Code viewer for World: Practical 1: Darragh McGon...
// Clicked Clone and edit on my already cloned world by mistake
// Cloned by Darragh McG on 2 Nov 2023 from World "Practical 1: Darragh McGonigle - A* - Complex World" by Darragh McG 
// Please leave this clone trail here.
 


// Cloned by Darragh McG on 31 Oct 2023 from World "Complex World" by Starter user 
// Please leave this clone trail here.
 



// ==== Starter World =================================================================================================
// This code is designed for use on the Ancient Brain site.
// This code may be freely copied and edited by anyone on the Ancient Brain site.
// To include a working run of this program on another site, see the "Embed code" links provided on Ancient Brain.
// ====================================================================================================================



// =============================================================================================
// More complex starter World 
// 3d-effect Maze World (really a 2-D problem)
// Movement is on a semi-visible grid of squares 
//
// This more complex World shows:
// - Skybox
// - Internal maze (randomly drawn each time)
// - Enemy actively chases agent
// - Music/audio
// - 2D world (clone this and set show3d = false)
// - User keyboard control (clone this and comment out Mind actions to see)
// =============================================================================================


// =============================================================================================
// Scoring:
// Bad steps = steps where enemy is within one step of agent.
// Good steps = steps where enemy is further away. 
// Score = good steps as percentage of all steps.
//
// There are situations where agent is trapped and cannot move.
// If this happens, you score zero.
// =============================================================================================


 





// ===================================================================================================================
// === Start of tweaker's box ======================================================================================== 
// ===================================================================================================================

// The easiest things to modify are in this box.
// You should be able to change things in this box without being a JavaScript programmer.
// Go ahead and change some of these. What's the worst that could happen?


AB.clockTick       = 100;    

	// Speed of run: Step every n milliseconds. Default 100.
	
AB.maxSteps        = 1000;    

	// Length of run: Maximum length of run in steps. Default 1000.

AB.screenshotStep  = 50;   
  
	// Take screenshot on this step. (All resources should have finished loading.) Default 50.



//---- global constants: -------------------------------------------------------

	const show3d = false;						// Switch between 3d and 2d view (both using Three.js) 

 // Darragh - Changed Textures
//  ----------------------------------------------------------------------------
 const TEXTURE_WALL 	= '/uploads/darraghmcg/wall.png' ;
 const TEXTURE_MAZE 	= '/uploads/darraghmcg/wall.png' ;
 // Pacman image credit https://upload.wikimedia.org/wikipedia/commons/thumb/1/1a/Original_PacMan.svg/800px-Original_PacMan.svg.png
 const TEXTURE_AGENT 	= '/uploads/darraghmcg/packman1.png' ;
 // Enemy ghoat image credit https://i.pinimg.com/736x/05/05/ce/0505cea3c74abd202c39969568803da2.jpg
 const TEXTURE_ENEMY 	= {
     0: '/uploads/darraghmcg/ghost1.png',
     1: '/uploads/darraghmcg/ghost2.png',
     2: '/uploads/darraghmcg/ghost3.png',
     3: '/uploads/darraghmcg/ghost4.png',
     4: '/uploads/darraghmcg/ghost5.png'
 } ;
 const TEXTURE_SEARCHPATH = '/uploads/darraghmcg/searchpathtext.png';
//  ----------------------------------------------------------------------------

// credits:
// https://commons.wikimedia.org/wiki/Category:Pac-Man_icons
// https://commons.wikimedia.org/wiki/Category:Skull_and_crossbone_icons

 
	const MUSIC_BACK  = '/uploads/starter/Defense.Line.mp3' ;
	const SOUND_ALARM = '/uploads/starter/air.horn.mp3' ;

// credits:
// http://www.dl-sounds.com/royalty-free/defense-line/
// http://soundbible.com/1542-Air-Horn.html 

	
	
const gridsize = 40; // 20;						// number of squares along side of world	   

const NOBOXES =  Math.trunc ( (gridsize * gridsize) / 4 );  // 10
		// density of maze - number of internal boxes
		// (bug) use trunc or can get a non-integer 

const squaresize = 100;					// size of square in pixels

const MAXPOS = gridsize * squaresize;		// length of one side in pixels 
	
const SKYCOLOR 	= 0xddffdd;				// a number, not a string 

 
const startRadiusConst	 	= MAXPOS * 0.8 ;		// distance from centre to start the camera at
const maxRadiusConst 		= MAXPOS * 10  ;		// maximum distance from camera we will render things  



