// The reconnect *policy* — which closes are retried and which end the pane.
// `createAttachConnection` itself needs a DOM and xterm, so the decision is
// tested here as the predicate the shell supplies, plus the backoff schedule
// it drives.

import { describe, expect, it } from "vitest";

import { INITIAL_RECONNECT_MS, MAX_RECONNECT_MS, shouldRetryClose } from "./reconnect.js";
import type { Session } from "./types.js";

function session(id: string, status: Session["status"]): Session {
  return {
    id,
    cwd: "/home/n",
    command: "bash",
    env: {},
    metadata: {},
    status,
    created_at: "2026-08-22T00:00:00Z",
  } as Session;
}

describe("shouldRetryClose", () => {
  const running = new Map([["a", session("a", "Running")]]);
  const dead = new Map([["a", session("a", "Dead")]]);
  const gone = new Map<string, Session>();

  it("retries a dropped link to a session that is still running", () => {
    expect(shouldRetryClose("a", 1006, running)).toBe(true);
    expect(shouldRetryClose("a", 1001, running)).toBe(true);
  });

  it("does not retry a session the daemon has marked dead", () => {
    // Its stream is sealed; nothing further will ever arrive.
    expect(shouldRetryClose("a", 1006, dead)).toBe(false);
  });

  it("does not retry a session that is no longer in the catalog", () => {
    expect(shouldRetryClose("a", 1006, gone)).toBe(false);
  });

  it("never retries an application close, which carries a daemon rejection", () => {
    // 4000+ means the proxy relayed a refusal — retrying would loop on it.
    expect(shouldRetryClose("a", 4502, running)).toBe(false);
  });

  it("never retries a clean close", () => {
    expect(shouldRetryClose("a", 1000, running)).toBe(false);
  });
});

describe("backoff bounds", () => {
  it("starts well under a second and caps at ten", () => {
    expect(INITIAL_RECONNECT_MS).toBeLessThan(1000);
    expect(MAX_RECONNECT_MS).toBe(10_000);
  });

  it("reaches the cap by doubling and never exceeds it", () => {
    let ms = INITIAL_RECONNECT_MS;
    for (let i = 0; i < 20; i++) ms = Math.min(ms * 2, MAX_RECONNECT_MS);
    expect(ms).toBe(MAX_RECONNECT_MS);
  });
});