=== app.py ===
import spaces
import gradio as gr
import torch
import numpy as np
from PIL import Image
from transformers import SamModel, SamProcessor
from datasets import load_dataset
import requests
from io import BytesIO
import warnings
warnings.filterwarnings("ignore")

# Global model and processor - Using SAM (Segment Anything Model)
device = "cuda" if torch.cuda.is_available() else "cpu"
model = None
processor = None

def load_model():
    """Load SAM model lazily"""
    global model, processor
    if model is None:
        print("Loading SAM model...")
        processor = SamProcessor.from_pretrained("facebook/sam-vit-base")
        model = SamModel.from_pretrained("facebook/sam-vit-base")
        if torch.cuda.is_available():
            model = model.to(device)
        print("Model loaded successfully!")
    return model, processor

# Public neuroimaging datasets on Hugging Face
NEUROIMAGING_DATASETS = {
    "Brain Tumor MRI": {
        "dataset": "sartajbhuvaji/brain-tumor-classification",
        "description": "Brain MRI scans with tumor classifications",
        "split": "train"
    },
    "Medical MNIST (Brain)": {
        "dataset": "alkzar90/NIH-Chest-X-ray-dataset",
        "description": "Medical imaging dataset",
        "split": "train"
    },
}

# Sample neuroimaging URLs (publicly available brain MRI examples)
SAMPLE_IMAGES = {
    "Brain MRI - Axial": "https://upload.wikimedia.org/wikipedia/commons/thumb/5/5e/MRI_of_Human_Brain.jpg/800px-MRI_of_Human_Brain.jpg",
    "Brain MRI - Sagittal": "https://upload.wikimedia.org/wikipedia/commons/1/1a/MRI_head_side.jpg",
    "Brain CT Scan": "https://upload.wikimedia.org/wikipedia/commons/thumb/9/9a/CT_of_brain_of_Mikael_H%C3%A4ggstr%C3%B6m_%28montage%29.png/800px-CT_of_brain_of_Mikael_H%C3%A4ggstr%C3%B6m_%28montage%29.png",
}

# Neuroimaging-specific prompts and presets
NEURO_PRESETS = {
    "Brain Structures": ["brain", "cerebrum", "cerebellum", "brainstem", "corpus callosum"],
    "Lobes": ["frontal lobe", "temporal lobe", "parietal lobe", "occipital lobe"],
    "Ventricles": ["ventricle", "lateral ventricle", "third ventricle", "fourth ventricle"],
    "Gray/White Matter": ["gray matter", "white matter", "cortex", "subcortical"],
    "Deep Structures": ["thalamus", "hypothalamus", "hippocampus", "amygdala", "basal ganglia"],
    "Lesions/Abnormalities": ["lesion", "tumor", "mass", "abnormality", "hyperintensity"],
    "Vascular": ["blood vessel", "artery", "vein", "sinus"],
    "Skull/Meninges": ["skull", "bone", "meninges", "dura"],
}

@spaces.GPU()
def segment_with_points(image: Image.Image, points: list, labels: list, structure_name: str):
    """
    Perform segmentation using SAM with point prompts.
    SAM uses point/box prompts, not text prompts.
    """
    if image is None:
        return None, "❌ Please upload a neuroimaging scan."
    
    try:
        sam_model, sam_processor = load_model()
        
        # Ensure image is RGB
        if image.mode != "RGB":
            image = image.convert("RGB")
        
        # Prepare inputs with point prompts
        if points and len(points) > 0:
            input_points = [points]  # Shape: (batch, num_points, 2)
            input_labels = [labels]   # Shape: (batch, num_points)
        else:
            # Use center point as default
            w, h = image.size
            input_points = [[[w // 2, h // 2]]]
            input_labels = [[1]]  # 1 = foreground
        
        inputs = sam_processor(
            image, 
            input_points=input_points,
            input_labels=input_labels,
            return_tensors="pt"
        )
        
        if torch.cuda.is_available():
            inputs = {k: v.to(device) for k, v in inputs.items()}
        
        with torch.no_grad():
            outputs = sam_model(**inputs)
        
        # Post-process masks
        masks = sam_processor.image_processor.post_process_masks(
            outputs.pred_masks.cpu(),
            inputs["original_sizes"].cpu(),
            inputs["reshaped_input_sizes"].cpu()
        )
        
        scores = outputs.iou_scores.cpu().numpy()[0]
        
        # Get best mask
        masks_np = masks[0].numpy()
        
        if masks_np.shape[0] == 0:
            return (image, []), f"❌ No segmentation found for the selected points."
        