//--- change ABWorld defaults: -------------------------------

ABHandler.MAXCAMERAPOS 	= maxRadiusConst ;

ABHandler.GROUNDZERO		= true;						// "ground" exists at altitude zero



//--- skybox: -------------------------------
// skybox is a collection of 6 files 
// x,y,z positive and negative faces have to be in certain order in the array 
// https://threejs.org/docs/#api/en/loaders/CubeTextureLoader 

// Darragh - Changed Skybox
// space skybox, credit:
// https://opengameart.org/content/space-skyboxes-0
//  ----------------------------------------------------------------------------
 const SKYBOX_ARRAY = [										 
                "/uploads/darraghmcg/bkg1_right.png",
                "/uploads/darraghmcg/bkg1_left.png",
                "/uploads/darraghmcg/bkg1_top.png",
                "/uploads/darraghmcg/bkg1_bot.png",
                "/uploads/darraghmcg/bkg1_front.png",
                "/uploads/darraghmcg/bkg1_back.png"
                ];
//  ----------------------------------------------------------------------------

// Darragh - Tweaker Select Movement Pattern
// 0 - AStar
// 1 - BFS
// 2 - Naive
// 3 - AStar Longest Path
// 4 - AStar Achilles
//  ----------------------------------------------------------------------------
const MOVEMENT_PATTERN = 0;
//  ----------------------------------------------------------------------------

// ===================================================================================================================
// === End of tweaker's box ==========================================================================================
// ===================================================================================================================


// You will need to be some sort of JavaScript programmer to change things below the tweaker's box.









//--- Mind can pick one of these actions -----------------

const ACTION_LEFT 			= 0;		   
const ACTION_RIGHT 			= 1;
const ACTION_UP 			= 2;		 
const ACTION_DOWN 			= 3;
const ACTION_STAYSTILL 		= 4;

// in initial view, (smaller-larger) on i axis is aligned with (left-right)
// in initial view, (smaller-larger) on j axis is aligned with (away from you - towards you)


// contents of a grid square

const GRID_BLANK 	= 0;
const GRID_WALL 	= 1;
const GRID_MAZE 	= 2;
 
 
 
 

var BOXHEIGHT;		// 3d or 2d box height 

var GRID 	= new Array(gridsize);			// can query GRID about whether squares are occupied, will in fact be initialised as a 2D array   

// Darragh - Added board variable to store game state
//  ----------------------------------------------------------------------------
let BOARD = new Array(gridsize);
//  ----------------------------------------------------------------------------

var theagent, theenemy;
 
 // Darragh - Added search path texture for search path blocks
//  ----------------------------------------------------------------------------
var wall_texture, agent_texture, enemy_texture, maze_texture, searchpath_texture;
//  ----------------------------------------------------------------------------


// enemy and agent position on squares
var ei, ej, ai, aj;

var badsteps;
var goodsteps;

// Darragh - Added varibles to store the starting points of the enemy and the agent for analysis
let enemy_start;
let agent_start;
//Track if the enemy is using the achilles movemnet pattern if they performed recalculations this step
//Darragh - Variables to store most recent eval time and count
//  ----------------------------------------------------------------------------
let enemyEvalTime = 0;
let enemyEvalCount = 0;
let achillesRecomp = false;
//  ----------------------------------------------------------------------------
	
function loadResources()		// asynchronous file loads - call initScene() when all finished 
{
	var loader1 = new THREE.TextureLoader();
	var loader2 = new THREE.TextureLoader();
	var loader3 = new THREE.TextureLoader();
	var loader4 = new THREE.TextureLoader();
	// Darragh - Added texture loader for searchpath block texture
	//  ----------------------------------------------------------------------------
	var loader5 = new THREE.TextureLoader();
	//  ----------------------------------------------------------------------------
	
	loader1.load ( TEXTURE_WALL, function ( thetexture )  		
	{
		thetexture.minFilter  = THREE.LinearFilter;
		wall_texture = thetexture;
		if ( asynchFinished() )	initScene();		// if all file loads have returned 
	});
		
	loader2.load ( TEXTURE_AGENT, function ( thetexture )  	 
	{
		thetexture.minFilter  = THREE.LinearFilter;
		agent_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});	
	
