//
//  MCGCDTimer.swift
//  GCD Timer
//
//  Created by Enhart on 2017/6/15.
//  Copyright © 2017年 Enhart. All rights reserved.
//

import UIKit

typealias ActionBlock = () -> ()

class MCGCDTimer {
    /// 单例
    static let shared = MCGCDTimer()
    
    private init(){}
    
    lazy var timerContainer = [String: DispatchSourceTimer]()
    
    /// GCD定时器
    ///
    /// - Parameters:
    ///   - name: 定时器名字
    ///   - timeInterval: 时间间隔
    
    ///   - queue: 队列
    ///   - repeats: 是否重复
    ///   - action: 执行任务的闭包
    func scheduledDispatchTimer(WithTimerName name: String, timeInterval: Double, queue: DispatchQueue, repeats: Bool, action: @escaping ActionBlock) {
        
        if isExistTimer(WithTimerName: name) {
            self.cancleTimer(WithTimerName: name)
        }
        
        var timer = timerContainer[name]
        if timer == nil {
            timer = DispatchSource.makeTimerSource(flags: [], queue: queue)
            timer?.resume()
            timerContainer[name] = timer
        }
        //精度0.1秒
        timer?.schedule(deadline: .now(), repeating: timeInterval, leeway: DispatchTimeInterval.milliseconds(100))
        timer?.setEventHandler(handler: { [weak self] in
            action()
            if repeats == false {
                self?.cancleTimer(WithTimerName: name)
            }
        })
    }
    
    /// 取消定时器
    ///
    /// - Parameter name: 定时器名字
    func cancleTimer(WithTimerName name: String) {
        let timer = timerContainer[name]
        if timer == nil {
            return
        }
        timerContainer.removeValue(forKey: name)
        timer?.cancel()
    }
    
    
    /// 检查定时器是否已存在
    ///
    /// - Parameter name: 定时器名字
    /// - Returns: 是否已经存在定时器
    func isExistTimer(WithTimerName name: String?) -> Bool {
        if timerContainer[name!] != nil {
            return true
        }
        return false
    }
    
}

extension MCGCDTimer {
    /// 取消所有定时器
    func cancleAll() {
        let values = timerContainer.values
        values.forEach {
            $0.cancel()
        }
        timerContainer.removeAll()
    }
}