import {z} from 'zod'

export type GetApiV4BillingUsageArgs = {unit?: ('MS' | 'TOK') | undefined, fromInterval: string, toInterval: string, userId?: (Array<string | string> | null) | undefined};

export type GetApiV4BillingUsageOptions = {baseUrl: string, fetch?: typeof fetch | undefined};

export const reportRow = z.object({day: z.string(), typ: z.string().nullable(), value: z.number().nullable()});

export const usageReport = z.object({rows: z.array(reportRow)});

export const responseMeta = z.object({requestId: z.string().optional(), timestamp: z.string().optional(), durationMs: z.number().int().nullable().optional()});

export const successResponseUsageReport = z.object({success: z.literal(true), data: usageReport, meta: responseMeta.optional()});

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 usage
 * 
 * GET /v4/billing/usage
 */
export const getApiV4BillingUsage = async (args: GetApiV4BillingUsageArgs, options: GetApiV4BillingUsageOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

if (args.unit != null) query.append("unit", String(args.unit))
if (args.fromInterval != null) query.append("fromInterval", String(args.fromInterval))
if (args.toInterval != null) query.append("toInterval", String(args.toInterval))
for (const item of args.userId ?? []) query.append("userId", String(item))

const url = `${baseUrl.replace(/\/+$/, '')}/v4/billing/usage${query.size > 0 ? `?${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(successResponseUsageReport, await res.json())
};