import {z} from 'zod'

export type FieldElement = string;

export type G1 = Array<FieldElement>;

export type G2 = Array<G1>;

export type SemaphoreProof = Array<G1 | G2>;

export type VerifySemaphoreProofRequest = {root: FieldElement, signalHash: FieldElement, nullifierHash: FieldElement, externalNullifierHash: FieldElement, proof: SemaphoreProof};

export type CreateApiVerifySemaphoreProofArgs = {maxRootAgeSeconds?: number | undefined, body: VerifySemaphoreProofRequest};

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

export const inclusionProofStatus = z.enum(["new", "failed", "pending", "mined"]);

export const verifySemaphoreProofResponse = z.object({root: z.string().optional(), status: inclusionProofStatus.optional(), pendingValidAsOf: z.string().optional(), minedValidAsOf: z.string().nullable().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
};

/**
 * Verifies a Semaphore proof
 * 
 * POST /verifySemaphoreProof
 */
export const createApiVerifySemaphoreProof = async (args: CreateApiVerifySemaphoreProofArgs, options?: CreateApiVerifySemaphoreProofOptions) => {
const {baseUrl = "http://localhost:8080", fetch: fetchFn = fetch} = options ?? {}

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

if (args.maxRootAgeSeconds != null) query.append("maxRootAgeSeconds", String(args.maxRootAgeSeconds))

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