pumpingStation/src/specificClass.js

const EventEmitter = require('events');
const {
  logger,
  configUtils,
  configManager,
  childRegistrationUtils,
  MeasurementContainer,
  coolprop,
  interpolation,
  POSITIONS
} = require('generalFunctions');

class PumpingStation {
  /**
   * PumpingStation — S88 Process Cell.
   *
   * Models a wet-well basin with inflow/outflow and orchestrates child
   * equipment (pumps via rotatingMachine, pump groups via MGC, nested
   * stations) to keep the water level within safe bounds.
   *
   * Full behaviour, threshold semantics, control modes, and the basin
   * diagram are documented in the wiki:
   *   wiki/functional-description.md  +  wiki/modes/*.md
   *
   * Tick loop (1 s): predicted volume → net flow → safety → control.
   */
  constructor(config = {}) {
    // --- Dependency injection & config merge ---
    this.emitter = new EventEmitter();
    this.configManager = new configManager();
    this.defaultConfig = this.configManager.getConfig('pumpingStation');
    this.configUtils = new configUtils(this.defaultConfig);
    // initConfig deep-merges user config over schema defaults so every
    // field is guaranteed present even if the caller omits it.
    this.config = this.configUtils.initConfig(config);
    this.interpolate = new interpolation();
    this.logger = new logger(this.config.general.logging.enabled, this.config.general.logging.logLevel, this.config.general.name);

    // --- Measurement store ---
    // autoConvert: incoming values in any unit are stored in their
    // original unit but getCurrentValue(targetUnit) converts on read.
    // preferredUnits: the canonical units used for ALL internal math.
    // Flow and netFlowRate MUST be m3/s because the volume integrator
    // multiplies flow × seconds to get m3.  Level in m and volume in m3
    // keep the basin geometry math unit-consistent.
    this.measurements = new MeasurementContainer({
      autoConvert: true,
      preferredUnits: { flow: 'm3/s', netFlowRate: 'm3/s', level: 'm', volume: 'm3' }
    });

    // --- Child registries ---
    // Children register via Port 2 handshake. Each dict is keyed by
    // the child's config.general.id.
    //   machines      : rotatingMachine instances (direct pumps, no MGC)
    //   stations      : nested pumpingStation instances (cascaded basins)
    //   machineGroups : MGC instances (each manages its own pump pool)
    this.childRegistrationUtils = new childRegistrationUtils(this);
    this.machines = {};
    this.stations = {};
    this.machineGroups = {};
    // predictedFlowChildren tracks predicted flow subscriptions per child.
    // Key = childId, value = { in: <last m3/s>, out: <last m3/s> }.
    // Only the highest-level aggregator is subscribed (MGC if present,
    // otherwise individual machines) to avoid double-counting.
    this.predictedFlowChildren = new Map();

    // --- Variant priority ---
    // Order determines which variant is used for CONTROL decisions:
    // 'measured' is preferred; 'predicted' is the fallback.
    //
    // IMPORTANT — both variants are ALWAYS computed regardless of which
    // one drives control.  The output exposes both values plus a flag
    // indicating which variant is currently driving control decisions.
    // This lets operators see the difference between measured and
    // predicted, which is valuable for:
    //   - Detecting sensor drift (measured diverges from predicted)
    //   - Validating the volume integrator (predicted tracks measured?)
    //   - Diagnosing control issues (was the wrong source active?)
    //
    // Implementation: _selectBestNetFlow computes both and stores both
    // in MeasurementContainer; it returns the winning variant as the
    // control source.  getOutput() exposes all variants.
    this.flowVariants = ['measured', 'predicted'];
    this.levelVariants = ['measured', 'predicted'];
    this.volVariants = ['measured', 'predicted'];
    // Position aliases — two naming conventions coexist because:
    //   - Measurement children (sensors) store their raw
    //     positionVsParent from config: 'upstream' / 'downstream'
    //   - Predicted-flow children (MGC, machines) map positions to
    //     shorthand: 'in' / 'out'  (see _registerPredictedFlowChild)
    //
    // The .sum() helper aggregates across an array of position names,
    // so this map gives each logical direction ALL its aliases.  This
    // way sum('flow', 'predicted', flowPositions.outflow) catches both
    // a measurement stored under 'downstream' AND a prediction stored
    // under 'out'.
    this.flowPositions = { inflow: ['in', 'upstream'], outflow: ['out', 'downstream'] };

    // --- Runtime state ---
    this.mode = this.config.control.mode;
    // state is the public snapshot updated at the end of each tick().
    // Consumers (nodeClass, dashboard) read this for display/telemetry.
    this.state = { direction: 'steady', netFlow: 0, flowSource: null, seconds: null, remainingSource: null };
    // percControl: the 0-100% demand sent to MGC / direct machines in
    // levelbased mode.  Exposed in getOutput() for dashboards.
    this.percControl = 0;

    // --- Level-armed hysteresis state ---
    // _shiftArmed flips true when level rises past shiftLevel (with
    // enableShiftedRamp). While armed, the demand ramp's lower foot
    // is startLevel instead of inflowLevel — so on the way down the
    // pumps stay aggressive until level falls below startLevel, at
    // which point the arm clears.
    this._shiftArmed = false;

    // --- Flow dead-band ---
    // flowThreshold (m3/s) prevents control actions on noise.
    // Default 1e-4 m3/s ≈ 0.36 m3/h — below this, net flow is
    // treated as 'steady' (no filling, no draining).
    const thresholdFromConfig = Number(this.config.general?.flowThreshold);
    this.flowThreshold = Number.isFinite(thresholdFromConfig) ? thresholdFromConfig : 1e-4;

    // Geometry + threshold ordering check. initBasinProperties seeds
    // predicted volume at minVol; _validateThresholdOrdering warns if
    // any physical/control invariant is violated. Non-fatal — prefer
    // continuity over refusal to start (availability-first).
    this.initBasinProperties();
    this.thresholdIssues = this._validateThresholdOrdering();
    this.logger.debug('PumpingStation initialized');
  }

