menu-clock-macos/Clocker/Dependencies/Date Additions/TimePeriod.swift

//
//  TimePeriod.swift
//  DateTools
//
//  Created by Grayson Webster on 8/17/16.
//  Copyright © 2016 Grayson Webster. All rights reserved.
//

import Foundation

/**
 *  In DateTools, time periods are represented by the TimePeriod protocol.
 *  Required variables and method impleementations are bound below. An inheritable
 *  implementation of the TimePeriodProtocol is available through the TimePeriodClass
 *
 *  [Visit our github page](https://github.com/MatthewYork/DateTools#time-periods) for more information.
 */
public protocol TimePeriodProtocol {
    // MARK: - Variables

    /**
     *  The start date for a TimePeriod representing the starting boundary of the time period
     */
    var beginning: Date? { get set }

    /**
     *  The end date for a TimePeriod representing the ending boundary of the time period
     */
    var end: Date? { get set }
}

public extension TimePeriodProtocol {
    // MARK: - Information

    /**
     *  True if the `TimePeriod`'s duration is zero
     */
    var isMoment: Bool {
        return beginning == end
    }

    /**
     *  The duration of the `TimePeriod` in years.
     *  Returns the max int if beginning or end are nil.
     */
    var years: Int {
        if beginning != nil, end != nil {
            return beginning!.yearsEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in weeks.
     *  Returns the max int if beginning or end are nil.
     */
    var weeks: Int {
        if beginning != nil, end != nil {
            return beginning!.weeksEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in days.
     *  Returns the max int if beginning or end are nil.
     */
    var days: Int {
        if beginning != nil, end != nil {
            return beginning!.daysEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in hours.
     *  Returns the max int if beginning or end are nil.
     */
    var hours: Int {
        if beginning != nil, end != nil {
            return beginning!.hoursEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in minutes.
     *  Returns the max int if beginning or end are nil.
     */
    var minutes: Int {
        if beginning != nil, end != nil {
            return beginning!.minutesEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in seconds.
     *  Returns the max int if beginning or end are nil.
     */
    var seconds: Int {
        if beginning != nil, end != nil {
            return beginning!.secondsEarlier(than: end!)
        }
        return Int.max
    }

    /**
     *  The duration of the `TimePeriod` in a time chunk.
     *  Returns a time chunk with all zeroes if beginning or end are nil.
     */
    var chunk: TimeChunk {
        if beginning != nil, end != nil {
            return beginning!.chunkBetween(date: end!)
        }
        return TimeChunk(seconds: 0, minutes: 0, hours: 0, days: 0, weeks: 0, months: 0, years: 0)
    }

    /**
     *  The length of time between the beginning and end dates of the
     * `TimePeriod` as a `TimeInterval`.
     */
    var duration: TimeInterval {
        if beginning != nil, end != nil {
            return abs(beginning!.timeIntervalSince(end!))
        }

