// opencode agent-state plugin: mirrors the session state into the tmux pane opencode runs in via
// ~/.config/tmux/scripts/agent-state.sh (oc busy|done|input|error). No-op outside tmux.
//
// Runs in the SERVER process, so TMUX_PANE is only right when the TUI in the pane spawned the
// server (plain `opencode`), not for `opencode serve` / `opencode attach`. Under the bwrap
// `opencodes` wrapper the tmux socket dir must be bound in, or the script gives up quietly.
// Child (subagent) sessions are skipped so a subagent finishing does not flag "done".
import type { Plugin } from "@opencode-ai/plugin"

export const AgentState: Plugin = async ({ client, $ }) => {
  const script = `${process.env.HOME}/.config/tmux/scripts/agent-state.sh`
  const set = async (state: string) => {
    if (!process.env.TMUX_PANE) return
    try {
      await $`${script} oc ${state}`.quiet().nothrow()
    } catch {}
  }
  const childCache = new Map<string, boolean>()
  const isChild = async (sessionID?: string) => {
    if (!sessionID) return false
    if (!childCache.has(sessionID)) {
      try {
        const r = await client.session.get({ path: { id: sessionID } })
        childCache.set(sessionID, Boolean(r.data?.parentID))
      } catch {
        childCache.set(sessionID, false)
      }
    }
    return childCache.get(sessionID) ?? false
  }
  return {
    event: async ({ event }) => {
      const p = (event as { properties?: Record<string, any> }).properties ?? {}
      switch (event.type) {
        case "message.updated": // a new user message = a prompt went in
          if (p.info?.role === "user" && !(await isChild(p.info?.sessionID))) await set("busy")
          break
        case "permission.asked":
          if (!(await isChild(p.sessionID))) await set("input")
          break
        case "permission.replied":
          if (!(await isChild(p.sessionID))) await set("busy")
          break
        case "session.idle":
          if (!(await isChild(p.sessionID))) await set("done")
          break
        case "session.error":
          if (!(await isChild(p.sessionID))) await set("error")
          break
      }
    },
  }
}