/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#import <XCTest/XCTest.h>

#import "OCMock/OCMock.h"

#import <React/RCTNativeAnimatedNodesManager.h>
#import <React/RCTValueAnimatedNode.h>
#import <React/RCTUIManager.h>

static const NSTimeInterval FRAME_LENGTH = 1.0 / 60.0;

@interface RCTFakeDisplayLink : CADisplayLink

@end

@implementation RCTFakeDisplayLink
{
  NSTimeInterval _timestamp;
}

- (instancetype)init
{
  self = [super init];
  if (self) {
    _timestamp = 1124.1234143251; // Random
  }
  return self;
}

- (NSTimeInterval)timestamp
{
  _timestamp += FRAME_LENGTH;
  return _timestamp;
}

@end

@interface RCTFakeValueObserver : NSObject<RCTValueAnimatedNodeObserver>

@property (nonatomic, strong) NSMutableArray<NSNumber *> *calls;

@end

@implementation RCTFakeValueObserver

- (instancetype)init
{
  self = [super init];
  if (self) {
    _calls = [NSMutableArray new];
  }
  return self;
}

- (void)animatedNode:(__unused RCTValueAnimatedNode *)node didUpdateValue:(CGFloat)value
{
  [_calls addObject:@(value)];
}

@end

@interface RCTFakeEvent : NSObject<RCTEvent>

@end

@implementation RCTFakeEvent
{
  NSArray *_arguments;
}

@synthesize eventName = _eventName;
@synthesize viewTag = _viewTag;
@synthesize coalescingKey = _coalescingKey;

- (instancetype)initWithName:(NSString *)name viewTag:(NSNumber *)viewTag arguments:(NSArray *)arguments
{
  self = [super init];
  if (self) {
    _eventName = name;
    _viewTag = viewTag;
    _arguments = arguments;
  }
  return self;
}

- (NSArray *)arguments
{
  return _arguments;
}

RCT_NOT_IMPLEMENTED(+ (NSString *)moduleDotMethod);
RCT_NOT_IMPLEMENTED(- (BOOL)canCoalesce);
RCT_NOT_IMPLEMENTED(- (id<RCTEvent>)coalesceWithEvent:(id<RCTEvent>)newEvent);

@end

static id RCTPropChecker(NSString *prop, NSNumber *value)
{
  return [OCMArg checkWithBlock:^BOOL(NSDictionary<NSString *, NSNumber *> *props) {
    BOOL match = fabs(props[prop].doubleValue - value.doubleValue) < FLT_EPSILON;
    if (!match) {
      NSLog(@"Props `%@` with value `%@` is not close to `%@`", prop, props[prop], value);
    }
    return match;
  }];
}

@interface RCTNativeAnimatedNodesManagerTests : XCTestCase

@end

@implementation RCTNativeAnimatedNodesManagerTests
{
  id _uiManager;
  RCTNativeAnimatedNodesManager *_nodesManager;
  RCTFakeDisplayLink *_displayLink;
}

- (void)setUp
{
  [super setUp];

  RCTBridge *bridge = [OCMockObject niceMockForClass:[RCTBridge class]];
  _uiManager = [OCMockObject niceMockForClass:[RCTUIManager class]];
  OCMStub([bridge uiManager]).andReturn(_uiManager);
  _nodesManager = [[RCTNativeAnimatedNodesManager alloc] initWithBridge:bridge surfacePresenter:bridge.surfacePresenter];
  _displayLink = [RCTFakeDisplayLink new];
}

/**
 * Generates a simple animated nodes graph and attaches the props node to a given viewTag
 * Parameter opacity is used as a initial value for the "opacity" attribute.
 *
 * Nodes are connected as follows (nodes IDs in parens):
 * ValueNode(1) -> StyleNode(3) -> PropNode(5)
 */
- (void)createSimpleAnimatedView:(NSNumber *)viewTag withOpacity:(CGFloat)opacity
{
  [_nodesManager createAnimatedNode:@101
                             config:@{@"type": @"value", @"value": @(opacity), @"offset": @0}];
  [_nodesManager createAnimatedNode:@201
                             config:@{@"type": @"style", @"style": @{@"opacity": @101}}];
  [_nodesManager createAnimatedNode:@301
                             config:@{@"type": @"props", @"props": @{@"style": @201}}];

