AirCube

/* AirCube USB serial wire protocol.
 *
 * Port of the JSON-lines half of aircubetray/aircubeapp/protocol.py, which
 * tracks firmware/main/serial_protocol.c. See the Serial Protocol Reference in
 * CONTRIBUTING.md for the authoritative message list.
 */

/** ESP32-H2 built-in USB Serial/JTAG. */
export const AIRCUBE_USB_FILTER = { usbVendorId: 0x303a, usbProductId: 0x1001 };
export const SERIAL_BAUD = 115200;
export const SEQ_NONE = 0xffff;

/** Slots per get_history page. Matches the tray's paging. */
export const HISTORY_PAGE = 48;

const JSON_PATTERN = /\{.*\}/;

/** Pull the JSON object out of a line that may carry ESP_LOG noise around it. */
export function extractJson(line) {
  const match = JSON_PATTERN.exec(line);
  if (!match) return null;
  try {
    const value = JSON.parse(match[0]);
    return value && typeof value === "object" ? value : null;
  } catch {
    return null;
  }
}

const num = (v) => {
  const n = Number(v);
  return Number.isFinite(n) ? n : 0;
};

/**
 * Parse the periodic sensor JSON object into a normalized live reading.
 *
 * Since firmware 1.5.0 `ens16x.aqi` is the VOC Level index (0-500), which is a
 * different number from `ens16x.etvoc` in ppb despite the similar names: the
 * tiles show etvoc, the advanced drawer shows the index. Pro units add
 * scd41.co2 and vcnl4040.lux; older firmware omits `model`, and firmware
 * before 2.0.3 omits `fw`.
 */
export function parseLive(data) {
  const ens210 = data.ens210 || {};
  const ens16x = data.ens16x || {};
  const scd41 = data.scd41 || {};
  const vcnl = data.vcnl4040 || {};
  const co2 = Math.round(num(scd41.co2));
  const model = data.model;
  return {
    temperatureC: num(ens210.temperature_c),
    humidity: num(ens210.humidity),
    vocLevel: Math.round(num(ens16x.aqi)),
    eco2: Math.round(num(ens16x.eco2)),
    etvoc: Math.round(num(ens16x.etvoc)),
    co2,
    lux: num(vcnl.lux),
    aqiUba: Math.round(num(ens16x.aqi_uba)),
    isPro: model !== undefined ? model === "pro" : co2 > 0,
    fwVersion: typeof data.fw === "string" ? data.fw : "",
    frcNeeded: Boolean(data.health && data.health.frc_needed),
    timestamp: Date.now() / 1000,
  };
}

/** Compare dotted firmware strings. Returns null if either side is unparseable. */
export function compareFw(a, b) {
  const parts = (s) => {
    const m = String(s || "").match(/(\d+)\.(\d+)(?:\.(\d+))?/);
    return m ? [Number(m[1]), Number(m[2]), Number(m[3] || 0)] : null;
  };
  const pa = parts(a);
  const pb = parts(b);
  if (!pa || !pb) return null;
  for (let i = 0; i < 3; i++) {
    if (pa[i] !== pb[i]) return pa[i] - pb[i];
  }
  return 0;
}

export function fwLte(version, ceiling) {
  const cmp = compareFw(version, ceiling);
  return cmp !== null && cmp <= 0;
}

/**
 * Parse one slot of a get_history page.
 *
 * Serial keys: t_*=temp x100, h_*=humidity x100, q_*=VOC level, c_*=CO2 (true
 * CO2 on Pro, eCO2 on Base), v_*=eTVOC.
 */
export function parseHistorySlot(s) {
  const seq = Math.round(num(s.seq));
  if (!Number.isFinite(seq) || seq === SEQ_NONE) return null;
  return {
    sequence: seq,
    timestamp: 0, // anchored by the caller; the device has no RTC
    tempAvg: num(s.t_a) / 100,
    tempMin: num(s.t_n) / 100,
    tempMax: num(s.t_x) / 100,
    humAvg: num(s.h_a) / 100,
    humMin: num(s.h_n) / 100,
    humMax: num(s.h_x) / 100,
    vocAvg: Math.round(num(s.q_a)),
    vocMin: Math.round(num(s.q_n)),
    vocMax: Math.round(num(s.q_x)),
    co2Avg: Math.round(num(s.c_a)),
    co2Min: Math.round(num(s.c_n)),
    co2Max: Math.round(num(s.c_x)),
    etvocAvg: Math.round(num(s.v_a)),
    etvocMin: Math.round(num(s.v_n)),
    etvocMax: Math.round(num(s.v_x)),
  };
}

export function parseHistoryInfo(info) {
  return {
    entries: Math.round(num(info.entries)),
    capacity: Math.round(num(info.capacity)),
    slotBytes: Math.round(num(info.slot_bytes)) || 32,
    windowS: Math.round(num(info.window_us) / 1e6) || 300,
  };
}

export function parseConfig(config) {
  const autoDim = config.auto_dim || {};
  return {
    intensity: num(config.intensity),
    readoutPeriod: Math.round(num(config.readout_period)) || 1000,
    autoDim: {
      enabled: Boolean(autoDim.enabled),
      nightEnterLux: num(autoDim.night_enter_lux),
      dayExitLux: num(autoDim.day_exit_lux),
      nightDimPct: Math.round(num(autoDim.night_dim_pct)),
    },
  };
}

// ----------------------------------------------------------------- commands

export const cmdGetConfig = () => '{"cmd":"get_config"}';

export const cmdSetIntensity = (fraction) =>
  JSON.stringify({ cmd: "set_intensity", value: Number(fraction.toFixed(2)) });

export const cmdSetReadoutPeriod = (ms) =>
  JSON.stringify({ cmd: "set_readout_period", value: Math.round(ms) });

export const cmdSetAutoDim = (o) =>
  JSON.stringify({
    cmd: "set_auto_dim",
    enabled: Boolean(o.enabled),
    night_enter_lux: Math.round(o.nightEnterLux),
    day_exit_lux: Math.round(o.dayExitLux),
    night_dim_pct: Math.round(o.nightDimPct),
  });

export const cmdGetHistoryInfo = () => '{"cmd":"get_history_info"}';

export const cmdGetHistory = (start, count) =>
  JSON.stringify({ cmd: "get_history", start, count });

export const cmdClearHistory = () => '{"cmd":"clear_history"}';

export const cmdScd41Frc = () => '{"cmd":"scd41_frc"}';

export const cmdScd41FrcAck = () => '{"cmd":"scd41_frc_ack"}';

// ------------------------------------------------------------- reply shapes

/** Matchers pair a sent command with the reply line that answers it. */
export const isConfigReply = (d) => d.config !== undefined;
export const isHistoryInfoReply = (d) => d.history_info !== undefined;
export const isHistoryReply = (d) => Array.isArray(d.history);
export const isLive = (d) => d.ens210 !== undefined;
export const statusReply = (cmd) => (d) => d.status !== undefined && d.cmd === cmd;
export const isScd41FrcReply = (d) => d.cmd === "scd41_frc";