//
//  PagerView.m
//  IBOSSHSH
//
//  Created by ssl on 2017/11/17.
//  Copyright © 2017年 elongtian. All rights reserved.
//

#import "PageSwitchView.h"
#import "PageSwitchModel.h"
@interface PageSwitchView()<UIScrollViewDelegate>{
    UIScrollView *scrollView;
    UIView *topView;
    UILabel *_sliderLabel;
    CGFloat oldContentOffSetX;
}
@end
@implementation PageSwitchView

/**
 初始化

 @param frame <#frame description#>
 @return <#return value description#>
 */
-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    self.translatesAutoresizingMaskIntoConstraints = NO;
    return self;
}

/**
 初始化

 @param aDecoder <#aDecoder description#>
 @return <#return value description#>
 */
-(instancetype)initWithCoder:(NSCoder *)aDecoder{
    self = [super initWithCoder:aDecoder];
    self.translatesAutoresizingMaskIntoConstraints = NO;
    return self;
}


/**
 构建布局

 @param datas <#datas description#>
 */
-(void) setDatas:(NSMutableArray *)datas{
    _datas = datas;
    
    topView = [[UIView alloc]init];
    topView.backgroundColor = [UIColor whiteColor];
    topView.translatesAutoresizingMaskIntoConstraints = NO;
    
    [self addSubview:topView];
    scrollView = [[UIScrollView alloc]init];
    scrollView.delegate = self;
    scrollView.backgroundColor = [UIColor whiteColor];
    scrollView.pagingEnabled = YES;
    scrollView.translatesAutoresizingMaskIntoConstraints = NO;
    scrollView.showsHorizontalScrollIndicator = NO;
    scrollView.showsVerticalScrollIndicator = NO;
    [self addSubview:scrollView];
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[topView(40)][scrollView]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(topView,scrollView)]];
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[topView]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(topView)]];
    [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[scrollView]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(scrollView)]];
    UIView *conview = [[UIView alloc] init];
    conview.translatesAutoresizingMaskIntoConstraints = NO;
    [scrollView addSubview:conview];
    [scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[conview(width)]|" options:0 metrics:@{@"width":@(Screen_Width*datas.count)} views:NSDictionaryOfVariableBindings(conview)]];
    [scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[conview(scrollView)]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(conview,scrollView)]];
    for (NSInteger i = 0; i< datas.count; i++) {
        PageSwitchModel *model = datas[i];
        UIView *view = model.controller.view;
        view.translatesAutoresizingMaskIntoConstraints = NO;
        [conview addSubview:view];
        
        [conview addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-left-[view(wh)]" options:0 metrics:@{@"left":@(Screen_Width*i),@"wh":@(Screen_Width)} views:NSDictionaryOfVariableBindings(view)]];
        
        [conview addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[view(conview)]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view,conview)]];
    }
    
    [scrollView setContentOffset:CGPointMake((scrollView.frame.size.width)*_currentIndex, 0) animated:YES];
    
    for (int i = 0; i<datas.count; i++) {
        PageSwitchModel *model = datas[i];
        NSString *title = model.title;
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
        [btn setTitleColor:[UIColor redColor] forState:UIControlStateSelected];
        [btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        btn.frame = CGRectMake(Screen_Width/datas.count*i, 0, Screen_Width/datas.count, 40);
        btn.titleLabel.font = [UIFont systemFontOfSize:TitleFontOfSize];
        [btn addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventTouchUpInside];
        [btn setTitle:title forState:UIControlStateNormal];
        btn.tag = i;
        if(i == 0){
            btn.selected = YES;
            // 选中后的红线
            _sliderLabel = [[UILabel alloc]initWithFrame:CGRectMake(btn.frame.origin.x, 40-2, Screen_Width/datas.count, 2)];
            UIView *line = [[UIView alloc] init];
            line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex])/2, 0, [self calculationWidth:_currentIndex], 2);
            line.backgroundColor = [UIColor redColor];
            [_sliderLabel addSubview:line];
            [topView addSubview:_sliderLabel];
        }
        [topView addSubview:btn];
    }
    
