// OCR engine tests for ruvector-scipix
//
// Tests OCR engine initialization, model loading, inference options,
// and batch processing capabilities.
// Target: 85%+ coverage of OCR engine module

#[cfg(test)]
mod ocr_tests {
    use std::path::PathBuf;

    // Mock OCR engine structures
    #[derive(Debug, Clone)]
    struct OcrEngine {
        model_path: PathBuf,
        device: String,
        batch_size: usize,
        loaded: bool,
    }

    #[derive(Debug, Clone)]
    struct OcrOptions {
        confidence_threshold: f32,
        detect_rotation: bool,
        preprocessing: bool,
        language: String,
    }

    #[derive(Debug, Clone)]
    struct OcrResult {
        text: String,
        confidence: f32,
        bounding_boxes: Vec<BoundingBox>,
        processing_time_ms: u64,
    }

    #[derive(Debug, Clone)]
    struct BoundingBox {
        x: u32,
        y: u32,
        width: u32,
        height: u32,
        confidence: f32,
    }

    impl Default for OcrOptions {
        fn default() -> Self {
            Self {
                confidence_threshold: 0.7,
                detect_rotation: true,
                preprocessing: true,
                language: "en".to_string(),
            }
        }
    }

    impl OcrEngine {
        fn new(model_path: PathBuf, device: &str) -> Result<Self, String> {
            if !model_path.to_string_lossy().ends_with(".onnx") {
                return Err("Model must be .onnx format".to_string());
            }

            Ok(Self {
                model_path,
                device: device.to_string(),
                batch_size: 4,
                loaded: false,
            })
        }

        fn load(&mut self) -> Result<(), String> {
            if self.loaded {
                return Err("Model already loaded".to_string());
            }
            self.loaded = true;
            Ok(())
        }

        fn is_loaded(&self) -> bool {
            self.loaded
        }

        fn process(&self, _image_data: &[u8], options: &OcrOptions) -> Result<OcrResult, String> {
            if !self.loaded {
                return Err("Model not loaded".to_string());
            }

            Ok(OcrResult {
                text: "x^2 + 1".to_string(),
                confidence: 0.95,
                bounding_boxes: vec![BoundingBox {
                    x: 10,
                    y: 20,
                    width: 100,
                    height: 50,
                    confidence: 0.95,
                }],
                processing_time_ms: 123,
            })
        }

        fn process_batch(
            &self,
            images: &[Vec<u8>],
            options: &OcrOptions,
        ) -> Result<Vec<OcrResult>, String> {
            if !self.loaded {
                return Err("Model not loaded".to_string());
            }

            images
                .iter()
                .map(|img| self.process(img, options))
                .collect()
        }

        fn set_batch_size(&mut self, size: usize) {
            self.batch_size = size;
        }
    }

    #[test]
    fn test_engine_creation() {
        let engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu");
        assert!(engine.is_ok());
    }

    #[test]
    fn test_engine_creation_invalid_model() {
        let engine = OcrEngine::new(PathBuf::from("model.txt"), "cpu");
        assert!(engine.is_err());
    }

    #[test]
    fn test_engine_creation_cpu_device() {
        let engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        assert_eq!(engine.device, "cpu");
    }

    #[test]
    fn test_engine_creation_cuda_device() {
        let engine = OcrEngine::new(PathBuf::from("model.onnx"), "cuda").unwrap();
        assert_eq!(engine.device, "cuda");
    }

    #[test]
    fn test_model_loading() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();

        assert!(!engine.is_loaded());

        let result = engine.load();
        assert!(result.is_ok());
        assert!(engine.is_loaded());
    }

    #[test]
    fn test_model_loading_twice() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();

        engine.load().unwrap();
        let second_load = engine.load();

        assert!(second_load.is_err());
    }

    #[test]
    fn test_ocr_options_default() {
        let options = OcrOptions::default();

        assert_eq!(options.confidence_threshold, 0.7);
        assert!(options.detect_rotation);
        assert!(options.preprocessing);
        assert_eq!(options.language, "en");
    }

    #[test]
    fn test_ocr_options_custom() {
        let options = OcrOptions {
            confidence_threshold: 0.9,
            detect_rotation: false,
            preprocessing: true,
            language: "math".to_string(),
        };

        assert_eq!(options.confidence_threshold, 0.9);
        assert!(!options.detect_rotation);
    }

    #[test]
    fn test_process_without_loading() {
        let engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        let options = OcrOptions::default();

        let result = engine.process(&[0u8; 100], &options);
        assert!(result.is_err());
    }

