#!python
import sys
import enumerate_markdown


def main():
    if len(sys.argv) not in (2, 3):
        print("Usage: {} <input-markdown-file> [<output-file>]")
        sys.exit(1)
    input_filename = sys.argv[1]

    with open(input_filename, "r") as f_in:
        enumerated_content = enumerate_markdown.enumerate_headers(f_in.read())
    if len(sys.argv) == 3:
        output_filename = sys.argv[2]
        with open(output_filename, "w") as f_out:
            f_out.write(enumerated_content)
    else:
        print(enumerated_content)


if __name__ == '__main__':
    main()