	// Darragh - Added selector so that diffrent enemy texture is used for diffrent movement options
	loader3.load ( TEXTURE_ENEMY[MOVEMENT_PATTERN], function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		enemy_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	loader4.load ( TEXTURE_MAZE, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		maze_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	
	// Darragh - Added load call for searchpath block texture
	//  ----------------------------------------------------------------------------
	loader5.load ( TEXTURE_SEARCHPATH, function ( thetexture )  
	{
		thetexture.minFilter  = THREE.LinearFilter;
		searchpath_texture = thetexture;
		if ( asynchFinished() )	initScene();		 
	});
	//  ----------------------------------------------------------------------------
	
}


function asynchFinished()		 // all file loads returned 
{
	if ( wall_texture && agent_texture && enemy_texture && maze_texture && searchpath_texture )   return true; 
	else return false;
}	
	
	
 

//--- grid system -------------------------------------------------------------------------------
// my numbering is 0 to gridsize-1

	
function occupied ( i, j )		// is this square occupied
{
 if ( ( ei == i ) && ( ej == j ) ) return true;		// variable objects 
 if ( ( ai == i ) && ( aj == j ) ) return true;

 if ( GRID[i][j] == GRID_WALL ) return true;		// fixed objects	 
 if ( GRID[i][j] == GRID_MAZE ) return true;		 
	 
 return false;
}

 
// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates
// logically, coordinates are: y=0, x and z all positive (no negative)    
// logically my dimensions are all positive 0 to MAXPOS
// to centre everything on origin, subtract (MAXPOS/2) from all dimensions 

function translate ( i, j )			
{
	var v = new THREE.Vector3();
	
	v.y = 0;	
	v.x = ( i * squaresize ) - ( MAXPOS/2 );   		 
	v.z = ( j * squaresize ) - ( MAXPOS/2 );   	
	
	return v;
}

// Darragh - Added Logging Classes to enable download of stats
//  ----------------------------------------------------------------------------
const logHeadings = ["gridsize", "no_boxes", "max_step", "enemy_start", "agent_start", "step", "agent_pos", "enemy_pos", "bad_steps", "good_steps", "score", "distance", "enemy_eval_count", "enemy_eval_time", "achilles_recomp", "heat_map"];
class LogFile
{
    constructor()
    {
        this.lines = [logHeadings];
    }
    
    addLine(logMesssage)
    {
        const logline = [logMesssage.gridsize,
        logMesssage.no_boxes,
        logMesssage.max_step,
        logMesssage.enemy_start,
        logMesssage.agent_start,
        logMesssage.step,
        logMesssage.agent_pos,
        logMesssage.enemy_pos,
        logMesssage.bad_steps,
        logMesssage.good_steps,
        logMesssage.score,
        logMesssage.distance,
        logMesssage.enemy_eval_count,
        logMesssage.enemy_eval_time,
        logMesssage.achilles_recomp,
        logMesssage.heat_map];
        this.lines.push(logline);
    }
}
const LOGFILE = new LogFile();

//Darragh - Download array example used
//https://medium.com/@idorenyinudoh10/how-to-export-data-from-javascript-to-a-csv-file-955bdfc394a9
function downloadLogFile()
{
    tsvString = LOGFILE.lines.map(line => line.map(field => JSON.stringify(field)).join("\t")).join("\n");
    const blob = new Blob([tsvString], { type: 'text/tsv;charset=utf-8,' });
    const objUrl = URL.createObjectURL(blob);
    
    const link = document.createElement('a');
    link.setAttribute('href', objUrl);
    link.setAttribute('download', `${new Date().toLocaleString("ja-JP")}ResultsMode${MOVEMENT_PATTERN}.tsv`);
    link.textContent = 'Click to Download';
    
    document. getElementById('user_span3').append(link);
    