  [_nodesManager connectAnimatedNodes:@101 childTag:@201];
  [_nodesManager connectAnimatedNodes:@201 childTag:@301];
  [_nodesManager connectAnimatedNodeToView:@301 viewTag:viewTag viewName:@"UIView"];
}

- (void)testFramesAnimation
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1}
                        endCallback:nil];

  for (NSNumber *frame in frames) {
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"opacity", frame)];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"opacity", @1)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testFramesAnimationLoop
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1, @"iterations": @5}
                        endCallback:nil];

  for (NSUInteger it = 0; it < 5; it++) {
    for (NSNumber *frame in frames) {
      [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                    viewName:@"UIView"
                                                       props:RCTPropChecker(@"opacity", frame)];
      [_nodesManager stepAnimations:_displayLink];
      [_uiManager verify];
    }
  }

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"opacity", @1)];

  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testNodeValueListenerIfNotListening
{
  NSNumber *nodeId = @101;
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];

  RCTFakeValueObserver *observer = [RCTFakeValueObserver new];
  [_nodesManager startListeningToAnimatedNodeValue:nodeId valueObserver:observer];

  [_nodesManager startAnimatingNode:@1
                            nodeTag:nodeId
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1}
                        endCallback:nil];

  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(observer.calls.count, 1UL);
  XCTAssertEqualObjects(observer.calls[0], @0);

  [_nodesManager stopListeningToAnimatedNodeValue:nodeId];

  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(observer.calls.count, 1UL);
}

- (void)testNodeValueListenerIfListening
{
  NSNumber *nodeId = @101;
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];

  RCTFakeValueObserver *observer = [RCTFakeValueObserver new];
  [_nodesManager startListeningToAnimatedNodeValue:nodeId valueObserver:observer];

  [_nodesManager startAnimatingNode:@1
                            nodeTag:nodeId
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1}
                        endCallback:nil];

  for (NSUInteger i = 0; i < frames.count; i++) {
    [_nodesManager stepAnimations:_displayLink];
    XCTAssertEqual(observer.calls.count, i + 1);
    XCTAssertEqualWithAccuracy(observer.calls[i].doubleValue, frames[i].doubleValue, FLT_EPSILON);
  }

  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(observer.calls.count, 7UL);
  XCTAssertEqualObjects(observer.calls[6], @1);

  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(observer.calls.count, 7UL);
}

- (void)performSpringAnimationTestWithConfig:(NSDictionary*)config isCriticallyDamped:(BOOL)testForCriticallyDamped
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:config
                        endCallback:nil];

  BOOL wasGreaterThanOne = NO;
  CGFloat previousValue = 0;
  __block CGFloat currentValue;
  [[[_uiManager stub] andDo:^(NSInvocation *invocation) {
    __unsafe_unretained NSDictionary<NSString *, NSNumber *> *props;
    [invocation getArgument:&props atIndex:4];
    currentValue = props[@"opacity"].doubleValue;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  // Run for 3 seconds.
  for (NSUInteger i = 0; i < 3 * 60; i++) {
    [_nodesManager stepAnimations:_displayLink];

    if (currentValue > 1) {
      wasGreaterThanOne = YES;
    }

    // Verify that animation step is relatively small.
    XCTAssertLessThan(fabs(currentValue - previousValue), 0.12);

    previousValue = currentValue;
  }

  // Verify that we've reach the final value at the end of animation.
  XCTAssertEqual(previousValue, 1.0);

  // Verify that value has reached some maximum value that is greater than the final value (bounce).
  if (testForCriticallyDamped) {
    XCTAssertFalse(wasGreaterThanOne);
  } else {
    XCTAssertTrue(wasGreaterThanOne);
  }