        return TimeInterval(Double.greatestFiniteMagnitude)
    }

    // MARK: - Time Period Relationships

    /**
     *  The relationship of the self `TimePeriod` to the given `TimePeriod`.
     *  Relations are stored in Enums.swift. Formal defnitions available in the provided
     *  links:
     *  [GitHub](https://github.com/MatthewYork/DateTools#relationships),
     *  [CodeProject](http://www.codeproject.com/Articles/168662/Time-Period-Library-for-NET)
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: The relationship between self and the given time period
     */
    func relation(to period: TimePeriodProtocol) -> Relation {
        // Make sure that all start and end points exist for comparison
        if beginning != nil, end != nil, period.beginning != nil, period.end != nil {
            // Make sure time periods are of positive durations
            if beginning!.isEarlier(than: end!), period.beginning!.isEarlier(than: period.end!) {
                // Make comparisons
                if period.end!.isEarlier(than: beginning!) {
                    return .after
                } else if period.end!.equals(beginning!) {
                    return .startTouching
                } else if period.beginning!.isEarlier(than: beginning!), period.end!.isEarlier(than: end!) {
                    return .startInside
                } else if period.beginning!.equals(beginning!), period.end!.isLater(than: end!) {
                    return .insideStartTouching
                } else if period.beginning!.equals(beginning!), period.end!.isEarlier(than: end!) {
                    return .enclosingStartTouching
                } else if period.beginning!.isLater(than: beginning!), period.end!.isEarlier(than: end!) {
                    return .enclosing
                } else if period.beginning!.isLater(than: beginning!), period.end!.equals(end!) {
                    return .enclosingEndTouching
                } else if period.beginning!.equals(beginning!), period.end!.equals(end!) {
                    return .exactMatch
                } else if period.beginning!.isEarlier(than: beginning!), period.end!.isLater(than: end!) {
                    return .inside
                } else if period.beginning!.isEarlier(than: beginning!), period.end!.equals(end!) {
                    return .insideEndTouching
                } else if period.beginning!.isEarlier(than: end!), period.end!.isLater(than: end!) {
                    return .endInside
                } else if period.beginning!.equals(end!), period.end!.isLater(than: end!) {
                    return .endTouching
                } else if period.beginning!.isLater(than: end!) {
                    return .before
                }
            }
        }

        return .none
    }

    /**
     *  If `self.beginning` and `self.end` are equal to the beginning and end of the
     *  given `TimePeriod`.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if the periods are the same
     */
    func equals(_ period: TimePeriodProtocol) -> Bool {
        return beginning == period.beginning && end == period.end
    }

    /**
     *  If the given `TimePeriod`'s beginning is before `self.beginning` and
     *  if the given 'TimePeriod`'s end is after `self.end`.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if self is inside of the given `TimePeriod`
     */
    func isInside(of period: TimePeriodProtocol) -> Bool {
        return period.beginning!.isEarlierThanOrEqual(to: beginning!) && period.end!.isLaterThanOrEqual(to: end!)
    }

    /**
     *  If the given Date is after `self.beginning` and before `self.end`.
     *
     * - parameter period: The time period to compare to self
     * - parameter interval: Whether the edge of the date is included in the calculation
     *
     * - returns: True if the given `TimePeriod` is inside of self
     */
    func contains(_ date: Date, interval: Interval) -> Bool {
        if interval == .open {
            return beginning!.isEarlier(than: date) && end!.isLater(than: date)
        } else if interval == .closed {
            return (beginning!.isEarlierThanOrEqual(to: date) && end!.isLaterThanOrEqual(to: date))
        }

        return false
    }

    /**
     *  If the given `TimePeriod`'s beginning is after `self.beginning` and
     *  if the given 'TimePeriod`'s after is after `self.end`.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if the given `TimePeriod` is inside of self
     */
    func contains(_ period: TimePeriodProtocol) -> Bool {
        return beginning!.isEarlierThanOrEqual(to: period.beginning!) && end!.isLaterThanOrEqual(to: period.end!)
    }

    /**
     *  If self and the given `TimePeriod` share any sub-`TimePeriod`.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if there is a period of time that is shared by both `TimePeriod`s
     */
    func overlaps(with period: TimePeriodProtocol) -> Bool {
        // Outside -> Inside
        if period.beginning!.isEarlier(than: beginning!), period.end!.isLater(than: beginning!) {
            return true
        }
        // Enclosing
        else if period.beginning!.isLaterThanOrEqual(to: beginning!), period.end!.isEarlierThanOrEqual(to: end!) {
            return true
        }
        // Inside -> Out
        else if period.beginning!.isEarlier(than: end!), period.end!.isLater(than: end!) {
            return true
        }
        return false
    }

    /**
     *  If self and the given `TimePeriod` overlap or the period's edges touch.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if there is a period of time or moment that is shared by both `TimePeriod`s
     */
    func intersects(with period: TimePeriodProtocol) -> Bool {
        return relation(to: period) != .after && relation(to: period) != .before
    }

    /**
     *  If self and the given `TimePeriod` have no overlap or touching edges.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if there is a period of time between self and the given `TimePeriod` not contained by either period
     */
    func hasGap(between period: TimePeriodProtocol) -> Bool {
        return isBefore(period: period) || isAfter(period: period)
    }

