import {ConfigInterface, ConfigParams} from '../base-types';
import {BillingInterval} from '../types';
import {BillingError} from '../error';
import {buildEmbeddedAppUrl} from '../auth/get-embedded-app-url';
import {GraphqlClient, graphqlClientClass} from '../clients/admin';
import {hashString} from '../../runtime/crypto';
import {HashFormat} from '../../runtime/crypto/types';
import {FutureFlagOptions} from '../../future/flags';

import {
  BillingConfigOneTimePlan,
  BillingRequestParams,
  BillingRequestResponse,
  RecurringPaymentResponse,
  RequestResponseData,
  SinglePaymentResponse,
  BillingConfigSubscriptionLineItemPlan,
  RequestConfigLineItemOverrides,
  BillingRequest,
  APP_SUBSCRIPTION_FRAGMENT,
} from './types';

const RECURRING_PURCHASE_MUTATION = `
  ${APP_SUBSCRIPTION_FRAGMENT}
  mutation AppSubscriptionCreate(
    $name: String!
    $returnUrl: URL!
    $test: Boolean
    $trialDays: Int
    $replacementBehavior: AppSubscriptionReplacementBehavior
    $lineItems: [AppSubscriptionLineItemInput!]!
  ) {
    appSubscriptionCreate(
      name: $name
      returnUrl: $returnUrl
      test: $test
      trialDays: $trialDays
      replacementBehavior: $replacementBehavior
      lineItems: $lineItems
    ) {
      appSubscription {
        ...AppSubscriptionFragment
      }
      confirmationUrl
      userErrors {
        field
        message
      }
    }
  }
`;

const ONE_TIME_PURCHASE_MUTATION = `
  mutation test(
    $name: String!
    $price: MoneyInput!
    $returnUrl: URL!
    $test: Boolean
  ) {
    appPurchaseOneTimeCreate(
      name: $name
      price: $price
      returnUrl: $returnUrl
      test: $test
    ) {
      appPurchaseOneTime {
        id
        name
        test
      }
      confirmationUrl
      userErrors {
        field
        message
      }
    }
  }
`;

interface RequestInternalParams {
  client: GraphqlClient;
  plan: string;
  returnUrl: string;
  isTest: boolean;
}

interface RequestOneTimePaymentInternalParams extends RequestInternalParams {
  billingConfig: BillingConfigOneTimePlan;
}

interface RequestSubscriptionParams extends RequestInternalParams {
  billingConfig: BillingConfigSubscriptionLineItemPlan;
}

export function request<
  Config extends ConfigInterface<Params>,
  Params extends ConfigParams<any, Future>,
  Future extends FutureFlagOptions,
>(config: Config): BillingRequest {
  return async function <Params extends BillingRequestParams>({
    session,
    plan,
    isTest = true,
    returnUrl: returnUrlParam,
    returnObject = false,
    ...overrides
  }: Params): Promise<BillingRequestResponse<Params>> {
    if (!config.billing || !config.billing[plan]) {
      throw new BillingError({
        message: `Could not find plan ${plan} in billing settings`,
        errorData: [],
      });
    }

    const billingConfig = {
      ...config.billing[plan],
    };
    const filteredOverrides = Object.fromEntries(
      Object.entries(overrides).filter(([_key, value]) => value !== undefined),
    );

    const cleanShopName = session.shop.replace('.myshopify.com', '');
    const embeddedAppUrl = buildEmbeddedAppUrl(config)(
      hashString(`admin.shopify.com/store/${cleanShopName}`, HashFormat.Base64),
    );

    const appUrl = `${config.hostScheme}://${config.hostName}?shop=${session.shop}`;

    // if provided a return URL, use it, otherwise use the embedded app URL or hosted app URL
    const returnUrl =
      returnUrlParam || (config.isEmbeddedApp ? embeddedAppUrl : appUrl);

    const GraphqlClient = graphqlClientClass({config});
    const client = new GraphqlClient({session});

    function isLineItemPlan(
      billingConfig: any,
    ): billingConfig is BillingConfigSubscriptionLineItemPlan {
      return 'lineItems' in billingConfig;
    }

    function isOneTimePlan(
      billingConfig: any,
    ): billingConfig is BillingConfigOneTimePlan {
      return billingConfig.interval === BillingInterval.OneTime;
    }

    let data: RequestResponseData;
    if (isLineItemPlan(billingConfig)) {
      const mergedBillingConfigs = mergeBillingConfigs(
        billingConfig,
        filteredOverrides,
      );
      const mutationRecurringResponse = await requestSubscriptionPayment({
        billingConfig: mergedBillingConfigs,
        plan,
        client,
        returnUrl,
        isTest,
      });

