#!/usr/bin/env python3

# (C) 2019 The Johns Hopkins University Applied Physics Laboratory LLC

import os
import subprocess
import re
import sys

COPYRIGHT = "2019 The Johns Hopkins University Applied Physics Laboratory LLC"

def is_text(filename):
    msg = subprocess.Popen(["file", filename], stdout=subprocess.PIPE).communicate()[0].decode()
    return re.search('text|empty', msg) != None

def main():
    foundUncopyrighted = False
    
    p = subprocess.Popen(["git", "diff", "-z", "--cached", "--name-status"], stdout = subprocess.PIPE)
    lines = p.communicate()[0].strip().decode('utf8').split(u'\x00')
    for i in range(0, len(lines) - 1, 2):
        if lines[i].upper() == "A":
            filename = lines[i + 1]
            if is_text(filename):
                p = subprocess.Popen(["grep", COPYRIGHT, filename], stdout = subprocess.DEVNULL)
                exitCode = p.wait()
                if exitCode != 0:
                    print("New file '" + lines[i + 1] + "' has no copyright header.")
                    foundUncopyrighted = True
    
    if foundUncopyrighted:
        sys.stdin = open("/dev/tty", "r")
        answer = input("\nAbort commit to add copyright? [Yn] ").strip()
        if answer == "" or answer.upper() == "Y" or answer.upper() == "yes":
            return 1
    
    return 0

if __name__ == "__main__":
    sys.exit(main())