from flask import Flask, request, abort, jsonify
from flask_sqlalchemy import SQLAlchemy
import subprocess
import random
import os


SUPPORT_KEY = "x2Dmw3hLRDPQa1sg59fAx2Dmw3hLRDPQa1sg59fA"
PUBKEYS = [
    "ssh-rsa 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 jean@toulza.fr"
]

app = Flask(__name__)
app.config['SECRET_KEY'] = '9OLWxND4o83j4K4iuopO'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///db.sqlite'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)


@app.route('/request', methods=["POST"])
def request_post():
    j = request.json
    if not j or j["key"] != SUPPORT_KEY:
        abort(403)
    if "pubKey" in j and "nom" in j and "prenom" in j and len(j["nom"]) > 3 and len(j["prenom"]) > 3:
        nom = j["nom"]
        prenom = j["prenom"]
        pubkey = j["pubKey"]
        ip = request.remote_addr
        localuser, randomport = create_user(nom, prenom, pubkey)
        print("IP: %s, localuser=%s randomport=%s" % (ip, localuser, randomport))
        return jsonify({"status": "ok", "pubkeys": "\n".join(PUBKEYS), "remoteport": randomport, "remoteuser": localuser})
    else:
        abort(403)


@app.route('/end', methods=["DELETE"])
def end_delete():
    j = request.json
    if not j or j["key"] != SUPPORT_KEY:
        print("no json or support key")
        print(request.data)
        print(request.form)
        abort(403)
    if "pubKey" in j:
        localuser = find_localuser_by_pubkey(j["pubKey"])
        if localuser:
            delete_localuser(localuser)
            print("deleted %s" % localuser)
        return jsonify({"status": "ok"})
    else:
        print("no pubkey")
        abort(403)


def find_localuser_by_pubkey(pubkey):
    for user in get_localusers():
        if os.path.exists("/home/%s/.ssh/authorized_keys" % user):
            with open("/home/%s/.ssh/authorized_keys" % user) as fp:
                content = fp.read()
            if pubkey in content:
                return user
    return None


def exec_cmd(cmd):
    p = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE)
    retcode = p.wait()
    stdout, stderr = p.communicate()
    stdout = stdout.decode("utf8").strip()
    return retcode, stdout


def get_localusers():
    retcode, out = exec_cmd("awk -F: '{ print $1 }' /etc/passwd")
    users = out.split("\n")
    return users


def localuser_exists(username):
    return username in get_localusers()


def create_user(nom, prenom, pubkey):
    username = (nom[0:3] + prenom[0:3]).lower()
    while localuser_exists(username):
        username = username + str(random.randint(1, 99))

    print("Creating user %s..." % username)

    retcode, out = exec_cmd("adduser \
   --system \
   --shell /bin/false \
   --gecos 'LIS67 user account for %s %s' \
   --group \
   --disabled-password \
   --home /home/%s \
   %s" % (nom, prenom, username, username))

    if retcode != 0:
        abort(500)

    try:
        os.mkdir("/home/%s/.ssh" % username)
    except:
        pass

    with open("/home/%s/.ssh/authorized_keys" % username, "w") as fp:
        fp.write(pubkey)

    random_port = find_localport()

    return username, random_port


def find_localport():
    retcode, out = exec_cmd("python -c 'import socket; s=socket.socket(); s.bind((\"\", 0)); print(s.getsockname()[1]); s.close()'")
    return int(out)


def delete_localuser(username):
    exec_cmd("userdel -r -f %s" % username)


if __name__ == "__main__":
    db.create_all()
    app.run(host="0.0.0.0")