import {z} from 'zod'

export type GetApiV2CustomersArgs = {limit?: number | undefined, starting_after?: string | undefined};

export type GetApiV2CustomersOptions = {baseUrl: string, LedgerUpApiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const unixTimestamp = z.number().int();

export const customer = z.object({id: z.string(), name: z.string().max(256), external_id: z.string().max(256).nullable(), stripe_customer_id: z.string().max(256).nullable(), quickbooks_customer_id: z.string().nullable(), created_at: unixTimestamp, updated_at: unixTimestamp});

export const customerList = z.object({data: z.array(customer), has_more: z.boolean()});

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
};

/**
 * List customers.
 * 
 * GET /v2/customers
 */
export const getApiV2Customers = async (args: GetApiV2CustomersArgs, options: GetApiV2CustomersOptions) => {
const {baseUrl, fetch: fetchFn = fetch, LedgerUpApiKey} = options ?? {}

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

if (args.limit != null) query.append("limit", String(args.limit))
if (args.starting_after != null) query.append("starting_after", String(args.starting_after))
if (LedgerUpApiKey !== undefined) headers.set("x-api-key", LedgerUpApiKey)

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