// harness/tests/fake_pi/fake_pi_rpc.mjs — scripted RPC test double (LF-only JSONL).
import fs from "node:fs";
const script = JSON.parse(fs.readFileSync(process.argv[2], "utf8"));
const out = (evt) => process.stdout.write(JSON.stringify(evt) + "\n");

let buf = "";
process.stdin.on("data", (chunk) => {
  buf += chunk.toString("utf8");
  for (let nl; (nl = buf.indexOf("\n")) !== -1; ) {
    const line = buf.slice(0, nl).replace(/\r$/, ""); buf = buf.slice(nl + 1);
    if (!line) continue;
    let cmd; try { cmd = JSON.parse(line); } catch { continue; }
    if (cmd.type === "prompt") {
      for (const step of script.on_prompt ?? []) {
        if (step.ui_request_descriptor) {
          const d = step.ui_request_descriptor;
          out({ type: "extension_ui_request", id: d.id, method: "input", title: JSON.stringify(d) });
        } else { out(step); }  // eventi non-UI (text_delta, agent_end, …) passano tali e quali
      }
    } else if (cmd.type === "extension_ui_response") {
      for (const evt of (script.on_response ?? {})[cmd.id] ?? []) out(evt);
    } else if (cmd.type === "get_available_models") {
      out({ type: "response", command: "get_available_models", id: cmd.id, success: true,
            data: { models: script.available_models ?? [] } });
    } else if (cmd.type === "steer") {
      out({ type: "response", command: "steer", id: cmd.id, success: true });
    } else if (cmd.type === "get_state") {
      out({ type: "response", command: "get_state", id: cmd.id, success: true,
            data: { sessionId: "fake", thinkingLevel: "medium", isStreaming: false } });
    }
  }
});
process.stdin.on("end", () => process.exit(0));