MagnusGreiff / ramverk2-project-v2-chat-functions

    "use strict";

    var cols,

        currentSort = {

            index: 0,

            desc: false

        };

    // returns the summary table element

    function getTable() { return document.querySelector('.coverage-summary'); }

    // returns the thead element of the summary table

    function getTableHeader() { return getTable().querySelector('thead tr'); }

    // returns the tbody element of the summary table

    function getNthColumn(n) { return getTableHeader().querySelectorAll('th')[n]; }

    // loads all columns

    function loadColumns() {

        var colNodes = getTableHeader().querySelectorAll('th'),

            colNode,

            cols = [],

            col,

            i;

        for (i = 0; i < colNodes.length; i += 1) {

            colNode = colNodes[i];

            col = {

                key: colNode.getAttribute('data-col'),

                sortable: !colNode.getAttribute('data-nosort'),

                type: colNode.getAttribute('data-type') || 'string'

            };

            cols.push(col);

            if (col.sortable) {

                col.defaultDescSort = col.type === 'number';

                colNode.innerHTML = colNode.innerHTML + '<span class="sorter"></span>';

            }

        }

        return cols;

    }

    // attaches a data attribute to every tr element with an object

    // of data values keyed by column name

    function loadRowData(tableRow) {

        var tableCols = tableRow.querySelectorAll('td'),

            colNode,

            col,

            data = {},

            i,

            val;

        for (i = 0; i < tableCols.length; i += 1) {

            colNode = tableCols[i];

            col = cols[i];

            val = colNode.getAttribute('data-value');

            if (col.type === 'number') {

                val = Number(val);

            }

            data[col.key] = val;

        }

        return data;

    }

    // loads all row data

    function loadData() {

        var rows = getTableBody().querySelectorAll('tr'),

            i;

        for (i = 0; i < rows.length; i += 1) {

            rows[i].data = loadRowData(rows[i]);

        }

    }

    // sorts the table using the data for the ith column

    function sortByIndex(index, desc) {

        var key = cols[index].key,

            sorter = function (a, b) {

                a = a.data[key];

                b = b.data[key];

                return a < b ? -1 : a > b ? 1 : 0;

            },

            finalSorter = sorter,

            tableBody = document.querySelector('.coverage-summary tbody'),

            rowNodes = tableBody.querySelectorAll('tr'),

            rows = [],

            i;

        if (desc) {

            finalSorter = function (a, b) {

                return -1 * sorter(a, b);

            };

        }

        for (i = 0; i < rowNodes.length; i += 1) {

            rows.push(rowNodes[i]);

            tableBody.removeChild(rowNodes[i]);

        }

        rows.sort(finalSorter);

        for (i = 0; i < rows.length; i += 1) {

            tableBody.appendChild(rows[i]);

        }

    }

    // removes sort indicators for current column being sorted

    function removeSortIndicators() {

        var col = getNthColumn(currentSort.index),

            cls = col.className;

        cls = cls.replace(/ sorted$/, '').replace(/ sorted-desc$/, '');

        col.className = cls;

    }

    // adds sort indicators for current column being sorted

    function addSortIndicators() {

        getNthColumn(currentSort.index).className += currentSort.desc ? ' sorted-desc' : ' sorted';

    }

    // adds event listeners for all sorter widgets

    function enableUI() {

        var i,

            el,

                var col = cols[i];

                return function () {

                    var desc = col.defaultDescSort;

                    if (currentSort.index === i) {

                        desc = !currentSort.desc;

                    }

                    sortByIndex(i, desc);

                    removeSortIndicators();

                    currentSort.index = i;

                    currentSort.desc = desc;

                    addSortIndicators();

                };

            };

        for (i =0 ; i < cols.length; i += 1) {

            if (cols[i].sortable) {

                // add the click event handler on the th so users

                // dont have to click on those tiny arrows

                el = getNthColumn(i).querySelector('.sorter').parentElement;

                if (el.addEventListener) {

                    el.addEventListener('click', ithSorter(i));

                } else {

                    el.attachEvent('onclick', ithSorter(i));

                }

            }

        }

    }

    // adds sorting functionality to the UI

    return function () {

        if (!getTable()) {

            return;

        }

        cols = loadColumns();

        addSortIndicators();

        enableUI();

    };

})();

window.addEventListener('load', addSorting);