import os
import glob
import cv2
import numpy as np
import torch
from ultralytics import YOLO
from tqdm import tqdm

# ---- CONFIGURATION ----
model_path = 'path/to/your/model/weights/best.pt'
test_img_dir = 'path/to/your/rgbd/test/images'
output_rgb_dir = 'outputs/rgb'
output_depth_dir = 'outputs/depth'
class_names = ['Feeding', 'Lateral_lying', 'Sitting', 'Standing', 'Sternal_lying']
confidence_threshold = 0.65
input_size = 640  # Model input size

os.makedirs(output_rgb_dir, exist_ok=True)
os.makedirs(output_depth_dir, exist_ok=True)

# ---- Define consistent colors for each class ----
COLORS = {
    'Feeding':        (255, 0, 0),     # Blue
    'Lateral_lying':  (0, 255, 0),     # Green
    'Sitting':        (0, 0, 255),     # Red
    'Standing':       (255, 255, 0),   # Cyan
    'Sternal_lying':  (255, 0, 255)    # Magenta
}

# ---- LOAD MODEL ----
model = YOLO(model_path).cuda().eval()

# ---- INFERENCE LOOP ----
image_paths = sorted(glob.glob(os.path.join(test_img_dir, '*.png')))

for img_path in tqdm(image_paths, desc="Visualizing Predictions"):
    base = os.path.splitext(os.path.basename(img_path))[0]

    # Load original 4-channel image
    img = cv2.imread(img_path, cv2.IMREAD_UNCHANGED)
    if img is None or img.shape[-1] != 4:
        print(f"Skipping {img_path}, invalid image format.")
        continue

    rgb = img[:, :, :3]
    depth = img[:, :, 3]
    orig_h, orig_w = rgb.shape[:2]

    # Resize to model input size for inference
    img_resized = cv2.resize(img, (input_size, input_size))
    input_tensor = torch.from_numpy(img_resized).permute(2, 0, 1).float() / 255.0
    input_tensor = input_tensor.unsqueeze(0).cuda()

    # Inference
    results = model.predict(input_tensor, imgsz=input_size, conf=confidence_threshold)[0]
    boxes = results.boxes
    classes = boxes.cls.cpu().numpy()
    confidences = boxes.conf.cpu().numpy()
    xyxy_resized = boxes.xyxy.cpu().numpy()


    # Scale boxes back to original image size
    scale_x = orig_w / input_size
    scale_y = orig_h / input_size
    xyxy_orig = np.copy(xyxy_resized)
    xyxy_orig[:, [0, 2]] *= scale_x
    xyxy_orig[:, [1, 3]] *= scale_y

    # Normalize depth to uint8 for visualization
    depth_norm = cv2.normalize(depth, None, 0, 255, cv2.NORM_MINMAX)
    depth_uint8 = depth_norm.astype('uint8')

    rgb_draw = rgb.copy()

    # Apply a colormap for better visualization
    depth_rgb = cv2.applyColorMap(depth_uint8, cv2.COLORMAP_VIRIDIS)  # Or COLORMAP_VIRIDIS, INFERNO, etc.
    depth_draw = cv2.cvtColor(depth_rgb, cv2.COLOR_BGR2RGB)  # Convert BGR to RGB for matplotlib

    # ---- Draw boxes on original-size RGB and Depth ----
    for box, cls, conf in zip(xyxy_orig, classes, confidences):
        x1, y1, x2, y2 = map(int, box)
        label = f"{class_names[int(cls)]} {conf:.2f}"
        color = COLORS.get(class_names[int(cls)], (255, 255, 255))  # Default to white

        # RGB
        cv2.rectangle(rgb_draw, (x1, y1), (x2, y2), color, 2)
        cv2.putText(rgb_draw, label, (x1, y1 - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.6, color, 2)

        # Depth
        cv2.rectangle(depth_draw, (x1, y1), (x2, y2), color, 2)
        cv2.putText(depth_draw, label, (x1, y1 - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.6, color, 2)

    # Save images
    cv2.imwrite(os.path.join(output_rgb_dir, f"{base}.png"), rgb_draw)
    cv2.imwrite(os.path.join(output_depth_dir, f"{base}.png"), depth_draw)