module.exports = function(RED) {

  function Z2MZG204ZVNode(config) {

    RED.nodes.createNode(this, config);

    var node = this;

    node.site = normalizeToken(config.site || config.mqttSite || "");

    node.location = normalizeToken(config.location || config.mqttRoom || "");

    node.accessory = normalizeLegacyDeviceId(normalizeToken(config.accessory || config.mqttSensor || ""));

    node.batteryLowThreshold = parseNumber(config.batteryLowThreshold, 20, 0);

    node.occupancyFadingTimeSec = parseNumber(config.occupancyFadingTimeSec, 300, 0);

    node.bootstrapDeadlineMs = 10000;

    node.hkCache = Object.create(null);

    node.occupancyTimer = null;

    node.startTimer = null;

    node.bootstrapTimer = null;

    node.lastMsgContext = null;

    node.stats = {

      controls: 0,

      last_inputs: 0,

      value_inputs: 0,

      hk_updates: 0,

      errors: 0

    };

    node.subscriptionState = {

      started: false,

      lastSubscribed: false,

      valueSubscribed: false

    };

    node.bootstrapState = {

      finalized: false,

      motion: false,

      temperature: false,

      humidity: false,

      illuminance: false,

      battery: false

    };

    node.sensorState = {

      active: false,

      site: node.site || "",

      location: node.location || "",

      deviceId: node.accessory || "",

      motionKnown: false,

      motion: false,

      occupancyKnown: false,

      occupancy: false,

      temperatureKnown: false,

      temperature: null,

      humidityKnown: false,

      humidity: null,

      illuminanceKnown: false,

      illuminance: null,

      batteryKnown: false,

      battery: null,

      batteryLowKnown: false,

      batteryLow: false,

      tamperedKnown: false,

      tampered: false

    };

    function parseNumber(value, fallback, min) {

      var n = Number(value);

      if (!Number.isFinite(n)) return fallback;

      if (typeof min === "number" && n < min) return fallback;

      return n;

    }

    function asBool(value) {

      if (typeof value === "boolean") return value;

      if (typeof value === "number") return value !== 0;

      if (typeof value === "string") {

        var v = value.trim().toLowerCase();

        if (v === "true" || v === "1" || v === "on" || v === "yes" || v === "online") return true;

        if (v === "false" || v === "0" || v === "off" || v === "no" || v === "offline") return false;

      }

      return null;

    }

    function asNumber(value) {

      if (typeof value === "number" && isFinite(value)) return value;

      if (typeof value === "string") {

        var trimmed = value.trim();

        if (!trimmed) return null;

        var parsed = Number(trimmed);

        if (isFinite(parsed)) return parsed;

      }

      return null;

    }

    function clamp(n, min, max) {

      return Math.max(min, Math.min(max, n));

    }

    function normalizeToken(value) {

      if (value === undefined || value === null) return "";

      return String(value).trim();

    }

    function normalizeLegacyDeviceId(value) {

      if (!value) return "";

      if (/^radar-/i.test(value)) return value.replace(/^radar-/i, "");

      return value;

    }

    function signature(value) {

      return JSON.stringify(value);

    }

    function shouldPublish(cacheKey, payload) {

      var sig = signature(payload);

      if (node.hkCache[cacheKey] === sig) return false;

      node.hkCache[cacheKey] = sig;

      return true;

    }

    function cloneBaseMsg(msg) {

      if (!msg || typeof msg !== "object") return {};

      var out = {};

      if (typeof msg.topic === "string") out.topic = msg.topic;

      if (msg._msgid) out._msgid = msg._msgid;

      return out;

    }

    function buildSubscriptionTopic(stream) {

      return [

        node.site,

        "home",

        node.location,

        "+",

        node.accessory,

        stream

      ].join("/");

    }

    function buildSubscribeMsgs() {

      return [

        {

          action: "subscribe",

          topic: buildSubscriptionTopic("last"),

          qos: 2,

          rh: 0,

          rap: true

        },

        {

          action: "subscribe",

          topic: buildSubscriptionTopic("value"),

          qos: 2,

          rh: 0,

          rap: true

        }

      ];

    }

    function buildUnsubscribeLastMsg(reason) {

      return {

        action: "unsubscribe",

        topic: buildSubscriptionTopic("last"),

        reason: reason

      };

    }

    function statusText(prefix) {

      var state = node.subscriptionState.lastSubscribed ? "cold" : (node.subscriptionState.started ? "live" : "idle");

      var device = node.sensorState.deviceId || node.accessory || "?";

      return [

        prefix || state,

        device,

        "l:" + node.stats.last_inputs,

        "v:" + node.stats.value_inputs,

        "hk:" + node.stats.hk_updates

      ].join(" ");