  /* --------------------------- Registration --------------------------- */

  registerChild(child, softwareType) {
    this.logger.debug(`Registering child (${softwareType}) "${child.config.general.name}"`);

    if (softwareType === 'measurement') {
      this._registerMeasurementChild(child);
      return;
    }

    if (softwareType === 'machine') {
      this.machines[child.config.general.id] = child;
    } else if (softwareType === 'pumpingstation') {
      this.stations[child.config.general.id] = child;
    } else if (softwareType === 'machinegroup') {
      this.machineGroups[child.config.general.id] = child;
    }

    // Register predicted-flow subscription. Only register the HIGHEST-
    // level aggregator: if a machinegroup is present, subscribe to IT
    // (its flow.predicted already aggregates all child machines). Do NOT
    // also subscribe to individual machines — that would double-count
    // because each pump's flow is included in the group total.
    //
    // Individual machines (softwareType='machine') are only subscribed
    // when there is NO machinegroup parent — i.e., pumps wired directly
    // to the pumping station without an MGC in between.
    if (softwareType === 'machinegroup' || softwareType === 'pumpingstation') {
      this._registerPredictedFlowChild(child);
    } else if (softwareType === 'machine' && Object.keys(this.machineGroups).length === 0) {
      // Direct-child machine, no group above it — register its flow.
      this._registerPredictedFlowChild(child);
    }
  }

  _registerMeasurementChild(child) {
    const position = child.config.functionality.positionVsParent;
    const measurementType = child.config.asset.type;
    const eventName = `${measurementType}.measured.${position}`;

    child.measurements.emitter.on(eventName, (eventData = {}) => {
      this.logger.debug(
        `Measurement update ${eventName} <- ${eventData.childName || child.config.general.name}: ${eventData.value} ${eventData.unit}`
      );

      this.measurements
        .type(measurementType)
        .variant('measured')
        .position(position)
        .value(eventData.value, eventData.timestamp, eventData.unit);

      this._handleMeasurement(measurementType, eventData.value, position, eventData);
    });
  }

  _registerPredictedFlowChild(child) {
    const position = (child.config.functionality.positionVsParent || '').toLowerCase();
    const childName = child.config.general.name;
    const childId = child.config.general.id ?? childName;

    let posKey;
    let eventName;
    switch (position) {
      case 'downstream':
      case 'out':
      case 'atequipment':
        posKey = 'out';
        // Subscribe to ONE event only. 'downstream' is the most specific
        // — avoids double-counting from 'atequipment' which carries the
        // same total flow on a different event name.
        eventName = 'flow.predicted.downstream';
        break;
      case 'upstream':
      case 'in':
        posKey = 'in';
        eventName = 'flow.predicted.upstream';
        break;
      default:
        this.logger.warn(`Unsupported predicted flow position "${position}" from ${childName}`);
        return;
    }

    if (!this.predictedFlowChildren.has(childId)) {
      this.predictedFlowChildren.set(childId, { in: 0, out: 0 });
    }

    const handler = (eventData = {}) => {
      const unit = eventData.unit || child.config?.general?.unit;
      const ts = eventData.timestamp || Date.now();

      this.logger.debug(`Emitting for child ${unit} `);
      this.measurements
        .type('flow')
        .variant('predicted')
        .position(posKey)
        .child(childId)
        .value(eventData.value, ts, unit);
    };

    child.measurements.emitter.on(eventName, handler);
  }

  /* --------------------------- Calibration --------------------------- */

  calibratePredictedVolume(calibratedVol, timestamp = Date.now()) {
    const volume = this.measurements.type('volume').variant('predicted').position('atequipment').get();
    const level = this.measurements.type('level').variant('predicted').position('atequipment').get();

    if (volume) {
      volume.values = [];
      volume.timestamps = [];
    }
    
    if (level) {
      level.values = [];
      level.timestamps = [];
    }

    this.measurements.type('volume').variant('predicted').position('atequipment').value(calibratedVol, timestamp, 'm3').unit('m3');
    this.measurements.type('level').variant('predicted').position('atequipment').value(this._calcLevelFromVolume(calibratedVol), timestamp, 'm');

    this._predictedFlowState = { inflow: 0, outflow: 0, lastTimestamp: timestamp };
  }

  calibratePredictedLevel(val, timestamp = Date.now(), unit = 'm') {
    // Rebuild the chain each time — MeasurementContainer is stateful
    // (its type/variant/position methods mutate the container itself,
    // so cached chain references share one cursor).
    const volMeas = this.measurements.type('volume').variant('predicted').position('atequipment');
    if (volMeas.exists()) {
      const m = volMeas.get();
      m.values = []; m.timestamps = [];
    }
    const lvlMeas = this.measurements.type('level').variant('predicted').position('atequipment');
    if (lvlMeas.exists()) {
      const m = lvlMeas.get();
      m.values = []; m.timestamps = [];
    }

    this.measurements.type('level').variant('predicted').position('atequipment').value(val, timestamp, unit);
    this.measurements.type('volume').variant('predicted').position('atequipment').value(this._calcVolumeFromLevel(val), timestamp, 'm3');

    this._predictedFlowState = { inflow: 0, outflow: 0, lastTimestamp: timestamp };
  }

  setManualInflow(value, timestamp = Date.now(), unit) {
    const num = Number(value);
    this.measurements.type('flow').variant('predicted').position('in').child('manual-qin').value(num, timestamp, unit);
  }

  setManualOutflow(value, timestamp = Date.now(), unit) {
    const num = Number(value);
    this.measurements.type('flow').variant('predicted').position('out').child('manual-qout').value(num, timestamp, unit);
  }

