import {z} from 'zod'

export type GetApiUsageMetricsArgs = {period_start_at?: string | undefined, period_end_at?: string | undefined, granularity?: ('hour' | 'day') | undefined, time_zone?: string | undefined, group_by?: ('product' | 'agent' | 'model' | 'api_key' | 'schedule' | 'device_class') | undefined};

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

export const usageMetricsPoint = z.object({agent: z.string().optional(), api_key: z.string().optional(), device_class: z.string().optional(), inference_cost_microdollars: z.number().int(), input_tokens: z.number().int(), model: z.string().optional(), output_tokens: z.number().int(), period_start_at: z.string(), product: z.enum(["session", "inference"]).optional(), schedule: z.string().optional(), session_cost_microdollars: z.number().int(), session_seconds: z.number().int(), total_cost_microdollars: z.number().int()});

export const usageMetricsResponse = z.object({points: z.array(usageMetricsPoint).nullable()});

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 metrics
 * 
 * GET /usage/metrics
 */
export const getApiUsageMetrics = async (args: GetApiUsageMetricsArgs, options?: GetApiUsageMetricsOptions) => {
const {baseUrl = "https://api.axilio.ai/api/v1", fetch: fetchFn = fetch, apiKeyAuth} = options ?? {}

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

if (args.period_start_at != null) query.append("period_start_at", String(args.period_start_at))
if (args.period_end_at != null) query.append("period_end_at", String(args.period_end_at))
if (args.granularity != null) query.append("granularity", String(args.granularity))
if (args.time_zone != null) query.append("time_zone", String(args.time_zone))
if (args.group_by != null) query.append("group_by", String(args.group_by))
if (apiKeyAuth !== undefined) headers.set("X-Axilio-Api-Key", apiKeyAuth)

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