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testUnderdampedSpringAnimation
{
  [self performSpringAnimationTestWithConfig:@{@"type": @"spring",
                                               @"stiffness": @230.3,
                                               @"damping": @22,
                                               @"mass": @1,
                                               @"initialVelocity": @0,
                                               @"toValue": @1,
                                               @"restSpeedThreshold": @0.001,
                                               @"restDisplacementThreshold": @0.001,
                                               @"overshootClamping": @NO}
                          isCriticallyDamped:NO];
}

- (void)testCritcallyDampedSpringAnimation
{
  [self performSpringAnimationTestWithConfig:@{@"type": @"spring",
                                               @"stiffness": @1000,
                                               @"damping": @500,
                                               @"mass": @3,
                                               @"initialVelocity": @0,
                                               @"toValue": @1,
                                               @"restSpeedThreshold": @0.001,
                                               @"restDisplacementThreshold": @0.001,
                                               @"overshootClamping": @NO}
                          isCriticallyDamped:YES];
}

- (void)testDecayAnimation
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"decay",
                                      @"velocity": @0.5,
                                      @"deceleration": @0.998}
                        endCallback:nil];


  __block CGFloat previousValue;
  __block CGFloat currentValue;
  CGFloat previousDiff = CGFLOAT_MAX;

  [_nodesManager stepAnimations:_displayLink];

  [[[_uiManager stub] andDo:^(NSInvocation *invocation) {
    __unsafe_unretained NSDictionary<NSString *, NSNumber *> *props;
    [invocation getArgument:&props atIndex:4];
    currentValue = props[@"opacity"].doubleValue;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  // Run 3 secs of animation.
  for (NSUInteger i = 0; i < 3 * 60; i++) {
    [_nodesManager stepAnimations:_displayLink];
    CGFloat currentDiff = currentValue - previousValue;
    // Verify monotonicity.
    // Greater *or equal* because the animation stops during these 3 seconds.
    XCTAssertGreaterThanOrEqual(currentValue, previousValue);
    // Verify decay.
    XCTAssertLessThanOrEqual(currentDiff, previousDiff);
    previousValue = currentValue;
    previousDiff = currentDiff;
  }

  // Should be done in 3 secs.
  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testDecayAnimationLoop
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"decay",
                                      @"velocity": @0.5,
                                      @"deceleration": @0.998,
                                      @"iterations": @5}
                        endCallback:nil];


  __block CGFloat previousValue;
  __block CGFloat currentValue;
  BOOL didComeToRest = NO;
  NSUInteger numberOfResets = 0;

  [[[_uiManager stub] andDo:^(NSInvocation *invocation) {
    __unsafe_unretained NSDictionary<NSString *, NSNumber *> *props;
    [invocation getArgument:&props atIndex:4];
    currentValue = props[@"opacity"].doubleValue;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  // Run 3 secs of animation five times.
  for (NSUInteger i = 0; i < 3 * 60 * 5; i++) {
    [_nodesManager stepAnimations:_displayLink];

    // Verify monotonicity when not resetting the animation.
    // Greater *or equal* because the animation stops during these 3 seconds.
    if (!didComeToRest) {
      XCTAssertGreaterThanOrEqual(currentValue, previousValue);
    }

    if (didComeToRest && currentValue != previousValue) {
      numberOfResets++;
      didComeToRest = NO;
    }

    // Test if animation has come to rest using the 0.1 threshold from DecayAnimation.m.
    didComeToRest = fabs(currentValue - previousValue) < 0.1;
    previousValue = currentValue;
  }

  // The animation should have reset 4 times.
  XCTAssertEqual(numberOfResets, 4u);

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testSpringAnimationLoop
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"spring",
                                      @"iterations": @5,
                                      @"stiffness": @230.2,
                                      @"damping": @22,
                                      @"mass": @1,
                                      @"initialVelocity": @0,
                                      @"toValue": @1,
                                      @"restSpeedThreshold": @0.001,
                                      @"restDisplacementThreshold": @0.001,
                                      @"overshootClamping": @NO}
                        endCallback:nil];
  