      data = mutationRecurringResponse.appSubscriptionCreate!;
    } else if (isOneTimePlan(billingConfig)) {
      const mutationOneTimeResponse = await requestSinglePayment({
        billingConfig: {...billingConfig, ...filteredOverrides},
        plan,
        client,
        returnUrl,
        isTest,
      });
      data = mutationOneTimeResponse.appPurchaseOneTimeCreate!;
    } else {
      throw new BillingError({
        message: `Invalid billing configuration for plan ${plan}. Must be either a one-time plan or a subscription plan with line items.`,
        errorData: [],
      });
    }

    if (data.userErrors?.length) {
      throw new BillingError({
        message: 'Error while billing the store',
        errorData: data.userErrors,
      });
    }

    if (returnObject) {
      return data as Omit<
        RequestResponseData,
        'userErrors'
      > as BillingRequestResponse<Params>;
    } else {
      return data.confirmationUrl as BillingRequestResponse<Params>;
    }
  };
}

async function requestSubscriptionPayment({
  billingConfig,
  plan,
  client,
  returnUrl,
  isTest,
}: RequestSubscriptionParams): Promise<RecurringPaymentResponse> {
  const lineItems = billingConfig.lineItems.map((item) => {
    if (
      item.interval === BillingInterval.Every30Days ||
      item.interval === BillingInterval.Annual
    ) {
      const appRecurringPricingDetails: any = {
        interval: item.interval,
        price: {
          amount: item.amount,
          currencyCode: item.currencyCode,
        },
      };

      if (item.discount) {
        appRecurringPricingDetails.discount = {
          durationLimitInIntervals: item.discount.durationLimitInIntervals,
          value: {
            amount: item.discount.value.amount,
            percentage: item.discount.value.percentage,
          },
        };
      }

      return {
        plan: {
          appRecurringPricingDetails,
        },
      };
    } else if (item.interval === BillingInterval.Usage) {
      const appUsagePricingDetails = {
        terms: item.terms,
        cappedAmount: {
          amount: item.amount,
          currencyCode: item.currencyCode,
        },
      };

      return {
        plan: {
          appUsagePricingDetails,
        },
      };
    } else {
      throw new BillingError({
        message: 'Invalid interval provided',
        errorData: [item],
      });
    }
  });

  const mutationResponse = await client.request<RecurringPaymentResponse>(
    RECURRING_PURCHASE_MUTATION,
    {
      variables: {
        name: plan,
        trialDays: billingConfig.trialDays,
        replacementBehavior: billingConfig.replacementBehavior,
        returnUrl,
        test: isTest,
        lineItems,
      },
    },
  );

  if (mutationResponse.errors) {
    throw new BillingError({
      message: 'Error while billing the store',
      errorData: mutationResponse.errors,
    });
  }

  return mutationResponse.data!;
}

async function requestSinglePayment({
  billingConfig,
  plan,
  client,
  returnUrl,
  isTest,
}: RequestOneTimePaymentInternalParams): Promise<SinglePaymentResponse> {
  const mutationResponse = await client.request<SinglePaymentResponse>(
    ONE_TIME_PURCHASE_MUTATION,
    {
      variables: {
        name: plan,
        returnUrl,
        test: isTest,
        price: {
          amount: billingConfig.amount,
          currencyCode: billingConfig.currencyCode,
        },
      },
    },
  );

  if (mutationResponse.errors) {
    throw new BillingError({
      message: 'Error while billing the store',
      errorData: mutationResponse.errors,
    });
  }

  return mutationResponse.data!;
}

function mergeBillingConfigs(
  billingConfig: BillingConfigSubscriptionLineItemPlan,
  overrides: RequestConfigLineItemOverrides,
): BillingConfigSubscriptionLineItemPlan {
  const mergedConfig = {...billingConfig, ...overrides};
  const mergedLineItems = [];

  if (billingConfig.lineItems && overrides.lineItems) {
    for (const i of billingConfig.lineItems) {
      let found = false;

      for (const j of overrides.lineItems) {
        if (i.interval === j!.interval) {
          mergedLineItems.push({...i, ...j});
          found = true;
          break;
        }
      }

      if (!found) {
        mergedLineItems.push(i);
      }
    }

    mergedConfig.lineItems = mergedLineItems;
  }

  return mergedConfig as BillingConfigSubscriptionLineItemPlan;
}