feat/#3 binary decoder for occupancy events and stubs

frontend/package-lock.json

@@ -19,6 +19,7 @@
         "bson": "^5.5.1",
         "country-flag-emoji-polyfill": "^0.1.8",
         "date-fns": "^3.6.0",
+        "date-fns-tz": "^3.1.3",
         "pinia": "^2.1.7",
         "primeflex": "^3.3.1",
         "primeicons": "^6.0.1",
@@ -4581,6 +4582,14 @@
         "url": "https://github.com/sponsors/kossnocorp"
       }
     },
+    "node_modules/date-fns-tz": {
+      "version": "3.1.3",
+      "resolved": "https://registry.npmjs.org/date-fns-tz/-/date-fns-tz-3.1.3.tgz",
+      "integrity": "sha512-ZfbMu+nbzW0mEzC8VZrLiSWvUIaI3aRHeq33mTe7Y38UctKukgqPR4nTDwcwS4d64Gf8GghnVsroBuMY3eiTeA==",
+      "peerDependencies": {
+        "date-fns": "^3.0.0"
+      }
+    },
     "node_modules/de-indent": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/de-indent/-/de-indent-1.0.2.tgz",

frontend/package.json

@@ -24,6 +24,7 @@
     "bson": "^5.5.1",
     "country-flag-emoji-polyfill": "^0.1.8",
     "date-fns": "^3.6.0",
+    "date-fns-tz": "^3.1.3",
     "pinia": "^2.1.7",
     "primeflex": "^3.3.1",
     "primeicons": "^6.0.1",

frontend/src/api/fetchRoomOccupancy.ts

@@ -36,7 +36,7 @@ export async function fetchRoomOccupancy(
         return null;
       }
       const data = new Uint8Array(roomsResponse);
-      roomOccupancyList = BSON.deserialize(data) as RoomOccupancyList;
+      roomOccupancyList = RoomOccupancyList.fromJSON(BSON.deserialize(data));
       return roomOccupancyList;
     });
 

frontend/src/components/RoomOccupationOffline.vue

@@ -31,6 +31,7 @@ import { useQuery } from "@tanstack/vue-query";
 import { watch } from "vue";
 import { fetchRoomOccupancy } from "@/api/fetchRoomOccupancy";
 import { isValid } from "date-fns";
+import { RoomOccupancyList } from "@/model/roomOccupancyList";
 
 const { t } = useI18n({ useScope: "global" });
 
@@ -70,6 +71,22 @@ const mobilePage = inject("mobilePage") as Ref<boolean>;
 
 const selectedRoom = computed(() => props.room);
 
+/**
+ * Transform decoded JSON object with binary data
+ * to anonymized occupancy events 
+ * @param data RoomOccupancyList with binary data
+ * @returns Anonymized occupancy events
+ */
+function transformData(data: RoomOccupancyList) {
+  const events = data
+    .decodeOccupancy(selectedRoom.value, new Date(currentDateFrom.value), new Date(currentDateTo.value))
+    .map((event, index) => ({
+      id: index,
+      event: event,
+    }));
+    return events;
+}
+
 const { data: occupations } = useQuery({
   queryKey: ["roomOccupation", selectedRoom, currentDateFrom, currentDateTo],
   queryFn: () =>
@@ -77,12 +94,7 @@ const { data: occupations } = useQuery({
       new Date(currentDateFrom.value).toISOString(),
       new Date(currentDateTo.value).toISOString()
     ),
-  select: (data) => data
-        .decodeOccupancy(selectedRoom.value, new Date(currentDateFrom.value), new Date(currentDateTo.value))
-        .map((event, index) => ({
-          id: index,
-          event: event,
-        })),
+  select: (data) => transformData(data),
   enabled: () => selectedRoom.value !== "" && currentDateFrom.value !== "",
   staleTime: 5000000, // 500 seconds
 });

