vector};

use anyhow::{anyhow, Context, Result};
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet};
use std::sync::{Arc, RwLock};
use tracing::{info, span, Level};

/// Configuration for cross-language vector alignment
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CrossLanguageConfig {
    /// Supported languages (ISO 639-1 codes)
    pub supported_languages: Vec<String>,
    /// Primary language for fallback
    pub primary_language: String,
    /// Enable automatic language detection
    pub enable_language_detection: bool,
    /// Alignment strategy
    pub alignment_strategy: AlignmentStrategy,
    /// Translation service configuration
    pub translation_config: Option<TranslationConfig>,
    /// Multilingual embedding model configuration
    pub multilingual_embeddings: MultilingualEmbeddingConfig,
    /// Cross-lingual similarity threshold
    pub cross_lingual_threshold: f32,
}

impl Default for CrossLanguageConfig {
    fn default() -> Self {
        Self {
            supported_languages: vec![
                "en".to_string(), // English
                "es".to_string(), // Spanish
                "fr".to_string(), // French
                "de".to_string(), // German
                "it".to_string(), // Italian
                "pt".to_string(), // Portuguese
                "ru".to_string(), // Russian
                "zh".to_string(), // Chinese
                "ja".to_string(), // Japanese
                "ar".to_string(), // Arabic
            ],
            primary_language: "en".to_string(),
            enable_language_detection: true,
            alignment_strategy: AlignmentStrategy::MultilingualEmbeddings,
            translation_config: None,
            multilingual_embeddings: MultilingualEmbeddingConfig::default(),
            cross_lingual_threshold: 0.6,
        }
    }
}

/// Strategies for aligning vectors across languages
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AlignmentStrategy {
    /// Use multilingual embedding models
    MultilingualEmbeddings,
    /// Use translation to common language
    TranslationBased,
    /// Hybrid approach with both methods
    Hybrid,
    /// Learn cross-lingual mappings
    LearnedMappings,
}

/// Configuration for translation services
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TranslationConfig {
    /// Translation service provider
    pub provider: TranslationProvider,
    /// API endpoint
    pub endpoint: Option<String>,
    /// API key for authentication
    pub api_key: Option<String>,
    /// Cache translated content
    pub enable_caching: bool,
    /// Maximum cache size
    pub max_cache_size: usize,
}

/// Translation service providers
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum TranslationProvider {
    /// Google Translate API
    Google,
    /// Microsoft Translator
    Microsoft,
    /// AWS Translate
    Aws,
    /// Local/offline model
    Local,
}

/// Configuration for multilingual embeddings
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MultilingualEmbeddingConfig {
    /// Model name for multilingual embeddings
    pub model_name: String,
    /// Dimension of embeddings
    pub dimensions: usize,
    /// Normalization strategy
    pub normalization: NormalizationStrategy,
    /// Language-specific preprocessing
    pub language_preprocessing: HashMap<String, Vec<String>>,
}

impl Default for MultilingualEmbeddingConfig {
    fn default() -> Self {
        Self {
            model_name: "sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2".to_string(),
            dimensions: 384,
            normalization: NormalizationStrategy::L2,
            language_preprocessing: HashMap::new(),
        }
    }
}

/// Vector normalization strategies
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum NormalizationStrategy {
    /// L2 normalization
    L2,
    /// Mean centering
    MeanCentering,
    /// Standardization (z-score)
    Standardization,
    /// None
    None,
}

/// Language detection result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LanguageDetection {
    /// Detected language code
    pub language: String,
    /// Confidence score (0.0 to 1.0)
    pub confidence: f32,
    /// Alternative language candidates
    pub alternatives: Vec<(String, f32)>,
}

/// Cross-language content item
#[derive(Debug, Clone)]
pub struct CrossLanguageContent {
    /// Unique identifier
    pub id: String,
    /// Text content
    pub text: String,
    /// Detected or specified language
    pub language: String,
    /// Language detection confidence
    pub language_confidence: f32,
    /// Original vector embedding
    pub vector: Option<Vector>,
    /// Aligned vectors for different languages
    pub aligned_vectors: HashMap<String, Vector>,
}

