import {z} from 'zod'

export type MetricName = 'EVENTS' | 'USAGE' | 'METER_USAGE' | 'NAMED_LICENSE_USAGE' | 'REVENUE' | 'USAGE_FOR_CYCLE' | 'REVENUE_FOR_CYCLE';

export type MetricQuery = {id: string, name: MetricName, aggregationPeriod: 'HOUR' | 'DAY' | 'WEEK' | 'MONTH', groupBy?: string | undefined, configs: unknown, filters?: Array<{fieldName: string, fieldValues: Array<string>}> | undefined};

export type GetMetricsRequest = {startTime: string, endTime: string, metricQueries: Array<MetricQuery>};

export type CreateApiMetricsArgs = {body: GetMetricsRequest};

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

export const metricName = z.enum(["EVENTS", "USAGE", "METER_USAGE", "NAMED_LICENSE_USAGE", "REVENUE", "USAGE_FOR_CYCLE", "REVENUE_FOR_CYCLE"]);

export const metricDataPoints = z.object({groupedBy: z.object({fieldName: z.string(), fieldValue: z.string()}).optional(), timestamps: z.array(z.string()), metricValues: z.array(z.number())});

export const metricQueryResponse = z.object({id: z.string(), name: metricName, data: z.array(metricDataPoints)});

export const getMetricsResponse = z.object({results: z.array(metricQueryResponse)});

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 Togai Metrics
 * 
 * POST /metrics
 */
export const createApiMetrics = async (args: CreateApiMetricsArgs, options?: CreateApiMetricsOptions) => {
const {baseUrl = "https://api.togai.com", fetch: fetchFn = fetch, bearerAuth} = options ?? {}

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

if (bearerAuth !== undefined) headers.set('authorization', `Bearer ${bearerAuth}`)

const url = `${baseUrl.replace(/\/+$/, '')}/metrics${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers, body: JSON.stringify(args.body)})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(getMetricsResponse, await res.json())
};