    }

    function setNodeStatus(prefix, fill, shape) {

      node.status({

        fill: fill || (node.stats.errors ? "red" : (node.subscriptionState.lastSubscribed ? "yellow" : "green")),

        shape: shape || "dot",

        text: statusText(prefix)

      });

    }

    function noteError(text, msg) {

      node.stats.errors += 1;

      node.warn(text);

      node.status({ fill: "red", shape: "ring", text: text });

      if (msg) node.debug(msg);

    }

    function clearOccupancyTimer() {

      if (node.occupancyTimer) {

        clearTimeout(node.occupancyTimer);

        node.occupancyTimer = null;

      }

    }

    function clearBootstrapTimer() {

      if (!node.bootstrapTimer) return;

      clearTimeout(node.bootstrapTimer);

      node.bootstrapTimer = null;

    }

    function makeHomeKitMsg(baseMsg, payload) {

      var out = RED.util.cloneMessage(baseMsg || {});

      out.payload = payload;

      return out;

    }

    function buildStatusFields() {

      return {

        StatusActive: !!node.sensorState.active,

        StatusFault: node.sensorState.active ? 0 : 1,

        StatusLowBattery: node.sensorState.batteryLow ? 1 : 0,

        StatusTampered: node.sensorState.tampered ? 1 : 0

      };

    }

    function buildMotionMsg(baseMsg) {

      if (!node.sensorState.motionKnown) return null;

      var payload = buildStatusFields();

      payload.MotionDetected = node.sensorState.motion ? 1 : 0;

      if (!shouldPublish("hk:motion", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function buildOccupancyMsg(baseMsg) {

      if (!node.sensorState.occupancyKnown) return null;

      var payload = buildStatusFields();

      payload.OccupancyDetected = node.sensorState.occupancy ? 1 : 0;

      if (!shouldPublish("hk:occupancy", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function buildTemperatureMsg(baseMsg) {

      if (!node.sensorState.temperatureKnown) return null;

      var payload = {

        CurrentTemperature: clamp(Number(node.sensorState.temperature), -100, 100)

      };

      if (!shouldPublish("hk:temperature", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function buildHumidityMsg(baseMsg) {

      if (!node.sensorState.humidityKnown) return null;

      var payload = {

        CurrentRelativeHumidity: clamp(Number(node.sensorState.humidity), 0, 100)

      };

      if (!shouldPublish("hk:humidity", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function buildLightMsg(baseMsg) {

      if (!node.sensorState.illuminanceKnown) return null;

      var lux = Number(node.sensorState.illuminance);

      var payload = {

        CurrentAmbientLightLevel: lux <= 0 ? 0.0001 : clamp(lux, 0.0001, 100000)

      };

      if (!shouldPublish("hk:light", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function buildBatteryMsg(baseMsg) {

      if (!node.sensorState.batteryKnown && !node.sensorState.batteryLowKnown) return null;

      var batteryLevel = node.sensorState.batteryKnown

        ? clamp(Math.round(Number(node.sensorState.battery)), 0, 100)

        : (node.sensorState.batteryLow ? 1 : 100);

      var payload = {

        StatusLowBattery: node.sensorState.batteryLow ? 1 : 0,

        BatteryLevel: batteryLevel,

        ChargingState: 2

      };

      if (!shouldPublish("hk:battery", payload)) return null;

      node.stats.hk_updates += 1;

      return makeHomeKitMsg(baseMsg, payload);

    }

    function clearSnapshotCache() {

      delete node.hkCache["hk:motion"];

      delete node.hkCache["hk:occupancy"];

      delete node.hkCache["hk:temperature"];

      delete node.hkCache["hk:humidity"];

      delete node.hkCache["hk:light"];

      delete node.hkCache["hk:battery"];

    }

    function buildBootstrapOutputs(baseMsg) {

      clearSnapshotCache();

      return [

        buildMotionMsg(baseMsg),

        buildOccupancyMsg(baseMsg),

        buildTemperatureMsg(baseMsg),

        buildHumidityMsg(baseMsg),

        buildLightMsg(baseMsg),

        buildBatteryMsg(baseMsg)

      ];

    }

    function emitTimerOccupancyClear() {

      node.occupancyTimer = null;

      if (!node.sensorState.occupancyKnown || !node.sensorState.occupancy) return;

      node.sensorState.occupancy = false;

      var baseMsg = cloneBaseMsg(node.lastMsgContext);

      var occupancyMsg = buildOccupancyMsg(baseMsg);

      if (occupancyMsg) {

        node.send([null, occupancyMsg, null, null, null, null, null]);

      }

      setNodeStatus();

