/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Demonstrates alignment behavior. Click (OS X) or touch (iOS) and drag; the white agent follows the mouse/touch location, and the cyan agents maintain the same heading as the white agent whenever the white agent is near.

 */

#import "AAPLAlignScene.h"

#import "AAPLAgentNode.h"

@interface AAPLAlignScene ()

@property AAPLAgentNode *player;

@property NSArray<AAPLAgentNode *> *friends;

@property GKGoal *alignGoal;

@property GKGoal *seekGoal;

@end

@implementation AAPLAlignScene

- (NSString *)sceneName {

    return @"ALIGNMENT";

}

- (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),

                                                                   CGRectGetMidY(self.frame))];

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

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

    self.player.agent.maxSpeed *= 1.2;

    // Create the seek goal, but add it to the behavior only in -setSeeking:.

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

    // The friend agents attempt to maintain consistent direction with the player agent.

    self.alignGoal = [GKGoal goalToAlignWithAgents:@[self.player.agent] maxDistance:100 maxAngle:M_PI*2];

    GKBehavior *behavior = [GKBehavior behaviorWithGoal:self.alignGoal weight:100];

    self.friends = @[

                     [self addFriendAtPoint:CGPointMake(CGRectGetMidX(self.frame) - 150, CGRectGetMidY(self.frame))],

                     [self addFriendAtPoint:CGPointMake(CGRectGetMidX(self.frame) + 150, CGRectGetMidY(self.frame))],

                     ];

    for (AAPLAgentNode *friend in self.friends) {

        friend.agent.behavior = behavior;

    }

}

- (AAPLAgentNode *)addFriendAtPoint:(CGPoint)point {

    AAPLAgentNode *friend = [[AAPLAgentNode alloc] initWithScene:self

                                                          radius:AAPLDefaultAgentRadius

                                                        position:point];

    friend.color = [SKColor cyanColor];

    [self.agentSystem addComponent:friend.agent];

    return friend;

}

- (void)setSeeking:(BOOL)seeking {

    [super setSeeking:seeking];

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

    for (GKAgent2D *agent in self.agentSystem) {

        if (seeking) {

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

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

        } 

        else {

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

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

        }

    }

}

@end