import {z} from 'zod'

export type UnixTimestamp = number;

export type UsageAggregation = 'sum' | 'min' | 'max' | 'avg' | 'latest' | 'count';

export type GetApiV2MetricsUsageMonthlyArgs = {start_at: UnixTimestamp, end_at: UnixTimestamp, aggregation?: UsageAggregation | undefined, currency?: string | undefined};

export type GetApiV2MetricsUsageMonthlyOptions = {baseUrl: string, LedgerUpApiKey?: string | undefined, fetch?: typeof fetch | undefined};

export const usageAggregation = z.enum(["sum", "min", "max", "avg", "latest", "count"]);

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

export const metricQuantity = z.object({metric_id: z.string(), currency: z.string().nullable(), quantity: z.string()});

export const monthlyMetricQuantities = z.object({period_start_at: unixTimestamp, data: z.array(metricQuantity)});

export const metricMonthlyUsage = z.object({aggregation: usageAggregation, data: z.array(monthlyMetricQuantities)});

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
};

/**
 * Monthly usage by metric
 * 
 * GET /v2/metrics/usage/monthly
 */
export const getApiV2MetricsUsageMonthly = async (args: GetApiV2MetricsUsageMonthlyArgs, options: GetApiV2MetricsUsageMonthlyOptions) => {
const {baseUrl, fetch: fetchFn = fetch, LedgerUpApiKey} = options ?? {}

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

if (args.start_at != null) query.append("start_at", String(args.start_at))
if (args.end_at != null) query.append("end_at", String(args.end_at))
if (args.aggregation != null) query.append("aggregation", String(args.aggregation))
if (args.currency != null) query.append("currency", String(args.currency))
if (LedgerUpApiKey !== undefined) headers.set("x-api-key", LedgerUpApiKey)

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