const { outputUtils, configManager } = require('generalFunctions');
const Specific = require("./specificClass");

class nodeClass {
  /**
   * Create a node.
   * @param {object} uiConfig - Node-RED node configuration.
   * @param {object} RED    - Node-RED runtime API.
   * @param {object} nodeInstance - The Node-RED node instance.
   * @param {string} nameOfNode - The name of the node, used for
   */
  constructor(uiConfig, RED, nodeInstance, nameOfNode) {

    // Preserve RED reference for HTTP endpoints if needed
    this.node = nodeInstance;
    this.RED = RED;
    this.name = nameOfNode;

    // Load default & UI config
    this._loadConfig(uiConfig,this.node);

    // Instantiate core class
    this._setupSpecificClass();

    // Wire up event and lifecycle handlers
    this._bindEvents();
    this._registerChild();
    this._startTickLoop();
    this._attachInputHandler();
    this._attachCloseHandler();
  }

  /**
   * Load and merge default config with user-defined settings.
   * @param {object} uiConfig - Raw config from Node-RED UI.
   */
  _loadConfig(uiConfig,node) {
    const cfgMgr = new configManager();
    this.defaultConfig = cfgMgr.getConfig(this.name);

    // Merge UI config over defaults
    this.config = {
      general: {
        name: this.name,
        id: node.id, // node.id is for the child registration process
        unit: uiConfig.unit, // add converter options later to convert to default units (need like a model that defines this which units we are going to use and then conver to those standards)
        logging: {
          enabled: uiConfig.enableLog,
          logLevel: uiConfig.logLevel
        }
      },
      functionality: {
        positionVsParent: uiConfig.positionVsParent,// Default to 'atEquipment' if not specified
        distance: uiConfig.hasDistance ? uiConfig.distance : undefined
      },
      basin:{
        volume: uiConfig.basinVolume,
        height: uiConfig.basinHeight,
        heightInlet: uiConfig.heightInlet,
        heightOutlet: uiConfig.heightOutlet,
        heightOverflow: uiConfig.heightOverflow,
      },
      hydraulics:{
        refHeight: uiConfig.refHeight,
        basinBottomRef: uiConfig.basinBottomRef,
      }
    };

    console.log(`position vs child for ${this.name} is ${this.config.functionality.positionVsParent} the distance is ${this.config.functionality.distance}`);

    // Utility for formatting outputs
    this._output = new outputUtils();
  }

  /**
   * Instantiate the core logic and store as source.
   */
  _setupSpecificClass() {
    this.source = new Specific(this.config);
    this.node.source = this.source; // Store the source in the node instance for easy access
  }

  /**
   * Bind Node-RED status updates.
   */
  _bindEvents() {
    
  }

  // init registration msg
  _registerChild() {
    setTimeout(() => {
      this.node.send([
        null,
        null,
        { topic: 'registerChild', payload: this.node.id , positionVsParent: this.config?.functionality?.positionVsParent || 'atEquipment' , distance: this.config?.functionality?.distance || null},
      ]);
    }, 100);
  }

  _updateNodeStatus() {
    const ps = this.source;

    const pickVariant = (type, prefer = ['measured', 'predicted'], position = 'atEquipment', unit) => {
      for (const variant of prefer) {
        const chain = ps.measurements.type(type).variant(variant).position(position);
        const value = unit ? chain.getCurrentValue(unit) : chain.getCurrentValue();
        if (value != null) return { value, variant };
      }
      return { value: null, variant: null };
    };

    const vol = pickVariant('volume', ['measured', 'predicted'], 'atEquipment', 'm3');
    const volPercent = pickVariant('volumePercent', ['measured','predicted'], 'atEquipment'); // already unitless
    const level = pickVariant('level', ['measured', 'predicted'], 'atEquipment', 'm');
    const netFlow = pickVariant('netFlowRate', ['measured', 'predicted'], 'atEquipment', 'm3/s');

    const maxVolBeforeOverflow = ps.basin?.maxVolOverflow ?? ps.basin?.maxVol ?? 0;
    const currentVolume = vol.value ?? 0;
    const currentvolPercent = volPercent.value ?? 0;
    const netFlowM3h = (netFlow.value ?? 0) * 3600;

    const direction = ps.state?.direction ?? 'unknown';
    const secondsRemaining = ps.state?.seconds ?? null;
    const timeRemainingMinutes = secondsRemaining != null ? Math.round(secondsRemaining / 60) : null;

    const badgePieces = [];
    badgePieces.push(`${currentvolPercent.toFixed(1)}% `);
    badgePieces.push(
      `V=${currentVolume.toFixed(2)} / ${maxVolBeforeOverflow.toFixed(2)} m³ (${'n/a'})`
    );
    badgePieces.push(`net=${netFlowM3h.toFixed(1)} m³/h (${'n/a'})`);
    if (timeRemainingMinutes != null) {
      badgePieces.push(`t≈${timeRemainingMinutes} min)`);
    }

    const { symbol, fill } = (() => {
      switch (direction) {
        case 'filling': return { symbol: '⬆️', fill: 'blue' };
        case 'draining': return { symbol: '⬇️', fill: 'orange' };
        case 'steady': return { symbol: '⏸️', fill: 'green' };
        default: return { symbol: '❔', fill: 'grey' };
      }
    })();

    badgePieces[0] = `${symbol} ${badgePieces[0]}`;

    return {
      fill,
      shape: 'dot',
      text: badgePieces.join(' | ')
    };
  }



  // any time based functions here
  _startTickLoop() {
    setTimeout(() => {
      this._tickInterval = setInterval(() => this._tick(), 1000);

      // Update node status on nodered screen every second ( this is not the best way to do this, but it works for now)
      this._statusInterval = setInterval(() => {
        const status = this._updateNodeStatus();
        this.node.status(status);
      }, 1000);

    }, 1000);
  }

  /**
   * Execute a single tick: update measurement, format and send outputs.
   */
  _tick() {
    
    //pumping station needs time based ticks to recalc level when predicted
    this.source.tick();
    const raw = this.source.getOutput();
    const processMsg = this._output.formatMsg(raw, this.config, 'process');
    const influxMsg  = this._output.formatMsg(raw, this.config, 'influxdb');

    // Send only updated outputs on ports 0 & 1
    this.node.send([processMsg, influxMsg]);
  }

  /**
   * Attach the node's input handler, routing control messages to the class.
   */
  _attachInputHandler() {
    this.node.on('input', (msg, send, done) => {
      switch (msg.topic) {
        //example
        /*case 'simulator':
          this.source.toggleSimulation();      
          break;
        default:
          this.source.handleInput(msg);
          break;
          */
        case 'registerChild':
          // Register this node as a child of the parent node
          const childId = msg.payload;
          const childObj = this.RED.nodes.getNode(childId); 
          this.source.childRegistrationUtils.registerChild(childObj.source ,msg.positionVsParent);
          break;
      }
      done();
    });
  }

  /**
   * Clean up timers and intervals when Node-RED stops the node.
   */
  _attachCloseHandler() {
    this.node.on('close', (done) => {
      clearInterval(this._tickInterval);
      clearInterval(this._statusInterval);
      done();
    });
  }
}

module.exports = nodeClass;