import hashlib
import hmac
import json
import threading
import time

import requests
from django.conf import settings
from django.db import transaction
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
@transaction.non_atomic_requests
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"])

        if "customer" in data and not user.abacus_debitor_number:
            user.set_increment_abacus_debitor_number()
            data["customer"]["id"] = user.abacus_debitor_number

        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" data-cy="pay-button">
                        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
    )