"use client"

// How this module's interactive components reach the API: through a transport the app provides
// (apps/web/src/ui/transport.tsx). A module may not import the app, and a server component cannot
// hand a function to a client one, so the seam is a context -- the same one every module with a
// client component declares for itself, until `@conusai-kit/ui/data` is the one shared facade.

import { createContext, type ReactElement, type ReactNode, useContext } from "react"

export type Transport = (procedure: string, input: unknown) => Promise<unknown>
export type DescribeError = (error: unknown) => string

interface Provided {
  readonly call: Transport
  readonly describe: DescribeError
}

const TransportContext = createContext<Provided | undefined>(undefined)

export function TransportProvider({ call, describe, children }: Provided & { children: ReactNode }): ReactElement {
  return <TransportContext.Provider value={{ call, describe }}>{children}</TransportContext.Provider>
}

export function useTransport(): Provided {
  const provided = useContext(TransportContext)
  if (!provided) throw new Error("branding: wrap the page in a TransportProvider (apps/web/src/ui/transport.tsx)")
  return provided
}