        # Format for AnnotatedImage
        annotations = []
        for i in range(min(3, masks_np.shape[1])):  # Top 3 masks
            mask = masks_np[0, i].astype(np.uint8)
            if mask.sum() > 0:  # Only add non-empty masks
                score = scores[0, i] if i < scores.shape[1] else 0.0
                label = f"{structure_name} (IoU: {score:.2f})"
                annotations.append((mask, label))
        
        if not annotations:
            return (image, []), "❌ No valid masks generated."
        
        info = f"""✅ **Segmentation Complete**

**Target:** {structure_name}
**Masks Generated:** {len(annotations)}
**Best IoU Score:** {scores.max():.3f}

*SAM generates multiple mask proposals - showing top results*"""
        
        return (image, annotations), info
        
    except Exception as e:
        import traceback
        return (image, []), f"❌ Error: {str(e)}\n\n{traceback.format_exc()}"

@spaces.GPU()
def segment_with_box(image: Image.Image, x1: int, y1: int, x2: int, y2: int, structure_name: str):
    """Segment using bounding box prompt"""
    if image is None:
        return None, "❌ Please upload an image."
    
    try:
        sam_model, sam_processor = load_model()
        
        if image.mode != "RGB":
            image = image.convert("RGB")
        
        # Prepare box prompt
        input_boxes = [[[x1, y1, x2, y2]]]
        
        inputs = sam_processor(
            image,
            input_boxes=input_boxes,
            return_tensors="pt"
        )
        
        if torch.cuda.is_available():
            inputs = {k: v.to(device) for k, v in inputs.items()}
        
        with torch.no_grad():
            outputs = sam_model(**inputs)
        
        masks = sam_processor.image_processor.post_process_masks(
            outputs.pred_masks.cpu(),
            inputs["original_sizes"].cpu(),
            inputs["reshaped_input_sizes"].cpu()
        )
        
        scores = outputs.iou_scores.cpu().numpy()[0]
        masks_np = masks[0].numpy()
        
        annotations = []
        for i in range(min(3, masks_np.shape[1])):
            mask = masks_np[0, i].astype(np.uint8)
            if mask.sum() > 0:
                score = scores[0, i] if i < scores.shape[1] else 0.0
                label = f"{structure_name} (IoU: {score:.2f})"
                annotations.append((mask, label))
        
        if not annotations:
            return (image, []), "❌ No valid masks generated from box."
        
        info = f"""✅ **Box Segmentation Complete**

**Target:** {structure_name}
**Box:** ({x1}, {y1}) to ({x2}, {y2})
**Masks Generated:** {len(annotations)}"""
        
        return (image, annotations), info
        
    except Exception as e:
        return (image, []), f"❌ Error: {str(e)}"

@spaces.GPU()
def auto_segment_grid(image: Image.Image, grid_size: int = 4):
    """Automatic segmentation using grid of points"""
    if image is None:
        return None, "❌ Please upload an image."
    
    try:
        sam_model, sam_processor = load_model()
        
        if image.mode != "RGB":
            image = image.convert("RGB")
        
        w, h = image.size
        
        # Create grid of points
        points = []
        step_x = w // (grid_size + 1)
        step_y = h // (grid_size + 1)
        
        for i in range(1, grid_size + 1):
            for j in range(1, grid_size + 1):
                points.append([step_x * i, step_y * j])
        
        all_annotations = []
        
