index.js

var admin = require('firebase-admin');
var Excel = require('exceljs');

var serviceAccount = require(`${__dirname}/key.json`);

admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    databaseURL: 'https://log-controller.firebaseio.com'
});

var defaultDatabase = admin.firestore();

console.log('até aqui, ok kkkk');

async function getDocks() {
    var docks = await defaultDatabase.collection('/companies/QJjGk7HG6wD0AVO94yqt/docks').listDocuments();

    var result = docks.map(async (ref) => {
        let data = await ref.get();

        console.log(`Lendo doca... ${data.id}`);
        var fields = data.data();

        return {
            dockId: data.id,
            code: fields.code,
            description: fields.description
        };
    });

    return Promise.all(result);
}

async function getEvents() {
    var events = await defaultDatabase.collection('/companies/QJjGk7HG6wD0AVO94yqt/events').listDocuments();

    var result = events.map(async (ref) => {
        let data = await ref.get();

        console.log(`Lendo evento... ${data.id}`);
        var fields = data.data();

        var eventChanges = await getChanges(data.id);

        return {
            eventId: data.id,
            dockId: fields.dockId,
            arrivedDate: fields.arrivedDate.toDate(),
            driverName: fields.driverName,
            itemsQuantity: fields.itemsQuantity,
            loadType: fields.loadType,
            nfCode: fields.nfCode,
            state: fields.state,
            type: fields.type,
            weight: fields.weight,
            changes: eventChanges
        };
    });

    return Promise.all(result);
}

async function getChanges(eventId) {
    var changes = await defaultDatabase.collection(`/companies/QJjGk7HG6wD0AVO94yqt/events/${eventId}/changes`).listDocuments();

    var result = changes.map(async (ref) => {
        let data = await ref.get();

        console.log(`Lendo change... ${data.id}`);
        var fields = data.data();

        return {
            eventId: eventId,
            reason: fields.reason,
            time: fields.time.toDate(),
            oldState: fields.fromState,
            newState: fields.toState
        };
    });

    return Promise.all(result);
}

async function run() {
    var docks = await getDocks();

    var events = await getEvents();

    console.log('deixando bonito o negócio:');

    var resultBonito = events.map((event) => {
        var dock = getDock(docks, event.dockId);

        return event.changes.map((change) => {
            return {
                eventId: event.eventId,
                dockId: event.dockId,
                dockDescription: dock.description,
                arrivedDate: event.arrivedDate,
                driverName: event.driverName,
                itemsQuantity: event.itemsQuantity,
                loadType: event.loadType,
                loadTypeDescription: getLoadDescription(event.loadType),
                nfCode: event.nfCode,
                currentState: event.state,
                currentStateDescription: getState(event.state),
                type: event.type,
                typeDescription: event.type == 0 ? 'Carga' : 'Descarga',
                weight: event.weight,
                stateChangedReason: change.reason,
                stateChangedReasonDescription: getReason(change.reason),
                stateChangedTime: change.time,
                oldState: change.oldState,
                oldStateDescription: getState(change.oldState),
                newState: change.newState,
                newStateDescription: getState(change.newState)
            };
        });
    });

    console.log(resultBonito);
    console.log('Gerando xlsx...');
    await createExcel(resultBonito);
}

function getReason(reason) {
    var reasons = { "0": "Falta de paleteiro", "1": "Falta de rack", "2": "Falta de conferente", "3": "Queda de sistema", "4": "Outros" };
    if (reason == null)
        return '';

    return reasons[reason];
}

async function createExcel(data) {
    var workbook = new Excel.Workbook();
    workbook.properties.date1904 = true;
    var sheet = workbook.addWorksheet('Dados');

    var columns = [];
    for (const key in data[0][0]) {
        if (data[0][0].hasOwnProperty(key)) {
            columns.push({ header: key, key: key });
        }
    }

    // Add column headers and define column keys and widths
    // Note: these column structures are a workbook-building convenience only,
    // apart from the column width, they will not be fully persisted.
    sheet.columns = columns;

    for (let eventIndex = 0; eventIndex < data.length; eventIndex++) {
        const element = data[eventIndex];

        for (let changeIndex = 0; changeIndex < element.length; changeIndex++) {
            const change = element[changeIndex];
            sheet.addRow(change);
        }
    }


    await workbook.xlsx.writeFile(`${__dirname}/dados.xlsx`);
}

function getState(state) {
    switch (state) {
        case 0:
            return 'Criado';
        case 1:
            return 'Iniciado';
        case 2:
            return 'Pausado';
        case 3:
            return 'Encerrado'

        default:
            break;
    }
}
function getDock(docks, dockId) {
    return docks.find((dock) => dock.dockId == dockId);
}

function getLoadDescription(loadType) {
    switch (loadType) {
        case 0:
            return 'Pallet';
        case 1:
            return 'Estivada';
        case 2:
            return 'Mista'
        default:
            break;
    }
}

run().then(() => {
    console.log('tudo ok');
}).catch((e) => {
    console.error(e);
});