  /* --------------------------- Tick / Control --------------------------- */

  tick() {
    this._updatePredictedVolume();

    const netFlow = this._selectBestNetFlow();
    const remaining = this._computeRemainingTime(netFlow);

    this._safetyController(remaining.seconds, netFlow.direction);
    if (this.safetyControllerActive) return;

    this._controlLogic(netFlow.direction);

    this.state = {
      direction: netFlow.direction,
      netFlow: netFlow.value,
      flowSource: netFlow.source,
      seconds: remaining.seconds,
      remainingSource: remaining.source
    };

    this.logger.debug(`netflow = ${JSON.stringify(netFlow)}`);
    this.logger.debug(
      `Height : ${this.measurements.type('level').variant('predicted').position('atequipment').getCurrentValue('m')} m`
    );
  }

  changeMode(newMode){
    if ( this.config.control.allowedModes.has(newMode) ){
      const currentMode = this.mode;
      this.logger.info(`Control mode changing from ${currentMode} to ${newMode}`);
      this.mode = newMode;
    }
    else{
      this.logger.warn(`Attempted to change to unsupported control mode: ${newMode}`);
    }

  }


  _controlLogic(direction) {
    switch (this.mode) {
      case 'levelbased':
        this._controlLevelBased(direction);
        break;
      case 'flowbased':
        this._controlFlowBased?.();
        break;
      case 'manual':
        break;
      default:
        this.logger.warn(`Unsupported control mode: ${this.mode}`);
    }
  }

  async _controlLevelBased(_direction) {
    const { startLevel, minLevel } = this.config.control.levelbased;
    const levelUnit = this.measurements.getUnit('level');

    const level = this._pickVariant('level', this.levelVariants, 'atequipment', levelUnit);
    if (level == null) {
      this.logger.warn('No valid level found');
      return;
    }

    // Level-based pump control via MGC (see wiki/modes/levelbased.md).
    //
    //   level < minLevel              → STOP (unconditional MGC shutdown)
    //   level < startLevel            → 0 % (pumps held off)
    //   level in [startLevel..rampStart] → 0 %  (HOLD zone)
    //   level in [rampStart..maxLevel]  → 0..100 % (linear or log curve)
    //   level > maxLevel              → ≥100 % (MGC clamps internally)
    //
    // With enableShiftedRamp:
    //   rampStart = inflowLevel by default
    //   when level rises past shiftLevel → arm  → rampStart = startLevel
    //   when level drops below startLevel → disarm → rampStart = inflowLevel
    // Without enableShiftedRamp: rampStart = inflowLevel always.

    if (level < minLevel) {
      this.percControl = 0;
      Object.values(this.machineGroups).forEach((group) => group.turnOffAllMachines());
      return;
    }

    this._updateShiftArmed(level);
    const rampStartLevel = this._levelBasedRampStart();
    const rampTopLevel = this._levelBasedRampTop();

    // HOLD/MINIMUM DEMAND — below the active ramp start, command 0 %
    // without latching dry-run. Dry-run remains the safety layer's job.
    if (level < rampStartLevel) {
      this.percControl = 0;
      await this._applyMachineGroupLevelControl(0);
      return;
    }

    // RUN — above rampStartLevel, compute demand and forward to MGC.
    // _scaleLevelToFlowPercent maps [rampStartLevel..rampTopLevel] → [0..100].
    // Above rampTopLevel demand saturates at 100 %.
    const rawPercControl = this._scaleLevelToFlowPercent(level, rampStartLevel, rampTopLevel);
    const percControl = Math.max(0, rawPercControl);
    this.percControl = percControl;
    this.logger.debug(`Level-based control: level=${level} armed=${this._shiftArmed} foot=${rampStartLevel} top=${rampTopLevel} percControl=${percControl}`);

    await this._applyMachineGroupLevelControl(percControl);
  }

  _controlFlowBased() {
    // placeholder for flow-based logic
  }

  /**
   * Forward a manual demand value to all child machine groups + direct
   * machines. Called from the 'Qd' topic handler when PS is in manual
   * mode — mirrors how rotatingMachine gates commands by mode.
   * @param {number} demand - the operator-set demand (interpretation
   *   depends on MGC scaling: 'absolute' = m³/h, 'normalized' = 0-100%)
   */
  async forwardDemandToChildren(demand) {
    this.logger.info(`Manual demand forwarded: ${demand}`);
    // Forward to machine groups (MGC)
    if (this.machineGroups && Object.keys(this.machineGroups).length > 0) {
      await Promise.all(
        Object.values(this.machineGroups).map((group) =>
          group.handleInput('parent', demand).catch((err) => {
            this.logger.error(`Failed to forward demand to group: ${err.message}`);
          })
        )
      );
    }
    // Forward to direct machines (if any)
    if (this.machines && Object.keys(this.machines).length > 0) {
      const perMachine = demand / Object.keys(this.machines).length;
      for (const machine of Object.values(this.machines)) {
        try {
          await machine.handleInput('parent', 'execMovement', perMachine);
        } catch (err) {
          this.logger.error(`Failed to forward demand to machine: ${err.message}`);
        }
      }
    }
  }

  async _applyMachineGroupLevelControl(percentControl) {
    if (!this.machineGroups || Object.keys(this.machineGroups).length === 0) return;
    await Promise.all(
      Object.values(this.machineGroups).map((group) =>
        group.handleInput('parent', percentControl).catch((err) => {
          this.logger.error(`Failed to send level control to group "${group.config.general.name}": ${err.message}`);
        })
      )
    );
  }

  async _applyMachineLevelControl(percentControl) {
    const machines = Object.values(this.machines).filter((machine) => {
      const pos = machine?.config?.functionality?.positionVsParent;
      return (pos === 'downstream' || pos === 'atequipment');
    });

    if (!machines.length) return;

    const perMachine = percentControl / machines.length;
    for (const machine of machines) {
      try {
        await machine.handleInput('parent', 'execSequence', 'startup');
        await machine.handleInput('parent', 'execMovement', perMachine);
      } catch (err) {
        this.logger.error(`Failed to start machine "${machine.config.general.name}": ${err.message}`);
      }
    }
  }