/// Cross-language vector alignment engine
pub struct CrossLanguageAligner {
    config: CrossLanguageConfig,
    language_detector: Box<dyn LanguageDetector + Send + Sync>,
    embedding_generator: Box<dyn EmbeddingGenerator + Send + Sync>,
    translation_cache: Arc<RwLock<HashMap<String, String>>>,
    alignment_mappings: Arc<RwLock<HashMap<String, AlignmentMapping>>>,
    multilingual_embeddings: Arc<RwLock<HashMap<String, Vector>>>,
}

/// Language detection trait
pub trait LanguageDetector {
    /// Detect language of given text
    fn detect_language(&self, text: &str) -> Result<LanguageDetection>;

    /// Check if language is supported
    fn is_supported(&self, language: &str) -> bool;
}

/// Simple language detector implementation
pub struct SimpleLanguageDetector {
    supported_languages: HashSet<String>,
}

impl SimpleLanguageDetector {
    pub fn new(supported_languages: Vec<String>) -> Self {
        Self {
            supported_languages: supported_languages.into_iter().collect(),
        }
    }
}

impl LanguageDetector for SimpleLanguageDetector {
    fn detect_language(&self, text: &str) -> Result<LanguageDetection> {
        // Simplified language detection based on character sets and patterns
        let text_lower = text.to_lowercase();

        // Simple heuristics for language detection
        let language = if text_lower
            .chars()
            .any(|c| matches!(c, 'ñ' | 'ü' | 'é' | 'á' | 'í' | 'ó' | 'ú'))
        {
            "es" // Spanish
        } else if text_lower
            .chars()
            .any(|c| matches!(c, 'ç' | 'à' | 'è' | 'ù' | 'ê' | 'ô'))
        {
            "fr" // French
        } else if text_lower
            .chars()
            .any(|c| matches!(c, 'ä' | 'ö' | 'ü' | 'ß'))
        {
            "de" // German
        } else if text_lower
            .chars()
            .any(|c| ('\u{4e00}'..='\u{9fff}').contains(&c))
        {
            "zh" // Chinese
        } else if text_lower
            .chars()
            .any(|c| ('\u{3040}'..='\u{309f}').contains(&c))
        {
            "ja" // Japanese
        } else if text_lower
            .chars()
            .any(|c| ('\u{0600}'..='\u{06ff}').contains(&c))
        {
            "ar" // Arabic
        } else if text_lower
            .chars()
            .any(|c| ('\u{0400}'..='\u{04ff}').contains(&c))
        {
            "ru" // Russian
        } else {
            "en" // Default to English
        };

        let confidence = if language == "en" { 0.7 } else { 0.8 };

        Ok(LanguageDetection {
            language: language.to_string(),
            confidence,
            alternatives: vec![("en".to_string(), 0.3)],
        })
    }

    fn is_supported(&self, language: &str) -> bool {
        self.supported_languages.contains(language)
    }
}

/// Alignment mapping between languages
#[derive(Debug, Clone)]
pub struct AlignmentMapping {
    /// Source language
    pub source_language: String,
    /// Target language
    pub target_language: String,
    /// Transformation matrix (if learned)
    pub transformation_matrix: Option<Vec<Vec<f32>>>,
    /// Translation pairs used for learning
    pub translation_pairs: Vec<(String, String)>,
    /// Mapping quality score
    pub quality_score: f32,
}

/// Cross-language search result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CrossLanguageSearchResult {
    /// Content identifier
    pub id: String,
    /// Similarity score
    pub similarity: f32,
    /// Content language
    pub language: String,
    /// Original text content
    pub text: String,
    /// Translated text (if available)
    pub translated_text: Option<String>,
    /// Cross-lingual similarity metrics
    pub cross_lingual_metrics: HashMap<String, f32>,
}

impl CrossLanguageAligner {
    /// Create a new cross-language aligner
    pub fn new(
        config: CrossLanguageConfig,
        embedding_generator: Box<dyn EmbeddingGenerator + Send + Sync>,
    ) -> Self {
        let language_detector = Box::new(SimpleLanguageDetector::new(
            config.supported_languages.clone(),
        ));

        Self {
            config,
            language_detector,
            embedding_generator,
            translation_cache: Arc::new(RwLock::new(HashMap::new())),
            alignment_mappings: Arc::new(RwLock::new(HashMap::new())),
            multilingual_embeddings: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    /// Process content and create cross-language representations
    pub async fn process_content(&self, content: &str, id: &str) -> Result<CrossLanguageContent> {
        let span = span!(Level::INFO, "process_content", content_id = %id);
        let _enter = span.enter();

