import hashlib
import hmac
import json
import threading
import time

import requests
from django.conf import settings
from django.http import HttpResponse, JsonResponse
from django.shortcuts import redirect
from django.views.decorators.csrf import csrf_exempt

from vbv_lernwelt.core.middleware.auth import django_view_authentication_exempt
from vbv_lernwelt.core.models import User


@csrf_exempt
@django_view_authentication_exempt
def fake_datatrans_api_view(request, api_url=""):
    if api_url == "/v1/transactions" and request.method == "POST":
        data = json.loads(request.body.decode("utf-8"))
        user = User.objects.get(id=data["user_id"])
        user.additional_json_data["datatrans_transaction_payload"] = data
        user.save()
        return JsonResponse({"transactionId": data["refno"]}, status=201)

    return HttpResponse(
        content="unknown api url", content_type="application/json", status=400
    )


@csrf_exempt
@django_view_authentication_exempt
def fake_datatrans_pay_view(request, api_url=""):
    def call_transaction_complete_webhook(
        webhook_url, transaction_id, datatrans_status="settled"
    ):
        time.sleep(1)

        payload = {
            "transactionId": transaction_id,
            "status": datatrans_status,
        }
        key_hex_bytes = bytes.fromhex(settings.DATATRANS_HMAC_KEY)

        # Create sign with timestamp and payload
        sign = hmac.new(
            key_hex_bytes, bytes(str(1) + json.dumps(payload), "utf-8"), hashlib.sha256
        )

        response = requests.post(
            url=webhook_url,
            json=payload,
            headers={"Datatrans-Signature": f"t=1,s0={sign.hexdigest()}"},
        )
        print(response)

    if api_url.startswith("/v1/start/"):
        transaction_id = api_url.split("/")[-1]
        transaction_user = User.objects.filter(
            additional_json_data__datatrans_transaction_payload__refno=transaction_id
        ).first()

        if transaction_user is None:
            return HttpResponse(
                content=f"""
                <h1>Fake Datatrans Payment</h1>
                <p>No active transaction found for {transaction_id}</p>
                """,
                status=404,
            )

        if request.method == "GET":
            return HttpResponse(
                content=f"""
                <h1>Fake Datatrans Payment</h1>
                <form action="{request.build_absolute_uri()}" method="post">
                  <fieldset>
                    <legend>Datatrans payment result status</legend>
                    <div>
                      <input type="radio" name="payment" value="settled" checked/>
                      <label>settled</label>

                      <input type="radio" name="payment" value="cancelled" />
                      <label>cancelled</label>

                      <input type="radio" name="payment" value="failed" />
                      <label>failed</label>
                    </div>
                    <div>
                      <button type="submit">
                        Pay with selected Status
                      </button>
                    </div>
                  </fieldset>
                </form>
                """
            )

        elif request.method == "POST":
            payment_status = request.POST.get("payment", "settled")

            if payment_status == "settled":
                success_url = transaction_user.additional_json_data[
                    "datatrans_transaction_payload"
                ]["redirect"]["successUrl"]

                # start new thread which will call webhook after 2 seconds
                webhook_url = transaction_user.additional_json_data[
                    "datatrans_transaction_payload"
                ]["webhook"]["url"]
                thread = threading.Thread(
                    target=call_transaction_complete_webhook,
                    args=(
                        webhook_url,
                        transaction_id,
                    ),
                )
                thread.start()

                # redirect to url
                return redirect(success_url + f"?datatransTrxId={transaction_id}")

            if payment_status == "cancelled":
                cancel_url = transaction_user.additional_json_data[
                    "datatrans_transaction_payload"
                ]["redirect"]["cancelUrl"]

                # redirect to url
                return redirect(cancel_url + f"?datatransTrxId={transaction_id}")

            if payment_status == "failed":
                error_url = transaction_user.additional_json_data[
                    "datatrans_transaction_payload"
                ]["redirect"]["errorUrl"]

                # redirect to url
                return redirect(error_url + f"?datatransTrxId={transaction_id}")

    return HttpResponse(
        content="unknown api url", content_type="application/json", status=400
    )