frontend/src/model/roomOccupancyList.test.ts

@@ -0,0 +1,651 @@
+//Calendar implementation for the HTWK Leipzig timetable. Evaluation and display of the individual dates in iCal format.
+//Copyright (C) 2024 HTWKalender support@htwkalender.de
+
+//This program is free software: you can redistribute it and/or modify
+//it under the terms of the GNU Affero General Public License as published by
+//the Free Software Foundation, either version 3 of the License, or
+//(at your option) any later version.
+
+//This program is distributed in the hope that it will be useful,
+//but WITHOUT ANY WARRANTY; without even the implied warranty of
+//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//GNU Affero General Public License for more details.
+
+//You should have received a copy of the GNU Affero General Public License
+//along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+import { beforeEach, describe, expect, test } from "vitest";
+import { RoomOccupancyList } from "./roomOccupancyList";
+import { Binary } from "bson";
+import { add, addHours, addMinutes, interval, subHours } from "date-fns";
+import { fromZonedTime, toZonedTime } from "date-fns-tz";
+
+const testListStart = new Date("2022-01-01T00:00:00Z");
+var testList : RoomOccupancyList; //= RoomOccupancyList.fromJSON({});
+var alternating : Uint8Array = new Uint8Array(Array(4).fill(0xF0));
+var booked : Uint8Array = new Uint8Array(Array(4).fill(0xFF));
+var empty : Uint8Array = new Uint8Array(Array(4).fill(0x00));
+var counting : Uint8Array = new Uint8Array([0x00, 0x01, 0x02, 0x03]);
+
+const localTimezone = "Europe/Berlin";
+
+describe("RoomOccupancyList", () => {
+    beforeEach(() => {
+        alternating = new Uint8Array(Array(4).fill(0xF0));
+        booked = new Uint8Array(Array(4).fill(0xFF));
+        empty = new Uint8Array(Array(4).fill(0x00));
+        counting = new Uint8Array([0x00, 0x01, 0x02, 0x03]);
+        testList = RoomOccupancyList.fromJSON({
+            start: testListStart,
+            granularity: 60,
+            blocks: 32,
+            rooms: [
+            {
+                name: "BOOKED",
+                occupancy: new Binary(booked, 0),
+            },
+            {
+                name: "EMPTY",
+                occupancy: new Binary(empty, 0),
+            },
+            {
+                name: "ALTERNATING",
+                occupancy: new Binary(alternating, 0),
+            },
+            {
+                name: "COUNTING",
+                occupancy: new Binary(counting, 0),
+            }
+            ]
+        });
+    });
+
+    describe("getRooms", () => {
+        test("get rooms", () => {
+            // act
+            const rooms = testList["getRooms"]();
+    
+            // assert
+            expect(rooms).toEqual([
+                "BOOKED",
+                "EMPTY",
+                "ALTERNATING",
+                "COUNTING"
+            ]);
+        });
+
+        test("get empty rooms", () => {
+            // arrange
+            const emptyRoomOccupancy = RoomOccupancyList.fromJSON({
+                start: testListStart,
+                granularity: 60,
+                blocks: 32,
+                rooms: []
+            });
+    
+            // act
+            const rooms = emptyRoomOccupancy["getRooms"]();
+    
+            // assert
+            expect(rooms).toEqual([]);
+        });
+    })
+
+    describe("decodeOccupancy", () => {
+        test("generate stubs for missing room", () => {
+            // arrange
+
+            // act
+            const decoded = testList["decodeOccupancy"](
+                "MISSING",
+                testListStart,
+                addHours(testListStart, 8),
+            );
+
+            // assert
+            expect(decoded).toEqual([
+                {
+                    start: "2022-01-01T06:00:00.000Z",
+                    end: "2022-01-01T08:00:00.000Z",
+                    rooms: "MISSING",
+                    free: true,
+                    stub: true
+                }
+            ]);
+        });
+
+        test("generate stubs out of range", () => {
+            // arrange
+
+            // act
+            const decoded = testList["decodeOccupancy"](
+                "BOOKED",
+                subHours(testListStart, 10),
+                testListStart,
+            );
+
+            // assert
+            expect(decoded).toEqual([
+                {
+                    start: "2021-12-31T14:00:00.000Z",
+                    end: "2021-12-31T19:00:00.000Z",
+                    rooms: "BOOKED",
+                    free: true,
+                    stub: true
+                }
+            ]);
+        });
+
+        test("decode occupancy in range", () => {
+            // arrange