        // Detect language
        let detection = if self.config.enable_language_detection {
            self.language_detector.detect_language(content)?
        } else {
            LanguageDetection {
                language: self.config.primary_language.clone(),
                confidence: 1.0,
                alternatives: Vec::new(),
            }
        };

        // Generate primary vector embedding
        let embeddable_content = crate::embeddings::EmbeddableContent::Text(content.to_string());
        let vector = self
            .embedding_generator
            .generate(&embeddable_content)
            .context("Failed to generate embedding")?;

        // Create aligned vectors for other languages
        let aligned_vectors = self
            .create_aligned_vectors(content, &detection.language, &vector)
            .await?;

        Ok(CrossLanguageContent {
            id: id.to_string(),
            text: content.to_string(),
            language: detection.language,
            language_confidence: detection.confidence,
            vector: Some(vector),
            aligned_vectors,
        })
    }

    /// Create aligned vectors for different languages
    async fn create_aligned_vectors(
        &self,
        content: &str,
        source_language: &str,
        source_vector: &Vector,
    ) -> Result<HashMap<String, Vector>> {
        let mut aligned_vectors = HashMap::new();

        match self.config.alignment_strategy {
            AlignmentStrategy::MultilingualEmbeddings => {
                // Use multilingual embedding model directly
                for target_lang in &self.config.supported_languages {
                    if target_lang != source_language {
                        let aligned_vector =
                            self.create_multilingual_embedding(content, target_lang)?;
                        aligned_vectors.insert(target_lang.clone(), aligned_vector);
                    }
                }
            }
            AlignmentStrategy::TranslationBased => {
                // Translate content and generate embeddings
                for target_lang in &self.config.supported_languages {
                    if target_lang != source_language {
                        let translated_text = self
                            .translate_text(content, source_language, target_lang)
                            .await?;
                        let embeddable_content =
                            crate::embeddings::EmbeddableContent::Text(translated_text);
                        let translated_vector =
                            self.embedding_generator.generate(&embeddable_content)?;
                        aligned_vectors.insert(target_lang.clone(), translated_vector);
                    }
                }
            }
            AlignmentStrategy::Hybrid => {
                // Use both multilingual embeddings and translation
                for target_lang in &self.config.supported_languages {
                    if target_lang != source_language {
                        let multilingual_vector =
                            self.create_multilingual_embedding(content, target_lang)?;
                        let translated_text = self
                            .translate_text(content, source_language, target_lang)
                            .await?;
                        let embeddable_content =
                            crate::embeddings::EmbeddableContent::Text(translated_text);
                        let translated_vector =
                            self.embedding_generator.generate(&embeddable_content)?;

                        // Combine vectors (simple average for now)
                        let combined_vector =
                            self.combine_vectors(&multilingual_vector, &translated_vector)?;
                        aligned_vectors.insert(target_lang.clone(), combined_vector);
                    }
                }
            }
            AlignmentStrategy::LearnedMappings => {
                // Apply learned transformation mappings
                for target_lang in &self.config.supported_languages {
                    if target_lang != source_language {
                        let mapped_vector = self.apply_learned_mapping(
                            source_vector,
                            source_language,
                            target_lang,
                        )?;
                        aligned_vectors.insert(target_lang.clone(), mapped_vector);
                    }
                }
            }
        }

        Ok(aligned_vectors)
    }

    /// Create multilingual embedding
    fn create_multilingual_embedding(
        &self,
        content: &str,
        target_language: &str,
    ) -> Result<Vector> {
        // For now, use the same embedding generator with language prefix
        let prefixed_content = format!("[{target_language}] {content}");
        let embeddable_content = crate::embeddings::EmbeddableContent::Text(prefixed_content);
        self.embedding_generator.generate(&embeddable_content)
    }

    /// Translate text between languages
    async fn translate_text(
        &self,
        text: &str,
        source_lang: &str,
        target_lang: &str,
    ) -> Result<String> {
        let cache_key = format!("{source_lang}:{target_lang}:{text}");

        // Check cache first
        {
            let cache = self
                .translation_cache
                .read()
                .expect("translation cache lock should not be poisoned");
            if let Some(cached_translation) = cache.get(&cache_key) {
                return Ok(cached_translation.clone());
            }
        }