  /* --------------------------- Measurements --------------------------- */

  _handleMeasurement(measurementType, value, position, context) {
    switch (measurementType) {
      case 'level':
        this._onLevelMeasurement(position, value, context);
        break;
      case 'pressure':
        this._onPressureMeasurement(position, value, context);
        break;
      default:
        break;
    }
  }

  _onLevelMeasurement(position, value, context = {}) {
    this.measurements.type('level').variant('measured').position(position).value(value).unit(context.unit);
    const levelSeries = this.measurements.type('level').variant('measured').position(position);
    const levelMeters = levelSeries.getCurrentValue('m');
    if (levelMeters == null) return;

    const volume = this._calcVolumeFromLevel(levelMeters);
    const percent = this.interpolate.interpolate_lin_single_point(
      volume,
      this.basin.minVol,
      this.basin.maxVolAtOverflow,
      0,
      100
    );

    this.measurements.type('volume').variant('measured').position('atequipment').value(volume, context.timestamp, 'm3');
    this.measurements
      .type('volumePercent')
      .variant('measured')
      .position('atequipment')
      .value(percent, context.timestamp, '%');
  }

  _onPressureMeasurement(position, value, context = {}) {
    let kelvinTemp =
      this.measurements.type('temperature').variant('measured').position('atequipment').getCurrentValue('K') ?? null;

    if (kelvinTemp === null) {
      this.logger.warn('No temperature measurement; assuming 15C for pressure to level conversion.');
      this.measurements.type('temperature').variant('assumed').position('atequipment').value(15, Date.now(), 'C');
      kelvinTemp = this.measurements.type('temperature').variant('assumed').position('atequipment').getCurrentValue('K');
    }

    if (kelvinTemp == null) return;

    const density = coolprop.PropsSI('D', 'T', kelvinTemp, 'P', 101325, 'Water');
    const pressurePa = this.measurements.type('pressure').variant('measured').position(position).getCurrentValue('Pa');
    if (!Number.isFinite(pressurePa) || !Number.isFinite(density)) return;

    const g = 9.80665;
    const level = pressurePa / (density * g);
    this.measurements.type('level').variant('predicted').position(position).value(level, context.timestamp, 'm');
  }

  /* --------------------------- Core Calculations --------------------------- */

  _pickVariant(type, variants, position, unit) {
    for (const variant of variants) {
      const val = this.measurements.type(type).variant(variant).position(position).getCurrentValue(unit);
      if (!Number.isFinite(val)) continue;
      return val;
    }
    return null;
  }

  _levelBasedRampStart() {
    const { startLevel, enableShiftedRamp } = this.config.control.levelbased;
    const inflowLevel = this.basin?.inflowLevel;
    if (enableShiftedRamp && this._shiftArmed) return startLevel;
    if (Number.isFinite(inflowLevel)) return inflowLevel;
    return startLevel;
  }

  _levelBasedRampTop() {
    // Returns the upper level at which demand saturates at 100 %.
    // While the shift is armed, top moves left from maxLevel to shiftLevel
    // so output reaches 100 % earlier and stays at 100 % until level
    // falls back through shiftLevel on the way down.
    const { maxLevel, enableShiftedRamp, shiftLevel } = this.config.control.levelbased;
    if (enableShiftedRamp && this._shiftArmed
        && Number.isFinite(shiftLevel) && shiftLevel > 0
        && shiftLevel <= maxLevel) {
      return shiftLevel;
    }
    return maxLevel;
  }

  _updateShiftArmed(level) {
    const { enableShiftedRamp, shiftLevel, startLevel } = this.config.control.levelbased;
    if (!enableShiftedRamp) {
      this._shiftArmed = false;
      return;
    }
    const trigger = Number.isFinite(shiftLevel) && shiftLevel > 0 ? shiftLevel : null;
    if (!this._shiftArmed && trigger != null && level >= trigger) {
      this._shiftArmed = true;
      this.logger.debug(`Shift armed at level=${level} (shiftLevel=${trigger})`);
    } else if (this._shiftArmed && Number.isFinite(startLevel) && level < startLevel) {
      this._shiftArmed = false;
      this.logger.debug(`Shift disarmed at level=${level} (startLevel=${startLevel})`);
    }
  }

  _scaleLevelToFlowPercent(level, rampStartLevel, rampTopLevel) {
    const { maxLevel, curveType = 'linear', logCurveFactor = 9 } = this.config.control.levelbased;
    const start = Number.isFinite(rampStartLevel) ? rampStartLevel : this.config.control.levelbased.startLevel;
    const top = Number.isFinite(rampTopLevel) ? rampTopLevel : maxLevel;
    if (!Number.isFinite(level) || !Number.isFinite(start) || !Number.isFinite(top)) return 0;
    if (top <= start) return level >= top ? 100 : 0;

    const x = Math.max(0, Math.min(1, (level - start) / (top - start)));
    if (curveType === 'log') {
      const factor = Number.isFinite(Number(logCurveFactor)) && Number(logCurveFactor) > 0
        ? Number(logCurveFactor)
        : 9;
      return 100 * (Math.log1p(factor * x) / Math.log1p(factor));
    }

    return x * 100;
  }

  _levelRate(variant) {
    const chain = this.measurements.type('level').variant(variant).position('atequipment');
    if (!chain.exists({ requireValues: true })) return null;
    const m = chain.get();
    const current = m?.getLaggedSample?.(0);
    const previous = m?.getLaggedSample?.(1);
    if (!current || !previous || previous.timestamp == null) return null;
    const dt = (current.timestamp - previous.timestamp) / 1000;
    if (!Number.isFinite(dt) || dt <= 0) return null;
    return (current.value - previous.value) / dt;
  }

