import os
import json

def extract_label_prefix(file_name):
    label_prefix = os.path.splitext(os.path.basename(file_name))[0]
    return label_prefix.replace(" ", "_").replace("-", "_")

def strip_keys(d):
    if isinstance(d, dict):
        return {k.strip(): strip_keys(v) for k, v in d.items()}
    elif isinstance(d, list):
        return [strip_keys(i) for i in d]
    else:
        return d

def format_json(json_data):
    formatted_json = "{\n  \"nodes\": [\n"
    for node in json_data['nodes']:
        formatted_json += f"    {json.dumps(node)},\n"
    formatted_json = formatted_json.rstrip(',\n') + "\n  ],\n  \"edges\": [\n"
    for edge in json_data['edges']:
        formatted_json += f"    {json.dumps(edge)},\n"
    formatted_json = formatted_json.rstrip(',\n') + "\n  ]\n}"
    return formatted_json

def validate_json(json_data):
    if not isinstance(json_data, dict) or 'nodes' not in json_data or 'edges' not in json_data:
        raise ValueError("JSON must contain 'nodes' and 'edges' keys")
    
    if not isinstance(json_data['nodes'], list) or not isinstance(json_data['edges'], list):
        raise ValueError("'nodes' and 'edges' must be lists")
    
    for node in json_data['nodes']:
        if 'id' not in node or 'label' not in node:
            raise ValueError("Each node must have 'id' and 'label' properties")
    
    for edge in json_data['edges']:
        if 'source' not in edge or 'target' not in edge or 'type' not in edge:
            raise ValueError("Each edge must have 'source', 'target', and 'type' properties")
        
        if edge['type'] != "->":
            raise ValueError("Edge type must be '->' strictly")