/*

    Copyright (C) 2015 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Demonstrates flee behavior. Click (OS X) or touch (iOS) and drag; the white agent follows the mouse/touch location, and the red agent avoids the white agent.

 */

#import "AAPLFleeScene.h"

#import "AAPLAgentNode.h"

@interface AAPLFleeScene ()

@property AAPLAgentNode *player;

@property AAPLAgentNode *enemy;

@property GKGoal *seekGoal;

@property GKGoal *fleeGoal;

@property (nonatomic) BOOL fleeing;

@end

@implementation AAPLFleeScene

- (NSString *)sceneName {

    return @"FLEEING";

}

- (void)didMoveToView:(nonnull SKView *)view {

    [super didMoveToView:view];

    // The player agent follows the tracking agent.

    self.player = [[AAPLAgentNode alloc] initWithScene:self

                                                radius:AAPLDefaultAgentRadius

                                              position:CGPointMake(CGRectGetMidX(self.frame) - 150,

                                                                   CGRectGetMidY(self.frame))];

    self.player.agent.behavior = [[GKBehavior alloc] init];

    [self.agentSystem addComponent:self.player.agent];

    // The enemy agent flees from the player agent.

    self.enemy = [[AAPLAgentNode alloc] initWithScene:self

                                               radius:AAPLDefaultAgentRadius

                                             position:CGPointMake(CGRectGetMidX(self.frame) + 150,

                                                                  CGRectGetMidY(self.frame))];

    self.enemy.color = [SKColor redColor];

    self.enemy.agent.behavior = [[GKBehavior alloc] init];

    [self.agentSystem addComponent:self.enemy.agent];

    // Create seek and flee goals, but add them to the agents' behaviors only in -setSeeking: / -setFleeing:.

    self.seekGoal = [GKGoal goalToSeekAgent:self.trackingAgent];

    self.fleeGoal = [GKGoal goalToFleeAgent:self.player.agent];

}

- (void)setSeeking:(BOOL)seeking {

    [super setSeeking:seeking];

    // Switch between enabling seek and stop goals so that the agent stops when not seeking.

    if (seeking) {

        [self.player.agent.behavior setWeight:1 forGoal:self.seekGoal];

        [self.player.agent.behavior setWeight:0 forGoal:self.stopGoal];

    }

    else {

        [self.player.agent.behavior setWeight:0 forGoal:self.seekGoal];

        [self.player.agent.behavior setWeight:1 forGoal:self.stopGoal];

    }

}

- (void)setFleeing:(BOOL)fleeing {

    _fleeing = fleeing;

    // Switch between enabling flee and stop goals so that the agent stops when not fleeing.

    if (fleeing) {

        [self.enemy.agent.behavior setWeight:1 forGoal:self.fleeGoal];

        [self.enemy.agent.behavior setWeight:0 forGoal:self.stopGoal];

    }

    else {

        [self.enemy.agent.behavior setWeight:0 forGoal:self.fleeGoal];

        [self.enemy.agent.behavior setWeight:1 forGoal:self.stopGoal];

    }

}

- (void)update:(NSTimeInterval)currentTime {

    float distance = vector_distance(self.player.agent.position, self.enemy.agent.position);

    const static float maxDistance = 200.0;

    self.fleeing = distance < maxDistance;

    [super update:currentTime];

}

@end