#!/usr/bin/python3
import flask
import sys
import argparse
import os
import subprocess
import crypt

from sqlalchemy import Column, Integer, String, Boolean, or_, and_
from sqlalchemy.orm import sessionmaker
from sqlalchemy.exc import IntegrityError
from sqlalchemy.sql import func

from flask_sqlalchemy import SQLAlchemy

app = flask.Flask("Flask-VSFTP-User-Tool")
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///database.sqlite'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)

HTTP_FORBIDDEN      = 401
HTTP_NOT_FOUND      = 404
HTTP_UNPROCESSABLE  = 422
HTTP_INTERNAL_ERR   = 500

# unix useradd requires exactly this salt, do not change
PAM_PASSWD_SALT = "22"

@app.route('/')
def index():
    return flask.render_template("index.html")

@app.route('/create-user', methods=["POST"])
def createUser():
    createUser(flask.request.form)
    return ("Success", 200)

@app.route('/delete-user', methods=["POST"])
def deleteUser():
    deleteUser(user=flask.request.get('user'))
    return ("Success", 200)

@app.route('/list-users')
def listUsers():
    users = db.session.query(FTPUser)
    return flask.render_template("list_users.html", users=users)

def createUser(webform):

    # command line useradd requires a pre-encrypted password
    cryptPass = crypt.crypt(webform['password'], PAM_PASSWD_SALT)
    subprocess.run(["./scripts/create_user.sh", cryptPass, webform['username']])

    # track added users to prevent deletion of other users and listing #
    db.session.add(FTPUser(webform.username))
    db.session.commit()


def executeScript(scriptName):
    path = os.path.expanduser(scriptName)
    subprocess.Popen(path)

class FTPUser(db.Model):

    __tablename__ = 'users'
    username      = Column(String, primary_key=True)

@app.before_first_request
def init():
    
    app.config["DB"] = db
    db.create_all()


if __name__ == "__main__":

    parser  = argparse.ArgumentParser(description="Flask-VSFTP-User-Tool", \
                                        formatter_class=argparse.ArgumentDefaultsHelpFormatter)

    parser.add_argument("-i", "--interface", default="0.0.0.0", help="Interface to listen on")
    parser.add_argument("-p", "--port", default="5000", help="Port to listen on")
    args = parser.parse_args()
    app.run(host=args.interface, port=args.port)