import {z} from 'zod'

export type GetApiPriceTickerArgs = {pair: 'usdngn' | 'btcusd' | 'usdkes' | 'usdzar' | 'zarngn' | 'kesngn'};

export type GetApiPriceTickerOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const priceTicker = z.object({status: z.string().optional(), data: z.object({ask: z.number().optional(), bid: z.number().optional(), timestamp: z.number().optional(), meta: z.object({pair: z.string().optional(), payoutMethods: z.array(z.string()).optional(), collectionMethods: z.array(z.string()).optional(), unitPricePerUsd: z.object({}).optional(), unitPricePerSat: z.object({}).optional(), fees: z.object({}).optional()}).optional()}).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
};

/**
 * Get price ticker for currency pair
 * 
 * GET /price/ticker
 */
export const getApiPriceTicker = async (args: GetApiPriceTickerArgs, options?: GetApiPriceTickerOptions) => {
const {baseUrl = "https://staging.api.mavapay.co/api/v1", fetch: fetchFn = fetch} = options ?? {}

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

if (args.pair != null) query.append("pair", String(args.pair))

const url = `${baseUrl.replace(/\/+$/, '')}/price/ticker${query.size > 0 ? `?${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(priceTicker, await res.json())
};