import {z} from 'zod'

export type GetApiV2FeesArgs = {currency: unknown, amount: number, amount_extra?: number | undefined, amount_postage?: number | undefined, payment_method?: string | undefined, fees_config?: number | undefined};

export type GetApiV2FeesOptions = {baseUrl?: string | undefined, APIKey?: {username: string, password: string} | undefined, fetch?: typeof fetch | undefined};

export const v2TransactionsFees = z.object({buyer: z.number().int(), config: z.number().int(), seller: z.number().int()});

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
};

/**
 * Get the Trustap fee for a transaction
 * 
 * GET /v2/fees
 * 
 * Also accepts auth: OAuth2
 */
export const getApiV2Fees = async (args: GetApiV2FeesArgs, options?: GetApiV2FeesOptions) => {
const {baseUrl = "https://api.test.trustap.com", fetch: fetchFn = fetch, APIKey} = options ?? {}

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

if (args.currency != null) query.append("currency", String(args.currency))
if (args.amount != null) query.append("amount", String(args.amount))
if (args.amount_extra != null) query.append("amount_extra", String(args.amount_extra))
if (args.amount_postage != null) query.append("amount_postage", String(args.amount_postage))
if (args.payment_method != null) query.append("payment_method", String(args.payment_method))
if (args.fees_config != null) query.append("fees_config", String(args.fees_config))
if (APIKey !== undefined) headers.set('authorization', `Basic ${btoa(`${APIKey.username}:${APIKey.password}`)}`)

const url = `${baseUrl.replace(/\/+$/, '')}/v2/fees${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "GET", headers})

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

return validateResponse(v2TransactionsFees, await res.json())
};