//
//  KKCutGridView.m
//  WWImageEdit
//
//  Created by 邬维 on 2017/1/16.
//  Copyright © 2017年 kook. All rights reserved.
//

#import "KKCutGridView.h"
#import "KKCutCircle.h"
#import "KKCutGridLayer.h"

static const NSUInteger kLeftTopCircleView = 1;
static const NSUInteger kLeftBottomCircleView = 2;
static const NSUInteger kRightTopCircleView = 3;
static const NSUInteger kRightBottomCircleView = 4;

@implementation KKCutGridView{
    KKCutGridLayer *_gridLayer;
    
    //4个角
    KKCutCircle *_ltView;
    KKCutCircle *_lbView;
    KKCutCircle *_rtView;
    KKCutCircle *_rbView;
}

- (id)initWithSuperview:(UIView*)superview frame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if(self){
        [superview addSubview:self];
        
        _gridLayer = [[KKCutGridLayer alloc] init];
        _gridLayer.frame = self.bounds;
        [self.layer addSublayer:_gridLayer];
        
        _ltView = [self clippingCircleWithTag:kLeftTopCircleView];
        _lbView = [self clippingCircleWithTag:kLeftBottomCircleView];
        _rtView = [self clippingCircleWithTag:kRightTopCircleView];
        _rbView = [self clippingCircleWithTag:kRightBottomCircleView];
        
        UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGridView:)];
        [self addGestureRecognizer:panGesture];
        
        self.clippingRect = self.bounds;
    }
    return self;
}

//4个角的拖动圆球
- (KKCutCircle*)clippingCircleWithTag:(NSInteger)tag
{
    KKCutCircle *view = [[KKCutCircle alloc] initWithFrame:CGRectMake(0, 0, 75, 75)];
    view.tag = tag;
    
    UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panCircleView:)];
    [view addGestureRecognizer:panGesture];
    
    [self.superview addSubview:view];
    
    return view;
}

- (void)removeFromSuperview
{
    [super removeFromSuperview];
    
    [_ltView removeFromSuperview];
    [_lbView removeFromSuperview];
    [_rtView removeFromSuperview];
    [_rbView removeFromSuperview];
}

- (void)setBgColor:(UIColor *)bgColor
{
    _gridLayer.bgColor = bgColor;
}

- (void)setGridColor:(UIColor *)gridColor
{
    _gridLayer.gridColor = gridColor;
    
}

- (void)setClippingRect:(CGRect)clippingRect
{
    _clippingRect = clippingRect;
    
    _ltView.center = [self.superview convertPoint:CGPointMake(_clippingRect.origin.x, _clippingRect.origin.y) fromView:self];
    _lbView.center = [self.superview convertPoint:CGPointMake(_clippingRect.origin.x, _clippingRect.origin.y+_clippingRect.size.height) fromView:self];
    _rtView.center = [self.superview convertPoint:CGPointMake(_clippingRect.origin.x+_clippingRect.size.width, _clippingRect.origin.y) fromView:self];
    _rbView.center = [self.superview convertPoint:CGPointMake(_clippingRect.origin.x+_clippingRect.size.width, _clippingRect.origin.y+_clippingRect.size.height) fromView:self];
    
    _gridLayer.clippingRect = clippingRect;
    [self setNeedsDisplay];
}

- (void)setNeedsDisplay
{
    [super setNeedsDisplay];
    [_gridLayer setNeedsDisplay];
}

//拖动4个角
- (void)panCircleView:(UIPanGestureRecognizer*)sender
{
    CGPoint point = [sender locationInView:self];
    CGPoint dp = [sender translationInView:self];
    
    CGRect rct = self.clippingRect;
    
    const CGFloat W = self.frame.size.width;
    const CGFloat H = self.frame.size.height;
    CGFloat minX = 0;
    CGFloat minY = 0;
    CGFloat maxX = W;
    CGFloat maxY = H;
    
    CGFloat ratio = (sender.view.tag == kLeftBottomCircleView || sender.view.tag == kRightTopCircleView) ? -0 : 0;
    
    switch (sender.view.tag) {
        case kLeftTopCircleView: // upper left
        {
            maxX = MAX((rct.origin.x + rct.size.width)  - 0.1 * W, 0.1 * W);
            maxY = MAX((rct.origin.y + rct.size.height) - 0.1 * H, 0.1 * H);
            
            if(ratio!=0){
                CGFloat y0 = rct.origin.y - ratio * rct.origin.x;
                CGFloat x0 = -y0 / ratio;
                minX = MAX(x0, 0);
                minY = MAX(y0, 0);
                