}

class LogMessage
{
    constructor(step, agent_pos, enemy_pos, bad_steps, good_steps, score, distance)
    {
        this.gridsize = gridsize;
        this.no_boxes = NOBOXES;
        this.max_step = AB.maxSteps;
        this.enemy_start = enemy_start;
        this.agent_start = agent_start;
        this.step = step;
        this.agent_pos = agent_pos;
        this.enemy_pos = enemy_pos;
        this.bad_steps = bad_steps;
        this.good_steps = good_steps;
        this.score = score;
        this.distance = distance;
        this.enemy_eval_count = enemyEvalCount,
        this.enemy_eval_time = enemyEvalTime,
        this.achilles_recomp = achillesRecomp,
        this.heat_map = structuredClone(heatmap.map);
    }
}

let heatmap;
class HeatMap
{
    constructor()
    {
        this.map = new Array(gridsize);
        for(let i=0; i < gridsize; i++)
        {
            this.map[i] = [];
            for(let j=0; j < gridsize; j++)
            {
                if (BOARD[i][j].wall) this.map[i].push(-1);
                else this.map[i].push(0);
            }
        }
    }
    
    increase(position)
    {
        this.map[position[1]][position[0]] = this.map[position[1]][position[0]] + 1;
    }
}
//  ----------------------------------------------------------------------------

	
function initScene()		// all file loads have returned 
{
	 var i,j, shape, thecube;
	 
	// set up GRID as 2D array
	 
	 for ( i = 0; i < gridsize ; i++ ) 
		GRID[i] = new Array(gridsize);		 


	// set up walls
	 
	 for ( i = 0; i < gridsize ; i++ ) 
	  for ( j = 0; j < gridsize ; j++ ) 
		if ( ( i===0 ) || ( i==gridsize-1 ) || ( j===0 ) || ( j==gridsize-1 ) )
		{
			GRID[i][j] = GRID_WALL;		 
			shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
			thecube  = new THREE.Mesh( shape );
			thecube.material = new THREE.MeshBasicMaterial( { map: wall_texture } );
			
			thecube.position.copy ( translate(i,j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
			ABWorld.scene.add(thecube);
		}
		else 
   			GRID[i][j] = GRID_BLANK;

		
   // set up maze 
   
    for ( var c=1 ; c <= NOBOXES ; c++ )
	{
		i = AB.randomIntAtoB(1,gridsize-2);		// inner squares are 1 to gridsize-2
		j = AB.randomIntAtoB(1,gridsize-2);
			
		GRID[i][j] = GRID_MAZE ;
		
		shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
		thecube  = new THREE.Mesh( shape );
		thecube.material = new THREE.MeshBasicMaterial( { map: maze_texture } );		  

		thecube.position.copy ( translate(i,j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
		ABWorld.scene.add(thecube);		
	}
	 	 
   
	// set up enemy 
	// start in random location
	
	 do
	 {
	  i = AB.randomIntAtoB(1,gridsize-2);
	  j = AB.randomIntAtoB(1,gridsize-2);
	 }
	 while ( occupied(i,j) );  	  // search for empty square 

	 ei = i;
	 ej = j;
	 
	 shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
	 theenemy = new THREE.Mesh( shape );
 	 theenemy.material =  new THREE.MeshBasicMaterial( { map: enemy_texture } );
	 ABWorld.scene.add(theenemy);
	 drawEnemy();		  

	 
	
	// set up agent 
	// start in random location
	
	 do
	 {
	  i = AB.randomIntAtoB(1,gridsize-2);
	  j = AB.randomIntAtoB(1,gridsize-2);
	 }
	 while ( occupied(i,j) );  	  // search for empty square 

	 ai = i;
	 aj = j;
 
	 shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
	 theagent = new THREE.Mesh( shape );
	 theagent.material =  new THREE.MeshBasicMaterial( { map: agent_texture } );
	 ABWorld.scene.add(theagent);
	 drawAgent(); 

    
    //Darragh - Store the initial starting points of Agent and Enemy
    //  ----------------------------------------------------------------------------
    enemy_start = [ei, ej];
    agent_start = [ai, aj];
    //  ----------------------------------------------------------------------------
    
  // finally skybox 
  // setting up skybox is simple 
  // just pass it array of 6 URLs and it does the asych load 
  
  	 ABWorld.scene.background = new THREE.CubeTextureLoader().load ( SKYBOX_ARRAY, 	function() 
	 { 
		ABWorld.render(); 
	 
		AB.removeLoading();
	
		AB.runReady = true; 		// start the run loop
	 });
	 
// Darragh - Create initial board and heatmap
//  ----------------------------------------------------------------------------
	 resetBoard();
	 heatmap = new HeatMap();
//  ----------------------------------------------------------------------------
}
 