  BOOL didComeToRest = NO;
  CGFloat previousValue = 0;
  NSUInteger numberOfResets = 0;
  __block CGFloat currentValue;
  [[[_uiManager stub] andDo:^(NSInvocation *invocation) {
    __unsafe_unretained NSDictionary<NSString *, NSNumber *> *props;
    [invocation getArgument:&props atIndex:4];
    currentValue = props[@"opacity"].doubleValue;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  
  // Run for 3 seconds five times.
  for (NSUInteger i = 0; i < 3 * 60 * 5; i++) {
    [_nodesManager stepAnimations:_displayLink];
    
    if (!didComeToRest) {
      // Verify that animation step is relatively small.
      XCTAssertLessThan(fabs(currentValue - previousValue), 0.12);
    }
    
    // Test to see if it reset after coming to rest
    if (didComeToRest && currentValue == 0) {
      didComeToRest = NO;
      numberOfResets++;
    }
    
    // Record that the animation did come to rest when it rests on toValue.
    didComeToRest = fabs(currentValue - 1) < 0.001 && fabs(currentValue - previousValue) < 0.001;
    
    previousValue = currentValue;
  }
  
  // Verify that value reset 4 times after finishing a full animation and is currently resting.
  XCTAssertEqual(numberOfResets, 4u);
  XCTAssertTrue(didComeToRest);
  
  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testAnimationCallbackFinish
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @1];

  __block NSInteger endCallbackCalls = 0;

  RCTResponseSenderBlock endCallback = ^(NSArray *response) {
    endCallbackCalls++;
    XCTAssertEqualObjects(response, @[@{@"finished": @YES}]);
  };

  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1}
                        endCallback:endCallback];

  [_nodesManager stepAnimations:_displayLink];
  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(endCallbackCalls, 0);
  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(endCallbackCalls, 1);
  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(endCallbackCalls, 1);
}

/**
 * Creates a following graph of nodes:
 * Value(1, firstValue) ----> Add(3) ---> Style(4) ---> Props(5) ---> View(viewTag)
 *                         |
 * Value(2, secondValue) --+
 *
 * Add(3) node maps to a "translateX" attribute of the Style(4) node.
 */
- (void)createAnimatedGraphWithAdditionNode:(NSNumber *)viewTag
                                 firstValue:(CGFloat)firstValue
                                secondValue:(CGFloat)secondValue
{
  [_nodesManager createAnimatedNode:@101
                             config:@{@"type": @"value", @"value": @(firstValue), @"offset": @0}];
  [_nodesManager createAnimatedNode:@201
                             config:@{@"type": @"value", @"value": @(secondValue), @"offset": @0}];
  [_nodesManager createAnimatedNode:@301
                             config:@{@"type": @"addition", @"input": @[@101, @201]}];
  [_nodesManager createAnimatedNode:@401
                             config:@{@"type": @"style", @"style": @{@"translateX": @301}}];
  [_nodesManager createAnimatedNode:@501
                             config:@{@"type": @"props", @"props": @{@"style": @401}}];

  [_nodesManager connectAnimatedNodes:@101 childTag:@301];
  [_nodesManager connectAnimatedNodes:@201 childTag:@301];
  [_nodesManager connectAnimatedNodes:@301 childTag:@401];
  [_nodesManager connectAnimatedNodes:@401 childTag:@501];
  [_nodesManager connectAnimatedNodeToView:@501 viewTag:viewTag viewName:@"UIView"];
}

- (void)testAdditionNode
{
  NSNumber *viewTag = @51;
  [self createAnimatedGraphWithAdditionNode:viewTag firstValue:100 secondValue:1000];

  NSArray<NSNumber *> *frames = @[@0, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @101}
                        endCallback:nil];
  [_nodesManager startAnimatingNode:@2
                            nodeTag:@201
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1010}
                        endCallback:nil];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1100)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1111)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1111)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

