/**
 * logRecorder.js - Gestione registrazione dati separata
 * Centralizza tutte le funzioni di logging del dataset
 */

const path = require('path');
const { datasetInit, appendData } = require('../datasetModels/datasetCore');

let app = null;
let recordingInterval = null;
let isRecording = false;

// Stato condiviso della registrazione
const recordingState = {
    active: false,
    startTime: null,
    entryCount: 0,
    currentFile: null,
    stream: null
};

/**
 * Inizializza il recorder con l'istanza di SignalK app
 */
function init(signalkApp) {
    app = signalkApp;
    console.log('[LogRecorder] Inizializzato');
}

/**
 * Raccoglie i dati dai sensori SignalK
 */
function collectSensorData() {
    const getSK = (p) => {
        const v = app.getSelfPath(p);
        return v && v.value !== undefined && v.value !== null ? v.value : null;
    };

    return {
        timestamp: new Date().toISOString(),
        
        // Posizione
        latitude: getSK('navigation.position')?.latitude ?? null,
        longitude: getSK('navigation.position')?.longitude ?? null,
        speed: getSK('navigation.speedOverGround'),
        heading: getSK('navigation.headingTrue'),
        
        // Batteria Trazione
        traction_voltage: getSK('electrical.batteries.traction.Voltage'),
        traction_current: getSK('electrical.batteries.traction.current'),
        traction_soc: getSK('electrical.batteries.traction.stateOfCharge'),
        traction_temperature: getSK('electrical.batteries.traction.temperature'),
        traction_power: getSK('electrical.batteries.traction.power'),
        
        // Batteria Servizio
        service_voltage: getSK('electrical.batteries.service.Voltage'),
        service_current: getSK('electrical.batteries.service.current'),
        service_soc: getSK('electrical.batteries.service.stateOfCharge'),
        service_temperature: getSK('electrical.batteries.service.temperature'),
        
        // Meteo (da OpenMeteo condiviso)
        temperature: getSK('meb.temperature'),
        windSpeed: getSK('meb.appleWindSpeed'),
        windDirection: getSK('meb.appleWindDirection'),
        
        // Onde
        waveHeight: getSK('meb.waves.waveHeight'),
        wavePeriod: getSK('meb.waves.wavePeriod'),
        waveDirection: getSK('meb.waves.waveDirection')
    };
}

/**
 * Crea un nuovo file di log
 */
function createNewLogFile() {
    const headers = [
        'timestamp',
        'latitude', 'longitude', 'speed', 'heading',
        'traction_voltage', 'traction_current', 'traction_soc', 'traction_temperature', 'traction_power',
        'service_voltage', 'service_current', 'service_soc', 'service_temperature',
        'temperature', 'windSpeed', 'windDirection',
        'waveHeight', 'wavePeriod', 'waveDirection'
    ];

    const result = datasetInit(headers);
    if (result) {
        recordingState.currentFile = result.fileName;
        recordingState.stream = result.stream;
        console.log(`[LogRecorder] Nuovo file: ${result.fileName}`);
    }
    return result;
}

/**
 * Scrive una riga di dati nel log
 */
function writeLogEntry(data) {
    if (!recordingState.stream) return false;
    
    const values = [
        data.timestamp,
        data.latitude, data.longitude, data.speed, data.heading,
        data.traction_voltage, data.traction_current, data.traction_soc, data.traction_temperature, data.traction_power,
        data.service_voltage, data.service_current, data.service_soc, data.service_temperature,
        data.temperature, data.windSpeed, data.windDirection,
        data.waveHeight, data.wavePeriod, data.waveDirection
    ];
    
    appendData(values);
    recordingState.entryCount++;
    return true;
}

/**
 * Avvia la registrazione
 * @param {number} intervalMs - Intervallo in millisecondi (default 2000)
 */
function startRecording(intervalMs = 2000) {
    if (isRecording) {
        console.log('[LogRecorder] Registrazione già attiva');
        return false;
    }

    if (!app) {
        console.error('[LogRecorder] App non inizializzata');
        return false;
    }

    const fileResult = createNewLogFile();
    if (!fileResult) {
        console.error('[LogRecorder] Impossibile creare file di log');
        return false;
    }

    recordingState.active = true;
    recordingState.startTime = Date.now();
    recordingState.entryCount = 0;
    isRecording = true;

    recordingInterval = setInterval(() => {
        const data = collectSensorData();
        writeLogEntry(data);
    }, intervalMs);

    console.log(`[LogRecorder] Registrazione avviata (ogni ${intervalMs}ms)`);
    return true;
}

/**
 * Ferma la registrazione
 */
function stopRecording() {
    if (!isRecording) {
        console.log('[LogRecorder] Nessuna registrazione attiva');
        return false;
    }

    if (recordingInterval) {
        clearInterval(recordingInterval);
        recordingInterval = null;
    }

    if (recordingState.stream) {
        recordingState.stream.end();
    }

    const duration = Date.now() - recordingState.startTime;
    console.log(`[LogRecorder] Registrazione fermata. Durata: ${Math.round(duration / 1000)}s, Entries: ${recordingState.entryCount}`);

    recordingState.active = false;
    recordingState.stream = null;
    isRecording = false;

    return {
        duration,
        entries: recordingState.entryCount,
        file: recordingState.currentFile
    };
}

/**
 * Riavvia la registrazione (nuovo file)
 */
function restartRecording(intervalMs = 2000) {
    stopRecording();
    return startRecording(intervalMs);
}

/**
 * Ottiene lo stato corrente della registrazione
 */
function getStatus() {
    return {
        isRecording,
        active: recordingState.active,
        startTime: recordingState.startTime,
        entryCount: recordingState.entryCount,
        currentFile: recordingState.currentFile,
        runningTime: isRecording ? Date.now() - recordingState.startTime : 0
    };
}

/**
 * Verifica se la registrazione è attiva
 */
function isActive() {
    return isRecording;
}

module.exports = {
    init,
    startRecording,
    stopRecording,
    restartRecording,
    getStatus,
    isActive,
    collectSensorData
};