+            // act
+            const decoded = testList["decodeOccupancy"](
+                "BOOKED",
+                subHours(testListStart, 2),
+                addHours(testListStart, 8),
+            );
+
+            expect(decoded).toEqual([
+                {
+                    start: "2022-01-01T00:00:00.000Z",
+                    end: "2022-01-01T08:00:00.000Z",
+                    rooms: "BOOKED",
+                    free: false,
+                    stub: false
+                }
+            ]);
+        });
+    });
+    
+    describe("sliceOccupancy", () => {
+        test.each([
+            booked,
+            empty,
+            alternating
+        ])("getCompleteOccupancy of %j", (occupancy) => {
+            // arrange
+            const startTime = new Date(testList.start);
+            const endTime = new Date(addHours(startTime, 32));
+            const sliceInterval = interval(startTime, endTime);
+    
+            // act
+            const sliced = testList["sliceOccupancy"](
+                sliceInterval,
+                occupancy
+            )
+    
+            // assert
+            expect(sliced).toEqual({
+                decodeSliceStart: startTime,
+                decodeSlice: new Uint8Array(occupancy),
+            });
+        });
+    
+        test("throws start out of bounds", () => {
+            // arrange
+            const startTime = new Date(subHours(testList.start,1));
+            const endTime = new Date(addHours(startTime, 32));
+            const sliceInterval = interval(startTime, endTime);
+    
+            // act and assert
+            expect(() => {
+                testList["sliceOccupancy"](
+                    sliceInterval,
+                    alternating
+                )
+            }).toThrowError();
+        });
+    
+        test("throws end out of bounds", () => {
+            // arrange
+            const startTime = new Date(testList.start);
+            const endTime = new Date(addHours(startTime, 33));
+            const sliceInterval = interval(startTime, endTime);
+    
+            // act and assert
+            expect(() => {
+                testList["sliceOccupancy"](
+                    sliceInterval,
+                    alternating
+                )
+            }).toThrowError();
+        });
+
+        test("range at byte boundaries", () => {
+            // arrange
+            const startTime = new Date(addHours(testList.start, 8));
+            const endTime = new Date(addHours(testList.start, 24));
+            const sliceInterval = interval(startTime, endTime);
+    
+            // act
+            const sliced = testList["sliceOccupancy"](
+                sliceInterval,
+                counting
+            )
+    
+            // assert
+            expect(sliced).toEqual({
+                decodeSliceStart: startTime,
+                decodeSlice: new Uint8Array([0x01, 0x02]),
+            });
+        });
+
+        test("range within byte boundaries", () => {
+            // arrange
+            const startTime = new Date(addMinutes(testListStart, 500));
+            const endTime = new Date(addHours(testListStart, 15));
+            const sliceInterval = interval(startTime, endTime);
+    
+            // act
+            const sliced = testList["sliceOccupancy"](
+                sliceInterval,
+                counting
+            )
+    
+            // assert
+            expect(sliced).toEqual({
+                decodeSliceStart: addHours(testListStart,8),
+                decodeSlice: new Uint8Array([0x01]),
+            });
+        });
+    });
+
+    describe("getOccupancyInterval", () => {
+        test("get empty interval", () => {
+            // arrange
+            const emptyRoomOccupancy = RoomOccupancyList.fromJSON({
+                start: testListStart,
+                granularity: 60,
+                blocks: 0,
+                rooms: []
+            });
+    
+            // act
+            const emptyInterval = emptyRoomOccupancy["getOccupancyInterval"]();
+    
+            // assert
+            expect(emptyInterval).toEqual(interval(testListStart, testListStart));
+        });
+
+        test("get interval of valid room occupancy list", () => {
+            // act
+            const testInterval = testList["getOccupancyInterval"]();
+    
+            // assert
+            expect(testInterval).toEqual(interval(testListStart, addHours(testListStart, 32)));
+        });
+    });
+
+    describe("decodeOccupancyData", () => {
+        test("decode occupancy without length", () => {
+            // arrange
+            // act
+            const decoded = RoomOccupancyList["decodeOccupancyData"](
+                new Uint8Array([]),