/**
 * Verifies that views are updated properly when one of the addition input nodes has started animating
 * while the other one has not.
 *
 * We expect that the output of the addition node will take the starting value of the second input
 * node even though the node hasn't been connected to an active animation driver.
 */
- (void)testViewReceiveUpdatesIfOneOfAnimationHasntStarted
{
  NSNumber *viewTag = @51;
  [self createAnimatedGraphWithAdditionNode:viewTag firstValue:100 secondValue:1000];

  NSArray<NSNumber *> *frames = @[@0, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @101}
                        endCallback:nil];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1100)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1101)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1101)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

/**
 * Verifies that views are updated properly when one of the addition input nodes animation finishes
 * before the other.
 *
 * We expect that the output of the addition node after one of the animation has finished will
 * take the last value of the animated node and the view will receive updates up until the second
 * animation is over.
 */
- (void)testViewReceiveUpdatesWhenOneOfAnimationHasFinished
{
  NSNumber *viewTag = @51;
  [self createAnimatedGraphWithAdditionNode:viewTag firstValue:100 secondValue:1000];

  NSArray<NSNumber *> *firstFrames = @[@0, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": firstFrames, @"toValue": @200}
                        endCallback:nil];
  NSArray<NSNumber *> *secondFrames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];
  [_nodesManager startAnimatingNode:@2
                            nodeTag:@201
                             config:@{@"type": @"frames", @"frames": secondFrames, @"toValue": @1010}
                        endCallback:nil];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1100)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  for (NSUInteger i = 1; i < secondFrames.count; i++) {
    CGFloat expected = 1200.0 + secondFrames[i].doubleValue * 10.0;
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"translateX", @(expected))];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @1210)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testMultiplicationNode
{
  NSNumber *viewTag = @51;
  [_nodesManager createAnimatedNode:@101
                             config:@{@"type": @"value", @"value": @1, @"offset": @0}];
  [_nodesManager createAnimatedNode:@201
                             config:@{@"type": @"value", @"value": @5, @"offset": @0}];
  [_nodesManager createAnimatedNode:@301
                             config:@{@"type": @"multiplication", @"input": @[@101, @201]}];
  [_nodesManager createAnimatedNode:@401
                             config:@{@"type": @"style", @"style": @{@"translateX": @301}}];
  [_nodesManager createAnimatedNode:@501
                             config:@{@"type": @"props", @"props": @{@"style": @401}}];

  [_nodesManager connectAnimatedNodes:@101 childTag:@301];
  [_nodesManager connectAnimatedNodes:@201 childTag:@301];
  [_nodesManager connectAnimatedNodes:@301 childTag:@401];
  [_nodesManager connectAnimatedNodes:@401 childTag:@501];
  [_nodesManager connectAnimatedNodeToView:@501 viewTag:viewTag viewName:@"UIView"];

  NSArray<NSNumber *> *frames = @[@0, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @2}
                        endCallback:nil];
  [_nodesManager startAnimatingNode:@2
                            nodeTag:@201
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @10}
                        endCallback:nil];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @5)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @20)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", @20)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testHandleStoppingAnimation
{
  [self createSimpleAnimatedView:@1001 withOpacity:0];
  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];

  __block BOOL endCallbackCalled = NO;

  RCTResponseSenderBlock endCallback = ^(NSArray *response) {
    endCallbackCalled = YES;
    XCTAssertEqualObjects(response, @[@{@"finished": @NO}]);
  };

  [_nodesManager startAnimatingNode:@404
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @1}
                        endCallback:endCallback];

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  [_nodesManager stopAnimation:@404];
  XCTAssertEqual(endCallbackCalled, YES);

  // Run "update" loop a few more times -> we expect no further updates nor callback calls to be
  // triggered
  for (NSUInteger i = 0; i < 5; i++) {
    [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }
}

