"""Shelly Gen2+ BLE support."""

from __future__ import annotations

BLE_SCAN_RESULT_EVENT = "ble.scan_result"

BLE_SCRIPT_NAME = "aioshelly_ble_integration"

BLE_SCAN_RESULT_VERSION = 2

VAR_EVENT_TYPE = "%event_type%"
VAR_ACTIVE = "%active%"
VAR_VERSION = "%version%"

BLE_CODE = """
// aioshelly BLE script 2.1
// Script automatically installed by Home Assistant for Bluetooth proxy support
// https://www.home-assistant.io/integrations/bluetooth/#remote-adapters-bluetooth-proxies
const queueServeTimer = 100; // in ms, timer for events emitting
const burstSendCount =  5; // number if events, emitted on timer event
const maxQueue =  32; // if the queue exceeds the limit, all new events are ignored until it empties
const packetsInSingleEvent = 16; // max number of packets in single event

let queue = [];
let timerHandler = null;

function timerCallback() {
  for(let i = 0; i < burstSendCount; i++) {
    if (queue.length <= 0) {
      break;
    }

    Shelly.emitEvent(
      "%event_type%", [
        %version%,
        queue.slice(0, packetsInSingleEvent),
      ]
    );
    queue = queue.slice(packetsInSingleEvent);
  }

  timerHandler = null;
  if (queue.length > 0) {
    timerHandler = Timer.set(queueServeTimer, false, timerCallback);
  }
}

function bleCallback(event, res) {
  if (event !== BLE.Scanner.SCAN_RESULT) {
    return;
  }

  if (queue.length > maxQueue) {
    return;
  }

  queue.push([
    res.addr,
    res.rssi,
    btoa(res.advData),
    btoa(res.scanRsp)
  ]);

  if(!timerHandler) {
    timerHandler = Timer.set(queueServeTimer, false, timerCallback);
  }
}

// Flip the scanner's active mode at runtime via Script.Eval; this is
// how on-demand active scan windows avoid rewriting the script body
// (and thus avoid a flash write) on every transition.
//
// Two device quirks shape this dance:
//   1. BLE.Scanner.Stop() is asynchronous - a Start() issued in the
//      same JS frame races with the still-in-progress stop and
//      silently fails. Defer Start onto a Timer so the underlying BLE
//      stack has time to settle.
//   2. BLE.Scanner.Subscribe() does NOT survive a Stop/Start cycle -
//      the subscription is dropped on Stop and must be re-attached
//      after each Start, or no scan results will be delivered.
let pendingActive = null;
function applyPendingActive() {
  if (pendingActive === null) {
    return;
  }
  BLE.Scanner.Start({
    duration_ms: -1,
    active: pendingActive,
  });
  BLE.Scanner.Subscribe(bleCallback);
  pendingActive = null;
}

function setActive(v) {
  pendingActive = v;
  if (BLE.Scanner.isRunning()) {
    BLE.Scanner.Stop();
    Timer.set(250, false, applyPendingActive);
  } else {
    applyPendingActive();
  }
}

setActive(%active%);
"""  # noqa: E501