        // Simulate translation (in real implementation, would call translation API)
        let translated = match (source_lang, target_lang) {
            ("en", "es") => format!("[ES] {text}"),
            ("en", "fr") => format!("[FR] {text}"),
            ("en", "de") => format!("[DE] {text}"),
            ("es", "en") => text.replace("[ES]", "[EN]"),
            ("fr", "en") => text.replace("[FR]", "[EN]"),
            ("de", "en") => text.replace("[DE]", "[EN]"),
            _ => {
                let upper_lang = target_lang.to_uppercase();
                format!("[{upper_lang}] {text}")
            }
        };

        // Cache the translation
        {
            let mut cache = self
                .translation_cache
                .write()
                .expect("translation cache lock should not be poisoned");
            if cache.len()
                >= self
                    .config
                    .translation_config
                    .as_ref()
                    .map(|c| c.max_cache_size)
                    .unwrap_or(10000)
            {
                // Simple cache eviction: remove first entry
                if let Some(key) = cache.keys().next().cloned() {
                    cache.remove(&key);
                }
            }
            cache.insert(cache_key, translated.clone());
        }

        Ok(translated)
    }

    /// Combine two vectors (simple averaging)
    fn combine_vectors(&self, vector1: &Vector, vector2: &Vector) -> Result<Vector> {
        let v1_f32 = vector1.as_f32();
        let v2_f32 = vector2.as_f32();

        if v1_f32.len() != v2_f32.len() {
            return Err(anyhow!("Vector dimensions must match for combination"));
        }

        let combined: Vec<f32> = v1_f32
            .iter()
            .zip(v2_f32.iter())
            .map(|(a, b)| (a + b) / 2.0)
            .collect();

        Ok(Vector::new(combined))
    }

    /// Apply learned mapping transformation
    fn apply_learned_mapping(
        &self,
        source_vector: &Vector,
        source_lang: &str,
        target_lang: &str,
    ) -> Result<Vector> {
        let mapping_key = format!("{source_lang}:{target_lang}");
        let mappings = self
            .alignment_mappings
            .read()
            .expect("alignment mappings lock should not be poisoned");

        if let Some(mapping) = mappings.get(&mapping_key) {
            if let Some(ref matrix) = mapping.transformation_matrix {
                return self.apply_matrix_transformation(source_vector, matrix);
            }
        }

        // Fallback to identity mapping
        Ok(source_vector.clone())
    }

    /// Apply matrix transformation to vector
    fn apply_matrix_transformation(&self, vector: &Vector, matrix: &[Vec<f32>]) -> Result<Vector> {
        let v_f32 = vector.as_f32();

        if matrix.is_empty() || matrix[0].len() != v_f32.len() {
            return Err(anyhow!("Matrix dimensions incompatible with vector"));
        }

        let transformed: Vec<f32> = matrix
            .iter()
            .map(|row| row.iter().zip(v_f32.iter()).map(|(m, v)| m * v).sum())
            .collect();

        Ok(Vector::new(transformed))
    }

    /// Cross-language similarity search
    pub fn cross_language_search(
        &self,
        query: &str,
        query_language: &str,
        content_items: &[CrossLanguageContent],
        k: usize,
    ) -> Result<Vec<CrossLanguageSearchResult>> {
        let span = span!(Level::INFO, "cross_language_search", query_lang = %query_language);
        let _enter = span.enter();

        // Generate query vector
        let embeddable_content = crate::embeddings::EmbeddableContent::Text(query.to_string());
        let query_vector = self.embedding_generator.generate(&embeddable_content)?;

        let mut results = Vec::new();

        for content in content_items {
            // Compute similarity with original vector
            let primary_similarity = if content.language == query_language {
                if let Some(ref content_vector) = content.vector {
                    SimilarityMetric::Cosine.compute(&query_vector, content_vector)?
                } else {
                    0.0
                }
            } else {
                0.0
            };

            // Compute cross-lingual similarity using aligned vectors
            let mut cross_lingual_similarities = HashMap::new();
            if let Some(aligned_vector) = content.aligned_vectors.get(query_language) {
                let cross_similarity =
                    SimilarityMetric::Cosine.compute(&query_vector, aligned_vector)?;
                cross_lingual_similarities.insert("cosine".to_string(), cross_similarity);
            }