- (void)testInterpolationNode
{
  NSNumber *viewTag = @51;
  [_nodesManager createAnimatedNode:@101
                             config:@{@"type": @"value", @"value": @10, @"offset": @0}];
  [_nodesManager createAnimatedNode:@201
                             config:@{@"type": @"interpolation",
                                      @"inputRange": @[@10, @20],
                                      @"outputRange": @[@0, @1],
                                      @"extrapolateLeft": @"extend",
                                      @"extrapolateRight": @"extend"}];
  [_nodesManager createAnimatedNode:@301
                             config:@{@"type": @"style", @"style": @{@"opacity": @201}}];
  [_nodesManager createAnimatedNode:@401
                             config:@{@"type": @"props", @"props": @{@"style": @301}}];

  [_nodesManager connectAnimatedNodes:@101 childTag:@201];
  [_nodesManager connectAnimatedNodes:@201 childTag:@301];
  [_nodesManager connectAnimatedNodes:@301 childTag:@401];
  [_nodesManager connectAnimatedNodeToView:@401 viewTag:viewTag viewName:@"UIView"];

  NSArray<NSNumber *> *frames = @[@0, @0.2, @0.4, @0.6, @0.8, @1];
  [_nodesManager startAnimatingNode:@1
                            nodeTag:@101
                             config:@{@"type": @"frames", @"frames": frames, @"toValue": @20}
                        endCallback:nil];

  for (NSNumber *frame in frames) {
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"opacity", frame)];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"opacity", @1)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];


  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (id<RCTEvent>)createScrollEventWithTag:(NSNumber *)viewTag value:(CGFloat)value
{
  // The event value is the 3rd argument.
  NSArray *arguments = @[@1, @1, @{@"contentOffset": @{@"y": @(value)}}];
  return [[RCTFakeEvent alloc] initWithName:@"topScroll"
                                    viewTag:viewTag
                                  arguments:arguments];
}

- (void)testNativeAnimatedEventDoUpdate
{
  NSNumber *viewTag = @1001;
  [self createSimpleAnimatedView:viewTag withOpacity:0];

  [_nodesManager addAnimatedEventToView:viewTag
                              eventName:@"topScroll"
                           eventMapping:@{@"animatedValueTag": @101,
                                          @"nativeEventPath": @[@"contentOffset", @"y"]}];



  // Make sure that the update actually happened synchronously in `handleAnimatedEvent` and does
  // not wait for the next animation loop.
  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:viewTag
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"opacity", @10)];
  [_nodesManager handleAnimatedEvent:[self createScrollEventWithTag:viewTag value:10]];
  [_uiManager verify];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

- (void)testNativeAnimatedEventDoNotUpdate
{
  NSNumber *viewTag = @1001;
  [self createSimpleAnimatedView:viewTag withOpacity:0];

  [_nodesManager addAnimatedEventToView:viewTag
                              eventName:@"otherEvent"
                           eventMapping:@{@"animatedValueTag": @101,
                                          @"nativeEventPath": @[@"contentOffset", @"y"]}];

  [_nodesManager addAnimatedEventToView:@999
                              eventName:@"topScroll"
                           eventMapping:@{@"animatedValueTag": @101,
                                          @"nativeEventPath": @[@"contentOffset", @"y"]}];

  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager handleAnimatedEvent:[self createScrollEventWithTag:viewTag value:10]];
  [_uiManager verify];
}

- (void) testGetValue
{
  __block NSInteger saveValueCallbackCalls = 0;
  NSNumber *nodeTag = @100;
  [_nodesManager createAnimatedNode:nodeTag
                             config:@{@"type": @"value", @"value": @1, @"offset": @0}];
  RCTResponseSenderBlock saveValueCallback = ^(NSArray *response) {
    saveValueCallbackCalls++;
    XCTAssertEqualObjects(response, @[@1]);
  };
  
  XCTAssertEqual(saveValueCallbackCalls, 0);
  
  [_nodesManager getValue:nodeTag saveCallback:saveValueCallback];
  XCTAssertEqual(saveValueCallbackCalls, 1);
}