+                testListStart,
+                15,
+                "Raum"
+            );
+    
+            // assert
+            expect(decoded).toEqual([]);
+        });
+
+        test("decode blocked occupancy", () => {
+            // arrange
+            // act
+            const decoded = RoomOccupancyList["decodeOccupancyData"](
+                booked,
+                testListStart,
+                15,
+                "BOOKED"
+            );
+    
+            // assert
+            expect(decoded).toEqual([
+                {
+                    start: testListStart.toISOString(),
+                    end: addHours(testListStart, 8).toISOString(),
+                    rooms: "BOOKED",
+                    free: false,
+                    stub: false
+                }
+            ]);
+        });
+
+        test("decode empty occupancy", () => {
+            // arrange
+            // act
+            const decoded = RoomOccupancyList["decodeOccupancyData"](
+                empty,
+                testListStart,
+                15,
+                "BOOKED"
+            );
+    
+            // assert
+            expect(decoded).toEqual([]);
+        });
+
+        test("decode alternating occupancy", () => {
+            // arrange
+            // act
+            const decoded = RoomOccupancyList["decodeOccupancyData"](
+                alternating,
+                new Date("2024-01-01T00:00:00Z"),
+                15,
+                "ALTERNATING"
+            );
+
+            // assert
+            expect(decoded).toEqual([
+                {
+                    start: "2024-01-01T00:00:00.000Z",
+                    end: "2024-01-01T01:00:00.000Z",
+                    rooms: "ALTERNATING",
+                    free: false,
+                    stub: false
+                },
+                {
+                    start: "2024-01-01T02:00:00.000Z",
+                    end: "2024-01-01T03:00:00.000Z",
+                    rooms: "ALTERNATING",
+                    free: false,
+                    stub: false
+                },
+                {
+                    start: "2024-01-01T04:00:00.000Z",
+                    end: "2024-01-01T05:00:00.000Z",
+                    rooms: "ALTERNATING",
+                    free: false,
+                    stub: false
+                },
+                {
+                    start: "2024-01-01T06:00:00.000Z",
+                    end: "2024-01-01T07:00:00.000Z",
+                    rooms: "ALTERNATING",
+                    free: false,
+                    stub: false
+                }
+            ]);
+        });
+    });
+
+    describe("generateStubEvents", () => {
+        test("no events if negative range", () => {
+            // arrange
+            const startTime = new Date("2022-01-01T00:00:00Z");
+            const endTime = new Date("2021-01-01T00:00:00Z");
+    
+            // act
+            const stubEvents = RoomOccupancyList["generateStubEvents"](
+                "ROOM",
+                startTime,
+                endTime
+            );
+    
+            // assert
+            expect(stubEvents).toEqual([]);
+        });
+
+        test("no events if start and end the same", () => {
+            // arrange
+            const startTime = new Date("2022-01-01T00:00:00Z");
+            const endTime = new Date("2022-01-01T00:00:00Z");
+    
+            // act
+            const stubEvents = RoomOccupancyList["generateStubEvents"](
+                "ROOM",
+                startTime,
+                endTime
+            );
+    
+            // assert
+            expect(stubEvents).toEqual([]);
+        });
+
+        test("generate week", () => {
+            // arrange
+            const startTime = new Date("2022-01-01T12:00:00Z");
+            const endTime = new Date("2022-01-07T12:30:00Z");
+
+            // act
+            const stubEvents = RoomOccupancyList["generateStubEvents"](
+                "ROOM",
+                startTime,
+                endTime
+            );
+
+            // assert
+            expect(stubEvents).toEqual([
+                {
+                    start: "2022-01-01T12:00:00.000Z",
+                    end: "2022-01-01T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-02T06:00:00.000Z",
+                    end: "2022-01-02T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-03T06:00:00.000Z",
+                    end: "2022-01-03T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-04T06:00:00.000Z",
+                    end: "2022-01-04T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-05T06:00:00.000Z",
+                    end: "2022-01-05T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-06T06:00:00.000Z",