}

/**
 按钮点击事件
 
 @param sender <#sender description#>
 */
- (void)sliderAction:(UIButton *)sender{
    if (self.currentIndex == sender.tag) {
        return;
    }
    // 切换controller
    [self sliderAnimationWithTag:(int)sender.tag];
    [UIView animateWithDuration:0.3 animations:^{
        scrollView.contentOffset = CGPointMake(Screen_Width*(sender.tag), 0);
        UIView *line = _sliderLabel.subviews[0];
        line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex])/2, 0, [self calculationWidth:_currentIndex], 2);
    } completion:^(BOOL finished) {
        
    }];
}

/**
 滑动tag
 
 @param tag <#tag description#>
 */
- (void)sliderAnimationWithTag:(int)tag{
    self.currentIndex = tag;
    
    for (int i = 0; i< topView.subviews.count; i++) {
        UIButton *sender = topView.subviews[i];
        if(![topView.subviews[i] isKindOfClass:[UILabel class]]){
            if(sender.tag != tag){
                sender.selected = NO;
            }else{
                sender.selected = YES;
            }
        }
    }
}

/**
 开始滚动

 @param scrollView <#scrollView description#>
 */
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    oldContentOffSetX = scrollView.contentOffset.x;
}
/**
 滑动label位置
 
 @param scrollView <#scrollView description#>
 */
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
    //实时计算当前位置,实现和titleView上的按钮的联动
    [[[UIApplication sharedApplication] keyWindow] endEditing:YES];
    CGFloat contentOffSetX = scrollView.contentOffset.x;
    CGFloat X = contentOffSetX/_datas.count;
    CGRect frame = _sliderLabel.frame;
    frame.origin.x = X;
    _sliderLabel.frame = frame;
    if(contentOffSetX - oldContentOffSetX > 0){
        if(fabs(contentOffSetX - oldContentOffSetX)>Screen_Width/2){
    
            [UIView animateWithDuration:0.2 animations:^{
               UIView *line = _sliderLabel.subviews[0];
               line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex+1])/2, 0, [self calculationWidth:_currentIndex+1], 2);
            } completion:^(BOOL finished) {
                
            }];
        }else{
            [UIView animateWithDuration:0.2 animations:^{
                UIView *line = _sliderLabel.subviews[0];
                line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex])/2, 0, [self calculationWidth:_currentIndex], 2);
            } completion:^(BOOL finished) {
                
            }];
        }
    }else{
        if(fabs(contentOffSetX - oldContentOffSetX)>Screen_Width/2){
          
            [UIView animateWithDuration:0.2 animations:^{
                UIView *line = _sliderLabel.subviews[0];
                line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex-1])/2, 0, [self calculationWidth:_currentIndex-1], 2);
            } completion:^(BOOL finished) {
                
            }];
        }else{
            [UIView animateWithDuration:0.2 animations:^{
                UIView *line = _sliderLabel.subviews[0];
                line.frame = CGRectMake(((Screen_Width/_datas.count)- [self calculationWidth:_currentIndex])/2, 0, [self calculationWidth:_currentIndex], 2);
            } completion:^(BOOL finished) {
                
            }];
        }
       
    }

}

/**
 滑动完成
 
 @param scrollView <#scrollView description#>
 */
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    CGFloat contentOffSetX = scrollView.contentOffset.x;
    int index_ = contentOffSetX/Screen_Width;
    [self sliderAnimationWithTag:index_];
}

/**
 计算标题文字的宽度

 @param index <#index description#>
 @return <#return value description#>
 */
- (CGFloat) calculationWidth:(int) index{
    if(index==_datas.count){
        index =(int)[_datas count] -1;
    }else if(index < 0){
        index = 0;
    }
    NSDictionary *attributes = @{NSFontAttributeName:[UIFont systemFontOfSize:17]};
    PageSwitchModel *model = _datas[index];
    CGSize textSize = [model.title boundingRectWithSize:CGSizeMake(100, 100) options:NSStringDrawingTruncatesLastVisibleLine attributes:attributes context:nil].size;;
    return textSize.width;
}
@end