    /**
     *  The period of time between self and the given `TimePeriod` not contained by either.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: The gap between the periods. Zero if there is no gap.
     */
    func gap(between period: TimePeriodProtocol) -> TimeInterval {
        if end!.isEarlier(than: period.beginning!) {
            return abs(end!.timeIntervalSince(period.beginning!))
        } else if period.end!.isEarlier(than: beginning!) {
            return abs(period.end!.timeIntervalSince(beginning!))
        }
        return 0
    }

    /**
     *  The period of time between self and the given `TimePeriod` not contained by either
     *  as a `TimeChunk`.
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: The gap between the periods, zero if there is no gap
     */
    func gap(between period: TimePeriodProtocol) -> TimeChunk? {
        if end != nil, period.beginning != nil {
            return (end?.chunkBetween(date: period.beginning!))!
        }
        return nil
    }

    /**
     *  If self is after the given `TimePeriod` chronologically. (A gap must exist between the two).
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if self is after the given `TimePeriod`
     */
    func isAfter(period: TimePeriodProtocol) -> Bool {
        return relation(to: period) == .after
    }

    /**
     *  If self is before the given `TimePeriod` chronologically. (A gap must exist between the two).
     *
     * - parameter period: The time period to compare to self
     *
     * - returns: True if self is after the given `TimePeriod`
     */
    func isBefore(period: TimePeriodProtocol) -> Bool {
        return relation(to: period) == .before
    }

    // MARK: - Shifts

    // MARK: In Place

    /**
     *  In place, shift the `TimePeriod` by a `TimeInterval`
     *
     * - parameter timeInterval: The time interval to shift the period by
     */
    mutating func shift(by timeInterval: TimeInterval) {
        beginning?.addTimeInterval(timeInterval)
        end?.addTimeInterval(timeInterval)
    }

    /**
     *  In place, shift the `TimePeriod` by a `TimeChunk`
     *
     * - parameter chunk: The time chunk to shift the period by
     */
    mutating func shift(by chunk: TimeChunk) {
        beginning = beginning?.add(chunk)
        end = end?.add(chunk)
    }

    // MARK: - Lengthen / Shorten

    // MARK: In Place

    /**
     *  In place, lengthen the `TimePeriod`, anchored at the beginning, end or center
     *
     * - parameter timeInterval: The time interval to lengthen the period by
     * - parameter anchor: The anchor point from which to make the change
     */
    mutating func lengthen(by timeInterval: TimeInterval, at anchor: Anchor) {
        switch anchor {
        case .beginning:
            end = end?.addingTimeInterval(timeInterval)
        case .center:
            beginning = beginning?.addingTimeInterval(-timeInterval / 2.0)
            end = end?.addingTimeInterval(timeInterval / 2.0)
        case .end:
            beginning = beginning?.addingTimeInterval(-timeInterval)
        }
    }

    /**
     *  In place, lengthen the `TimePeriod`, anchored at the beginning or end
     *
     * - parameter chunk: The time chunk to lengthen the period by
     * - parameter anchor: The anchor point from which to make the change
     */
    mutating func lengthen(by chunk: TimeChunk, at anchor: Anchor) {
        switch anchor {
        case .beginning:
            end = end?.add(chunk)
        case .center:
            // Do not lengthen by TimeChunk at center
            Swift.print("Mutation via chunk from center anchor is not supported.")
        case .end:
            beginning = beginning?.subtract(chunk)
        }
    }

    /**
     *  In place, shorten the `TimePeriod`, anchored at the beginning, end or center
     *
     * - parameter timeInterval: The time interval to shorten the period by
     * - parameter anchor: The anchor point from which to make the change
     */
    mutating func shorten(by timeInterval: TimeInterval, at anchor: Anchor) {
        switch anchor {
        case .beginning:
            end = end?.addingTimeInterval(-timeInterval)
        case .center:
            beginning = beginning?.addingTimeInterval(timeInterval / 2.0)
            end = end?.addingTimeInterval(-timeInterval / 2.0)
        case .end:
            beginning = beginning?.addingTimeInterval(timeInterval)
        }
    }

