/** Handlers for events in datatables **/

var addTableLength = (menuList, lengthToAdd, dataLength) => {
    if(dataLength >= lengthToAdd) {
        newList = structuredClone(menuList);//menuList.slice(0, menuList.length); // shallow copy
        newList.push(lengthToAdd);
        return newList;
    }
    return menuList;
};

var defaultLengthMenu = (data) => {
    menuList = []
    var lengths = [10, 25, 50, 100, 1000];
    if(data.length > 1000) {
        lengths.push(data.length)
    }
    lengths.forEach((len) => {
        menuList = addTableLength(menuList, len, data.length);
    });
    return menuList;
};

var buildDataTable = (tableId, data = [], columns = [], userSettings = {}) => {
    var defaultSettings = {
        responsive: true,
        layout: {
            topStart: null,
            topEnd: null,
            bottomStart: null,
            bottomEnd: null,
        },
        select: true,
        lengthMenu: defaultLengthMenu(data),
        language: {
            processing: "Processing… Please wait.",
            loadingRecords: "Loading table data… Please wait.",
            lengthMenu: "",
            info: ""
        },
        drawCallback: function (settings) {
            var api = this.api();
            api.rows({selected: true}).nodes().each((node, index) => {
                $(node).find('input[type="checkbox"]:checked')
                      .prop("checked", true);
            });
            api.rows({selected: false}).nodes().each((node, index) => {
                $(node).find('input[type="checkbox"]:not(:checked)')
                    .prop("checked", false);
            });
        }
    }
    var theDataTable = $(tableId).DataTable({
        ...defaultSettings,
        ...userSettings,
        ...(data.length == 0 ? {} : {data: data}),
        ...(columns.length == 0 ? {} : {columns: columns})
    });
    theDataTable.on("select", (event, datatable, type, indexes) => {
        datatable
            .rows(indexes)
            .nodes()
            .each((node, index) => {
                $(node).find('input[type="checkbox"]:not(:checked)')
                    .prop("checked", true);
            });
    });
    theDataTable.on("deselect", (event, datatable, type, indexes) => {
        datatable
            .rows(indexes)
            .nodes()
            .each(function(node, index) {
                $(node).find('input[type="checkbox"]:checked')
                    .prop("checked", false);
            });
    });
    return theDataTable;
};