import assert from "node:assert/strict";
import { startFakeDecoder } from "./browser_fake_decoder.js";

export async function runDecoderReconnectSmoke({ evaluate, navigate, savedState, waitFor, pause, base }) {
  const patchState = async patch => {
    const current = await savedState();
    Object.assign(current, patch);
    const response = await fetch(base + "/api/state", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(current) });
    assert.equal(response.ok, true);
  };
  const badgeOnline = () => evaluate('document.getElementById("connectionBadge")?.classList.contains("badge-online")');

  const decoder = await startFakeDecoder();
  try {
    const seeded = await savedState();
    await patchState({ settings: { ...seeded.settings, autoReconnect: true, wsUrl: `ws://127.0.0.1:${decoder.port}` } });

    await navigate("events", "eventForm");
    await waitFor(async () => await badgeOnline(), "decoder connects on page load");
    assert.equal(decoder.activeConnections(), 1, "exactly one live connection after the initial connect");
    assert.equal(decoder.totalConnections(), 1, "a clean initial connect makes exactly one connection attempt");

    // Simulate a real network/decoder interruption: drop the TCP connection with a raw
    // reset rather than a clean WS close handshake, the way a lost cable or a decoder
    // power-cycle actually would - see src/decoder_runtime.js's wsClient.onclose.
    decoder.dropConnections();
    await waitFor(async () => (await badgeOnline()) === false, "badge shows offline once the drop is detected");
    assert.equal(decoder.activeConnections(), 0, "no lingering connection right after the drop");

    // decoder_runtime.js schedules exactly one reconnect attempt 2000ms after onclose.
    await waitFor(async () => decoder.totalConnections() >= 2, "a reconnect attempt reaches the decoder socket");
    await waitFor(async () => await badgeOnline(), "badge shows online again after auto-reconnect");
    assert.equal(decoder.totalConnections(), 2, "auto-reconnect made exactly one new connection attempt, not several");
    assert.equal(decoder.activeConnections(), 1, "auto-reconnect settles on exactly one live connection, not a duplicate");
    console.log("PASS decoder auto-reconnects after a dropped socket onto exactly one connection");

    // A second drop must not leave a stray reconnect timer running once autoReconnect is
    // turned off - the retry loop should stop, not silently keep firing in the background.
    // Toggling it through the real Settings form (not a raw state patch) matters here:
    // a raw backend patch never reaches this already-loaded page's in-memory state, only
    // a fresh navigation would, and that would also drop and reopen the live connection.
    await navigate("settings", "settingsForm");
    await waitFor(async () => await badgeOnline(), "decoder is connected on the settings page");
    await evaluate('document.querySelector("#settingsForm [name=autoReconnect]").checked = false');
    await evaluate('document.getElementById("settingsForm").requestSubmit()');
    const connectionsBeforeDrop = decoder.totalConnections();
    decoder.dropConnections();
    await waitFor(async () => (await badgeOnline()) === false, "badge shows offline after the second drop");
    await pause(3000);
    assert.equal(decoder.totalConnections(), connectionsBeforeDrop, "no reconnect attempt is made once autoReconnect is disabled");
    assert.equal(await badgeOnline(), false, "stays offline with autoReconnect disabled");
    assert.equal(decoder.activeConnections(), 0, "no duplicate or stray connection appears while disabled");
    console.log("PASS disabling auto-reconnect stops further reconnect attempts after a drop");
  } finally {
    const cleanup = await savedState();
    await patchState({ settings: { ...cleanup.settings, autoReconnect: false } });
    await decoder.close();
  }
}