// Darragh
// -- Reset Game Board
// Reinistialised a blacnk game board to clear previous BoardPositions
//  ----------------------------------------------------------------------------
function resetBoard()
{
    for(let i = 0; i < GRID.length; i++){
        const row = GRID[i];
        const rowList = new Array(row.length);
        for (let j = 0; j < row.length; j++)
        {
            const isWall = row[j] > 0;
            const position = new BoardPosition(i, j, isWall);
            rowList[j] = position;
        }
        BOARD[i] = rowList;
    }
}
//  ----------------------------------------------------------------------------


// --- draw moving objects -----------------------------------


function drawEnemy()		// given ei, ej, draw it 
{
	theenemy.position.copy ( translate(ei,ej) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 

	ABWorld.lookat.copy ( theenemy.position );	 		// if camera moving, look back at where the enemy is  
}


function drawAgent()		// given ai, aj, draw it 
{
	theagent.position.copy ( translate(ai,aj) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 

	ABWorld.follow.copy ( theagent.position );			// follow vector = agent position (for camera following agent)
}


// Darragh - Options for enemy movement patters
//  ----------------------------------------------------------------------------
// Darragh - Naive Movement Pattern
// This is the defualt movement but with no diagonals
// It simply aims to reduce distance between itself and the target with no regard for obstacles
function moveEnemyNaive()
{
    // move towards agent 
    // put some randomness in so it won't get stuck with barriers 
 const start = new Date().getTime();
 var i, j;
 if ( ei < ai ) i = AB.randomIntAtoB(ei, ei+1); 
 if ( ei == ai ) i = ei; 
 if ( ei > ai ) i = AB.randomIntAtoB(ei-1, ei); 

 if ( ej < aj ) j = AB.randomIntAtoB(ej, ej+1); 
 if ( ej == aj ) j = ej; 
 if ( ej > aj ) j = AB.randomIntAtoB(ej-1, ej); 
 
 // Count the 6 evalutaions above
 enemyEvalCount += 6;
 
 // Darragh - 
 // Remove Diagonal Moves by only allowing enemy to move in either the i of the j direction per game step
 if (i !== ei && ! occupied(i,ej) )  	// if no obstacle then move, else just miss a turn
 {
  ei = i;
 }
 else if (!occupied(ei, j))
 {
    ej = j;
 }
 enemyEvalTime = new Date().getTime() - start;
}
// - End of Naive Movement Pattern

// Darragh - A* Movement Pattern
// As described by the brief enemy will use A* to find the shortest path to the enemy
// This will be recalculated each step

// Work based on "World: A star" https://ancientbrain.com/world.php?world=2230793148 as shown in the lab session
// Also based on Daniel Shiffman

// Darragh - Adapted Shiffman's functions "Spot" and changed it to a class as personal preference
class BoardPosition{
    constructor(i, j, wall)
    {
        // Position coords i = x, j = y
        this.i = i; 
        this.j = j;
        
        // f, g, h values for A*
        this.f = 0;
        this.g = 0;
        this.h = 0;
        
        //Neighbours
        this.neighbours = [];
        
        //Previous Postion in path
        this.previous = undefined;
        
        // Darragh - Changed wall check to be done prior to creation
        this.wall = wall;
    }
    
    addNeighbours()
    {
        if (this.i < GRID.length - 1)   this.neighbours.push(BOARD[this.i + 1][this.j]);
        if (this.i > 0)          this.neighbours.push(BOARD[this.i - 1][this.j]);
        if (GRID.length && this.j < GRID[0].length - 1)   this.neighbours.push(BOARD[this.i][this.j + 1]);
        if (this.j > 0)          this.neighbours.push(BOARD[this.i][this.j - 1]);
    }
}

// Default AStar hueristic from "World: A star" with abs replaces with Math.abs as abs is a p5 function
function defaultAStarHeuristic ( a, b ) 
{
    return ( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
}

// Darragh - Hueristic that returns constant value
// As shown in the lab exercise this should effectivly perform BFS instead of AStar
function bfsHeuristic ( a, b ) 
{
    return ( 0 );
}

// Darragh - Hueristic that returns inverted value to allow for longest path search
function invertedAStarHeuristic (a, b)
{
    return -( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
}


// Default AStar gfn from "World: A star" with abs replaces with Math.abs as abs is a p5 function
function defaultGFN ( a, b ) 
{
    return ( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
}

// Darragh - GFN that returns inverted value to allow for longest path search
function invertedGFN ( a, b ) 
{
    return -( Math.abs(a.i - b.i) + Math.abs(a.j - b.j) );
}


