import { randomUUID } from 'node:crypto'
import { RpcDispatcher, type DispatcherOptions } from '../runtime/rpc/dispatcher'
import type { OrcaRuntimeService } from '../runtime/orca-runtime'
import type { PluginRuntimeRpc } from './workers/host-api/plugin-host-workspace-method-bindings'

/** An error the runtime answered, with its code (`selector_not_found`, ...). */
export class PluginRuntimeRpcError extends Error {
  constructor(
    readonly code: string,
    message: string
  ) {
    super(message)
  }
}

/**
 * The runtime methods the `orca` CLI calls, dispatched in process with the CLI's identity, so a
 * plugin's workspace actions run the same code on the host that owns the workspace.
 */
export function pluginRuntimeRpc(
  runtime: OrcaRuntimeService,
  methods: DispatcherOptions['methods']
): PluginRuntimeRpc {
  let dispatcher: RpcDispatcher | null = null
  return async (method, params, options = {}) => {
    dispatcher ??= new RpcDispatcher({ runtime, methods })
    // The dispatcher maps a throw to an error answer; keep the original so its code reaches the plugin.
    let refusal: unknown = null
    const response = await dispatcher.dispatch(
      { id: randomUUID(), authToken: 'plugin-host', method, params },
      {
        // Why the CLI's identity: a mod's action is automation, as an agent's `orca` call is.
        caller: { kind: 'local-cli' },
        ...(options.signal ? { signal: options.signal } : {}),
        beforeInvoke: () => {
          try {
            options.signal?.throwIfAborted()
            options.beforeEffect?.()
          } catch (error) {
            refusal = error
            throw error
          }
        }
      }
    )
    if (refusal !== null) {
      throw refusal
    }
    if (!response.ok) {
      throw new PluginRuntimeRpcError(response.error.code, response.error.message)
    }
    return response.result
  }
}