  _updatePredictedVolume() {
    const flowUnit = 'm3/s'; // this has to be in m3/s for the actions below
    const now = Date.now();

    const inflow = this.measurements.sum('flow', 'predicted', this.flowPositions.inflow, flowUnit) || 0;
    const outflow = this.measurements.sum('flow', 'predicted', this.flowPositions.outflow, flowUnit) || 0;

    if (!this._predictedFlowState) {
      this._predictedFlowState = { inflow, outflow, lastTimestamp: now };
    }

    const timestampPrev = this._predictedFlowState.lastTimestamp ?? now;
    const deltaSeconds = Math.max((now - timestampPrev) / 1000, 0);
    const netVolumeChange = deltaSeconds > 0 ? (inflow - outflow) * deltaSeconds : 0;

    const volumeSeries = this.measurements.type('volume').variant('predicted').position('atequipment');
    const currentVolume = volumeSeries.getCurrentValue('m3');  
  
    const nextVolume = currentVolume + netVolumeChange;
    const writeTimestamp = timestampPrev + deltaSeconds * 1000;

    volumeSeries.value(nextVolume, writeTimestamp, 'm3').unit('m3'); //olifant

    const nextLevel = this._calcLevelFromVolume(nextVolume);
    this.measurements
      .type('level')
      .variant('predicted')
      .position('atequipment')
      .value(nextLevel, writeTimestamp, 'm')
      .unit('m');

    const percent = this.interpolate.interpolate_lin_single_point(
      nextVolume,
      this.basin.minVol,
      this.basin.maxVolAtOverflow,
      0,
      100
    );

    this.measurements
      .type('volumePercent')
      .variant('predicted')
      .position('atequipment')
      .value(percent, writeTimestamp, '%');

    this._predictedFlowState = { inflow, outflow, lastTimestamp: writeTimestamp };
  }

  _selectBestNetFlow() {
    const type = 'flow';
    const unit = this.measurements.getUnit(type) || 'm3/s';

    for (const variant of this.flowVariants) {
      const bucket = this.measurements.measurements?.[type]?.[variant];
      if (!bucket || Object.keys(bucket).length === 0) continue;

      const inflow = this.measurements.sum(type, variant, this.flowPositions.inflow, unit) || 0;
      const outflow = this.measurements.sum(type, variant, this.flowPositions.outflow, unit) || 0;
      if (Math.abs(inflow) < this.flowThreshold && Math.abs(outflow) < this.flowThreshold) continue;

      const net = inflow - outflow;
      this.measurements.type('netFlowRate').variant(variant).position('atequipment').value(net, Date.now(), unit);
      return { value: net, source: variant, direction: this._deriveDirection(net) };
    }

    // Fallback: level trend
    for (const variant of this.levelVariants) {
      const rate = this._levelRate(variant);
      if (!Number.isFinite(rate)) continue;
      const netFlow = rate * this.basin.surfaceArea;
      return { value: netFlow, source: `level:${variant}`, direction: this._deriveDirection(netFlow) };
    }

    this.logger.warn('No usable measurements to compute net flow; assuming steady.');
    return { value: 0, source: null, direction: 'steady' };
  }

  _computeRemainingTime(netFlow) {
    if (!netFlow || Math.abs(netFlow.value) < this.flowThreshold) return { seconds: null, source: null };

    const { overflowLevel, outflowLevel, surfaceArea } = this.basin;
    if (!Number.isFinite(surfaceArea) || surfaceArea <= 0) return { seconds: null, source: null };

    for (const variant of this.levelVariants) {
      const lvl = this.measurements.type('level').variant(variant).position('atequipment').getCurrentValue('m');
      if (!Number.isFinite(lvl)) continue;

      const remainingHeight = netFlow.value > 0 ? Math.max(overflowLevel - lvl, 0) : Math.max(lvl - outflowLevel, 0);
      const seconds = (remainingHeight * surfaceArea) / Math.abs(netFlow.value);
      if (!Number.isFinite(seconds)) continue;

      return { seconds, source: `${netFlow.source}/${variant}` };
    }

    return { seconds: null, source: netFlow.source };
  }

  _deriveDirection(netFlow) {
    if (netFlow > this.flowThreshold) return 'filling';
    if (netFlow < -this.flowThreshold) return 'draining';
    return 'steady';
  }

  /* --------------------------- Safety --------------------------- */

  /**
   * Safety controller — two hard rules:
   *
   * 1. BELOW minLevel (dry-run): pumps CANNOT start.
   *    Shuts down all downstream machines + machine groups.
   *    Only a manual override or emergency can restart them.
   *    safetyControllerActive = true → blocks _controlLogic.
   *
   * 2. ABOVE high-volume safety level: pumps CANNOT stop.
   *    Shuts down UPSTREAM equipment only (stop more water coming in).
   *    Does NOT shut down downstream pumps or machine groups — they
   *    must keep draining. Does NOT set safetyControllerActive — the
   *    level-based control keeps running so pumps stay at the demand
   *    dictated by the current level (which will be >100% near overflow,
   *    meaning all pumps at maximum via the normal demand curve).
   *    Only a manual override or emergency stop can shut pumps during
   *    a high-volume or overflowing event.
   */
  _safetyController(remainingTime, direction) {
    this.safetyControllerActive = false;

    const volUnit = this.measurements.getUnit('volume');
    const vol = this._pickVariant('volume', this.volVariants, 'atequipment', volUnit);
    if (vol == null) {
      Object.values(this.machines).forEach((machine) => machine.handleInput('parent', 'execSequence', 'shutdown'));
      this.logger.warn('No volume data available to safe guard system; shutting down all machines.');
      this.safetyControllerActive = true;
      return;
    }

    const {
      enableDryRunProtection,
      dryRunThresholdPercent,
      enableOverfillProtection,
      enableHighVolumeSafety,
      timeleftToFullOrEmptyThresholdSeconds
    } = this.config.safety || {};