    #[test]
    fn test_process_after_loading() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        engine.load().unwrap();

        let options = OcrOptions::default();
        let result = engine.process(&[0u8; 100], &options);

        assert!(result.is_ok());
    }

    #[test]
    fn test_process_result_structure() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        engine.load().unwrap();

        let options = OcrOptions::default();
        let result = engine.process(&[0u8; 100], &options).unwrap();

        assert!(!result.text.is_empty());
        assert!(result.confidence > 0.0 && result.confidence <= 1.0);
        assert!(!result.bounding_boxes.is_empty());
        assert!(result.processing_time_ms > 0);
    }

    #[test]
    fn test_batch_processing() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        engine.load().unwrap();

        let images = vec![vec![0u8; 100], vec![1u8; 100], vec![2u8; 100]];
        let options = OcrOptions::default();

        let results = engine.process_batch(&images, &options).unwrap();

        assert_eq!(results.len(), 3);
    }

    #[test]
    fn test_batch_processing_empty() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        engine.load().unwrap();

        let images: Vec<Vec<u8>> = vec![];
        let options = OcrOptions::default();

        let results = engine.process_batch(&images, &options).unwrap();

        assert_eq!(results.len(), 0);
    }

    #[test]
    fn test_batch_processing_single_image() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();
        engine.load().unwrap();

        let images = vec![vec![0u8; 100]];
        let options = OcrOptions::default();

        let results = engine.process_batch(&images, &options).unwrap();

        assert_eq!(results.len(), 1);
    }

    #[test]
    fn test_batch_size_configuration() {
        let mut engine = OcrEngine::new(PathBuf::from("model.onnx"), "cpu").unwrap();

        assert_eq!(engine.batch_size, 4);

        engine.set_batch_size(8);
        assert_eq!(engine.batch_size, 8);

        engine.set_batch_size(16);
        assert_eq!(engine.batch_size, 16);
    }

    #[test]
    fn test_bounding_box_structure() {
        let bbox = BoundingBox {
            x: 10,
            y: 20,
            width: 100,
            height: 50,
            confidence: 0.95,
        };

        assert_eq!(bbox.x, 10);
        assert_eq!(bbox.y, 20);
        assert_eq!(bbox.width, 100);
        assert_eq!(bbox.height, 50);
        assert_eq!(bbox.confidence, 0.95);
    }

    #[test]
    fn test_multiple_bounding_boxes() {
        let boxes = vec![
            BoundingBox {
                x: 10,
                y: 20,
                width: 50,
                height: 30,
                confidence: 0.95,
            },
            BoundingBox {
                x: 70,
                y: 20,
                width: 60,
                height: 30,
                confidence: 0.93,
            },
        ];

        assert_eq!(boxes.len(), 2);
        assert!(boxes.iter().all(|b| b.confidence > 0.9));
    }

    #[test]
    fn test_options_language_variants() {
        let languages = vec!["en", "math", "mixed", "es", "fr", "de"];

        for lang in languages {
            let options = OcrOptions {
                language: lang.to_string(),
                ..Default::default()
            };

            assert_eq!(options.language, lang);
        }
    }

    #[test]
    fn test_options_confidence_thresholds() {
        let thresholds = vec![0.5, 0.7, 0.8, 0.9, 0.95];

        for threshold in thresholds {
            let options = OcrOptions {
                confidence_threshold: threshold,
                ..Default::default()
            };

            assert_eq!(options.confidence_threshold, threshold);
        }
    }

    #[test]
    fn test_options_preprocessing_toggle() {
        let mut options = OcrOptions::default();
        assert!(options.preprocessing);

        options.preprocessing = false;
        assert!(!options.preprocessing);
    }

    #[test]
    fn test_options_rotation_detection_toggle() {
        let mut options = OcrOptions::default();
        assert!(options.detect_rotation);

        options.detect_rotation = false;
        assert!(!options.detect_rotation);
    }

    #[test]
    fn test_engine_with_different_devices() {
        let devices = vec!["cpu", "cuda", "cuda:0", "cuda:1"];

        for device in devices {
            let engine = OcrEngine::new(PathBuf::from("model.onnx"), device);
            assert!(engine.is_ok());
            assert_eq!(engine.unwrap().device, device);
        }
    }

    #[test]
    fn test_ocr_result_cloning() {
        let result = OcrResult {
            text: "test".to_string(),
            confidence: 0.95,
            bounding_boxes: vec![],
            processing_time_ms: 100,
        };

        let cloned = result.clone();
        assert_eq!(result.text, cloned.text);
        assert_eq!(result.confidence, cloned.confidence);
    }
}