import random
import string
from datetime import datetime, timedelta

import user_agents
from django.http import HttpResponse
from django.shortcuts import render
from django.template.context import RequestContext
from django.template.context_processors import csrf
from django.utils import timezone
from jose import jwt

from .Common import send
from .models import *


def id_generator(size=6, chars=string.ascii_uppercase + string.digits):
    x = "".join(random.choice(chars) for _ in range(size))
    if not User_Keys.objects.filter(properties__shas="$.key=" + x).exists():
        return x
    else:
        return id_generator(size, chars)


def getUserAgent(request):
    id = id = request.session.get("td_id", None)
    if id:
        tk = User_Keys.objects.get(id=id)
        if tk.properties.get("user_agent", "") != "":
            ua = user_agents.parse(tk.properties["user_agent"])
            res = render(None, "TrustedDevices/user-agent.html", context={"ua": ua})
            return HttpResponse(res)
    return HttpResponse("")


def trust_device(request):
    tk = User_Keys.objects.get(id=request.session["td_id"])
    tk.properties["status"] = "trusted"
    tk.save()
    del request.session["td_id"]
    return HttpResponse("OK")


def checkTrusted(request):
    res = ""
    id = request.session.get("td_id", "")
    if id != "":
        try:
            tk = User_Keys.objects.get(id=id)
            if tk.properties["status"] == "trusted":
                res = "OK"
        except:
            pass
    return HttpResponse(res)


def getCookie(request):
    tk = User_Keys.objects.get(id=request.session["td_id"])

    if tk.properties["status"] == "trusted":
        context = {"added": True}
        response = render(request, "TrustedDevices/Done.html", context)

        expires = datetime.now() + timedelta(days=180)
        tk.expires = expires
        tk.save()
        response.set_cookie("deviceid", tk.properties["signature"], expires=expires)
        return response


def add(request):
    context = csrf(request)
    if request.method == "GET":
        return render(request, "TrustedDevices/Add.html", context)
    else:
        key = request.POST["key"].replace("-", "").replace(" ", "").upper()
        context["username"] = request.POST["username"]
        context["key"] = request.POST["key"]
        trusted_keys = User_Keys.objects.filter(
            username=request.POST["username"], properties__has="$.key=" + key
        )
        cookie = False
        if trusted_keys.exists():
            tk = trusted_keys[0]
            request.session["td_id"] = tk.id
            ua = request.META["HTTP_USER_AGENT"]
            agent = user_agents.parse(ua)
            if agent.is_pc:
                context["invalid"] = "This is a PC, it can't used as a trusted device."
            else:
                tk.properties["user_agent"] = ua
                tk.save()
                context["success"] = True

        else:
            context[
                "invalid"
            ] = "The username or key is wrong, please check and try again."

        return render(request, "TrustedDevices/Add.html", context)


def start(request):
    if (
        User_Keys.objects.filter(
            username=request.user.username, key_type="Trusted Device"
        ).count()
        >= 2
    ):
        return render(request, "TrustedDevices/start.html", {"not_allowed": True})
    td = None
    if not request.session.get("td_id", None):
        td = User_Keys()
        td.username = request.user.username
        td.properties = {"key": id_generator(), "status": "adding"}
        td.key_type = "Trusted Device"
        td.save()
        request.session["td_id"] = td.id
    try:
        if td == None:
            td = User_Keys.objects.get(id=request.session["td_id"])
        context = {"key": td.properties["key"]}
    except:
        del request.session["td_id"]
        return start(request)
    return render(request, "TrustedDevices/start.html", context)


def send_email(request):
    body = render(request, "TrustedDevices/email.html", {}).content
    e = request.user.email
    if e == "":
        e = request.session.get("user", {}).get("email", "")
    if e == "":
        res = "User has no email on the system."
    elif send([e], "Add Trusted Device Link", body):
        res = "Sent Successfully"
    else:
        res = "Error occured, please try again later."
    return HttpResponse(res)


def verify(request):
    if request.COOKIES.get("deviceid", None):
        json = jwt.decode(request.COOKIES.get("deviceid"), settings.SECRET_KEY)
        if json["username"].lower() == request.session["base_username"].lower():
            try:
                uk = User_Keys.objects.get(
                    username=request.POST["username"].lower(),
                    properties__has="$.key=" + json["key"],
                )
                if uk.enabled and uk.properties["status"] == "trusted":
                    uk.last_used = timezone.now()
                    uk.save()
                    request.session["mfa"] = {
                        "verified": True,
                        "method": "Trusted Device",
                        "id": uk.id,
                    }
                    return True
            except:
                return False
    return False