added frontend and updated backend with docker, wrote some initial instructions

backend/service/date/dateFormat.go

@@ -0,0 +1,47 @@
+package date
+
+import "time"
+
+func GetDateFromWeekNumber(year int, weekNumber int, dayName string) (time.Time, error) {
+	// Create a time.Date for the first day of the year
+	firstDayOfYear := time.Date(year, time.January, 1, 0, 0, 0, 0, time.UTC)
+
+	// Calculate the number of days to add to reach the desired week
+	daysToAdd := time.Duration((weekNumber-1)*7) * 24 * time.Hour
+
+	// Find the starting day of the week (e.g., Monday)
+	startingDayOfWeek := firstDayOfYear
+
+	// check if the first day of the year is friday or saturday or sunday
+
+	if startingDayOfWeek.Weekday() == time.Friday || startingDayOfWeek.Weekday() == time.Saturday || startingDayOfWeek.Weekday() == time.Sunday {
+		for startingDayOfWeek.Weekday() != time.Monday {
+			startingDayOfWeek = startingDayOfWeek.Add(24 * time.Hour)
+		}
+	} else {
+		for startingDayOfWeek.Weekday() != time.Monday {
+			startingDayOfWeek = startingDayOfWeek.Add(-24 * time.Hour)
+		}
+	}
+
+	// Calculate the desired date by adding daysToAdd and adjusting for the day name
+	desiredDate := startingDayOfWeek.Add(daysToAdd)
+
+	// Find the day of the week
+	dayOfWeek := map[string]time.Weekday{
+		"Montag":     time.Monday,
+		"Dienstag":   time.Tuesday,
+		"Mittwoch":   time.Wednesday,
+		"Donnerstag": time.Thursday,
+		"Freitag":    time.Friday,
+		"Samstag":    time.Saturday,
+		"Sonntag":    time.Sunday,
+	}[dayName]
+
+	// Adjust to the desired day of the week
+	for desiredDate.Weekday() != dayOfWeek {
+		desiredDate = desiredDate.Add(24 * time.Hour)
+	}
+
+	return desiredDate, nil
+}

backend/service/date/dateFormat_test.go

@@ -0,0 +1,64 @@
+package date
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func Test_getDateFromWeekNumber(t *testing.T) {
+	type args struct {
+		year       int
+		weekNumber int
+		dayName    string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    time.Time
+		wantErr bool
+	}{
+		{
+			name: "Test 1",
+			args: args{
+				year:       2021,
+				weekNumber: 1,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2021, 1, 4, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "Test 2",
+			args: args{
+				year:       2023,
+				weekNumber: 57,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2024, 1, 29, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+		{
+			name: "Test 3",
+			args: args{
+				year:       2023,
+				weekNumber: 1,
+				dayName:    "Montag",
+			},
+			want:    time.Date(2023, 1, 2, 0, 0, 0, 0, time.UTC),
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := GetDateFromWeekNumber(tt.args.year, tt.args.weekNumber, tt.args.dayName)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("getDateFromWeekNumber() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("getDateFromWeekNumber() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}