import {z} from 'zod'

export type PrioritizedAlias = {priority: number, tag: string, id: string};

export type PostEvent = {user_id?: string | undefined, aliases?: Array<PrioritizedAlias> | undefined, name: string, view_id?: string | undefined, session_id?: string | undefined, segments?: Array<number> | undefined, cohorts?: Array<string> | undefined, properties?: Record<string, never> | undefined};

export type CreateApiEventsArgs = {enrich?: boolean | undefined, sdkp?: boolean | undefined, body: PostEvent};

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

export const eventResponse = z.object({user_id: z.string(), name: z.string().optional(), time: z.string().optional(), view_id: z.string().optional(), session_id: z.string().optional(), segments: z.array(z.number().int()).optional(), cohorts: z.array(z.string()).optional(), properties: z.object({}).optional()});

export const eventUnenrichedResponse = z.object({user_id: z.string(), time: z.string()});

export const createApiEventsResponse = z.union([eventResponse, eventUnenrichedResponse]);

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
};

/**
 * Track an event
 * 
 * POST /events
 * 
 * Also accepts auth: Parameter
 */
export const createApiEvents = async (args: CreateApiEventsArgs, options?: CreateApiEventsOptions) => {
const {baseUrl = "https://api.permutive.app", fetch: fetchFn = fetch, Header} = options ?? {}

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

if (args.enrich != null) query.append("enrich", String(args.enrich))
if (args.sdkp != null) query.append("sdkp", String(args.sdkp))
if (Header !== undefined) headers.set("X-API-Key", Header)

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