import type {
  StripeExpressCheckoutElementOptions,
  StripePaymentElementOptions,
} from '@stripe/stripe-js';

type PaywallCheckoutExpressOptionsInput = {
  amountCents: number;
  summaryLabel: string;
};

type PaywallCheckoutPaymentElementOptionsInput = {
  email?: string | null;
};

type PaywallCheckoutBillingDetailsInput = {
  email?: string | null;
  name?: string | null;
};

const normalizePaywallCheckoutBillingName = ({
  email,
  name,
}: PaywallCheckoutBillingDetailsInput): string => {
  const normalizedName = name?.trim();
  if (normalizedName) {
    return normalizedName;
  }

  const normalizedEmail = email?.trim();
  if (normalizedEmail) {
    const localPart = normalizedEmail
      .split('@')[0]
      ?.replace(/[._-]+/g, ' ')
      .trim();
    if (localPart) {
      return localPart;
    }
  }

  return 'Customer';
};

export function buildPaywallCheckoutExpressOptions({
  amountCents,
  summaryLabel,
}: PaywallCheckoutExpressOptionsInput): StripeExpressCheckoutElementOptions {
  return {
    buttonHeight: 55,
    buttonTheme: {
      applePay: 'black',
      googlePay: 'black',
    },
    buttonType: {
      applePay: 'check-out',
      googlePay: 'checkout',
    },
    emailRequired: true,
    layout: {
      maxColumns: 1,
      maxRows: 0,
      overflow: 'never',
    },
    lineItems: [
      {
        name: summaryLabel.trim() || 'Selected plan',
        amount: amountCents,
      },
    ],
    paymentMethodOrder: ['link', 'apple_pay', 'google_pay'],
    paymentMethods: {
      amazonPay: 'never',
      applePay: 'always',
      googlePay: 'always',
      klarna: 'never',
      paypal: 'never',
    },
  };
}

export function buildPaywallCheckoutPaymentElementOptions({
  email,
}: PaywallCheckoutPaymentElementOptionsInput): StripePaymentElementOptions {
  const normalizedEmail = email?.trim() || '';
  const emailFieldMode = normalizedEmail ? 'never' : 'auto';

  return {
    defaultValues: normalizedEmail
      ? {
          billingDetails: {
            email: normalizedEmail,
          },
        }
      : undefined,
    fields: {
      billingDetails: {
        address: 'if_required',
        email: emailFieldMode,
        name: 'never',
        phone: 'auto',
      },
    },
    layout: {
      type: 'tabs',
    },
    paymentMethodOrder: ['card'],
    wallets: {
      applePay: 'never',
      googlePay: 'never',
      link: 'never',
    },
  };
}

export function buildPaywallCheckoutBillingDetails({
  email,
  name,
}: PaywallCheckoutBillingDetailsInput): {
  email?: string;
  name: string;
} {
  const normalizedEmail = email?.trim() || undefined;

  return {
    email: normalizedEmail,
    name: normalizePaywallCheckoutBillingName({
      email: normalizedEmail,
      name,
    }),
  };
}