    const dryRunEnabled = Boolean(enableDryRunProtection);
    const highVolumeSafetyEnabled = Boolean(enableHighVolumeSafety ?? enableOverfillProtection);
    const timeProtectionEnabled = timeleftToFullOrEmptyThresholdSeconds > 0;
    const safety = this._computeSafetyPoints();
    const triggerHighVol = safety.highVolumeSafetyVol;
    const triggerLowVol = safety.dryRunSafetyVol;
    const currentLevel = this._pickVariant('level', this.levelVariants, 'atequipment', 'm');

    this.safetyState = {
      dryRunActive: false,
      highVolumeActive: false,
      isOverflowing: Number.isFinite(currentLevel) && currentLevel >= this.basin.overflowLevel,
      dryRunLevel: safety.dryRunLevel,
      highVolumeSafetyLevel: safety.highVolumeSafetyLevel,
      dryRunSafetyVol: safety.dryRunSafetyVol,
      highVolumeSafetyVol: safety.highVolumeSafetyVol
    };

    // Rule 1: DRY-RUN — below minLevel, pumps cannot run.
    if (direction === 'draining') {
      const timeTriggered = timeProtectionEnabled && remainingTime != null && remainingTime < timeleftToFullOrEmptyThresholdSeconds;
      const dryRunTriggered = dryRunEnabled && vol < triggerLowVol;
      if (timeTriggered || dryRunTriggered) {
        this.safetyState.dryRunActive = true;
        // Shut down all downstream equipment — pumps must stop.
        Object.values(this.machines).forEach((machine) => {
          const pos = machine?.config?.functionality?.positionVsParent;
          if ((pos === 'downstream' || pos === 'atequipment') && machine._isOperationalState()) {
            machine.handleInput('parent', 'execSequence', 'shutdown');
          }
        });
        Object.values(this.stations).forEach((station) => station.handleInput('parent', 'execSequence', 'shutdown'));
        Object.values(this.machineGroups).forEach((group) => group.turnOffAllMachines());
        this.logger.warn(
          `Dry-run safety: vol=${vol.toFixed(2)} m3, remainingTime=${remainingTime ? remainingTime.toFixed(1) : 'N/A'} s; shutting down downstream equipment`
        );
        // Block _controlLogic so level-based control can't restart pumps.
        this.safetyControllerActive = true;
      }
    }

    // Rule 2: OVERFILL — above overflow level, pumps cannot stop.
    // Only shut down UPSTREAM equipment. Downstream pumps + machine
    // groups keep running at whatever the level control demands
    // (which will be >100% near overflow = all pumps at max).
    // Do NOT set safetyControllerActive — _controlLogic must keep
    // running to maintain pump demand.
    if (direction === 'filling') {
      const timeTriggered = timeProtectionEnabled && remainingTime != null && remainingTime < timeleftToFullOrEmptyThresholdSeconds;
      const highVolumeTriggered = highVolumeSafetyEnabled && vol > triggerHighVol;
      if (timeTriggered || highVolumeTriggered) {
        this.safetyState.highVolumeActive = true;
        // Shut down UPSTREAM only — stop more water coming in.
        Object.values(this.machines).forEach((machine) => {
          const pos = machine?.config?.functionality?.positionVsParent;
          if (pos === 'upstream' && machine._isOperationalState()) {
            machine.handleInput('parent', 'execSequence', 'shutdown');
          }
        });
        Object.values(this.stations).forEach((station) => station.handleInput('parent', 'execSequence', 'shutdown'));
        // NOTE: machine groups (downstream pumps) are NOT shut down.
        // They must keep draining to prevent overflow from worsening.
        this.logger.warn(
          `High-volume safety: vol=${vol.toFixed(2)} m3, remainingTime=${remainingTime ? remainingTime.toFixed(1) : 'N/A'} s; shutting down upstream equipment only — pumps keep running`
        );
        // NOTE: safetyControllerActive is NOT set — level control
        // keeps commanding pumps at maximum demand.
      }
    }
  }

  _computeSafetyPoints() {
    const safety = this.config.safety || {};
    const dryRunPct = Number(safety.dryRunThresholdPercent) || 0;
    const highPct = Number(
      safety.highVolumeSafetyThresholdPercent ?? safety.overfillThresholdPercent ?? 98
    ) || 0;
    const dryRunSafetyVol = this.basin.minVol * (1 + (dryRunPct / 100));
    const dryRunLevel = this._calcLevelFromVolume(dryRunSafetyVol);
    const highVolumeSafetyVol = this.basin.maxVolAtOverflow * (highPct / 100);
    const highVolumeSafetyLevel = this._calcLevelFromVolume(highVolumeSafetyVol);

    return {
      dryRunSafetyVol,
      dryRunLevel,
      highVolumeSafetyVol,
      highVolumeSafetyLevel
    };
  }

  /* --------------------------- Basin --------------------------- */

  /**
   * Compute basin geometry from config and seed the initial predicted
   * volume at the operational floor.
   *
   * Basin is modelled as a rectangular prism (constant cross-section),
   * so `volume = level × surfaceArea`. See the wiki's basin-model
   * diagram for the full threshold layout and naming conventions:
   *   wiki/functional-description.md#basin-model
   *
   * `minHeightBasedOn` ('inlet' | 'outlet') selects which pipe height
   * defines `minVol` — the 0 % point of fill-percent and the default
   * dry-run reference.
   */
  initBasinProperties() {
    const minHeightBasedOn = this.config.hydraulics.minHeightBasedOn;
    const volEmptyBasin = this.config.basin.volume;       // m3 — total basin capacity
    const heightBasin = this.config.basin.height;         // m  — floor to rim
    const inflowLevel = this.config.basin.inflowLevel;    // m  — inlet pipe bottom/invert
    const outflowLevel = this.config.basin.outflowLevel;  // m  — outlet/pump suction pipe top
    const overflowLevel = this.config.basin.overflowLevel; // m — overflow weir crest
    const inletPipeDiameter = this.config.basin.inletPipeDiameter;
    const outletPipeDiameter = this.config.basin.outletPipeDiameter;

