import os
import re

def transform_filename(filename):
    # Remove extension temporarily
    name, ext = os.path.splitext(filename)

    # Replace 'Class' or 'class' with 'Notes'
    name = re.sub(r'1.2.2 Medieval India', '1.2.2 - Medieval India', name)
    name = re.sub(r'1.2.3 Modern Indian', '1.2.3 - Modern Indian', name)
    name = re.sub(r'1.2.4 Post Independence', '1.2.4 - Post Independence', name)
    name = re.sub(r'1.3 World History', '1.3 - World History', name)

    # Reattach extension
    return name + ext

def rename_md_files(root_dir):
    for dirpath, _, filenames in os.walk(root_dir):
        for filename in filenames:
            if filename.endswith('.md'):
                new_filename = transform_filename(filename)
                if filename != new_filename:
                    old_path = os.path.join(dirpath, filename)
                    new_path = os.path.join(dirpath, new_filename)
                    print(f"Renaming:\n  {filename} → {new_filename}")
                    os.rename(old_path, new_path)

# 📁 Set your target directory here
target_directory = 'v-md-notes'
rename_md_files(target_directory)