#!/usr/bin/env python3

""" API client for bocal-site """

import argparse
import hashlib
import hmac
import json
import os.path
import sys
import urllib.request
from datetime import date, datetime


def sendReq(url):
    def send(payload, host):
        try:
            req = urllib.request.Request(
                "https://{}/{}".format(host, url), json.dumps(payload).encode("ascii")
            )
            req.add_header("Content-Type", "application/json")
            handle = urllib.request.urlopen(req)
            code = handle.getcode()
            content = handle.read()
            handle.close()
            return (code, content.decode("utf-8"))
        except urllib.error.HTTPError as e:
            return (e.code, e.read().decode("utf-8"))

    def authentify(apiKey, payload):
        keyId, key = apiKey.split("$")
        keyId = int(keyId)
        time = datetime.now().timestamp()
        mac = hmac.new(
            key.encode("utf-8"),
            msg=str(int(time)).encode("utf-8"),
            digestmod=hashlib.sha256,
        )
        payload_enc = json.dumps(payload)
        mac.update(payload_enc.encode("utf-8"))

        auth = {
            "keyId": keyId,
            "timestamp": time,
            "hmac": mac.hexdigest(),
        }

        return {
            "auth": auth,
            "req": payload_enc,
        }

    def decorator(fct):
        """Decorator. Adds authentication layer."""

        def wrap(host, apiKey, *args, **kwargs):
            innerReq = fct(*args, **kwargs)
            payload = authentify(apiKey, innerReq)
            return send(payload, host)

        return wrap

    return decorator


@sendReq(url="api/publish")
def publish(bocId, url, date):
    return {
        "id": bocId,
        "url": url,
        "date": date.strftime("%Y-%m-%d"),
    }


###############################################################################

TOKEN_DFT_FILE = os.path.expanduser("~/.bocal_api_token")
DFT_HOST = "bocal.cof.ens.fr"


def read_token(path):
    token = ""
    try:
        with open(path, "r") as handle:
            token = handle.readline().strip()
    except FileNotFoundError:
        print(
            "[Erreur] Fichier d'identifiants absent (`{}`).".format(path),
            file=sys.stderr,
        )
        sys.exit(1)
    return token


def cmd(func):
    def wrap(parse_args, *args, **kwargs):
        token = read_token(parse_args.creds)
        return func(token, parse_args, *args, **kwargs)

    return wrap


@cmd
def cmd_publish(token, args):
    if not args.date:
        publish_date = date.today()
    else:
        year, month, day = [int(x) for x in args.date.strip().split("-")]
        publish_date = date(year=year, month=month, day=day)
    (ret_code, ret_str) = publish(args.host, token, args.numero, args.url, publish_date)
    if ret_code == 200:
        print("Succès :)")
    else:
        print("[Erreur :c] {} : {}".format(ret_code, ret_str))
        sys.exit(1)


def setup_argparse():
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--host",
        help=("Adresse du site à contacter (par défaut, " "`{}`).".format(DFT_HOST)),
    )
    parser.add_argument(
        "--creds",
        help=(
            "Fichier contenant le token API à utiliser "
            "(par défaut, `{}`)".format(TOKEN_DFT_FILE)
        ),
    )
    parser.set_defaults(creds=TOKEN_DFT_FILE, host=DFT_HOST)
    subparsers = parser.add_subparsers()

    parser_publish = subparsers.add_parser("publier", help="Publier un numéro du BOcal")
    parser_publish.add_argument("numero", help="Numéro du BOcal")
    parser_publish.add_argument("url", help="Adresse (locale) du PDF du BOcal")
    parser_publish.add_argument("-d", "--date", help="Date de publication indiquée")
    parser_publish.set_defaults(func=cmd_publish)

    out_args = parser.parse_args()
    if "func" not in out_args:  # No subcommand provided
        print("You must provide a command.", file=sys.stderr)
        print(parser.parse_args(["-h"]), file=sys.stderr)
        sys.exit(1)
    return out_args


def main():
    args = setup_argparse()
    args.func(args)


if __name__ == "__main__":
    main()