import os
import shutil
from PIL import Image

def process_and_crop(img_path, output_path):
    """
    Read image, horizontally crop in half (left/right), keep only the left half, and save to output_path.
    """
    if not os.path.exists(img_path):
        print(f"File does not exist: {img_path}")
        return False
    
    try:
        with Image.open(img_path) as img:
            width, height = img.size
            # Crop in half horizontally, keep only the left half
            left_half = img.crop((0, 0, width // 2, height))
            left_half.save(output_path)
        print(f"Successfully saved the cropped left-half image: {output_path}")
        return True
    except Exception as e:
        print(f"Error processing image {img_path}: {e}")
        return False

def main():
    img_label_dir = "skins"
    control_dir = "control_imgs"
    
    if not os.path.exists(img_label_dir):
        print(f"Error: Directory {img_label_dir} does not exist.")
        return
        
    # Get all png files in the img_label directory
    png_files = sorted([f for f in os.listdir(img_label_dir) if f.lower().endswith(".png")])
    
    processed_count = 0
    skipped_count = 0
    
    for filename in png_files:
        if filename.startswith("half_"):
            # Skip files that already start with half_
            continue
            
        # Target filename
        half_filename = f"half_{filename}"
        
        # Define source and destination paths
        src_img_label = os.path.join(img_label_dir, filename)
        dst_img_label = os.path.join(img_label_dir, half_filename)
        
        base_name, _ = os.path.splitext(filename)
        
        src_control = os.path.join(control_dir, filename)
        dst_control = os.path.join(control_dir, half_filename)
        
        # Check if all corresponding target files already exist
        has_control = os.path.exists(src_control)
        
        img_label_exists = os.path.exists(dst_img_label)
        control_exists = not has_control or os.path.exists(dst_control)
        
        if img_label_exists and control_exists:
            skipped_count += 1
            continue
            
        print(f"\nProcessing {filename}...")
        processed_count += 1
        
        # 1. Process PNG image
        if img_label_exists:
            print(f"  [Skip] Image {dst_img_label} already exists.")
        else:
            try:
                shutil.copy(src_img_label, dst_img_label)
                print(f"  [Success] Copied image to {dst_img_label}")
            except Exception as e:
                print(f"  [Error] Failed to copy image to {dst_img_label}: {e}")
                
        # 2. Process corresponding image
        if has_control:
            if control_exists:
                print(f"  [Skip] Cropped image {dst_control} already exists.")
            else:
                process_and_crop(src_control, dst_control)
        else:
            print(f"  [Note] No corresponding image {src_control} in control_imgs directory")

    print(f"\nProcessing complete! Newly processed {processed_count} pairs, skipped {skipped_count} existing pairs.")

if __name__ == "__main__":
    main()