+                    end: "2022-01-06T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                },
+                {
+                    start: "2022-01-07T06:00:00.000Z",
+                    end: "2022-01-07T12:30:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                }
+            ]);
+        });
+
+        test("generate day", () => {
+            // arrange
+            const startTime = new Date("2022-01-01T16:00:00Z");
+            const endTime = new Date("2022-01-01T19:00:00Z");
+
+            // act
+            const stubEvents = RoomOccupancyList["generateStubEvents"](
+                "ROOM",
+                startTime,
+                endTime
+            );
+
+            // assert
+            expect(stubEvents).toEqual([
+                {
+                    start: "2022-01-01T16:00:00.000Z",
+                    end: "2022-01-01T19:00:00.000Z",
+                    rooms: "ROOM",
+                    free: true,
+                    stub: true,
+                }
+            ]);
+        });
+    });
+
+    describe("shiftTimeForwardInsideWorkday", () => {
+        test("shift time to next day", () => {
+            // arrange
+            const startTime = new Date("2022-01-01T20:00:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeForwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-01T23:00:00Z"));
+        });
+
+        test("don't shift time on the same day", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T01:00:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeForwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-02T01:00:00Z"));
+        });
+
+        test("don't shift if already inside workday", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeForwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-02T12:30:00Z"));
+        });
+    });
+
+    describe("shiftTimeBackwardInsideWorkday", () => {
+        test("shift time to last day", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T05:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeBackwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-01T22:59:59.999Z"));
+        });
+
+        test("don't shift time on the same day", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T22:00:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeBackwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-02T22:00:00Z"));
+        });
+
+        test("don't shift if already inside workday", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["shiftTimeBackwardInsideWorkday"](startTime);
+    
+            // assert
+            expect(toZonedTime(shiftedTime, localTimezone)).toEqual(new Date("2022-01-02T12:30:00Z"));
+        });
+    });
+
+    describe("setTimeOfDay", () => {
+        test("set time to 00:00:00", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["setTimeOfDay"](startTime, {});
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-01-01T23:00:00Z"));
+        });
+
+        test("set time to 23:59:59", () => {
+            // arrange
+            const startTime = new Date("2022-06-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["setTimeOfDay"](startTime, {hours: 23, minutes: 59, seconds: 59});
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-06-02T21:59:59Z"));
+        });
+
+        test("set same time", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["setTimeOfDay"](startTime, {hours: 13, minutes: 30, seconds: 0});
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-01-02T12:30:00Z"));
+        });
+    });
+
+    describe("startOfDay", () => {
+        test("in the winter", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["startOfDay"](startTime);
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-01-01T23:00:00Z"));
+        });
+
+        test("in the summer", () => {
+            // arrange
+            const startTime = new Date("2022-06-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["startOfDay"](startTime);
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-06-01:22:00Z"));
+        });
+    });
+
+    describe("endOfDay", () => {
+        test("in the winter", () => {
+            // arrange
+            const startTime = new Date("2022-01-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["startOfDay"](startTime);
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-01-01T23:00:00Z"));
+        });
+
+        test("in the summer", () => {
+            // arrange
+            const startTime = new Date("2022-06-02T12:30:00Z");
+    
+            // act
+            const shiftedTime = RoomOccupancyList["startOfDay"](startTime);
+    
+            // assert
+            expect(shiftedTime).toEqual(new Date("2022-06-01:22:00Z"));
+        });
+    });
+    
+});