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
                
                if(-dp.x*ratio + dp.y > 0){ point.x = (point.y - y0) / ratio; }
                else{ point.y = point.x * ratio + y0; }
            }
            else{
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
            }
            
            rct.size.width  = rct.size.width  - (point.x - rct.origin.x);
            rct.size.height = rct.size.height - (point.y - rct.origin.y);
            rct.origin.x = point.x;
            rct.origin.y = point.y;
            break;
        }
        case kLeftBottomCircleView: // lower left
        {
            maxX = MAX((rct.origin.x + rct.size.width)  - 0.1 * W, 0.1 * W);
            minY = MAX(rct.origin.y + 0.1 * H, 0.1 * H);
            
            if(ratio!=0){
                CGFloat y0 = (rct.origin.y + rct.size.height) - ratio* rct.origin.x ;
                CGFloat xh = (H - y0) / ratio;
                minX = MAX(xh, 0);
                maxY = MIN(y0, H);
                
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
                
                if(-dp.x*ratio + dp.y < 0){ point.x = (point.y - y0) / ratio; }
                else{ point.y = point.x * ratio + y0; }
            }
            else{
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
            }
            
            rct.size.width  = rct.size.width  - (point.x - rct.origin.x);
            rct.size.height = point.y - rct.origin.y;
            rct.origin.x = point.x;
            break;
        }
        case kRightTopCircleView: // upper right
        {
            minX = MAX(rct.origin.x + 0.1 * W, 0.1 * W);
            maxY = MAX((rct.origin.y + rct.size.height) - 0.1 * H, 0.1 * H);
            
            if(ratio!=0){
                CGFloat y0 = rct.origin.y - ratio * (rct.origin.x + rct.size.width);
                CGFloat yw = ratio * W + y0;
                CGFloat x0 = -y0 / ratio;
                maxX = MIN(x0, W);
                minY = MAX(yw, 0);
                
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
                
                if(-dp.x*ratio + dp.y > 0){ point.x = (point.y - y0) / ratio; }
                else{ point.y = point.x * ratio + y0; }
            }
            else{
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
            }
            
            rct.size.width  = point.x - rct.origin.x;
            rct.size.height = rct.size.height - (point.y - rct.origin.y);
            rct.origin.y = point.y;
            break;
        }
        case kRightBottomCircleView: // lower right
        {
            minX = MAX(rct.origin.x + 0.1 * W, 0.1 * W);
            minY = MAX(rct.origin.y + 0.1 * H, 0.1 * H);
            
            if(ratio!=0){
                CGFloat y0 = (rct.origin.y + rct.size.height) - ratio * (rct.origin.x + rct.size.width);
                CGFloat yw = ratio * W + y0;
                CGFloat xh = (H - y0) / ratio;
                maxX = MIN(xh, W);
                maxY = MIN(yw, H);
                
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
                
                if(-dp.x*ratio + dp.y < 0){ point.x = (point.y - y0) / ratio; }
                else{ point.y = point.x * ratio + y0; }
            }
            else{
                point.x = MAX(minX, MIN(point.x, maxX));
                point.y = MAX(minY, MIN(point.y, maxY));
            }
            
            rct.size.width  = point.x - rct.origin.x;
            rct.size.height = point.y - rct.origin.y;
            break;
        }
        default:
            break;
    }
    self.clippingRect = rct;
}

//移动裁剪view
- (void)panGridView:(UIPanGestureRecognizer*)sender
{
    static BOOL dragging = NO;
    static CGRect initialRect;
    
    if(sender.state==UIGestureRecognizerStateBegan){
        CGPoint point = [sender locationInView:self];
        dragging = CGRectContainsPoint(_clippingRect, point);
        initialRect = self.clippingRect;
    }
    else if(dragging){
        CGPoint point = [sender translationInView:self];
        CGFloat left  = MIN(MAX(initialRect.origin.x + point.x, 0), self.frame.size.width-initialRect.size.width);
        CGFloat top   = MIN(MAX(initialRect.origin.y + point.y, 0), self.frame.size.height-initialRect.size.height);
        
        CGRect rct = self.clippingRect;
        rct.origin.x = left;
        rct.origin.y = top;
        self.clippingRect = rct;
    }
}


@end