    /**
     *  In place, shorten the `TimePeriod`, anchored at the beginning or end
     *
     * - parameter chunk: The time chunk to shorten the period by
     * - parameter anchor: The anchor point from which to make the change
     */
    mutating func shorten(by chunk: TimeChunk, at anchor: Anchor) {
        switch anchor {
        case .beginning:
            end = end?.subtract(chunk)
        case .center:
            // Do not shorten by TimeChunk at center
            Swift.print("Mutation via chunk from center anchor is not supported.")
        case .end:
            beginning = beginning?.add(chunk)
        }
    }
}

/**
 *  In DateTools, time periods are represented by the case TimePeriod class
 *  and come with a suite of initializaiton, manipulation, and comparison methods
 *  to make working with them a breeze.
 *
 *  [Visit our github page](https://github.com/MatthewYork/DateTools#time-periods) for more information.
 */
open class TimePeriod: TimePeriodProtocol {
    // MARK: - Variables

    /**
     *  The start date for a TimePeriod representing the starting boundary of the time period
     */
    public var beginning: Date?

    /**
     *  The end date for a TimePeriod representing the ending boundary of the time period
     */
    public var end: Date?

    // MARK: - Initializers

    init() {}

    init(beginning: Date?, end: Date?) {
        self.beginning = beginning
        self.end = end
    }

    init(beginning: Date, duration: TimeInterval) {
        self.beginning = beginning
        end = beginning + duration
    }

    init(end: Date, duration: TimeInterval) {
        self.end = end
        beginning = end.addingTimeInterval(-duration)
    }

    init(beginning: Date, chunk: TimeChunk) {
        self.beginning = beginning
        end = beginning + chunk
    }

    init(end: Date, chunk: TimeChunk) {
        self.end = end
        beginning = end - chunk
    }

    init(chunk: TimeChunk) {
        beginning = Date()
        end = beginning?.add(chunk)
    }

    // MARK: - Shifted

    /**
     *  Shift the `TimePeriod` by a `TimeInterval`
     *
     * - parameter timeInterval: The time interval to shift the period by
     *
     * - returns: The new, shifted `TimePeriod`
     */
    func shifted(by timeInterval: TimeInterval) -> TimePeriod {
        let timePeriod = TimePeriod()
        timePeriod.beginning = beginning?.addingTimeInterval(timeInterval)
        timePeriod.end = end?.addingTimeInterval(timeInterval)
        return timePeriod
    }

    /**
     *  Shift the `TimePeriod` by a `TimeChunk`
     *
     * - parameter chunk: The time chunk to shift the period by
     *
     * - returns: The new, shifted `TimePeriod`
     */
    func shifted(by chunk: TimeChunk) -> TimePeriod {
        let timePeriod = TimePeriod()
        timePeriod.beginning = beginning?.add(chunk)
        timePeriod.end = end?.add(chunk)
        return timePeriod
    }

    // MARK: - Lengthen / Shorten

    // MARK: New

    /**
     *  Lengthen the `TimePeriod` by a `TimeInterval`
     *
     * - parameter timeInterval: The time interval to lengthen the period by
     * - parameter anchor: The anchor point from which to make the change
     *
     * - returns: The new, lengthened `TimePeriod`
     */
    func lengthened(by timeInterval: TimeInterval, at anchor: Anchor) -> TimePeriod {
        let timePeriod = TimePeriod()
        switch anchor {
        case .beginning:
            timePeriod.beginning = beginning
            timePeriod.end = end?.addingTimeInterval(timeInterval)
        case .center:
            timePeriod.beginning = beginning?.addingTimeInterval(-timeInterval)
            timePeriod.end = end?.addingTimeInterval(timeInterval)
        case .end:
            timePeriod.beginning = beginning?.addingTimeInterval(-timeInterval)
            timePeriod.end = end
        }