    // Constant cross-section assumption: volume = level × area
    const surfaceArea = volEmptyBasin / heightBasin;

    // Volume at each critical height
    const maxVol = heightBasin * surfaceArea;          // ≡ volEmptyBasin (see note above)
    const maxVolAtOverflow = overflowLevel * surfaceArea; // spill threshold
    const minVolAtOutflow = outflowLevel * surfaceArea;        // dry-run threshold
    const minVolAtInflow = inflowLevel * surfaceArea;          // gravity-feed threshold

    // Operational floor: which pipe defines "basin too low"
    const minVol = minHeightBasedOn === 'inlet' ? minVolAtInflow : minVolAtOutflow;

    this.basin = {
      volEmptyBasin,
      heightBasin,
      inflowLevel,
      outflowLevel,
      overflowLevel,
      inletPipeDiameter,
      outletPipeDiameter,
      surfaceArea,
      maxVol,
      maxVolAtOverflow,
      minVolAtInflow,
      minVolAtOutflow,
      minVol,
      minHeightBasedOn
    };

    // Seed predicted volume at operational floor — the station assumes
    // the basin is at minimum until calibrated by a real measurement.
    this.measurements.type('volume').variant('predicted').position('atequipment').value(minVol).unit('m3');
  }

  /**
   * Validate basin + control threshold ordering.
   *
   * Every pair is a strict physical or control invariant. Violations
   * don't throw — they log a warning and return the list so callers
   * (tests, node-status, the eval harness) can surface them. Returning
   * [] means "all invariants hold".
   *
   * Strict invariants (bottom → top):
   *   0 < outflowLevel < inflowLevel < overflowLevel ≤ basinHeight
   *   dryRunLevel ≤ minLevel ≤ startLevel ≤ inflowLevel < maxLevel ≤ highVolumeSafetyLevel < overflowLevel
   *
   * dryRunLevel and highVolumeSafetyLevel are DERIVED — computed
   * from minVol × (1 + dryRunThresholdPercent/100) and overflowLevel ×
   * highVolumeSafetyThresholdPercent/100 in the safety layer. Validating those
   * catches config that would let minLevel sit below where safety has
   * already force-stopped the pumps (no-op control band).
   */
  _validateThresholdOrdering() {
    const basin = this.basin;
    const lvl = this.config.control?.levelbased || {};

    const safetyPoints = this._computeSafetyPoints();
    const dryRunLevel = safetyPoints.dryRunLevel;
    const highVolumeSafetyLevel = safetyPoints.highVolumeSafetyLevel;

    const checks = [
      ['outflowLevel', basin.outflowLevel, '<', 'inflowLevel', basin.inflowLevel],
      ['inflowLevel', basin.inflowLevel, '<', 'overflowLevel', basin.overflowLevel],
      ['overflowLevel', basin.overflowLevel, '<=', 'basinHeight', basin.heightBasin],
      ['dryRunLevel', dryRunLevel, '<=', 'minLevel', lvl.minLevel],
      ['minLevel', lvl.minLevel, '<=', 'startLevel', lvl.startLevel],
      ['startLevel', lvl.startLevel, '<=', 'inflowLevel', basin.inflowLevel],
      ['inflowLevel', basin.inflowLevel, '<', 'maxLevel', lvl.maxLevel],
      ['maxLevel', lvl.maxLevel, '<=', 'highVolumeSafetyLevel', highVolumeSafetyLevel],
      ['highVolumeSafetyLevel', highVolumeSafetyLevel, '<', 'overflowLevel', basin.overflowLevel],
    ];

    const issues = [];
    for (const [aName, a, op, bName, b] of checks) {
      if (!Number.isFinite(a) || !Number.isFinite(b)) continue;
      const ok = op === '<' ? a < b : a <= b;
      if (!ok) {
        const msg = `Threshold invariant violated: ${aName} (${a}) must be ${op} ${bName} (${b})`;
        issues.push({ aName, a, op, bName, b, msg });
        this.logger.warn(msg);
      }
    }
    return issues;
  }

  /** Convert level (m from floor) → volume (m3).  Clamps to 0. */
  _calcVolumeFromLevel(level) {
    return Math.max(level, 0) * this.basin.surfaceArea;
  }

  /** Convert volume (m3) → level (m from floor).  Clamps to 0. */
  _calcLevelFromVolume(volume) {
    return Math.max(volume, 0) / this.basin.surfaceArea;
  }

  /* --------------------------- Output --------------------------- */

  getOutput() {
    const output = this.measurements.getFlattenedOutput();
    const safety = this._computeSafetyPoints();
    output.direction = this.state.direction;
    output.flowSource = this.state.flowSource;
    output.timeleft = this.state.seconds;
    output.volEmptyBasin = this.basin.volEmptyBasin;
    output.inflowLevel = this.basin.inflowLevel;
    output.outflowLevel = this.basin.outflowLevel;
    output.overflowLevel = this.basin.overflowLevel;
    output.inletPipeDiameter = this.basin.inletPipeDiameter;
    output.outletPipeDiameter = this.basin.outletPipeDiameter;
    output.maxVol = this.basin.maxVol;
    output.minVol = this.basin.minVol;
    output.maxVolAtOverflow = this.basin.maxVolAtOverflow;
    output.minVolAtOutflow = this.basin.minVolAtOutflow;
    output.minVolAtInflow = this.basin.minVolAtInflow;
    output.minHeightBasedOn = this.basin.minHeightBasedOn;
    output.dryRunLevel = safety.dryRunLevel;
    output.dryRunSafetyVol = safety.dryRunSafetyVol;
    output.highVolumeSafetyLevel = safety.highVolumeSafetyLevel;
    output.highVolumeSafetyVol = safety.highVolumeSafetyVol;
    output.isOverflowing = Boolean(this.safetyState?.isOverflowing);
    output.safetyState = this._deriveSafetyState();
    output.percControl = this.percControl;
    return output;
  }

