#import "PWDView.h"

@interface PWDView ()
//保存路径
@property(nonatomic,strong)NSMutableArray *pathArray;
//临时路径 拖拽过程中的路径 不会放到路径数组中
@property(nonatomic,strong)UIBezierPath *tempPath;

@end
@implementation PWDView
{
    //判断一开始是否选中一个节点
    BOOL _isSelectStartPoint;
    //起点
    CGPoint _startPoint;
    //结束点
    CGPoint _endPoint;
}
/** 懒加载pathArray */
- (NSMutableArray *)pathArray{
    if (!_pathArray) {
        _pathArray = [NSMutableArray array];
    }
    return _pathArray;
}

- (void)awakeFromNib
{   //布局点
    [self allViews];
    
}
/** 布局九个点 */
- (void)allViews{
    //高
    CGFloat height = 50;
    //宽
    CGFloat width = 50;
    //行间距
    CGFloat widthclip = (375 - 150) / 4;
    //列间距
    CGFloat heightclip = (500 - 150) / 4;
    //循环添加
    for (int i = 0; i<3; i++) {
        for (int j = 0; j<3; j++) {
            UIView *v = [[UIView alloc]init];
            v.frame = CGRectMake(widthclip + (widthclip + width) * i, heightclip +(heightclip +height) * j, width, height);
            v.backgroundColor = [UIColor blackColor];
            v.layer.cornerRadius = width / 2;
            [self addSubview:v];
        }
    }
}

/** 开始触摸 */
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    //清空状态
    [self.pathArray removeAllObjects];
    for (UIView *v in self.subviews) {
        v.backgroundColor = [UIColor blackColor];
        v.userInteractionEnabled = YES;
    }
    
    
    //拿到触摸起点
    _startPoint = [[touches anyObject] locationInView:self];
    //检测接触到屏幕的点是否在节点上
    for (UIView *v in self.subviews) {
        //判断是否在节点内
        if (CGRectContainsPoint(v.frame, _startPoint)) {
            //改变节点背景
            v.backgroundColor = [UIColor purpleColor];
            //开始选中了第一个节点
            _isSelectStartPoint = YES;
            //把开始触摸点改到节点的中心点
            _startPoint = v.center;
            //关闭交互 不能被再次选中
            v.userInteractionEnabled = NO;
        }
    }
    
}

/** 触摸中 */
- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    //拿到移动过程中最后一点
    _endPoint = [[touches anyObject] locationInView:self];
    //判断是否在第一个节点 如果有 继续
    if (_isSelectStartPoint) {
        //创建当前路径
        self.tempPath = [UIBezierPath bezierPath];
        //将开始点赋值给路径
        [self.tempPath moveToPoint:_startPoint];
        //将移动中的点赋值给路径
        [self.tempPath addLineToPoint:_endPoint];
        //渲染 调用drawRect方法
        [self setNeedsDisplay];
        
        //检测移动接触到屏幕的点是否到了节点上
        for (UIView *v in self.subviews) {
            //判断是否在节点内
            if (CGRectContainsPoint(v.frame, _endPoint) && v.userInteractionEnabled) {
                //重新生成路径
                self.tempPath = [UIBezierPath bezierPath];
                //给出路径的起点
                [self.tempPath moveToPoint:_startPoint];
                //将节点的中心点作为结束点
                [self.tempPath addLineToPoint:v.center];
                //将路径放入数组
                [self.pathArray addObject:self.tempPath];
                v.userInteractionEnabled = NO;
                //将最新选中的节点的中心点作为下一个路径的起点
                _startPoint = v.center;
                //改变新节点背景
                v.backgroundColor = [UIColor purpleColor];
            }
        }

    }
    
}

/** 结束触摸 */
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    self.tempPath = nil;
    [self setNeedsDisplay];
    _isSelectStartPoint = NO;

}


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
//    绘制所有路径
    for (UIBezierPath *path in self.pathArray ) {
        path.lineWidth = 5;
        [path stroke];
    }

    self.tempPath.lineWidth = 5;
    [self.tempPath stroke];
}


@end