        # Process each point
        for idx, point in enumerate(points[:9]):  # Limit to 9 points for speed
            input_points = [[point]]
            input_labels = [[1]]
            
            inputs = sam_processor(
                image,
                input_points=input_points,
                input_labels=input_labels,
                return_tensors="pt"
            )
            
            if torch.cuda.is_available():
                inputs = {k: v.to(device) for k, v in inputs.items()}
            
            with torch.no_grad():
                outputs = sam_model(**inputs)
            
            masks = sam_processor.image_processor.post_process_masks(
                outputs.pred_masks.cpu(),
                inputs["original_sizes"].cpu(),
                inputs["reshaped_input_sizes"].cpu()
            )
            
            scores = outputs.iou_scores.cpu().numpy()[0]
            masks_np = masks[0].numpy()
            
            # Get best mask for this point
            if masks_np.shape[1] > 0:
                best_idx = scores[0].argmax()
                mask = masks_np[0, best_idx].astype(np.uint8)
                if mask.sum() > 100:  # Minimum size threshold
                    score = scores[0, best_idx]
                    label = f"Region {idx + 1} (IoU: {score:.2f})"
                    all_annotations.append((mask, label))
        
        if not all_annotations:
            return (image, []), "❌ No regions found with auto-segmentation."
        
        info = f"""✅ **Auto-Segmentation Complete**

**Grid Points:** {len(points)}
**Regions Found:** {len(all_annotations)}

*Automatic discovery of distinct regions in the image*"""
        
        return (image, all_annotations), info
        
    except Exception as e:
        return (image, []), f"❌ Error: {str(e)}"

def load_sample_image(sample_name: str):
    """Load a sample neuroimaging image"""
    if sample_name not in SAMPLE_IMAGES:
        return None, "Sample not found"
    
    try:
        url = SAMPLE_IMAGES[sample_name]
        response = requests.get(url, timeout=10)
        image = Image.open(BytesIO(response.content)).convert("RGB")
        return image, f"✅ Loaded: {sample_name}"
    except Exception as e:
        return None, f"❌ Failed to load sample: {str(e)}"

def load_from_hf_dataset(dataset_name: str, index: int = 0):
    """Load image from Hugging Face dataset"""
    try:
        if dataset_name == "Brain Tumor MRI":
            ds = load_dataset("sartajbhuvaji/brain-tumor-classification", split="train", streaming=True)
            for i, sample in enumerate(ds):
                if i == index:
                    image = sample["image"]
                    if image.mode != "RGB":
                        image = image.convert("RGB")
                    return image, f"✅ Loaded from Brain Tumor MRI dataset (index {index})"
        return None, "Dataset not available"
    except Exception as e:
        return None, f"❌ Error loading dataset: {str(e)}"

def get_click_point(image, evt: gr.SelectData):
    """Get point coordinates from image click"""
    if evt is None:
        return [], [], "Click on the image to add points"
    
    x, y = evt.index
    return [[x, y]], [1], f"Point added at ({x}, {y})"

# Store points for multi-point selection
current_points = []
current_labels = []

def add_point(image, evt: gr.SelectData, points_state, labels_state, point_type):
    """Add a point to the current selection"""
    if evt is None or image is None:
        return points_state, labels_state, "Click on image to add points"
    
    x, y = evt.index
    label = 1 if point_type == "Foreground (+)" else 0
    
    points_state = points_state + [[x, y]]
    labels_state = labels_state + [label]
    
    point_info = f"Added {'foreground' if label == 1 else 'background'} point at ({x}, {y})\n"
    point_info += f"Total points: {len(points_state)}"
    
    return points_state, labels_state, point_info

def clear_points():
    """Clear all selected points"""
    return [], [], "Points cleared"

def clear_all():
    """Clear all inputs and outputs"""
    return None, None, [], [], 0.5, "brain region", "📝 Upload a neuroimaging scan and click to add points for segmentation."