            // Determine the best similarity score
            let best_similarity = primary_similarity.max(
                cross_lingual_similarities
                    .values()
                    .copied()
                    .fold(0.0, f32::max),
            );

            if best_similarity >= self.config.cross_lingual_threshold {
                results.push(CrossLanguageSearchResult {
                    id: content.id.clone(),
                    similarity: best_similarity,
                    language: content.language.clone(),
                    text: content.text.clone(),
                    translated_text: None, // Could add translation here
                    cross_lingual_metrics: cross_lingual_similarities,
                });
            }
        }

        // Sort by similarity (descending)
        results.sort_by(|a, b| {
            b.similarity
                .partial_cmp(&a.similarity)
                .unwrap_or(std::cmp::Ordering::Equal)
        });
        results.truncate(k);

        Ok(results)
    }

    /// Learn alignment mapping between languages
    pub fn learn_alignment_mapping(
        &mut self,
        source_language: &str,
        target_language: &str,
        translation_pairs: Vec<(String, String)>,
    ) -> Result<()> {
        let span = span!(Level::INFO, "learn_alignment_mapping",
                          source = %source_language, target = %target_language);
        let _enter = span.enter();

        // Generate embeddings for translation pairs
        let mut source_vectors = Vec::new();
        let mut target_vectors = Vec::new();

        for (source_text, target_text) in &translation_pairs {
            let source_embeddable = crate::embeddings::EmbeddableContent::Text(source_text.clone());
            let target_embeddable = crate::embeddings::EmbeddableContent::Text(target_text.clone());
            let source_vector = self.embedding_generator.generate(&source_embeddable)?;
            let target_vector = self.embedding_generator.generate(&target_embeddable)?;

            source_vectors.push(source_vector.as_f32());
            target_vectors.push(target_vector.as_f32());
        }

        // Learn transformation matrix (simplified - in practice would use more sophisticated methods)
        let transformation_matrix =
            self.compute_transformation_matrix(&source_vectors, &target_vectors)?;

        // Evaluate mapping quality
        let quality_score = self.evaluate_mapping_quality(
            &source_vectors,
            &target_vectors,
            &transformation_matrix,
        )?;

        let mapping = AlignmentMapping {
            source_language: source_language.to_string(),
            target_language: target_language.to_string(),
            transformation_matrix: Some(transformation_matrix),
            translation_pairs,
            quality_score,
        };

        let mapping_key = format!("{source_language}:{target_language}");
        let mut mappings = self
            .alignment_mappings
            .write()
            .expect("alignment mappings lock should not be poisoned");
        mappings.insert(mapping_key, mapping);

        info!(
            "Learned alignment mapping with quality score: {:.3}",
            quality_score
        );
        Ok(())
    }

    /// Compute transformation matrix using simple linear regression
    fn compute_transformation_matrix(
        &self,
        source_vectors: &[Vec<f32>],
        target_vectors: &[Vec<f32>],
    ) -> Result<Vec<Vec<f32>>> {
        if source_vectors.is_empty() || source_vectors.len() != target_vectors.len() {
            return Err(anyhow!("Invalid vector sets for learning transformation"));
        }

        let dim = source_vectors[0].len();

        // Simple identity matrix as baseline (in practice, would use proper linear algebra)
        let mut matrix = vec![vec![0.0; dim]; dim];
        for (i, row) in matrix.iter_mut().enumerate().take(dim) {
            row[i] = 1.0;
        }

        // Add small random perturbations to simulate learned transformation
        for (i, row) in matrix.iter_mut().enumerate().take(dim) {
            for (j, row_val) in row.iter_mut().enumerate().take(dim) {
                if i != j {
                    *row_val = (i as f32 * j as f32 * 0.001) % 0.1 - 0.05;
                }
            }
        }

        Ok(matrix)
    }

    /// Evaluate quality of learned mapping
    fn evaluate_mapping_quality(
        &self,
        source_vectors: &[Vec<f32>],
        target_vectors: &[Vec<f32>],
        matrix: &[Vec<f32>],
    ) -> Result<f32> {
        let mut total_similarity = 0.0;
        let mut count = 0;

        for (source, target) in source_vectors.iter().zip(target_vectors) {
            let transformed_vector = Vector::new(source.clone());
            let transformed = self.apply_matrix_transformation(&transformed_vector, matrix)?;
            let target_vector = Vector::new(target.clone());

            let similarity = SimilarityMetric::Cosine.compute(&transformed, &target_vector)?;
            total_similarity += similarity;
            count += 1;
        }

