import base64
import json
from decimal import Decimal

import requests
from django.conf import settings
from django.urls import reverse

from shop.exceptions import RedsysPaymentException
from shop.models import Order, ShopSettings
from shop.settings import TransactionTypes
from shop.utils import compute_signature, decode_b64_dict


class RedsysClient:
    DEBUG_ENVIRONMENT_URL = "https://sis-t.redsys.es:25443/sis/realizarPago"
    PROD_ENVIRONMENT_URL = "https://sis.redsys.es/sis/realizarPago"

    REST_DEBUG_ENVIRONMENT_URL = (
        "https://sis-t.redsys.es:25443/sis/rest/trataPeticionREST"
    )
    REST_PROD_ENVIRONMENT_URL = "https://sis.redsys.es/sis/rest/trataPeticionREST"

    def __init__(self):
        self.settings = ShopSettings.load()

    def get_target_url(self):
        if settings.DEBUG:
            return self.DEBUG_ENVIRONMENT_URL
        return self.PROD_ENVIRONMENT_URL

    def get_rest_target_url(self):
        if settings.DEBUG:
            return self.REST_DEBUG_ENVIRONMENT_URL
        return self.REST_PROD_ENVIRONMENT_URL

    def get_merchant_code(self) -> str:
        return self.settings.merchant_code

    def get_terminal(self) -> str:
        return self.settings.terminal

    def get_currency_code(self) -> str:
        return self.settings.currency_code

    def get_merchant_url_ok_for_order(self, order: Order) -> str:
        path = reverse("web:order", kwargs={"uuid": order.uuid})
        return f"{self.settings.tpv_domain}{path}"

    def to_integer(self, value: Decimal):
        return int(value * 100)

    def get_merchant_url_ko_for_order(self, order: Order) -> str:
        path = reverse("web:order", kwargs={"uuid": order.uuid})
        return f"{self.settings.tpv_domain}{path}"

    def get_webhook_url_for_order(self, order: Order) -> str:
        path = reverse("shop:webhook", kwargs={"uuid": order.uuid})
        return f"{self.settings.tpv_domain}{path}"

    def get_shared_secret(self) -> str:
        return self.settings.shared_secret

    def get_signature(self, hash, payload: str):
        key = self.get_shared_secret()
        return compute_signature(str(hash), payload, key).decode()

    def _get_merchant_parameters_for_order(
        self,
        order: Order,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> dict:
        merchant_code = self.get_merchant_code()

        return {
            "DS_MERCHANT_AMOUNT": str(self.to_integer(order.total)),
            "DS_MERCHANT_CURRENCY": self.get_currency_code(),
            "DS_MERCHANT_MERCHANTCODE": merchant_code,
            # Webhook
            "DS_MERCHANT_MERCHANTURL": self.get_webhook_url_for_order(order),
            "DS_MERCHANT_ORDER": order.code,
            "DS_MERCHANT_TERMINAL": self.get_terminal(),
            "DS_MERCHANT_TRANSACTIONTYPE": order_type,
            # Página informativa al usuario - Pago erróneo
            "DS_MERCHANT_URLKO": self.get_merchant_url_ko_for_order(order),
            # Página informativa al usuario - Pago confirmado
            "DS_MERCHANT_URLOK": self.get_merchant_url_ok_for_order(order),
        }

    def _get_encoded_merchant_parameters_for_order(
        self,
        order: Order,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> str:
        body = self._get_merchant_parameters_for_order(order, order_type)
        return self._encode_body(body)

    def get_body_for_order(
        self,
        order: Order,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> dict:
        merchant_parameters = self._get_encoded_merchant_parameters_for_order(
            order, order_type
        )
        signature = self.get_signature(order.code, merchant_parameters)

        return {
            "Ds_MerchantParameters": merchant_parameters,
            "Ds_SignatureVersion": "HMAC_SHA256_V1",
            "Ds_Signature": signature,
        }

    def _encode_body(self, value):
        stringified_body = json.dumps(value)
        return base64.b64encode(stringified_body.encode()).decode("utf-8")

    def _get_rest_merchant_parameters_for_order(
        self,
        order: Order,
        pan: str,
        expiry_date: str,
        cvv2: str,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> dict:
        merchant_code = self.get_merchant_code()

        return {
            "DS_MERCHANT_AMOUNT": str(self.to_integer(order.total)),
            "DS_MERCHANT_CURRENCY": self.get_currency_code(),
            "DS_MERCHANT_CVV2": cvv2,
            "DS_MERCHANT_EXPIRYDATE": expiry_date,
            "DS_MERCHANT_MERCHANTCODE": merchant_code,
            "DS_MERCHANT_ORDER": order.uuid.hex,
            "DS_MERCHANT_PAN": pan,
            "DS_MERCHANT_TERMINAL": "1",
            "DS_MERCHANT_TRANSACTIONTYPE": order_type,
        }

    def _get_rest_encoded_merchant_parameters_for_order(
        self,
        order: Order,
        pan: str,
        expiry_date: str,
        cvv2: str,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> str:
        body = self._get_rest_merchant_parameters_for_order(
            order,
            pan=pan,
            expiry_date=expiry_date,
            cvv2=cvv2,
            order_type=order_type,
        )
        return self._encode_body(body)

    def _get_rest_body_for_order(
        self,
        order: Order,
        pan: str,
        expiry_date: str,
        cvv2: str,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ) -> dict:
        merchant_parameters = self._get_rest_encoded_merchant_parameters_for_order(
            order=order,
            pan=pan,
            expiry_date=expiry_date,
            cvv2=cvv2,
            order_type=order_type,
        )
        signature = self.get_signature(order.code, merchant_parameters)

        return {
            "Ds_MerchantParameters": merchant_parameters,
            "Ds_SignatureVersion": "HMAC_SHA256_V1",
            "Ds_Signature": signature,
        }

    def make_request_for_order(
        self,
        order: Order,
        pan: str,
        expiry_date: str,
        cvv2: str,
        order_type: int = TransactionTypes.AUTHORIZATION,
    ):
        body = self._get_rest_body_for_order(
            order=order,
            pan=pan,
            expiry_date=expiry_date,
            cvv2=cvv2,
            order_type=order_type,
        )
        url = self.get_rest_target_url()
        response = requests.post(url, body)
        return response

    def pay_order_rest(self, order: Order, pan: str, expiry_date: str, cvv2: str):
        response = self.make_request_for_order(order, pan, expiry_date, cvv2)
        data = response.json()
        error_code: str = data.get("errorCode", "")

        if error_code:
            error_code.replace("SIS0", "0")

            raise RedsysPaymentException(error_code)

        merchant_parameters = data.get("Ds_MerchantParameters")
        parameters = decode_b64_dict(merchant_parameters)

        return parameters