        return timePeriod
    }

    /**
     *  Lengthen the `TimePeriod` by a `TimeChunk`
     *
     * - parameter chunk: The time chunk to lengthen the period by
     * - parameter anchor: The anchor point from which to make the change
     *
     * - returns: The new, lengthened `TimePeriod`
     */
    func lengthened(by chunk: TimeChunk, at anchor: Anchor) -> TimePeriod {
        let timePeriod = TimePeriod()
        switch anchor {
        case .beginning:
            timePeriod.beginning = beginning
            timePeriod.end = end?.add(chunk)
        case .center:
            Swift.print("Mutation via chunk from center anchor is not supported.")
        case .end:
            timePeriod.beginning = beginning?.add(-chunk)
            timePeriod.end = end
        }

        return timePeriod
    }

    /**
     *  Shorten the `TimePeriod` by a `TimeInterval`
     *
     * - parameter timeInterval: The time interval to shorten the period by
     * - parameter anchor: The anchor point from which to make the change
     *
     * - returns: The new, shortened `TimePeriod`
     */
    func shortened(by timeInterval: TimeInterval, at anchor: Anchor) -> TimePeriod {
        let timePeriod = TimePeriod()
        switch anchor {
        case .beginning:
            timePeriod.beginning = beginning
            timePeriod.end = end?.addingTimeInterval(-timeInterval)
        case .center:
            timePeriod.beginning = beginning?.addingTimeInterval(-timeInterval / 2)
            timePeriod.end = end?.addingTimeInterval(timeInterval / 2)
        case .end:
            timePeriod.beginning = beginning?.addingTimeInterval(timeInterval)
            timePeriod.end = end
        }

        return timePeriod
    }

    /**
     *  Shorten the `TimePeriod` by a `TimeChunk`
     *
     * - parameter chunk: The time chunk to shorten the period by
     * - parameter anchor: The anchor point from which to make the change
     *
     * - returns: The new, shortened `TimePeriod`
     */
    func shortened(by chunk: TimeChunk, at anchor: Anchor) -> TimePeriod {
        let timePeriod = TimePeriod()
        switch anchor {
        case .beginning:
            timePeriod.beginning = beginning
            timePeriod.end = end?.subtract(chunk)
        case .center:
            Swift.print("Mutation via chunk from center anchor is not supported.")
        case .end:
            timePeriod.beginning = beginning?.add(-chunk)
            timePeriod.end = end
        }

        return timePeriod
    }

    // MARK: - Operator Overloads

    /**
     *  Operator overload for checking if two `TimePeriod`s are equal
     */
    static func == (leftAddend: TimePeriod, rightAddend: TimePeriod) -> Bool {
        return leftAddend.equals(rightAddend)
    }

    // Default anchor = beginning
    /**
     *  Operator overload for lengthening a `TimePeriod` by a `TimeInterval`
     */
    static func + (leftAddend: TimePeriod, rightAddend: TimeInterval) -> TimePeriod {
        return leftAddend.lengthened(by: rightAddend, at: .beginning)
    }

    /**
     *  Operator overload for lengthening a `TimePeriod` by a `TimeChunk`
     */
    static func + (leftAddend: TimePeriod, rightAddend: TimeChunk) -> TimePeriod {
        return leftAddend.lengthened(by: rightAddend, at: .beginning)
    }

    // Default anchor = beginning
    /**
     *  Operator overload for shortening a `TimePeriod` by a `TimeInterval`
     */
    static func - (minuend: TimePeriod, subtrahend: TimeInterval) -> TimePeriod {
        return minuend.shortened(by: subtrahend, at: .beginning)
    }

    /**
     *  Operator overload for shortening a `TimePeriod` by a `TimeChunk`
     */
    static func - (minuend: TimePeriod, subtrahend: TimeChunk) -> TimePeriod {
        return minuend.shortened(by: subtrahend, at: .beginning)
    }

    /**
     *  Operator overload for checking if a `TimePeriod` is equal to a `TimePeriodProtocol`
     */
    static func == (left: TimePeriod, right: TimePeriodProtocol) -> Bool {
        return left.equals(right)
    }
}