// Darragh - Removes old search path blocks between runs to avoid clutter
function cleanOldPath()
{
    // Find all objects in the Three.js scene with the searchpath texture and remove them
    const cubesToDelete = ABWorld.scene.children.filter((child) => child.material && child.material.map.image.src.includes(TEXTURE_SEARCHPATH));
    for (let cube of cubesToDelete) ABWorld.scene.remove(cube);
}

// Darragh - Helper fucntion to return a list containing the path from enemy to agent
function getPath(end)
{
    const path = [];
    //If no path exists
    if(!end.previous)
    {
        console.log("No Path Found")
        return path;
    }
    // Start from the position before agent 
    let current = end.previous;
    //While not back to enemy
    while (current.previous)
    {
        path.unshift(current);
		
		current = current.previous;
    }
    return path;
}

// Darragh - Helper function to draw a path of positions 
// In the "World: A star" example the draw function is internalied into the "Spot" function
// However I chose to split it out as in that case it handles the drawing of the whole board where in this case the board is already drawn so I just need to draw a few positions
function drawPath(path)
{
    for (let square of path)
    {
        shape    = new THREE.BoxGeometry ( squaresize, BOXHEIGHT, squaresize );			 
		thecube  = new THREE.Mesh( shape );
		thecube.material = new THREE.MeshBasicMaterial( { map: searchpath_texture } );		  

		thecube.position.copy ( translate(square.i,square.j) ); 		  	// translate my (i,j) grid coordinates to three.js (x,y,z) coordinates 
		ABWorld.scene.add(thecube);
    }
}


// Darragh - Adapted default "World: A star" AStar fucntion
// Darragh - Added "heurictic" as a property so that diffrent heuristics can be passed in
function calculateAStar(heuristic, gfn, endPos=BOARD[ai][aj])
{
    const openSet = [];
    const closedSet = [];
    
    // Start search at current enemy position
    let startPos = BOARD[ei][ej];
    
    openSet.push(startPos);
    
    while (openSet.length)
    {
        //Track squares evalutated
        enemyEvalCount++
        
        let winner = 0;
        
        for (let i = 0; i < openSet.length; i++)
            if (openSet[i].f < openSet[winner].f)
                winner = i;
        
        const current = openSet[winner];
        
        //If the endPosition is found
        if (current === endPos)
        {
            break;
        }
        
        // Darragh - Opt to use the "winner" index as opposed to "World: A star" which uses a seperate function to iterate the openSet and remove
        // This serves the same purpose, as "winner" is the index of current in the openSet as seen on the line above
        // Remove current from openSet and put it in closedSet
        openSet.splice(winner, 1);
        closedSet.push(current);
        
        // Darragh - Added call to "addNeighbours" function only when needed
        // This should save on memory as opposed to the alternative approach from "World: A star" where neighbours are computed at setup time for every "Spot" even those that are never visited
        current.addNeighbours();
        const neighbours = current.neighbours;
        
        // Darragh - Changed to a for of loop rather than standard i=0; i < lenght; i++
        for(let neighbour of neighbours)
        {
            if (!closedSet.includes(neighbour) && !neighbour.wall)
            {
                var g = current.g + gfn(neighbour, current);
                
                // Is this a better path
                let newPath = false;
                if (openSet.includes(neighbour))
                {
                    if (g < neighbour.g)
                    {
                        neighbour.g = g;
                        newPath = true;
                    }
                }
                else{
                    neighbour.g = g;
                    newPath = true;
                    openSet.push(neighbour);
                }
                
                if(newPath)
                {
                    neighbour.h = heuristic ( neighbour, endPos );
                    neighbour.f = neighbour.g + neighbour.h;
                    neighbour.previous = current;
                }
            }
        }
        
    }
    
    return endPos;

    
    
}

// Darragh - Seperated AStar calulation into another function to allow resuse in other movement patterns with diffrent heuristics
function moveEnemyAStar(heuristic, gfn=defaultGFN)
{
    const start = new Date().getTime();
    const endPosition = calculateAStar(heuristic, gfn);
    
    //Perform Time analysis before drawing path to eliminate bias of long path draw times    
    enemyEvalTime = new Date().getTime() - start;
    
    const path = getPath(endPosition);
    
    // Don't move if next to agent
    // Program will work without this check but there will be console errors
    if (path.length)
    {
         ei = path[0].i;
        ej = path[0].j;
    }
    drawPath(path.slice(1));
}

