/*

 Copyright (C) 2018 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Exposes D-Pad game controller type functionality with screen-rendered buttons.

 */

#import "AAPLPadOverlay.h"

@implementation AAPLPadOverlay {

    UITouch* _trackingTouch;

    CGPoint _startLocation;

    SKShapeNode* _stick;

    SKShapeNode* _background;

}

- (instancetype)init {

    self = [super init];

    if (self) {

        _size = CGSizeMake(150, 150);

        self.alpha = 0.7;

        self.userInteractionEnabled = YES;

        [self buildPad];

    }

    return self;

}

- (void)setSize:(CGSize)size {

    if (!CGSizeEqualToSize(_size, size)) {

        _size = size;

        [self updateForSizeChange];

    }

}

- (void)buildPad {

    CGRect backgroundRect = CGRectMake(0, 0, _size.width, _size.height);

    _background = [[SKShapeNode alloc] init];

    _background.path = CGPathCreateWithEllipseInRect(backgroundRect, NULL);

    _background.strokeColor = [SKColor blackColor];

    _background.lineWidth = 3.0;

    [self addChild:_background];

    CGRect stickRect = CGRectZero;

    stickRect.size = self.stickSize;

    _stick = [[SKShapeNode alloc] init];

    _stick.path = CGPathCreateWithEllipseInRect(stickRect, NULL);

    _stick.lineWidth = 2.0;

//#if TARGET_OS_OSX

    _stick.fillColor = [SKColor whiteColor];

//#endif

    _stick.strokeColor = [SKColor blackColor];

    [self addChild:_stick];

    [self updateStickPosition];

}

- (void)updateForSizeChange {

    CGRect backgroundRect = CGRectMake(0, 0, _size.width, _size.height);

    _background.path = CGPathCreateWithEllipseInRect(backgroundRect, NULL);

    CGRect stickRect = CGRectMake(0, 0, _size.width / 3.0,  _size.height / 3.0);

    _stick.path = CGPathCreateWithEllipseInRect(stickRect, NULL);

}

- (CGSize)stickSize {

    return CGSizeMake(_size.width / 3.0,  _size.height / 3.0);

}

- (void)updateStickPosition {

    const CGSize stickSize = self.stickSize;

    _stick.position =

        CGPointMake(_size.width / 2.0 - stickSize.width / 2.0 + _size.width / 2.0 * self.stickPosition.x,

                    _size.height / 2.0 - stickSize.height / 2.0 + _size.width / 2.0 * self.stickPosition.y);

}

- (void)setStickPosition:(CGPoint)stickPosition {

    _stickPosition = stickPosition;

    [self updateStickPosition];

}

- (void)updateStickPositionForTouchLocation:(CGPoint)location {

    vector_float2 l_vec = {location.x - _startLocation.x, location.y - _startLocation.y};

    l_vec.x = (l_vec.x / _size.width   - 0.5) * 2.0;

    l_vec.y = (l_vec.y / _size.height  - 0.5) * 2.0;

    if (vector_length_squared(l_vec) > 1)

        l_vec = vector_normalize(l_vec);

    location.x = l_vec.x;

    location.y = l_vec.y;

    self.stickPosition = location;

}

- (void)resetInteraction {

    self.stickPosition = CGPointZero;

    _trackingTouch = nil;

    _startLocation = CGPointZero;

    if ([self.delegate respondsToSelector:@selector(padOverlayVirtualStickInteractionDidEnd:)]) {

        [self.delegate padOverlayVirtualStickInteractionDidEnd:self];

    }

}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {

    _trackingTouch = [touches anyObject];

    _startLocation = [_trackingTouch locationInNode:self];

    // Center start location

    _startLocation.x -= _size.width / 2.0;

    _startLocation.y -= _size.height / 2.0;

    [self updateStickPositionForTouchLocation:[_trackingTouch locationInNode:self]];

    if ([self.delegate respondsToSelector:@selector(padOverlayVirtualStickInteractionDidStart:)]) {

        [self.delegate padOverlayVirtualStickInteractionDidStart:self];

    }

}

- (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {

    if ([touches containsObject:_trackingTouch]) {

        [self updateStickPositionForTouchLocation:[_trackingTouch locationInNode:self]];

        if ([self.delegate respondsToSelector:@selector(padOverlayVirtualStickInteractionDidChange:)]) {

            [self.delegate padOverlayVirtualStickInteractionDidChange:self];

        }

    }

}

- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {

    if ([touches containsObject:_trackingTouch]) {

        [self resetInteraction];

    }

}

- (void)touchesCancelled:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event {

    if ([touches containsObject:_trackingTouch]) {

        [self resetInteraction];

    }

}

@end