import {z} from 'zod'

export type CurrencyId = 'EUR' | 'CHF';

export type Metadata = {[key: string]: unknown} | null;

export type Language = 'de' | 'en';

export type EasyOnboarding = {success_link?: string | undefined, abort_link?: string | undefined};

export type CountryId = 'DE' | 'AT' | 'CH';

export type Xs2aPay = {amount: number, currency_id: CurrencyId, purpose: string, recipient_holder: string, recipient_iban: string, metadata?: Metadata | undefined, language?: Language | undefined, merchant_id?: string | undefined, fints_product_id?: string | undefined, with_intermission?: boolean | undefined, easy_onboarding?: EasyOnboarding | undefined, sender_holder?: string | undefined, sender_iban?: string | undefined, sender_bic?: string | undefined, sender_country_id?: CountryId | undefined, sender_bank_code?: string | undefined, recipient_bic?: string | undefined, recipient_street?: string | undefined, recipient_zip?: string | undefined, recipient_city?: string | undefined, recipient_country_id?: CountryId | undefined};

export type CreateApiPaymentsArgs = {body: Xs2aPay};

export type CreateApiPaymentsOptions = {baseUrl?: string | undefined, basicAuth?: {username: string, password: string} | undefined, fetch?: typeof fetch | undefined};

export const wizardSessionResponse = z.object({wizard_session_key: z.string().optional(), transaction: z.string().optional()});

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Create xs2a.pay object
 * 
 * POST /payments
 */
export const createApiPayments = async (args: CreateApiPaymentsArgs, options?: CreateApiPaymentsOptions) => {
const {baseUrl = "https://api.xs2a.com/v1", fetch: fetchFn = fetch, basicAuth} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('content-type', "application/json")
headers.set('accept', "application/json")

if (basicAuth !== undefined) headers.set('authorization', `Basic ${btoa(`${basicAuth.username}:${basicAuth.password}`)}`)

const url = `${baseUrl.replace(/\/+$/, '')}/payments${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers, body: JSON.stringify(args.body)})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(wizardSessionResponse, await res.json())
};