// Darragh - Inspired by the paradox of Achilles and the tortoise the enemy performs AStar and determines a path to the enemys potistion
// It will not adjust its target until it reaches its previous target
// It does still recompute its path every step as to avoid collisions with the agent

//variable that holds current target location of the achillesAStar search 
let achillesTarget = null;
function moveEnemyAchillesAStar()
{
    const start = new Date().getTime()
    // If enemy has reached its target reset target
    if (achillesTarget){
        if (ei === achillesTarget[0] && ej === achillesTarget[1])
        {
            achillesTarget = null;
        }
    }
    
    //If enemy has no target observe agent position
    if (!achillesTarget){
        achillesRecomp = true
        achillesTarget = [ai, aj];
    }
    
    // Perform a star towards target
    const endPosition = calculateAStar(defaultAStarHeuristic, defaultGFN, BOARD[achillesTarget[0]][achillesTarget[1]]);
    
    //Perform Time analysis before drawing path to eliminate bias of long path draw times    
    enemyEvalTime = new Date().getTime() - start;
    
    const path = getPath(endPosition);
    
    // getPath function doesn't include endPosition so add it back
    path.push(endPosition);
    
    // if there is a space to move to move
    if (path.length && !occupied(path[0].i, path[0].j))
    {
         ei = path[0].i;
         ej = path[0].j;
    }
    drawPath(path.slice(1));
}

// - End  of Options for enemy movement patters


// --- take actions -----------------------------------

// Darragh -  Enemy Movement Selector
// variables holding analysis data about emeny eval time and number
function moveLogicalEnemy()
{ 
    // Remove old search path
    resetBoard();
    cleanOldPath();
    
    //Reset eval time and count variables
    enemyEvalTime = 0
    enemyEvalCount = 0
    achillesRecomp = false
    
    // 0 - AStar
    // 1 - BFS
    // 2 - Naive
    // 3 - AStar Longest Path
    // 4 - AStar Achilles
    switch(MOVEMENT_PATTERN)
    {
         case 0:
            moveEnemyAStar(defaultAStarHeuristic);
            break;
        case 1:
            moveEnemyAStar(bfsHeuristic);
            break;
        case 2:
            moveEnemyNaive();
            break;
        case 3:
            moveEnemyAStar(invertedAStarHeuristic, invertedGFN);
            break;
        case 4:
            moveEnemyAchillesAStar();
            break;
        
    }

    heatmap.increase([ei,ej]);
}
//  ----------------------------------------------------------------------------

function moveLogicalAgent( a )			// this is called by the infrastructure that gets action a from the Mind 
{ 
 var i = ai;
 var j = aj;		 

      if ( a == ACTION_LEFT ) 	i--;
 else if ( a == ACTION_RIGHT ) 	i++;
 else if ( a == ACTION_UP ) 		j++;
 else if ( a == ACTION_DOWN ) 	j--;

 if ( ! occupied(i,j) ) 
 {
  ai = i;
  aj = j;
 }
}




// --- key handling --------------------------------------------------------------------------------------
// This is hard to see while the Mind is also moving the agent:
// AB.mind.getAction() and AB.world.takeAction() are constantly running in a loop at the same time 
// have to turn off Mind actions to really see user key control 

// we will handle these keys: 

var OURKEYS = [ 37, 38, 39, 40 ];

function ourKeys ( event ) { return ( OURKEYS.includes ( event.keyCode ) ); }
	

function keyHandler ( event )		
{
	if ( ! AB.runReady ) return true; 		// not ready yet 

   // if not one of our special keys, send it to default key handling:
	
	if ( ! ourKeys ( event ) ) return true;
	
	// else handle key and prevent default handling:
	
	if ( event.keyCode == 37 )   moveLogicalAgent ( ACTION_LEFT 	);   
    if ( event.keyCode == 38 )   moveLogicalAgent ( ACTION_DOWN  	); 	 
    if ( event.keyCode == 39 )   moveLogicalAgent ( ACTION_RIGHT 	); 	 
    if ( event.keyCode == 40 )   moveLogicalAgent ( ACTION_UP		);   
	
