倒計時按鈕，根據時間單位轉化

//
//  CountdownButton.h
//  Standardization
//
//  Created by YuFly on 2017/10/16.
//  Copyright © 2017年 strong. All rights reserved.
//

#import <UIKit/UIKit.h>
@class CountdownButton;

typedef void(^Completion)(CountdownButton *countdownButton);
@interface CountdownButton : UIButton

/**
 倒計時

 @param startTime  倒計時時間
 @param timeUnit   時間單位
 @param completion 結束回調
 */
- (void)countDownButtonWithStartTime:(NSInteger)startTime
                           timeUnit:(NSString *)timeUnit
                            endTitle:(NSString *)endTitle
                          completion:(Completion)completion;
@end

//
//  CountdownButton.m
//  Standardization
//
//  Created by YuFly on 2017/10/16.
//  Copyright © 2017年 strong. All rights reserved.
//

#import "CountdownButton.h"

@implementation CountdownButton

- (void)countDownButtonWithStartTime:(NSInteger)startTime
                            timeUnit:(NSString *)timeUnit
                            endTitle:(NSString *)endTitle
                          completion:(Completion)completion{
    __unsafe_unretained CountdownButton *ws=self;
    NSInteger beginTime = startTime;
    if([[timeUnit lowercaseString] isEqualToString:@"s"])
        beginTime = startTime;
    else if([[timeUnit lowercaseString] isEqualToString:@"min"])
        beginTime = startTime*60;
    else if([[timeUnit lowercaseString] isEqualToString:@"h"])
        beginTime = startTime*60*60;
    __block NSInteger remainTime = beginTime;
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
    dispatch_source_set_timer(timer, DISPATCH_TIME_NOW, 1.0 * NSEC_PER_SEC, 0 * NSEC_PER_SEC);
    dispatch_source_set_event_handler(timer, ^{
        if (remainTime <= 0) { // 倒計時結束
            dispatch_source_cancel(timer);
            dispatch_async(dispatch_get_main_queue(), ^{
                 [ws setTitle:[NSString stringWithFormat:@"%@",endTitle] forState:UIControlStateDisabled];
                ws.enabled = YES;
                completion(ws);
            });
        } else {
            NSString *timeStr = [ws getMMSSFromSS:[NSString stringWithFormat:@"%ld", remainTime] timeUnit:timeUnit];
            dispatch_async(dispatch_get_main_queue(), ^{
                [ws setTitle:[NSString stringWithFormat:@"容許%@倒計時%@",endTitle,timeStr] forState:UIControlStateDisabled];
                ws.enabled = NO;
            });
            remainTime--;
        }
    });
    dispatch_resume(timer);
}


-(NSString *)getMMSSFromSS:(NSString *)timeString timeUnit:(NSString *)timeUnit{
    
    NSInteger seconds = [timeString integerValue];
    NSString *hour = [NSString stringWithFormat:@"%02ld",seconds/3600];
    NSString *minute = [NSString stringWithFormat:@"%02ld",(seconds%3600)/60];
    NSString *second = [NSString stringWithFormat:@"%02ld",seconds%60];
    NSString *format_time = [NSString stringWithFormat:@"%@:%@:%@",hour,minute,second];
    
    if([[timeUnit lowercaseString] isEqualToString:@"s"])
    {
        format_time= timeUnit;
    }
    else if([[timeUnit lowercaseString] isEqualToString:@"min"])
    {
        format_time = [NSString stringWithFormat:@"%@:%@",minute,second];
    }
    return format_time;
}

@end