import {z} from 'zod'

export type ResolveRequest = {intent: string};

export type CreateApiResolveArgs = {body: ResolveRequest};

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

export const parameter = z.object({type: z.string(), required: z.boolean()});

export const passthroughRequest = z.object({method: z.string(), url: z.string(), body: z.string().optional()});

export const paymentEntry = z.object({scheme: z.literal("exact"), network: z.string(), asset: z.string(), amount: z.string()});

export const payment = z.object({accepts: z.array(paymentEntry)});

export const candidate = z.object({listing: z.string(), airnode: z.string(), operation: z.string(), address: z.string(), attestation: z.enum(["first-party", "third-party"]), parameters: z.record(z.string(), parameter), example: z.record(z.string(), z.unknown()), passthrough: passthroughRequest, returns: z.record(z.string(), z.string()), payment: payment.nullable(), why: z.string()});

export const unresolvedInput = z.object({requirement: z.string(), needed: z.string(), reason: z.enum(["missing", "unverified", "unsupported", "noIntent"])});

export const resolution = z.object({intent: z.string(), candidates: z.array(candidate), unresolvedInputs: z.array(unresolvedInput)});

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
};

/**
 * Find Airnode operations for an intent
 * 
 * POST /resolve
 */
export const createApiResolve = async (args: CreateApiResolveArgs, options?: CreateApiResolveOptions) => {
const {baseUrl = "https://airnodehub.api3.org", fetch: fetchFn = fetch} = options ?? {}

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

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