import {z} from 'zod'

export type GetApiV2RatesArgs = {tokens: Array<unknown>, currencies: Array<string>};

export type GetApiV2RatesOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const tokenRates = z.object({diff_24h: z.record(z.string(), z.string()).optional(), diff_30d: z.record(z.string(), z.string()).optional(), diff_7d: z.record(z.string(), z.string()).optional(), prices: z.record(z.string(), z.number()).optional()});

export const getApiV2RatesResponse = z.object({rates: z.record(z.string(), tokenRates)});

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 token price in the chosen currency for display only. Don’t use this for financial transactions.
 * 
 * GET /v2/rates
 */
export const getApiV2Rates = async (args: GetApiV2RatesArgs, options?: GetApiV2RatesOptions) => {
const {baseUrl = "https://tonapi.io", fetch: fetchFn = fetch} = options ?? {}

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

if (args.tokens != null) query.append("tokens", args.tokens.join(','))
if (args.currencies != null) query.append("currencies", args.currencies.join(','))

const url = `${baseUrl.replace(/\/+$/, '')}/v2/rates${query.size > 0 ? `?${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(getApiV2RatesResponse, await res.json())
};