# Gradio Interface
with gr.Blocks(
    theme=gr.themes.Soft(),
    title="NeuroSAM - Neuroimaging Segmentation",
    css="""
    .gradio-container {max-width: 1400px !important;}
    .neuro-header {background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); padding: 20px; border-radius: 10px; margin-bottom: 20px;}
    .neuro-header h1 {color: white !important; margin: 0 !important;}
    .neuro-header p {color: rgba(255,255,255,0.9) !important;}
    .info-box {background: #e8f4f8; padding: 15px; border-radius: 8px; margin: 10px 0;}
    """,
    footer_links=[{"label": "Built with anycoder", "url": "https://huggingface.co/spaces/akhaliq/anycoder"}]
) as demo:
    
    # State for point selection
    points_state = gr.State([])
    labels_state = gr.State([])
    
    gr.HTML(
        """
        <div class="neuro-header">
            <h1>🧠 NeuroSAM - Neuroimaging Segmentation</h1>
            <p>Interactive segmentation using Meta's Segment Anything Model (SAM)</p>
            <p style="font-size: 0.9em;">Built with <a href="https://huggingface.co/spaces/akhaliq/anycoder" style="color: #FFD700;">anycoder</a> | Model: facebook/sam-vit-base</p>
        </div>
        """
    )
    
    gr.Markdown("""
    ### ℹ️ About SAM (Segment Anything Model)
    
    **SAM** is a foundation model for image segmentation by Meta AI. Unlike text-based models, SAM uses **visual prompts**:
    - **Point prompts**: Click on the region you want to segment
    - **Box prompts**: Draw a bounding box around the region
    - **Automatic mode**: Discovers all segmentable regions
    
    *Note: SAM is a general-purpose segmentation model, not specifically trained on medical images. For clinical use, specialized medical imaging models should be used.*
    """)
    
    with gr.Row():
        with gr.Column(scale=1):
            gr.Markdown("### 📤 Input")
            
            image_input = gr.Image(
                label="Neuroimaging Scan (Click to add points)",
                type="pil",
                height=400,
                interactive=True,
            )
            
            with gr.Accordion("📂 Load Sample Images", open=True):
                sample_dropdown = gr.Dropdown(
                    label="Sample Neuroimaging Images",
                    choices=list(SAMPLE_IMAGES.keys()),
                    value=None,
                    info="Load publicly available brain imaging examples"
                )
                load_sample_btn = gr.Button("Load Sample", size="sm")
                
                gr.Markdown("**Or load from Hugging Face Datasets:**")
                with gr.Row():
                    hf_dataset = gr.Dropdown(
                        label="Dataset",
                        choices=["Brain Tumor MRI"],
                        value="Brain Tumor MRI"
                    )
                    hf_index = gr.Number(label="Image Index", value=0, minimum=0, maximum=100)
                load_hf_btn = gr.Button("Load from HF", size="sm")
            
            gr.Markdown("### 🎯 Segmentation Mode")
            
            with gr.Tab("Point Prompt"):
                gr.Markdown("**Click on the image to add points, then segment**")
                
                point_type = gr.Radio(
                    choices=["Foreground (+)", "Background (-)"],
                    value="Foreground (+)",
                    label="Point Type",
                    info="Foreground = include region, Background = exclude region"
                )
                
                structure_name = gr.Textbox(
                    label="Structure Label",
                    value="brain region",
                    placeholder="e.g., hippocampus, ventricle, tumor...",
                    info="Label for the segmented region"
                )
                
                points_info = gr.Textbox(
                    label="Selected Points",
                    value="Click on image to add points",
                    interactive=False
                )
                
                with gr.Row():
                    clear_points_btn = gr.Button("Clear Points", variant="secondary")
                    segment_points_btn = gr.Button("🎯 Segment", variant="primary")
            
            with gr.Tab("Box Prompt"):
                gr.Markdown("**Define a bounding box around the region**")
                
                with gr.Row():
                    box_x1 = gr.Number(label="X1 (left)", value=50)
                    box_y1 = gr.Number(label="Y1 (top)", value=50)
                with gr.Row():
                    box_x2 = gr.Number(label="X2 (right)", value=200)
                    box_y2 = gr.Number(label="Y2 (bottom)", value=200)
                
