#!/usr/bin/env python
# -*- coding: utf-8 -*-
#                     The LLVM Compiler Infrastructure
#
# This file is distributed under the University of Illinois Open Source
# License. See LICENSE.TXT for details.

import os
import os.path
import argparse
import json


def main():
    """ append entry to a compilation database. """
    parser = argparse.ArgumentParser()
    parser.add_argument('--cdb', required=True)
    parser.add_argument('--command', required=True)
    parser.add_argument('--file', required=True)
    args = parser.parse_args()
    # read existing content from target file
    entries = []
    if os.path.exists(args.cdb):
        with open(args.cdb, 'r') as handle:
            entries = json.load(handle)
    # update with the current invocation
    current = {
        'directory': os.getcwd(),
        'command': args.command,
        'file': args.file
    }
    entries.append(current)
    # write the result back
    with open(args.cdb, 'w') as handle:
        json.dump(list(entries), handle, sort_keys=True, indent=4)
    return 0