        Ok(if count > 0 {
            total_similarity / count as f32
        } else {
            0.0
        })
    }

    /// Get language statistics
    pub fn get_language_statistics(&self) -> HashMap<String, usize> {
        let embeddings = self
            .multilingual_embeddings
            .read()
            .expect("multilingual embeddings lock should not be poisoned");
        let mut stats = HashMap::new();

        for lang in &self.config.supported_languages {
            stats.insert(lang.clone(), embeddings.len());
        }

        stats
    }

    /// Get supported languages
    pub fn get_supported_languages(&self) -> &[String] {
        &self.config.supported_languages
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::embeddings::MockEmbeddingGenerator;

    #[test]
    fn test_cross_language_config_creation() {
        let config = CrossLanguageConfig::default();
        assert!(!config.supported_languages.is_empty());
        assert_eq!(config.primary_language, "en");
        assert!(config.enable_language_detection);
    }

    #[test]
    fn test_language_detector_creation() {
        let languages = vec!["en".to_string(), "es".to_string(), "fr".to_string()];
        let detector = SimpleLanguageDetector::new(languages.clone());

        assert!(detector.is_supported("en"));
        assert!(detector.is_supported("es"));
        assert!(!detector.is_supported("de"));
    }

    #[test]
    fn test_language_detection() -> Result<()> {
        let detector = SimpleLanguageDetector::new(vec!["en".to_string(), "es".to_string()]);

        let detection = detector.detect_language("Hello world")?;
        assert_eq!(detection.language, "en");
        assert!(detection.confidence > 0.0);

        let detection = detector.detect_language("Hola mundo")?;
        assert_eq!(detection.language, "en"); // Simple detector defaults to English
        Ok(())
    }

    #[test]
    fn test_alignment_strategy_variants() {
        let strategies = vec![
            AlignmentStrategy::MultilingualEmbeddings,
            AlignmentStrategy::TranslationBased,
            AlignmentStrategy::Hybrid,
            AlignmentStrategy::LearnedMappings,
        ];

        for strategy in strategies {
            let config = CrossLanguageConfig {
                alignment_strategy: strategy.clone(),
                ..Default::default()
            };
            assert_eq!(config.alignment_strategy, strategy);
        }
    }

    #[tokio::test]
    async fn test_cross_language_aligner_creation() {
        let config = CrossLanguageConfig::default();
        let embedding_generator = Box::new(MockEmbeddingGenerator::new());

        let aligner = CrossLanguageAligner::new(config, embedding_generator);
        assert_eq!(aligner.get_supported_languages().len(), 10);
    }

    #[tokio::test]
    async fn test_content_processing() -> Result<()> {
        let config = CrossLanguageConfig::default();
        let embedding_generator = Box::new(MockEmbeddingGenerator::new());

        let aligner = CrossLanguageAligner::new(config, embedding_generator);
        let content = aligner.process_content("Hello world", "test_id").await?;

        assert_eq!(content.id, "test_id");
        assert_eq!(content.text, "Hello world");
        assert!(content.vector.is_some());
        assert!(!content.aligned_vectors.is_empty());
        Ok(())
    }

    #[test]
    fn test_vector_combination() -> Result<()> {
        let config = CrossLanguageConfig::default();
        let embedding_generator = Box::new(MockEmbeddingGenerator::new());
        let aligner = CrossLanguageAligner::new(config, embedding_generator);

        let vector1 = Vector::new(vec![1.0, 2.0, 3.0]);
        let vector2 = Vector::new(vec![2.0, 4.0, 6.0]);

        let combined = aligner.combine_vectors(&vector1, &vector2)?;
        let combined_f32 = combined.as_f32();

        assert_eq!(combined_f32, vec![1.5, 3.0, 4.5]);
        Ok(())
    }

    #[test]
    fn test_cross_language_search_result() {
        let result = CrossLanguageSearchResult {
            id: "test".to_string(),
            similarity: 0.8,
            language: "en".to_string(),
            text: "test content".to_string(),
            translated_text: Some("contenido de prueba".to_string()),
            cross_lingual_metrics: HashMap::new(),
        };

        assert_eq!(result.id, "test");
        assert_eq!(result.similarity, 0.8);
        assert_eq!(result.language, "en");
    }
}