//
//  HomeHeaderView.m
//  redstar
//
//  Created by admin on 15/10/26.
//  Copyright © 2015年 ZWF. All rights reserved.
//

#import "HomeHeaderView.h"
#define kCount 5

@interface HomeHeaderView () <UIScrollViewDelegate>
{
    UIImageView *_centerView;
    UIImageView *_reusableView;
}
@property (nonatomic,assign) BOOL isDragging;               //是否正在拖动
@property (nonatomic,strong) NSTimer *timer;                 //设置动画

@end

@implementation HomeHeaderView

#pragma mark - init
- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = kMineBackGroundColor;
        [self setup];
    }
    return self;
}


#pragma mark - Private Methods
- (void)setup
{
    // 天气label
    self.weatherLabel.text = @"上海 ⛅️ 多云转晴 21-29℃";
    
    // 设置代理
    self.scrollView.delegate = self;
    CGFloat w = _scrollView.frame.size.width;
    CGFloat h = _scrollView.frame.size.height;
    _scrollView.pagingEnabled = YES;
    _scrollView.contentSize = CGSizeMake(w * 3, 0);
    _scrollView.contentOffset = CGPointMake(w, 0);
    _scrollView.showsHorizontalScrollIndicator = NO;
    
    _centerView = [[UIImageView alloc] init];
    _centerView.image = [UIImage imageNamed:@"00.jpg"];
    _centerView.frame = CGRectMake(w, 0, w, h);
    _centerView.tag = 0;
    _centerView.userInteractionEnabled = YES;
    [_scrollView addSubview:_centerView];
    
    // 添加点击事件
    UITapGestureRecognizer *tapCenterGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGRClick:)];
    [_centerView addGestureRecognizer:tapCenterGR];
    
    _reusableView = [[UIImageView alloc] init];
    _reusableView.frame = _scrollView.bounds;
    
    UITapGestureRecognizer *tapReusableGR = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapGRClick:)];
    [_reusableView addGestureRecognizer:tapReusableGR];
    
    //  设置时钟动画 定时器
    self.timer = [NSTimer scheduledTimerWithTimeInterval:1.5f target:self selector:@selector(update:) userInfo:nil repeats:YES];
    //  将定时器添加到主线程
    [[NSRunLoop mainRunLoop] addTimer:self.timer forMode:NSRunLoopCommonModes];

}

- (void)update:(NSTimer *)timer{
    //定时移动
    if (_isDragging == YES) {
        return ;
    }
    CGPoint offSet = self.scrollView.contentOffset;
    offSet.x +=offSet.x;
    [self.scrollView setContentOffset:offSet animated:YES];
    
    if (offSet.x >= self.frame.size.width *2) {
        offSet.x = self.frame.size.width;
    }    
}

- (void)tapGRClick:(UITapGestureRecognizer *)sender
{
    NSLog(@"轮播图点击···");
}


#pragma mark - UIScrollView Delegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat offsetX = scrollView.contentOffset.x;
    CGFloat w = scrollView.frame.size.width;
    
    // 1.设置 循环利用view 的位置
    CGRect f = _reusableView.frame;
    NSInteger index = 0;
    if (offsetX > _centerView.frame.origin.x) { // 显示在最右边
        
        f.origin.x = scrollView.contentSize.width - w;
        
        index = _centerView.tag + 1;
        if (index >= kCount) index = 0;
    } else { // 显示在最左边
        f.origin.x = 0;
        
        index = _centerView.tag - 1;
        if (index < 0) index = kCount - 1;
    }
    _reusableView.frame = f;
    _reusableView.tag = index;
    NSString *icon = [NSString stringWithFormat:@"0%ld.jpg", (long)index];
    _reusableView.image = [UIImage imageNamed:icon];
    
    // 2.显示了 最左 或者 最右 的图片
    if (offsetX <= 0 || offsetX >= w * 2) {
        // 2.1.交换 中间的 和 循环利用的
        UIImageView *temp = _centerView;
        _centerView = _reusableView;
        _reusableView = temp;
        
        // 2.2.设置显示位置
        _centerView.frame = _reusableView.frame;
        scrollView.contentOffset = CGPointMake(w, 0);
        
        [_reusableView removeFromSuperview];
    } else {
        [_scrollView addSubview:_reusableView];
    }
}

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    _isDragging = YES;
}
//  停止滚动
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    _isDragging = NO;
}

#pragma mark - lazy loading
- (UIScrollView *)scrollView
{
    if (!_scrollView) {
        _scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.height)];
        _scrollView.bounces = NO;
        _scrollView.pagingEnabled = YES;
        _scrollView.showsHorizontalScrollIndicator = NO;
        _scrollView.showsVerticalScrollIndicator = NO;
        [self addSubview:_scrollView];
    }
    return _scrollView;
}

- (UILabel *)weatherLabel
{
    if (!_weatherLabel) {
        _weatherLabel = [[UILabel alloc] init];
        _weatherLabel.translatesAutoresizingMaskIntoConstraints = NO;
        _weatherLabel.textAlignment = NSTextAlignmentRight;
        _weatherLabel.textColor = [UIColor whiteColor];
        _weatherLabel.font = [UIFont boldSystemFontOfSize:14.0];
        [self insertSubview:_weatherLabel aboveSubview:self.scrollView];
        
        NSLayoutConstraint *weatherHeight = [NSLayoutConstraint constraintWithItem:_weatherLabel attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0 constant:20];
        [_weatherLabel addConstraint:weatherHeight];
        
        NSLayoutConstraint *weatherRight = [NSLayoutConstraint constraintWithItem:_weatherLabel attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeRight multiplier:1.0 constant:-10];
        [self addConstraint:weatherRight];
        
        NSLayoutConstraint *weatherBottom = [NSLayoutConstraint constraintWithItem:_weatherLabel attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeBottom multiplier:1.0 constant:0];
        [self addConstraint:weatherBottom];
    }
    return _weatherLabel;
}
@end