frontend/src/model/roomOccupancyList.ts

@@ -15,8 +15,16 @@
 //along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 import { Binary } from "bson";
-import { AnonymizedEventDTO, AnonymizedOccupancy } from "./event";
-import { Duration, NormalizedInterval, add, addDays, addMinutes, clamp, differenceInMinutes, eachDayOfInterval, endOfDay, interval, isAfter, isBefore, isEqual, max, min, startOfDay, startOfTomorrow, subDays } from "date-fns";
+import { AnonymizedOccupancy } from "./event";
+import { Duration, NormalizedInterval, add, addDays, addMinutes, clamp, differenceInMinutes, eachDayOfInterval, endOfDay, interval, isAfter, isBefore, isEqual, max, min, startOfDay, subDays } from "date-fns";
+import { fromZonedTime, toZonedTime } from "date-fns-tz";
+
+/// The start time of the day. 07:00
+const START_OF_WORKDAY : Duration = {hours: 7};
+/// The end time of the day. 20:00
+const END_OF_WORKDAY : Duration = {hours: 20};
+/// The timezone of the data (Leipzig)
+const TIMEZONE = "Europe/Berlin";
 
 /**
  * Represents the occupancy of a single room.
@@ -29,11 +37,6 @@ class RoomOccupancy {
   ) {}
 }
 
-/// The start time of the day. 08:00
-const START_OF_WORKDAY : Duration = {hours: 8};
-/// The end time of the day. 20:00
-const END_OF_WORKDAY : Duration = {hours: 20};
-
 /**
  * Represents the occupancy of multiple rooms.
  * start is the start date of the occupancy list.
@@ -65,7 +68,6 @@ export class RoomOccupancyList {
    * @returns a list of AnonymizedEventDTO objects representing the occupancy of the room.
    */
   public decodeOccupancy(room : string, from : Date, to : Date) : AnonymizedOccupancy[] {
-    console.log("Decoding occupancy for room " + room + " from " + from.toISOString() + " to " + to.toISOString());
     const roomOccupancy = this.rooms.find((r) => r.name === room);
     
     if (roomOccupancy === undefined) {
@@ -77,15 +79,10 @@ export class RoomOccupancyList {
     // Get start and end of decoded time range (within encoded list and requested range)
     let decodeInterval = interval(clamp(from, this.getOccupancyInterval()), clamp(to, this.getOccupancyInterval()));
 
-    // Calculate the slice of bytes, that are needed to decode the requested time range
-    let minutesFromStart = differenceInMinutes(this.start, decodeInterval.start);
-    let minutesToEnd = differenceInMinutes(this.start, decodeInterval.end);
-
-    let firstByte = Math.floor(minutesFromStart / this.granularity / 8);
-    let lastByte = Math.floor(minutesToEnd / this.granularity / 8);
-
-    let decodeSliceStart = addMinutes(this.start, firstByte * 8 * this.granularity);
-    let decodeSlice = roomOccupancy.occupancy.buffer.slice(firstByte, lastByte + 1);
+    let {decodeSliceStart, decodeSlice} = this.sliceOccupancy(
+      decodeInterval,
+      roomOccupancy.occupancy.buffer
+    );
 
     // Decode the occupancy data
     occupancyList.push(...RoomOccupancyList.decodeOccupancyData(new Uint8Array(decodeSlice), decodeSliceStart, this.granularity, room));
@@ -102,6 +99,36 @@ export class RoomOccupancyList {
     return occupancyList;
   }
 
+  /**
+   * Slice the important parts of the occupancy list for a given time range.
+   * @param from the start of the time range.
+   * @param to the end of the time range.
+   * @returns a new occupancy byte array with the starting time of the first byte
+   * @throws an error, if the selected time range is outside of the occupancy list.
+   */
+  private sliceOccupancy(decodeInterval : NormalizedInterval, occupancy : Uint8Array) : {decodeSliceStart: Date, decodeSlice: Uint8Array} {
+    // Calculate the slice of bytes, that are needed to decode the requested time range
+    // Note: differenceInMinutes calculates (left - right)
+    let minutesFromStart = differenceInMinutes(decodeInterval.start, this.start);
+    let minutesToEnd = differenceInMinutes(decodeInterval.end, this.start);
+
+    let firstByte = Math.floor(minutesFromStart / this.granularity / 8);
+    let lastByte = Math.ceil(minutesToEnd / this.granularity / 8);
+
+    // check if firstByte and lastByte are within the bounds of the occupancy array and throw an error if not
+    if (
+      firstByte < 0 || firstByte >= occupancy.length ||
+      lastByte < 0 || lastByte > occupancy.length
+    ) {
+      throw new Error("Requested time range is outside of the occupancy list.");
+    }
+    
+    let decodeSliceStart = addMinutes(this.start, firstByte * 8 * this.granularity);
+    let decodeSlice = occupancy.buffer.slice(firstByte, lastByte);
+
+    return { decodeSliceStart, decodeSlice: new Uint8Array(decodeSlice) };
+  }
+
   /**
    * Get the decoded time interval within the current occupancy list.
    * @returns the interval of the occupancy list.
@@ -128,7 +155,7 @@ export class RoomOccupancyList {
 