/**
 * Creates a following graph of nodes:
 * Value(3, initialValue) ----> Style(4) ---> Props(5) ---> View(viewTag)
 *
 * Value(3) is set to track Value(1) via Tracking(2) node with the provided animation config
 */
- (void)createAnimatedGraphWithTrackingNode:(NSNumber *)viewTag
                               initialValue:(CGFloat)initialValue
                            animationConfig:(NSDictionary *)animationConfig
{
  [_nodesManager createAnimatedNode:@101
                             config:@{@"type": @"value", @"value": @(initialValue), @"offset": @0}];
  [_nodesManager createAnimatedNode:@301
                             config:@{@"type": @"value", @"value": @(initialValue), @"offset": @0}];

  [_nodesManager createAnimatedNode:@201
                             config:@{@"type": @"tracking",
                                      @"animationId": @70,
                                      @"value": @301,
                                      @"toValue": @101,
                                      @"animationConfig": animationConfig}];
  [_nodesManager createAnimatedNode:@401
                             config:@{@"type": @"style", @"style": @{@"translateX": @301}}];
  [_nodesManager createAnimatedNode:@501
                             config:@{@"type": @"props", @"props": @{@"style": @401}}];

  [_nodesManager connectAnimatedNodes:@101 childTag:@201];
  [_nodesManager connectAnimatedNodes:@301 childTag:@401];
  [_nodesManager connectAnimatedNodes:@401 childTag:@501];
  [_nodesManager connectAnimatedNodeToView:@501 viewTag:viewTag viewName:@"UIView"];
}

/**
 * In this test we verify that when value is being tracked we can update destination value in the
 * middle of ongoing animation and the animation will update and animate to the new spot. This is
 * tested using simple 5 frame backed timing animation.
 */
- (void)testTracking
{
  NSArray *frames = @[@0, @0.25, @0.5, @0.75, @1];
  NSDictionary *animationConfig = @{@"type": @"frames", @"frames": frames};
  [self createAnimatedGraphWithTrackingNode:@1001 initialValue:0 animationConfig:animationConfig];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                viewName:@"UIView"
                                                   props:RCTPropChecker(@"translateX", 0)];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  // update "toValue" to 100, we expect tracking animation to animate now from 0 to 100 in 5 steps
  [_nodesManager setAnimatedNodeValue:@101 value:@100];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  for (NSNumber *frame in frames) {
    NSNumber *expected = @([frame doubleValue] * 100);
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"translateX", expected)];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  // update "toValue" to 0 but run only two frames from the animation,
  // we expect tracking animation to animate now from 100 to 75
  [_nodesManager setAnimatedNodeValue:@101 value:@0];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  for (int i = 0; i < 2; i++) {
    NSNumber *expected = @(100. * (1. - [frames[i] doubleValue]));
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"translateX", expected)];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  // at this point we expect tracking value to be at 75
  // we update "toValue" again to 100 and expect the animation to restart from the current place
  [_nodesManager setAnimatedNodeValue:@101 value:@100];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  for (NSNumber *frame in frames) {
    NSNumber *expected = @(50. + 50. * [frame doubleValue]);
    [[_uiManager expect] synchronouslyUpdateViewOnUIThread:@1001
                                                  viewName:@"UIView"
                                                     props:RCTPropChecker(@"translateX", expected)];
    [_nodesManager stepAnimations:_displayLink];
    [_uiManager verify];
  }

  [_nodesManager stepAnimations:_displayLink];
  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

/**
 * In this test we verify that when tracking is set up for a given animated node and when the
 * animation settles it will not be registered as an active animation and therefore will not
 * consume resources on running the animation that has already completed. Then we verify that when
 * the value updates the animation will resume as expected and the complete again when reaches the
 * end.
 */

 - (void)testTrackingPausesWhenEndValueIsReached
{
  NSArray *frames = @[@0, @0.5, @1];
  NSDictionary *animationConfig = @{@"type": @"frames", @"frames": frames};
  [self createAnimatedGraphWithTrackingNode:@1001 initialValue:0 animationConfig:animationConfig];

  [_nodesManager setAnimatedNodeValue:@101 value:@100];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  __block int callCount = 0;
  [[[_uiManager stub] andDo:^(NSInvocation* __unused invocation) {
    callCount++;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  for (NSUInteger i = 0; i < frames.count; i++) {
    [_nodesManager stepAnimations:_displayLink];
  }
  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(callCount, 4);

