//
//  NSDate+Utilities.swift
//  ResearchUXFactory
//
//  Copyright © 2016 Sage Bionetworks. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// 1.  Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//
// 2.  Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation and/or
// other materials provided with the distribution.
//
// 3.  Neither the name of the copyright holder(s) nor the names of any contributors
// may be used to endorse or promote products derived from this software without
// specific prior written permission. No license is granted to the trademarks of
// the copyright holders even if such marks are included in this software.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//

import UIKit

extension Date {
    
    public func startOfDay() -> Date {
        let calendar = Calendar.current
        let unitFlags: NSCalendar.Unit = [.day, .month, .year]
        let components = (calendar as NSCalendar).components(unitFlags, from: self)
        return calendar.date(from: components) ?? self
    }
    
    public var isToday: Bool {
        return self.startOfDay() == Date().startOfDay()
    }
    
    public var isTomorrow: Bool {
        return self.startOfDay() == Date().startOfDay().addingNumberOfDays(1)
    }
    
    public func addingNumberOfDays(_ days: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .day, value: days, to: self, wrappingComponents: false)!
    }
    
    public func addingNumberOfYears(_ years: Int) -> Date {
        let calendar = Calendar.current
        return calendar.date(byAdding: .year, value: years, to: self, wrappingComponents: false)!
    }
    
    public func dateOnly() -> DateComponents {
        let calendar = Calendar.current
        return calendar.dateComponents([.day, .month, .year], from: self)
    }
    
    public func timeOnly() -> DateComponents {
        let calendar = Calendar.current
        return calendar.dateComponents([.hour, .minute], from: self)
    }
}
