import csv
import json
import sys
import os

def csv_to_json(csv_filepath, json_filepath):
    data = []
    with open(csv_filepath, encoding='utf-8') as csvf:
        csv_reader = csv.DictReader(csvf)
        for row in csv_reader:
            data.append(row)
    with open(json_filepath, 'w', encoding='utf-8') as jsonf:
        jsonf.write(json.dumps(data, indent=4))

def json_to_csv(json_filepath, csv_filepath):
    with open(json_filepath, 'r', encoding='utf-8') as jsonf:
        data = json.load(jsonf)
    if data:
        with open(csv_filepath, 'w', encoding='utf-8', newline='') as csvf:
            writer = csv.DictWriter(csvf, fieldnames=data[0].keys())
            writer.writeheader()
            writer.writerows(data)

def auto_convert(input_file):
    file_name, file_extension = os.path.splitext(input_file)
    if file_extension.lower() == ".csv":
        output_file = f"{file_name}.json"
        csv_to_json(input_file, output_file)
        print(f"Converted {input_file} to {output_file}")
    elif file_extension.lower() == ".json":
        output_file = f"{file_name}.csv"
        json_to_csv(input_file, output_file)
        print(f"Converted {input_file} to {output_file}")
    else:
        print("Unsupported file format. Please provide a .csv or .json file.")
        sys.exit(1)

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python convert.py <input_file>")
        sys.exit(1)
    input_file = sys.argv[1]
    auto_convert(input_file)