Display free rooms based on solely the room scheduling website

src/background.ts

@@ -1,11 +1,11 @@
 // These scripts run in the background continuously
 import './assets/temp_icon.png';
-
 import './features/canvas/CanvasIntegration';
 import './features/tempBookmarks/TemporaryBookmarks';
-
 import Settings from './shared/settings';
 import './shared/hot_reload';
+import './popup.pug';
+import './features/FreeRooms/FreeRooms';
 
 import {name, version} from '../package.json';
 // To see the console output, click the "background page" link on `chrome://extensions`

src/features/FreeRooms/FreeRooms.ts

@@ -0,0 +1,335 @@
+import ROOMS from './Rooms';
+
+async function getRoomSchedHTML(year, semester) {
+    /*
+    Input is an integer representing the year that you'd like to query
+    as well as a string representing the semester for which you'd like
+    to query.
+
+    Possible Semester Values:
+    F - Fall
+    S - Spring
+    A - Summer Session A
+    B - Summer Session B
+    W - Winter Session
+
+    Output is a Promise that, if successful, returns a string of HTML
+    that is received when making a GET request to the
+    Stevens room schedule website.
+    */
+
+    try {
+        const response = await fetch(
+            `https://web.stevens.edu/roomsched?year=${year}&session=${semester}`,
+            {
+                method: 'GET',
+                headers: {
+                    'Content-Type': 'text/html',
+                },
+            }
+        );
+        return await response.text();
+    } catch (e) {
+        console.error(e);
+    }
+}
+
+async function getTablesPerRoom(year, semester) {
+    /*
+    Input is an integer representing the year that you'd like to query
+    as well as a string representing the semester for which you'd like
+    to query.
+
+    Output is an object whose properties are the names of the rooms listed on
+    web.stevens.edu and whose values for those properties are the HTML table elements objects
+    corresponding to those rooms.
+    */
+    let HTMLString;
+    let roomTableDict = {};
+    HTMLString = await getRoomSchedHTML(year, semester);
+    let domparser = new DOMParser();
+    let document = domparser.parseFromString(HTMLString, 'text/html');
+    let roomTables = document.querySelectorAll('table');
+    for (let i = 0; i < ROOMS.length; i++) {
+        //match all of the tables loaded in the HTML to a the name of a room
+        //checking by hand, it seems there are only as many tables as there are rooms
+        //no other tables for decoration or some other data, etc.
+        roomTableDict[ROOMS[i]] = roomTables[i];
+    }
+    return roomTableDict;
+}
+
+function getDaysRow(day, table) {
+    /*
+    Input is an integer representing the day of the week, and a
+    HTML table object that corresponds to a room.
+
+    Output is a table row object that corresponds to the selected day.
+    */
+
+    if (day === 0 || day === 6) {
+        //It's the weekend, there are no classes scheduled
+        return null;
+    }
+    const dayOfWeek = {
+        1: 'M',
+        2: 'T',
+        3: 'W',
+        4: 'R',
+        5: 'F',
+    };
+
+    let tableRow;
+    //filter through all rows of the table, finding the one that
+    //has a td tag with today's day and returning that one
+    table.querySelectorAll('tr').forEach(row => {
+        row.querySelectorAll('td').forEach(td => {
+            if (td.innerHTML === dayOfWeek[day]) {
+                tableRow = row;
+            }
+        });
+    });
+    return tableRow;
+}
+
+function hasNoScheduledEvent(row, time) {
+    /*
+    Input is an HTML row representing a room's availability
+    for a given day, and a time given by a Date().
+
+    Output is a boolean indicating whether the room has an event
+    during the time passed in.
+    */
+
+    if (!row) {
+        //It's the weekend
+        return true;
+    }
+
+    //Each row is subdivided into 56 different segments
+    //with the first segment representing the time 8:00 AM
+    //and the last segment representing 9:45 PM.
+
+    //There are a additional 3 segments that are on the table but unaccounted for.
+
+    if (time.getHours() < 8 || time.getHours() > 22) {
+        //These times are outside building operation hours
+        return false;
+    }
+    let colspanTime = convertTimetoColspan(time);
+    let totalColspan = 0;
+    let flag = false;
+    let dataElements = row.querySelectorAll('td');
+    for (let td of dataElements) {
+        if (td.hasAttribute('colspan')) {
+            totalColspan += parseInt(td.getAttribute('colspan'));
+            if (totalColspan >= colspanTime) {
+                if (td.innerHTML === '') {
+                    flag = true;
+                } else {
+                    break;
+                }
+            }
+        }
+    }
+    return flag;
+}
+
+function convertTimetoColspan(time) {
+    /*
+    Input is a time given by a Date() object between
+    8 AM and 9:45 PM.
+    Output is the column of the table this time occupies on the
+    room scheduling website.
+    */
+
+    //8 AM -> 0, 9:45 PM -> 55
+
+    let hours = time.getHours();
