import {z} from 'zod'

export type GetApiDataFlowKeyProviderArgs = {flow: string, key: string, provider: string, startPeriod?: string | undefined, endPeriod?: string | undefined, updatedAfter?: string | undefined, firstNObservations?: number | undefined, lastNObservations?: number | undefined, dimensionAtObservation?: string | undefined, detail?: ('full' | 'dataonly' | 'serieskeysonly' | 'nodata') | undefined, includeHistory?: boolean | undefined, 'Accept-Encoding'?: ('br' | 'compress' | 'deflate' | 'exi' | 'gzip' | 'identity' | 'pack200-gzip' | 'zstd') | undefined, 'Accept-Language'?: string | undefined, 'If-Modified-Since'?: string | undefined};

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

export const getApiDataFlowKeyProviderResponse = z.string();

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 data
 * 
 * GET /data/{flow}/{key}/{provider}
 */
export const getApiDataFlowKeyProvider = async (args: GetApiDataFlowKeyProviderArgs, options?: GetApiDataFlowKeyProviderOptions) => {
const {baseUrl = "https://sdw-wsrest.ecb.europa.eu/service", fetch: fetchFn = fetch} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('accept', "application/vnd.sdmx.data+json;version=1.0.0")

if (args.startPeriod != null) query.append("startPeriod", String(args.startPeriod))
if (args.endPeriod != null) query.append("endPeriod", String(args.endPeriod))
if (args.updatedAfter != null) query.append("updatedAfter", String(args.updatedAfter))
if (args.firstNObservations != null) query.append("firstNObservations", String(args.firstNObservations))
if (args.lastNObservations != null) query.append("lastNObservations", String(args.lastNObservations))
if (args.dimensionAtObservation != null) query.append("dimensionAtObservation", String(args.dimensionAtObservation))
if (args.detail != null) query.append("detail", String(args.detail))
if (args.includeHistory != null) query.append("includeHistory", String(args.includeHistory))
if (args['Accept-Encoding'] != null) headers.set("Accept-Encoding", String(args['Accept-Encoding']))
if (args['Accept-Language'] != null) headers.set("Accept-Language", String(args['Accept-Language']))
if (args['If-Modified-Since'] != null) headers.set("If-Modified-Since", String(args['If-Modified-Since']))

const url = `${baseUrl.replace(/\/+$/, '')}/data/${encodeURIComponent(String(args.flow))}/${encodeURIComponent(String(args.key))}/${encodeURIComponent(String(args.provider))}${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(getApiDataFlowKeyProviderResponse, await res.json())
};