                box_structure = gr.Textbox(
                    label="Structure Label",
                    value="selected region"
                )
                
                segment_box_btn = gr.Button("🎯 Segment Box", variant="primary")
            
            with gr.Tab("Auto Segment"):
                gr.Markdown("**Automatically discover all segmentable regions**")
                
                grid_size = gr.Slider(
                    minimum=2,
                    maximum=5,
                    value=3,
                    step=1,
                    label="Grid Density",
                    info="Higher = more points sampled"
                )
                
                auto_segment_btn = gr.Button("🔍 Auto-Segment All", variant="primary")
            
            clear_btn = gr.Button("🗑️ Clear All", variant="secondary")
        
        with gr.Column(scale=1):
            gr.Markdown("### 📊 Output")
            
            image_output = gr.AnnotatedImage(
                label="Segmented Result",
                height=450,
                show_legend=True,
            )
            
            info_output = gr.Markdown(
                value="📝 Upload a neuroimaging scan and click to add points for segmentation.",
                label="Results"
            )
    
    gr.Markdown("### 📚 Available Datasets on Hugging Face")
    
    with gr.Row():
        with gr.Column():
            gr.Markdown("""
            **🧠 Brain/Neuro Imaging**
            - `sartajbhuvaji/brain-tumor-classification` - Brain MRI with tumor labels
            - `keremberke/brain-tumor-object-detection` - Brain tumor detection
            - `TrainingDataPro/brain-mri-dataset` - Brain MRI scans
            """)
        with gr.Column():
            gr.Markdown("""
            **🏥 Medical Imaging**
            - `alkzar90/NIH-Chest-X-ray-dataset` - Chest X-rays
            - `marmal88/skin_cancer` - Dermatology images
            - `hf-vision/chest-xray-pneumonia` - Pneumonia detection
            """)
        with gr.Column():
            gr.Markdown("""
            **🔬 Specialized**
            - `Francesco/cell-segmentation` - Cell microscopy
            - `segments/sidewalk-semantic` - Semantic segmentation
            - `detection-datasets/coco` - General objects
            """)
    
    gr.Markdown("""
    ### 💡 How to Use
    
    1. **Load an image**: Upload your own or select from samples/HuggingFace datasets
    2. **Choose segmentation mode**:
       - **Point Prompt**: Click on regions you want to segment (green = include, red = exclude)
       - **Box Prompt**: Define coordinates for a bounding box
       - **Auto Segment**: Let SAM discover all distinct regions automatically
    3. **View results**: Segmented regions appear with colored overlays
    
    ### ⚠️ Important Notes
    
    - SAM is a **general-purpose** model, not specifically trained for medical imaging
    - For clinical applications, use validated medical imaging AI tools
    - Results should be reviewed by qualified medical professionals
    """)
    
    # Event handlers
    load_sample_btn.click(
        fn=load_sample_image,
        inputs=[sample_dropdown],
        outputs=[image_input, info_output]
    )
    
    load_hf_btn.click(
        fn=load_from_hf_dataset,
        inputs=[hf_dataset, hf_index],
        outputs=[image_input, info_output]
    )
    
    # Point selection on image click
    image_input.select(
        fn=add_point,
        inputs=[image_input, points_state, labels_state, point_type],
        outputs=[points_state, labels_state, points_info]
    )
    
    clear_points_btn.click(
        fn=clear_points,
        outputs=[points_state, labels_state, points_info]
    )
    
    segment_points_btn.click(
        fn=segment_with_points,
        inputs=[image_input, points_state, labels_state, structure_name],
        outputs=[image_output, info_output]
    )
    
    segment_box_btn.click(
        fn=segment_with_box,
        inputs=[image_input, box_x1, box_y1, box_x2, box_y2, box_structure],
        outputs=[image_output, info_output]
    )
    
    auto_segment_btn.click(
        fn=auto_segment_grid,
        inputs=[image_input, grid_size],
        outputs=[image_output, info_output]
    )
    
    clear_btn.click(
        fn=clear_all,
        outputs=[image_input, image_output, points_state, labels_state, grid_size, structure_name, info_output]
    )

if __name__ == "__main__":
    demo.launch()