  // the animation has completed, we expect no updates to be done
  [[[_uiManager stub] andDo:^(NSInvocation* __unused invocation) {
    XCTFail("Expected not to be called");
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];

  // restore rejected method, we will use it later on
  callCount = 0;
  [[[_uiManager stub] andDo:^(NSInvocation* __unused invocation) {
    callCount++;
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  // we update end value and expect the animation to restart
  [_nodesManager setAnimatedNodeValue:@101 value:@200];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  for (NSUInteger i = 0; i < frames.count; i++) {
    [_nodesManager stepAnimations:_displayLink];
  }
  [_nodesManager stepAnimations:_displayLink];
  XCTAssertEqual(callCount, 4);

  // the animation has completed, we expect no updates to be done
  [[_uiManager reject] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];
  [_nodesManager stepAnimations:_displayLink];
  [_uiManager verify];
}

/**
 * In this test we verify that when tracking is configured to use spring animation and when the
 * destination value updates the current speed of the animated value will be taken into account
 * while updating the spring animation and it will smoothly transition to the new end value.
 */
- (void) testSpringTrackingRetainsSpeed
{
  // this spring config corresponds to tension 20 and friction 0.5 which makes the spring settle
  // very slowly
  NSDictionary *springConfig = @{@"type": @"spring",
                                 @"restSpeedThreshold": @0.001,
                                 @"mass": @1,
                                 @"restDisplacementThreshold": @0.001,
                                 @"initialVelocity": @0.5,
                                 @"damping": @2.5,
                                 @"stiffness": @157.8,
                                 @"overshootClamping": @NO};
  [self createAnimatedGraphWithTrackingNode:@1001 initialValue:0 animationConfig:springConfig];

  __block CGFloat lastTranslateX = 0;
  [[[_uiManager stub] andDo:^(NSInvocation *invocation) {
    __unsafe_unretained NSDictionary *props = nil;
    [invocation getArgument:&props atIndex:4];
    lastTranslateX = [props[@"translateX"] doubleValue];
  }] synchronouslyUpdateViewOnUIThread:OCMOCK_ANY viewName:OCMOCK_ANY props:OCMOCK_ANY];

  // update "toValue" to 1, we expect tracking animation to animate now from 0 to 1
  [_nodesManager setAnimatedNodeValue:@101 value:@1];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  // we run several steps of animation until the value starts bouncing, has negative speed and
  // passes the final point (that is 1) while going backwards
  BOOL isBoucingBack = NO;
  CGFloat previousValue = 0;
  for (int maxFrames = 500; maxFrames > 0; maxFrames--) {
    [_nodesManager stepAnimations:_displayLink]; // kick off the tracking
    if (previousValue >= 1. && lastTranslateX < 1.) {
      isBoucingBack = YES;
      break;
    }
    previousValue = lastTranslateX;
  }
  XCTAssert(isBoucingBack);

  // we now update "toValue" to 1.5 but since the value have negative speed and has also pretty
  // low friction we expect it to keep going in the opposite direction for a few more frames
  [_nodesManager setAnimatedNodeValue:@101 value:@1.5];
  [_nodesManager stepAnimations:_displayLink]; // kick off the tracking

  int bounceBackInitialFrames = 0;
  BOOL hasTurnedForward = NO;

  // we run 8 seconds of animation
  for (int i = 0; i < 8 * 60; i++) {
    [_nodesManager stepAnimations:_displayLink];
    if (!hasTurnedForward) {
      if (lastTranslateX <= previousValue) {
        bounceBackInitialFrames++;
      } else {
        hasTurnedForward = true;
      }
    }
    previousValue = lastTranslateX;
  }
  XCTAssert(hasTurnedForward);
  XCTAssertGreaterThan(bounceBackInitialFrames, 3);
  XCTAssertEqual(lastTranslateX, 1.5);
}

@end