  _deriveSafetyState() {
    if (this.safetyState?.isOverflowing) return 'overflowing';
    if (this.safetyState?.highVolumeActive) return 'highVolume';
    if (this.safetyState?.dryRunActive) return 'dryRun';
    return 'normal';
  }
}

module.exports = PumpingStation;
/* ------------------------------------------------------------------------- */
/* Example usage                                                             */
/* ------------------------------------------------------------------------- */

if (require.main === module) {
  const Measurement = require('../../measurement/src/specificClass');
  const RotatingMachine = require('../../rotatingMachine/src/specificClass');

  function createPumpingStationConfig(name) {
    return {
      general: {
        logging: { enabled: true, logLevel: 'debug' },
        name,
        id: `${name}-${Date.now()}`,
        flowThreshold: 1e-4
      },
      functionality: {
        softwareType: 'pumpingStation',
        role: 'stationcontroller'
      },
      basin: {
        volume: 43.75,
        height: 10,
        inflowLevel: 3,
        outflowLevel: 0.2,
        overflowLevel: 3.2,
        inletPipeDiameter: 0.4,
        outletPipeDiameter: 0.3
      },
      hydraulics: {
        refHeight: 'NAP',
        basinBottomRef: 0,
        minHeightBasedOn: 'outlet'
      },
      safety: {
        enableDryRunProtection:false,
        enableHighVolumeSafety:false,
        highVolumeSafetyThresholdPercent: 98
      }
    };
  }

  function createLevelMeasurementConfig(name) {
    return {
      general: {
        logging: { enabled: true, logLevel: 'debug' },
        name,
        id: `${name}-${Date.now()}`,
        unit: 'm'
      },
      functionality: {
        softwareType: 'measurement',
        role: 'sensor',
        positionVsParent: 'atequipment'
      },
      asset: {
        category: 'sensor',
        type: 'level',
        model: 'demo-level',
        supplier: 'demoCo',
        unit: 'm'
      },
      scaling: { enabled: false },
      smoothing: { smoothWindow: 5, smoothMethod: 'none' }
    };
  }

  function createFlowMeasurementConfig(name, position) {
    return {
      general: {
        logging: { enabled: true, logLevel: 'debug' },
        name,
        id: `${name}-${Date.now()}`,
        unit: 'm3/s'
      },
      functionality: {
        softwareType: 'measurement',
        role: 'sensor',
        positionVsParent: position
      },
      asset: {
        category: 'sensor',
        type: 'flow',
        model: 'demo-flow',
        supplier: 'demoCo',
        unit: 'm3/s'
      },
      scaling: { enabled: false },
      smoothing: { smoothWindow: 5, smoothMethod: 'none' }
    };
  }

  function createMachineConfig(name,position) {
    return {
      general: {
        name,
        logging: { enabled: false, logLevel: 'debug' }
      },
      functionality: {
        softwareType: "machine",
        positionVsParent: position
      },
      asset: {
        supplier: 'Hydrostal',
        type: 'pump',
        category: 'centrifugal',
        model: 'hidrostal-H05K-S03R'
      }
    };
  }

  function createMachineStateConfig() {
    return {
      general: {
        logging: {
          enabled: true,
          logLevel: 'debug'
        }
      },
      movement: { speed: 1 },
      time: {
        starting: 2,
        warmingup: 3,
        stopping: 2,
        coolingdown: 3
      }
    };
  }

  function seedSample(measurement, type, value, unit) {
    const pos = measurement.config.functionality.positionVsParent;
    measurement.measurements.type(type).variant('measured').position(pos).value(value, Date.now(), unit);
  }

  (async function demo() {
    const station = new PumpingStation(createPumpingStationConfig('PumpingStationDemo'));
    const pump1 = new RotatingMachine(createMachineConfig('Pump1','downstream'), createMachineStateConfig());
    //const pump2 = new RotatingMachine(createMachineConfig('Pump2','upstream'), createMachineStateConfig());

    //const levelSensor = new Measurement(createLevelMeasurementConfig('WetWellLevel'));
    //const inflowSensor = new Measurement(createFlowMeasurementConfig('InfluentFlow', 'in'));
    //const outflowSensor = new Measurement(createFlowMeasurementConfig('PumpDischargeFlow', 'out'));

    //station.childRegistrationUtils.registerChild(levelSensor, levelSensor.config.functionality.softwareType);
    //station.childRegistrationUtils.registerChild(inflowSensor, inflowSensor.config.functionality.softwareType);
    //station.childRegistrationUtils.registerChild(outflowSensor, outflowSensor.config.functionality.softwareType);
    
    station.childRegistrationUtils.registerChild(pump1, 'machine');
    //station.childRegistrationUtils.registerChild(pump2, 'machine');

    // Seed initial measurements
    
    //seedSample(levelSensor, 'level', 1.8, 'm');
    //seedSample(inflowSensor, 'flow', 0.35, 'm3/s');
    //seedSample(outflowSensor, 'flow', 0.20, 'm3/s');

    

    setInterval(
      () => station.tick(), 1000);

      await new Promise((resolve) => setTimeout(resolve, 10));

      console.log('Initial state:', station.state);
      station.setManualInflow(300,Date.now(),'l/s');
      station.calibratePredictedVolume(3.4);
      //await pump1.handleInput('parent', 'execSequence', 'startup');
      //await pump1.handleInput('parent', 'execMovement', 10);
//
      //await pump2.handleInput('parent', 'execSequence', 'startup');
      //await pump2.handleInput('parent', 'execMovement', 10);

      console.log('Station state:', station.state);
      console.log('Station output:', station.getOutput());
    })().catch((err) => {
      console.error('Demo failed:', err);
    });
}
  //*/