Timer

//  Timer+Extension.swift
//  MGDS_Swift
//  Created by i-Techsys.com on 2017/8/25.
//  Copyright © 2017年 i-Techsys. All rights reserved.
// https://github.com/LYM-mg
// http://www.jianshu.com/u/57b58a39b70e

import Foundation

extension Timer {
    
    // MARK: Schedule timers
    
    /// Create and schedule a timer that will call `block` once after the specified time.
    @discardableResult
    public class func after(_ interval: TimeInterval, _ block: @escaping () -> Void) -> Timer {
        let timer = Timer.new(after: interval, block)
        timer.start()
        return timer
    }
    
    /// Create and schedule a timer that will call `block` repeatedly in specified time intervals.
    
    @discardableResult
    public class func every(_ interval: TimeInterval, _ block: @escaping () -> Void) -> Timer {
        let timer = Timer.new(every: interval, block)
        timer.start()
        return timer
    }
    
    /// Create and schedule a timer that will call `block` repeatedly in specified time intervals.
    /// (This variant also passes the timer instance to the block)
    
    @nonobjc @discardableResult
    public class func every(_ interval: TimeInterval, _ block: @escaping (Timer) -> Void) -> Timer {
        let timer = Timer.new(every: interval, block)
        timer.start()
        return timer
    }
    
    // MARK: Create timers without scheduling
    
    /// Create a timer that will call `block` once after the specified time.
    ///
    /// - Note: The timer won't fire until it's scheduled on the run loop.
    ///         Use `NSTimer.after` to create and schedule a timer in one step.
    /// - Note: The `new` class function is a workaround for a crashing bug when using convenience initializers (rdar://18720947)
    
    public class func new(after interval: TimeInterval, _ block: @escaping () -> Void) -> Timer {
        return CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault, CFAbsoluteTimeGetCurrent() + interval, 0, 0, 0) { _ in
            block()
        }
    }
    
    /// Create a timer that will call `block` repeatedly in specified time intervals.
    ///
    /// - Note: The timer won't fire until it's scheduled on the run loop.
    ///         Use `NSTimer.every` to create and schedule a timer in one step.
    /// - Note: The `new` class function is a workaround for a crashing bug when using convenience initializers (rdar://18720947)
    
    public class func new(every interval: TimeInterval, _ block: @escaping () -> Void) -> Timer {
        return CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault, CFAbsoluteTimeGetCurrent() + interval, interval, 0, 0) { _ in
            block()
        }
    }
    
    /// Create a timer that will call `block` repeatedly in specified time intervals.
    /// (This variant also passes the timer instance to the block)
    ///
    /// - Note: The timer won't fire until it's scheduled on the run loop.
    ///         Use `NSTimer.every` to create and schedule a timer in one step.
    /// - Note: The `new` class function is a workaround for a crashing bug when using convenience initializers (rdar://18720947)
    
    @nonobjc public class func new(every interval: TimeInterval, _ block: @escaping (Timer) -> Void) -> Timer {
        var timer: Timer!
        timer = CFRunLoopTimerCreateWithHandler(kCFAllocatorDefault, CFAbsoluteTimeGetCurrent() + interval, interval, 0, 0) { _ in
            block(timer)
        }
        return timer
    }
    
    // MARK: Manual scheduling
    
    /// Schedule this timer on the run loop
    ///
    /// By default, the timer is scheduled on the current run loop for the default mode.
    /// Specify `runLoop` or `modes` to override these defaults.
    public func start(runLoop: RunLoop = .current, modes: RunLoop.Mode...) {
        let modes = modes.isEmpty ? [RunLoop.Mode.default] : modes
        
        for mode in modes {
            runLoop.add(self, forMode: mode)
        }
    }
}

// MARK: - Time extensions
extension Double {
    public var millisecond: TimeInterval  { return self / 1000 }
    public var milliseconds: TimeInterval { return self / 1000 }
    public var ms: TimeInterval           { return self / 1000 }
    
    public var second: TimeInterval       { return self }
    public var seconds: TimeInterval      { return self }
    
    public var minute: TimeInterval       { return self * 60 }
    public var minutes: TimeInterval      { return self * 60 }
    
    public var hour: TimeInterval         { return self * 3600 }
    public var hours: TimeInterval        { return self * 3600 }
    
    public var day: TimeInterval          { return self * 3600 * 24 }
    public var days: TimeInterval         { return self * 3600 * 24 }
}