import {z} from 'zod'

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

export const filterItem = z.object({fieldName: z.enum(["country", "countryGroup", "language", "source", "sourceType", "postType", "contentType", "authorAge", "authorSubscribers", "gender"]), op: z.enum(["oneOf", "notOneOf", "greaterOrEqual", "lessOrEqual"]), value: z.string()});

export const customFilter = z.object({op: z.enum(["and", "or"]).optional(), filters: z.array(filterItem).optional()});

export const topicQuery = z.object({textQuery: z.string().nullable().optional(), viQuery: z.string().nullable().optional(), filter: customFilter.nullable().optional()});

export const topicInfo = z.object({id: z.number().int().optional(), name: z.string().optional(), topicQuery: topicQuery.optional(), sampling: z.number().nullable().optional()});

export const getApiTopicsResponse = z.object({topics: z.array(topicInfo).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
};

/**
 * List topics
 * 
 * GET /topics
 * 
 * Also accepts auth: ApiKeyQuery
 */
export const getApiTopics = async (options?: GetApiTopicsOptions) => {
const {baseUrl = "https://api.youscan.io/api/external", fetch: fetchFn = fetch, ApiKeyHeader} = options ?? {}

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

if (ApiKeyHeader !== undefined) headers.set("X-API-KEY", ApiKeyHeader)

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