#!/usr/bin/python3
# gentoo-infra: infra/githooks.git:local/gentoo_push_notification.py

import hmac
import sys
import urllib.request
import urllib.error
import urllib.parse
import json
import time

# rough json format;
# dict(project=name,
#    repo_url=RO-checkout-url,
#    timestamp=epoch (integer)
#    updates_count=2,
#    updates=[
#      dict(old="rev1", new="rev2", branch=name]),
#      dict(old="rev3", new="rev4")
#    ]
# )
# finally, the string content of that is stuck into a
# header named; Gentoo-Hook-HMAC;
# this is done to allow simple validation that someone
# isn't being a bastard.

HMAC_HEADER = "Gentoo-Hook-HMAC"

def convert_stdin():
    d = {}
    updates = d["updates"] = []
    for line in sys.stdin:
        old_ref, new_ref, name = line.split(None, 2)
        if not name.startswith("refs/heads/"):
            continue
        name = name.split("/", 2)[2].rstrip()
        updates.append(dict(old=old_ref, new=new_ref, branch=name))
    i = d["updates_count"] = len(d["updates"])
    if not i:
        # the hell?
        return {}
    d["timestamp"] = int(time.time())
    return d


def main(submit_url, hmac_key, project_name, checkout_url, timeout=None):
    data = convert_stdin()
    if not data:
        return 0
    data["repository_url"] = checkout_url
    data["project"] = project_name
    data_s = json.dumps(data)
    chksum = hmac.new(hmac_key, msg=data_s).hexdigest()
    request = urllib.request.Request(submit_url, data_s, {HMAC_HEADER:chksum})
    try:
        if timeout is not None:
            result = urllib.request.urlopen(request, timeout=float(timeout))
        else:
            result = urllib.request.urlopen(request)
    except Exception as e:
        print("exception occured: %s" % (e,))
        return 2
    code = result.getcode()
    if code != 200:
        print(code)
        return 1
    return 0


if __name__ == '__main__':
    sys.exit(main(sys.argv[1],
                  sys.argv[2],
                  sys.argv[3],
                  sys.argv[4],
                  timeout=sys.argv[5]))