import {z} from 'zod'

export type StatsAggregationType = 'DAY' | 'WEEK' | 'MONTH';

export type GetApiApiStatsArgs = {start_date?: (string | null) | undefined, end_date?: (string | null) | undefined, aggregation?: (StatsAggregationType | null) | undefined};

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

export const statsAggregationType = z.enum(["DAY", "WEEK", "MONTH"]);

export const actionType = z.enum(["DOCUMENT_SENT", "DOCUMENT_RECEIVED"]);

export const actionStats = z.object({action: actionType, stat_date: z.string(), count: z.number().int().gte(0)});

export const statsResponse = z.object({tenant_id: z.string(), period_start: z.string(), period_end: z.string(), aggregation: statsAggregationType, actions: z.array(actionStats), total_days: z.number().int().gte(1), average_daily_usage: z.number().gte(0), budget_estimation_days: z.number().gte(0).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 Statistics
 * 
 * GET /api/stats
 */
export const getApiApiStats = async (args: GetApiApiStatsArgs, options?: GetApiApiStatsOptions) => {
const {baseUrl = "https://api.e-invoice.be", fetch: fetchFn = fetch, HTTPBearer} = options ?? {}

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

if (args.start_date != null) query.append("start_date", String(args.start_date))
if (args.end_date != null) query.append("end_date", String(args.end_date))
if (args.aggregation != null) query.append("aggregation", String(args.aggregation))
if (HTTPBearer !== undefined) headers.set('authorization', `Bearer ${HTTPBearer}`)

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