    }

    function applyMotionSample(rawDetected) {

      var detected = !!rawDetected;

      node.sensorState.motionKnown = true;

      node.sensorState.motion = detected;

      if (node.occupancyFadingTimeSec <= 0) {

        clearOccupancyTimer();

        node.sensorState.occupancyKnown = true;

        node.sensorState.occupancy = detected;

        return;

      }

      node.sensorState.occupancyKnown = true;

      if (detected) {

        node.sensorState.occupancy = true;

        clearOccupancyTimer();

        node.occupancyTimer = setTimeout(emitTimerOccupancyClear, Math.round(node.occupancyFadingTimeSec * 1000));

      } else if (!node.sensorState.occupancy) {

        clearOccupancyTimer();

      }

    }

    function unsubscribeLast(reason, send) {

      if (!node.subscriptionState.lastSubscribed) return null;

      node.subscriptionState.lastSubscribed = false;

      node.stats.controls += 1;

      var controlMsg = buildUnsubscribeLastMsg(reason);

      if (typeof send === "function") {

        send([null, null, null, null, null, null, controlMsg]);

      }

      return controlMsg;

    }

    function markBootstrapSatisfied(capability) {

      if (capability === "motion" && node.sensorState.motionKnown) {

        node.bootstrapState.motion = true;

      } else if (capability === "temperature" && node.sensorState.temperatureKnown) {

        node.bootstrapState.temperature = true;

      } else if (capability === "humidity" && node.sensorState.humidityKnown) {

        node.bootstrapState.humidity = true;

      } else if (capability === "illuminance" && node.sensorState.illuminanceKnown) {

        node.bootstrapState.illuminance = true;

      } else if ((capability === "battery" || capability === "battery_low") && (node.sensorState.batteryKnown || node.sensorState.batteryLowKnown)) {

        node.bootstrapState.battery = true;

      }

    }

    function isBootstrapComplete() {

      return node.bootstrapState.motion

        && node.bootstrapState.temperature

        && node.bootstrapState.humidity

        && node.bootstrapState.illuminance

        && node.bootstrapState.battery;

    }

    function finalizeBootstrap(reason, send) {

      if (node.bootstrapState.finalized) return false;

      if (!node.subscriptionState.lastSubscribed) return false;

      node.bootstrapState.finalized = true;

      clearBootstrapTimer();

      send = send || function(msgs) { node.send(msgs); };

      var outputs = buildBootstrapOutputs(cloneBaseMsg(node.lastMsgContext));

      var controlMsg = unsubscribeLast(reason);

      send([

        outputs[0],

        outputs[1],

        outputs[2],

        outputs[3],

        outputs[4],

        outputs[5],

        controlMsg

      ]);

      setNodeStatus("live");

      return true;

    }

    function parseTopic(topic) {

      if (typeof topic !== "string") return null;

      var tokens = topic.split("/").map(function(token) {

        return token.trim();

      }).filter(function(token) {

        return !!token;

      });

      if (tokens.length !== 6) return null;

      if (tokens[1] !== "home") return null;

      if (tokens[5] !== "value" && tokens[5] !== "last") return null;

      if (node.site && tokens[0] !== node.site) return null;

      if (node.location && tokens[2] !== node.location) return null;

      if (node.accessory && tokens[4] !== node.accessory) return null;

      return {

        site: tokens[0],

        location: tokens[2],

        capability: tokens[3],

        deviceId: tokens[4],

        stream: tokens[5]

      };

    }

    function extractValue(stream, payload) {

      if (payload && typeof payload === "object" && !Array.isArray(payload) && Object.prototype.hasOwnProperty.call(payload, "value")) {

        return payload.value;

      }

      return payload;

    }

    function updateBatteryLowFromThreshold() {

      if (!node.sensorState.batteryKnown || node.sensorState.batteryLowKnown) return;

      node.sensorState.batteryLow = Number(node.sensorState.battery) <= node.batteryLowThreshold;

    }

    function processCapability(baseMsg, parsed, value) {

      var motionMsg = null;

      var occupancyMsg = null;

      var temperatureMsg = null;

      var humidityMsg = null;

      var lightMsg = null;

      var batteryMsg = null;

      node.sensorState.active = true;

      node.sensorState.site = parsed.site;

      node.sensorState.location = parsed.location;

      node.sensorState.deviceId = parsed.deviceId;

      node.lastMsgContext = cloneBaseMsg(baseMsg);

      if (parsed.capability === "motion") {

        var detected = asBool(value);

        if (detected === null) return [null, null, null, null, null, null];

        applyMotionSample(detected);

        motionMsg = buildMotionMsg(baseMsg);

        occupancyMsg = buildOccupancyMsg(baseMsg);