       // Iterate over all bits in the current byte
       for (let bit_i = 0; bit_i < 8; bit_i++) {
-        let isOccupied = (byte & (1 << bit_i)) !== 0;
+        let isOccupied = (byte & (1 << (7-bit_i))) !== 0;
 
         if (firstOccupancyBit === null && isOccupied) {
           firstOccupancyBit = byte_i * 8 + bit_i;
@@ -141,7 +168,8 @@ export class RoomOccupancyList {
             startTime.toISOString(),
             endTime.toISOString(),
             room,
-            true
+            false,
+            false,
           ));
 
           firstOccupancyBit = null;
@@ -158,7 +186,8 @@ export class RoomOccupancyList {
         startTime.toISOString(),
         endTime.toISOString(),
         room,
-        true
+        false,
+        false,
       ));
     }
 
@@ -195,6 +224,21 @@ export class RoomOccupancyList {
     });
   }
 
+  /**
+   * Generate RoomOccupancyList from plain JSON object.
+   * For performance no deep copy is made, reference attributes will be shared.
+   * @param json the JS object to read from.
+   * @returns a RoomOccupancyList object.
+   */
+  public static fromJSON(json : any) : RoomOccupancyList {
+    return new RoomOccupancyList(
+      json.start,
+      json.granularity,
+      json.blocks,
+      json.rooms.map((room : any) => new RoomOccupancy(room.name, room.occupancy)
+    ));
+  }
+
   /**
    * Shift the time forward to the start of the next day if it is after the end of the current day.
    * 
@@ -205,7 +249,7 @@ export class RoomOccupancyList {
     // if the time of date is after the end of the workday
     if (isAfter(date, RoomOccupancyList.setTimeOfDay(date, END_OF_WORKDAY))) {
       // shift the time to the start of the next day
-      return startOfDay(addDays(date,1));
+      return RoomOccupancyList.startOfDay(addDays(date,1));
     } else {
       return date;
     }
@@ -221,20 +265,41 @@ export class RoomOccupancyList {
     // if the time of date is before the start of the workday
     if (isBefore(date, RoomOccupancyList.setTimeOfDay(date, START_OF_WORKDAY))) {
       // shift the time to the end of the previous day
-      return endOfDay(subDays(date,1));
+      return RoomOccupancyList.endOfDay(subDays(date,1));
     } else {
       return date;
     }
   }
 
   /**
-   * Sets the date to the specified time after 00:00.
+   * Sets the date to the specified time after 00:00 in the current local timezone.
    * @param date the date object to extract the day from.
    * @param time the time as Duration after 00:00.
    * @returns new date with changed time values.
    */
   private static setTimeOfDay(date : Date, time : Duration) : Date {
-    return add(startOfDay(date), time);
+    return add(RoomOccupancyList.startOfDay(date), time);
   }
+
+  /**
+   * Start of day in server timezone defined as const TIMEZONE.
+   * @param date 
+   * @returns the start of the day.
+   */
+  private static startOfDay(date : Date) : Date {
+    const dateInLocalTimezone = toZonedTime(date, TIMEZONE);
+    return fromZonedTime(startOfDay(dateInLocalTimezone), TIMEZONE);
+  }
+
+  /**
+   * End of day in server timezone defined as const TIMEZONE.
+   * @param date
+   * @returns the end of the day.
+   */
+  private static endOfDay(date : Date) : Date {
+    const dateInLocalTimezone = toZonedTime(date, TIMEZONE);
+    return fromZonedTime(endOfDay(dateInLocalTimezone), TIMEZONE);
+  }
+
 }