// Optional WebSocket producer — pipes external JSON commands into the bus.
// Server -> client message shapes:
//   { id?: string, command: Command }
//   { id?: string, script: Command[] }
//   { id?: string, dsl: string }
// Client -> server replies: { id, ok: true } | { id, ok: false, error: string }

import { commandBus, type Command } from "./bus"
import { runScriptText } from "./script"

type ServerMessage =
  | { id?: string; command: Command }
  | { id?: string; script: Command[] }
  | { id?: string; dsl: string }

export type CommandSocket = {
  close: () => void
  socket: () => WebSocket | null
}

export function connectCommandSocket(
  url: string,
  opts: { reconnect?: boolean; reconnectDelayMs?: number } = {},
): CommandSocket {
  const { reconnect = true, reconnectDelayMs = 2000 } = opts
  let ws: WebSocket | null = null
  let closed = false

  const open = () => {
    ws = new WebSocket(url)

    ws.addEventListener("open", () => {
      console.log("[command-ws] connected", url)
    })

    ws.addEventListener("message", async (event) => {
      let msg: ServerMessage
      try {
        msg = JSON.parse(event.data)
      } catch (err) {
        ws?.send(JSON.stringify({ error: "invalid_json", detail: String(err) }))
        return
      }
      try {
        if ("dsl" in msg) await runScriptText(msg.dsl)
        else if ("script" in msg) await commandBus.run(msg.script)
        else if ("command" in msg) await commandBus.dispatch(msg.command)
        else throw new Error("missing 'command', 'script', or 'dsl'")
        ws?.send(JSON.stringify({ id: msg.id, ok: true }))
      } catch (err) {
        ws?.send(JSON.stringify({ id: msg.id, ok: false, error: String(err) }))
      }
    })

    ws.addEventListener("close", () => {
      if (closed || !reconnect) return
      setTimeout(open, reconnectDelayMs)
    })

    ws.addEventListener("error", () => ws?.close())
  }

  open()

  return {
    close: () => {
      closed = true
      ws?.close()
    },
    socket: () => ws,
  }
}