//
//  ViewController.m
//
//  Created by Nick Lockwood on 03/02/2013.
//  Copyright (c) 2013 Charcoal Design. All rights reserved.
//

#import "ViewController.h"
#import <QuartzCore/QuartzCore.h>

@interface ViewController ()

@property (nonatomic, weak) IBOutlet UIImageView *hourHand;
@property (nonatomic, weak) IBOutlet UIImageView *minuteHand;
@property (nonatomic, weak) IBOutlet UIImageView *secondHand;
@property (nonatomic, weak) NSTimer *timer;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	
    //adjust anchor points
    self.secondHand.layer.anchorPoint = CGPointMake(0.5f, 0.9f);
    self.minuteHand.layer.anchorPoint = CGPointMake(0.5f, 0.9f);
    self.hourHand.layer.anchorPoint = CGPointMake(0.5f, 0.9f);

    //start timer
    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                                  target:self
                                                selector:@selector(tick)
                                                userInfo:nil
                                                 repeats:YES];
    
    //set initial hand positions
    [self updateHandsAnimated:NO];
}

- (void)tick
{
    [self updateHandsAnimated:YES];
}

- (void)updateHandsAnimated:(BOOL)animated
{
    //convert time to hours, minutes and seconds
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSUInteger units = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
    NSDateComponents *components = [calendar components:units fromDate:[NSDate date]];
    
    //calculate hour hand angle
    CGFloat hourAngle = (components.hour / 12.0) * M_PI * 2.0;
    
    //calculate minute hand angle
    CGFloat minuteAngle = (components.minute / 60.0) * M_PI * 2.0;
    
    //calculate second hand angle
    CGFloat secondAngle = (components.second / 60.0) * M_PI * 2.0;
    
    //rotate hands
    [self setAngle:hourAngle forHand:self.hourHand animated:animated];
    [self setAngle:minuteAngle forHand:self.minuteHand animated:animated];
    [self setAngle:secondAngle forHand:self.secondHand animated:animated];
}

- (void)setAngle:(CGFloat)angle
         forHand:(UIView *)handView
        animated:(BOOL)animated
{
    //generate transform
    CATransform3D transform = CATransform3DMakeRotation(angle, 0, 0, 1);
    
    if (animated)
    {
        //create transform animation
        CABasicAnimation *animation = [CABasicAnimation animation];
        animation.keyPath = @"transform";
        animation.toValue = [NSValue valueWithCATransform3D:transform];
        animation.duration = 0.5;
        animation.delegate = self;
        [animation setValue:handView forKey:@"handView"];
        [handView.layer addAnimation:animation forKey:nil];
    }
    else
    {
        //set transform directly
        handView.layer.transform = transform;
    }
}

- (void)animationDidStop:(CABasicAnimation *)anim finished:(BOOL)flag
{
    //set final position for hand view
    UIView *handView = [anim valueForKey:@"handView"];
    handView.layer.transform = [anim.toValue CATransform3DValue];
}

@end
