import {z} from 'zod'

export type MemoryRetrieveRequest = {agent_id: string, user_hash?: (string | null) | undefined, scope_user_id?: (string | null) | undefined, query_text: string, top_k?: number | undefined, include_active?: boolean | undefined, include_passive?: boolean | undefined, scope?: (string | null) | undefined};

export type CreateApiMemoryRetrieveArgs = {body: MemoryRetrieveRequest};

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

export const memoryRetrievalHit = z.object({fragment_id: z.string(), score: z.number(), text: z.string(), timestamp_ms: z.number().int(), episode_id: z.string(), agent_id: z.string(), source: z.string(), entities: z.array(z.string()).optional(), metadata: z.object({}).nullable().optional()});

export const memoryRetrieveResponse = z.object({hits: z.array(memoryRetrievalHit).optional(), total_hits: z.number().int(), active_episodes_searched: z.number().int(), passive_episodes_searched: z.number().int()});

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
};

/**
 * Unified episodic memory retrieval — routes across active and passive tiers
 * 
 * POST /memory/retrieve
 */
export const createApiMemoryRetrieve = async (args: CreateApiMemoryRetrieveArgs, options: CreateApiMemoryRetrieveOptions) => {
const {baseUrl, fetch: fetchFn = fetch, HTTPBearer} = options ?? {}

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

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

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