=== utils.py ===
"""
Utility functions for neuroimaging preprocessing and analysis
"""
import numpy as np
from PIL import Image

def normalize_medical_image(image_array: np.ndarray) -> np.ndarray:
    """
    Normalize medical image intensities to 0-255 range
    Handles various bit depths common in medical imaging
    """
    img = image_array.astype(np.float32)
    
    # Handle different intensity ranges
    if img.max() > 255:
        # Likely 12-bit or 16-bit image
        p1, p99 = np.percentile(img, [1, 99])
        img = np.clip(img, p1, p99)
    
    # Normalize to 0-255
    img_min, img_max = img.min(), img.max()
    if img_max > img_min:
        img = (img - img_min) / (img_max - img_min) * 255
    
    return img.astype(np.uint8)

def apply_window_level(image_array: np.ndarray, window: float, level: float) -> np.ndarray:
    """
    Apply window/level (contrast/brightness) adjustment
    Common in CT viewing
    
    Args:
        image_array: Input image
        window: Window width (contrast)
        level: Window center (brightness)
    """
    img = image_array.astype(np.float32)
    
    min_val = level - window / 2
    max_val = level + window / 2
    
    img = np.clip(img, min_val, max_val)
    img = (img - min_val) / (max_val - min_val) * 255
    
    return img.astype(np.uint8)

def enhance_brain_contrast(image: Image.Image) -> Image.Image:
    """
    Enhance contrast specifically for brain MRI visualization
    """
    img_array = np.array(image)
    
    # Convert to grayscale if needed
    if len(img_array.shape) == 3:
        gray = np.mean(img_array, axis=2)
    else:
        gray = img_array
    
    # Apply histogram equalization
    from PIL import ImageOps
    enhanced = ImageOps.equalize(Image.fromarray(gray.astype(np.uint8)))
    
    # Convert back to RGB
    enhanced_array = np.array(enhanced)
    rgb_array = np.stack([enhanced_array] * 3, axis=-1)
    
    return Image.fromarray(rgb_array)

# Common neuroimaging structure mappings
STRUCTURE_ALIASES = {
    "hippocampus": ["hippocampal formation", "hippocampal", "medial temporal"],
    "ventricle": ["ventricular system", "lateral ventricle", "CSF space"],
    "white matter": ["WM", "cerebral white matter", "deep white matter"],
    "gray matter": ["GM", "cortical gray matter", "cortex"],
    "tumor": ["mass", "lesion", "neoplasm", "growth"],
    "thalamus": ["thalamic", "diencephalon"],
    "basal ganglia": ["striatum", "caudate", "putamen", "globus pallidus"],
}

def get_structure_aliases(structure: str) -> list:
    """Get alternative names for a neuroanatomical structure"""
    structure_lower = structure.lower()
    
    for key, aliases in STRUCTURE_ALIASES.items():
        if structure_lower == key or structure_lower in aliases:
            return [key] + aliases
    
    return [structure]

# Hugging Face datasets for neuroimaging
HF_NEUROIMAGING_DATASETS = {
    "brain-tumor-classification": {
        "repo": "sartajbhuvaji/brain-tumor-classification",
        "description": "Brain MRI scans classified by tumor type (glioma, meningioma, pituitary, no tumor)",
        "image_key": "image",
        "label_key": "label"
    },
    "brain-tumor-detection": {
        "repo": "keremberke/brain-tumor-object-detection",
        "description": "Brain MRI with bounding box annotations for tumors",
        "image_key": "image",
        "label_key": "objects"
    },
    "chest-xray": {
        "repo": "alkzar90/NIH-Chest-X-ray-dataset",
        "description": "Chest X-ray images with disease labels",
        "image_key": "image",
        "label_key": "labels"
    }
}