      } else if (parsed.capability === "presence") {

        return [null, null, null, null, null, null];

      } else if (parsed.capability === "temperature") {

        var temperature = asNumber(value);

        if (temperature === null) return [null, null, null, null, null, null];

        node.sensorState.temperatureKnown = true;

        node.sensorState.temperature = temperature;

        temperatureMsg = buildTemperatureMsg(baseMsg);

      } else if (parsed.capability === "humidity") {

        var humidity = asNumber(value);

        if (humidity === null) return [null, null, null, null, null, null];

        node.sensorState.humidityKnown = true;

        node.sensorState.humidity = humidity;

        humidityMsg = buildHumidityMsg(baseMsg);

      } else if (parsed.capability === "illuminance") {

        var illuminance = asNumber(value);

        if (illuminance === null) return [null, null, null, null, null, null];

        node.sensorState.illuminanceKnown = true;

        node.sensorState.illuminance = illuminance;

        lightMsg = buildLightMsg(baseMsg);

      } else if (parsed.capability === "battery") {

        var battery = asNumber(value);

        if (battery === null) return [null, null, null, null, null, null];

        node.sensorState.batteryKnown = true;

        node.sensorState.battery = clamp(Math.round(battery), 0, 100);

        updateBatteryLowFromThreshold();

        batteryMsg = buildBatteryMsg(baseMsg);

        motionMsg = buildMotionMsg(baseMsg);

        occupancyMsg = buildOccupancyMsg(baseMsg);

      } else if (parsed.capability === "battery_low") {

        var batteryLow = asBool(value);

        if (batteryLow === null) return [null, null, null, null, null, null];

        node.sensorState.batteryLowKnown = true;

        node.sensorState.batteryLow = batteryLow;

        batteryMsg = buildBatteryMsg(baseMsg);

        motionMsg = buildMotionMsg(baseMsg);

        occupancyMsg = buildOccupancyMsg(baseMsg);

      } else if (parsed.capability === "tamper") {

        var tampered = asBool(value);

        if (tampered === null) return [null, null, null, null, null, null];

        node.sensorState.tamperedKnown = true;

        node.sensorState.tampered = tampered;

        motionMsg = buildMotionMsg(baseMsg);

        occupancyMsg = buildOccupancyMsg(baseMsg);

        batteryMsg = buildBatteryMsg(baseMsg);

      } else {

        return [null, null, null, null, null, null];

      }

      return [motionMsg, occupancyMsg, temperatureMsg, humidityMsg, lightMsg, batteryMsg];

    }

    function startSubscriptions() {

      if (node.subscriptionState.started) return;

      if (!node.site || !node.location || !node.accessory) {

        noteError("missing site, location or accessory");

        return;

      }

      node.subscriptionState.started = true;

      node.subscriptionState.lastSubscribed = true;

      node.subscriptionState.valueSubscribed = true;

      clearBootstrapTimer();

      node.bootstrapTimer = setTimeout(function() {

        finalizeBootstrap("bootstrap-timeout");

      }, node.bootstrapDeadlineMs);

      node.stats.controls += 1;

      node.send([null, null, null, null, null, null, buildSubscribeMsgs()]);

      setNodeStatus("cold");

    }

    node.on("input", function(msg, send, done) {

      send = send || function() { node.send.apply(node, arguments); };

      try {

        var parsed = parseTopic(msg && msg.topic);

        if (!parsed) {

          noteError("invalid topic");

          if (done) done();

          return;

        }

        var value = extractValue(parsed.stream, msg.payload);

        var controlMsg = null;

        if (parsed.stream === "last") node.stats.last_inputs += 1;

        else node.stats.value_inputs += 1;

        var outputs = processCapability(msg, parsed, value);

        markBootstrapSatisfied(parsed.capability);

        send([

          outputs[0],

          outputs[1],

          outputs[2],

          outputs[3],

          outputs[4],

          outputs[5],

          controlMsg

        ]);

        setNodeStatus();

        if (done) done();

      } catch (err) {

        node.stats.errors += 1;

        node.status({ fill: "red", shape: "ring", text: "error: " + err.message });

        if (done) done(err);

        else node.error(err, msg);

      }

    });

    node.on("close", function() {

      clearBootstrapTimer();

      clearOccupancyTimer();

      if (node.startTimer) {

        clearTimeout(node.startTimer);

        node.startTimer = null;

      }

    });

    node.startTimer = setTimeout(startSubscriptions, 250);

    node.status({ fill: "grey", shape: "ring", text: "starting" });

  }

  RED.nodes.registerType("zg-204zv-homekit-adapter", Z2MZG204ZVNode);

};