+    let minutes = time.getMinutes();
+    return (hours - 8) * 4 + Math.floor(minutes / 15);
+}
+
+function getSemesterFromDate(date) {
+    /*
+    Input is a Date() object.
+
+    Output is the current semester that corresponds to that date.
+    */
+
+    //TODO: more accurately determine the current semester
+    //without relying only on the month
+
+    let month = date.getMonth();
+    if (month === 0) {
+        return 'W';
+    } else if (month >= 1 && month <= 4) {
+        return 'S';
+    } else if (month === 5) {
+        return 'A';
+    } else if (month >= 6 && month <= 7) {
+        return 'B';
+    }
+    return 'F';
+}
+
+async function getAvailableRooms(date) {
+    /*
+    Input is a Date() object.
+
+    Output is a Promise that on success
+    returns an array of rooms with no classes scheduled according
+    to the room scheduling website.
+    */
+
+    let availableRooms = [];
+
+    let year = date.getFullYear();
+    let semester = getSemesterFromDate(date);
+    let day = date.getDay();
+
+    let tables = await getTablesPerRoom(year, semester);
+    for (let room in tables) {
+        let row = getDaysRow(day, tables[room]);
+        if (hasNoScheduledEvent(row, date)) {
+            availableRooms.push(room);
+        }
+    }
+    return availableRooms;
+}
+
+chrome.runtime.onInstalled.addListener(details => {
+    getAvailableRooms(new Date()).then(rooms => {
+        chrome.storage.local.set({availableRooms: rooms});
+        chrome.alarms.create('rooms', {
+            periodInMinutes: 15,
+        });
+    });
+
+    chrome.alarms.onAlarm.addListener(alarm => {
+        if (alarm.name === 'rooms') {
+            getAvailableRooms(new Date()).then(rooms => {
+                chrome.storage.local.set({availableRooms: rooms});
+            });
+        }
+    });
+});
+
+// async function testGetAvailableRooms() {
+//     /*
+//     A test to ensure that getAvailableRooms is functional. Returns
+//     true if working as expected.
+//     */
+
+//     const availableRooms = await getAvailableRooms(
+//         new Date('February 24, 2020 08:00:00')
+//     );
+//     console.log(
+//         'getAvailableRooms() thinks that these are the available rooms on Monday at 8 AM:'
+//     );
+//     console.log(availableRooms);
+//     return (
+//         JSON.stringify(availableRooms) ===
+//         JSON.stringify([
+//             'A115',
+//             'A501',
+//             'ABS301',
+//             'B123',
+//             'B126',
+//             'B312',
+//             'B313',
+//             'B314',
+//             'B430',
+//             'B514',
+//             'B517',
+//             'B518',
+//             'B519',
+//             'B620',
+//             'B714',
+//             'B715',
+//             'BC104',
+//             'BC110',
+//             'BC122',
+//             'BC202',
+//             'BC203',
+//             'BC204',
+//             'BC210',
+//             'BC212',
+//             'BC219',
+//             'BC220',
+//             'BC221',
+//             'BC304',
+//             'BC310',
+//             'BC312',
+//             'BC319',
+//             'BC320',
+//             'BC321',
+//             'BC532B',
+//             'BC541',
+//             'BCHFSL',
+//             'C315',
+//             'D231',
+//             'D242',
+//             'E011',
+//             'E111',
+//             'E130',
+//             'E201',
+//             'E229',
+//             'E229A',
+//             'E231',
+//             'E308',
+//             'E329',
+//             'E330',
+//             'GN204',
+//             'GN213',
+//             'GN303',
+//             'GS021',
+//             'GS024',
+//             'GS025',
+//             'GS121',
+//             'GS122',
+//             'GS123',
+//             'GS216',
+//             'K228',
+//             'K350',
+//             'K360',
+//             'K380',
+//             'K390',
+//             'M101',
+//             'M105',
+//             'M201',
+//             'M203',
+//             'M205',
+//             'M324',
+//             'NB101',
+//             'NB102',
+//             'NB105',
+//             'P116',
+//             'P120',
+//             'P216',
+//             'P218',
+//             'P220',
+//             'R201',
+//             'S4TH',
+//             'X003',
+//             'X004',
+//             'X011',
+//             'X104',
+//             'X105',
+//             'X106',
+//             'X118',
+//             'X119',
+//             'X120',
+//             'X203',
+//             'X218A',
+//             'X218B',
+//             'X219',
+//             'X323',
+//             'X414',
+//             'X429',
+//             'X504',
+//             'X510',
+//             'X522',
+//         ])
+//     );
+// }

src/features/FreeRooms/FreeRoomsDisplay.pug

@@ -0,0 +1,9 @@
+h3 Available Rooms
+p
+| These are the available rooms as reflected by the data available on the
+a(href='https://web.stevens.edu/roomsched/')  web.stevens.edu/roomsched/
+|  website.
+p
+ul
+    each room in availableRooms ? availableRooms : []
+        li= room