import {z} from 'zod'

export type CreateApiAppAutomationsInterpretArgs = {body: {intent: string, context?: (Record<string, never> | null) | undefined}};

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

export const appAutomationConfigFieldSchema = z.object({label: z.string(), value: z.string(), filledByAi: z.boolean()});

export const appAutomationSpecSchema = z.object({id: z.string(), intentText: z.string(), title: z.string(), summary: z.string(), signal: z.string(), signalLabel: z.string(), trigger: z.string(), direction: z.enum(["increase", "decrease", "pause", "launch"]), deltaPct: z.number().int(), target: z.string(), scope: z.string(), channels: z.array(z.string()), guardrails: z.string(), requiredConfig: z.array(appAutomationConfigFieldSchema), confidence: z.string()});

export const createApiAppAutomationsInterpretResponse = z.array(appAutomationSpecSchema);

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
};

/**
 * Interpret a natural-language intent into proposed automations
 * 
 * POST /app/automations/interpret
 */
export const createApiAppAutomationsInterpret = async (args: CreateApiAppAutomationsInterpretArgs, options: CreateApiAppAutomationsInterpretOptions) => {
const {baseUrl, 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 = `${baseUrl.replace(/\/+$/, '')}/app/automations/interpret${query.size > 0 ? `?${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(createApiAppAutomationsInterpretResponse, await res.json())
};