gistfile1.swift

func showStreakIndicator(#today: NSDate, yesterday: NSDate?, tomorrow: NSDate?) -> (top: Bool, bottom: Bool) {
        var tuple = (top: false, bottom: false)
        let calendar = NSCalendar.currentCalendar()

        if yesterday == nil && tomorrow == nil {
            tuple.top = true

            return tuple
        }

        if let yest = yesterday {
            let components = calendar.components(.DayCalendarUnit, fromDate: yest, toDate: today, options: nil)

            if components.day == 0 || components.day == 1 {
                tuple.bottom = true
            }
        } else {
            // this is explicit and I can remove it later
            tuple.bottom = false
        }

        if let tom = tomorrow {
            let components = calendar.components(.DayCalendarUnit, fromDate: today, toDate: tom, options: nil)

            if components.day == 0 || components.day == 1 {
                tuple.top = true
            }
        } else {
            // today here is always the most recent meditation session
            // use NSDate() for today's date to compare last session today's date
            let components = calendar.components(.DayCalendarUnit, fromDate: today, toDate: NSDate(), options: nil)

            if components.day > 1 {
                // if your last day was more than 1 day ago, don't show the top streak indicator
                tuple.top = false
            } else {
                // so the top cell always has an encouraging future streak if you sat < 1 days ago
                tuple.top = true
            }
        }

        return tuple
    }

    func prepareEntries() {
        let appDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
        let managedObjectContext = appDelegate.managedObjectContext!
        let request = NSFetchRequest(entityName: "Meditation")
        let sortDescriptor = NSSortDescriptor(key: "date", ascending: false)
        request.sortDescriptors = [sortDescriptor]
        var error: NSError?

        var showStreak = (top: false, bottom: false)

        let result = managedObjectContext.executeFetchRequest(request, error: &error)
        if let objects = result as? [Meditation] {
            for (index, object) in enumerate(objects) {
                // note: item 0 is most recent, item 30 is a month away

                if objects.count == 1 {
                    showStreak = showStreakIndicator(today: object.date, yesterday: nil, tomorrow: nil)
                } else {
                    // handles the first element of the array, tomorrow is nil
                    if ((index - 1) == -1 ) {
                        showStreak = showStreakIndicator(today: object.date, yesterday: objects[index + 1].date, tomorrow: nil)
                    } else {
                        if (index != objects.count - 1) {
                            showStreak = showStreakIndicator(today: object.date, yesterday: objects[index + 1].date, tomorrow: objects[index - 1].date)
                        } else {
                            // handles the last element of the array, yesterday is nil
                            showStreak = showStreakIndicator(today: object.date, yesterday: nil, tomorrow: objects[index - 1].date)
                        }
                    }
                }

                var timeLabel = lengthMinutesLabel(minutesString: lengthMinutes(object.length))

                var entry = Entry(sessionLength: lengthMinutes(object.length), sessionTimeUnit: timeLabel, sessionStartTime: "\(object.date.format())", sessionJournalEntry: object.journalEntry, sessionStreakTop: showStreak.top, sessionStreakBottom: showStreak.bottom)

                arrayOfEntriesNew.append(entry)
            }
        }
    }