	// when the World is embedded in an iframe in a page, we want arrow key events handled by World and not passed up to parent 

	event.stopPropagation(); event.preventDefault(); return false;
}





// --- score: -----------------------------------


function badstep()			// is the enemy within one square of the agent
{
 if ( ( Math.abs(ei - ai) < 2 ) && ( Math.abs(ej - aj) < 2 ) ) return true;
 else return false;
}


function agentBlocked()			// agent is blocked on all sides, run over
{
 return ( 	occupied (ai-1,aj) 		&& 
		occupied (ai+1,aj)		&&
		occupied (  ai,aj+1)		&&
		occupied (  ai,aj-1) 	);		
} 


function updateStatusBefore(a)
// this is called before anyone has moved on this step, agent has just proposed an action
// update status to show old state and proposed move 
{
 var x 		= AB.world.getState();
 AB.msg ( " Step: " + AB.step + " &nbsp; x = (" + x.toString() + ") &nbsp; a = (" + a + ") " ); 
}


function   updateStatusAfter()		// agent and enemy have moved, can calculate score
{
 // new state after both have moved
 
 var y 		= AB.world.getState();
 var score = ( goodsteps / AB.step ) * 100;
 //Darragh Added distance readout
 //  ----------------------------------------------------------------------------
 let distance = defaultAStarHeuristic(BOARD[ai][aj], BOARD[ei][ej]);
//  ----------------------------------------------------------------------------
 AB.msg ( " &nbsp; y = (" + y.toString() + ") <br>" +
		" Bad steps: " + badsteps + 
		" &nbsp; Good steps: " + goodsteps + 
		" &nbsp; Score: " + score.toFixed(2) + "% " +
		"&nbsp; Distance: " + distance, 2 );
		
//Darragh - Save status to log file
const logMessage = new LogMessage(AB.step, [ai, aj], [ei, ej], badsteps, goodsteps, score, distance);
LOGFILE.addLine(logMessage);
}





AB.world.newRun = function() 
{
	AB.loadingScreen();

	AB.runReady = false;  

	badsteps = 0;	
	goodsteps = 0;

	
	if ( show3d )
	{
	 BOXHEIGHT = squaresize;
	 ABWorld.init3d ( startRadiusConst, maxRadiusConst, SKYCOLOR  ); 	
	}	     
	else
	{
	 BOXHEIGHT = 1;
	 ABWorld.init2d ( startRadiusConst, maxRadiusConst, SKYCOLOR  ); 		     
	}
	
	
	loadResources();		// aynch file loads		
							// calls initScene() when it returns 

	document.onkeydown = keyHandler;	
		 
};



AB.world.getState = function()
{
 var x = [ ai, aj, ei, ej ];
  return ( x );  
};



AB.world.takeAction = function ( a )
{
  updateStatusBefore(a);			// show status line before moves 

  moveLogicalAgent(a);

  if ( ( AB.step % 2 ) === 0 )		// slow the enemy down to every nth step
    moveLogicalEnemy();


  if ( badstep() )  badsteps++;
  else   			goodsteps++;

   drawAgent();
   drawEnemy();
   updateStatusAfter();			// show status line after moves  


  if ( agentBlocked() )			// if agent blocked in, run over 
  {
	AB.abortRun = true;
	goodsteps = 0;			// you score zero as far as database is concerned 			 
	musicPause();
	soundAlarm();
  }

};



AB.world.endRun = function()
{
console.log(LOGFILE);
  musicPause(); 
  if ( AB.abortRun ) AB.msg ( " <br> <font color=red> <B> Agent trapped. Final score zero. </B> </font>   ", 3  );
  else    				AB.msg ( " <br> <font color=green> <B> Run over. </B> </font>   ", 3  );
  
  AB.msg ( ' <br> <input id="clickMe" type="button" value="Request LogFile" onclick="downloadLogFile();" />   ', 3  );
};

 
AB.world.getScore = function()
{
    // only called at end - do not use AB.step because it may have just incremented past AB.maxSteps
    
    var s = ( goodsteps / AB.maxSteps ) * 100;   // float like 93.4372778 
    var x = Math.round (s * 100);                // 9344
    return ( x / 100 );                          // 93.44
};


 




// --- music and sound effects ----------------------------------------

var backmusic = AB.backgroundMusic ( MUSIC_BACK );

function musicPlay()   { backmusic.play();  }
function musicPause()  { backmusic.pause(); }

											 
function soundAlarm()
{
	var alarm = new Audio ( SOUND_ALARM );
	alarm.play();							// play once, no loop 
}