import {z} from 'zod'

export type GetApiCalendarArgs = {date: string, calendar: string, la?: string | undefined};

export type GetApiCalendarOptions = {baseUrl?: string | undefined, oauth2?: string | undefined, fetch?: typeof fetch | undefined};

export const calendarDate = z.object({calendar_date: z.object({id: z.number().int(), name: z.string(), year: z.number(), month: z.number(), day: z.number(), leap: z.number().nullable(), year_name: z.string().nullable(), month_name: z.string()})});

export const calendarDateResponse = z.object({status: z.string(), data: calendarDate});

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
};

/**
 * Calendar
 * 
 * GET /calendar
 */
export const getApiCalendar = async (args: GetApiCalendarArgs, options?: GetApiCalendarOptions) => {
const {baseUrl = "https://api.prokerala.com/v2", fetch: fetchFn = fetch, oauth2} = options ?? {}

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

if (args.date != null) query.append("date", String(args.date))
if (args.calendar != null) query.append("calendar", String(args.calendar))
if (args.la != null) query.append("la", String(args.la))
if (oauth2 !== undefined) headers.set('authorization', `Bearer ${oauth2}`)

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