/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
// Cube class
var Cube = Container.expand(function () {
	var self = Container.call(this);
	// Cube base
	var cubeGfx = self.attachAsset('cube', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Arrow overlay
	self.arrowGfx = null;
	// Grid position
	self.gridX = 0;
	self.gridY = 0;
	// Direction index (0:up, 1:down, 2:left, 3:right)
	self.dir = 0;
	// Is this cube currently animating?
	self.isSliding = false;
	// Set direction and update arrow
	self.setDirection = function (dirIdx) {
		self.dir = dirIdx;
		if (self.arrowGfx) {
			self.removeChild(self.arrowGfx);
		}
		// Defensive: Only set arrow if dirIdx is valid
		if (dirIdx >= 0 && dirIdx < DIRS.length) {
			var dir = DIRS[dirIdx];
			self.arrowGfx = self.attachAsset(dir.arrow, {
				anchorX: 0.5,
				anchorY: 0.5
			});
			// For left/right, rotate arrow to point correctly
			if (dir.name === 'left') {
				self.arrowGfx.rotation = Math.PI;
			} else if (dir.name === 'up') {
				self.arrowGfx.rotation = -Math.PI / 2;
			} else if (dir.name === 'down') {
				self.arrowGfx.rotation = Math.PI / 2;
			} else {
				self.arrowGfx.rotation = 0;
			}
		} else {
			// Fallback: show no arrow if direction is invalid
			self.arrowGfx = null;
		}
	};
	// Called when tapped
	self.down = function (x, y, obj) {
		if (self.isSliding) {
			return;
		}
		if (game.isAnimating) {
			return;
		}
		game.trySlideCube(self);
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222831
});

/**** 
* Game Code
****/ 
// Cube directions
// Tween for sliding animation
// Arrow assets: 120x60, colored arrows for each direction
// Cube asset: 200x200, white box
// Grid config
var DIRS = [{
	name: 'up',
	dx: 0,
	dy: -1,
	arrow: 'arrow_up',
	rot: 0
}, {
	name: 'down',
	dx: 0,
	dy: 1,
	arrow: 'arrow_down',
	rot: 0
}, {
	name: 'left',
	dx: -1,
	dy: 0,
	arrow: 'arrow_left',
	rot: 0
}, {
	name: 'right',
	dx: 1,
	dy: 0,
	arrow: 'arrow_right',
	rot: 0
}];
var GRID_SIZE = 4;
var CELL_SIZE = 260; // 200px cube + 60px gap
var GRID_ORIGIN_X = Math.floor((2048 - GRID_SIZE * CELL_SIZE) / 2) + CELL_SIZE / 2;
var GRID_ORIGIN_Y = Math.floor((2732 - GRID_SIZE * CELL_SIZE) / 2) + CELL_SIZE / 2;
// Game state
var cubes = []; // 2D array [y][x] of Cube or null
var cubeList = []; // Flat list of all Cube objects
var isAnimating = false;
// Score text
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Helper: get grid cell center position
function gridToPos(gx, gy) {
	return {
		x: GRID_ORIGIN_X + gx * CELL_SIZE,
		y: GRID_ORIGIN_Y + gy * CELL_SIZE
	};
}
// Helper: check if (gx,gy) is inside grid
function inGrid(gx, gy) {
	return gx >= 0 && gx < GRID_SIZE && gy >= 0 && gy < GRID_SIZE;
}
// Helper: update score display
function updateScore() {
	var left = 0;
	for (var y = 0; y < GRID_SIZE; ++y) {
		for (var x = 0; x < GRID_SIZE; ++x) {
			if (cubes[y][x]) {
				left++;
			}
		}
	}
	scoreTxt.setText(left + "");
}
// Try to slide a cube in its direction
game.trySlideCube = function (cube) {
	// Only allow one animation at a time
	if (game.isAnimating) {
		return;
	}
	if (cube.isSliding) {
		return;
	}
	var dir = DIRS[cube.dir];
	var gx = cube.gridX;
	var gy = cube.gridY;
	var dx = dir.dx;
	var dy = dir.dy;
	// Find farthest empty cell in direction
	var nx = gx;
	var ny = gy;
	while (true) {
		var tx = nx + dx;
		var ty = ny + dy;
		if (!inGrid(tx, ty)) {
			// Out of grid, can slide out
			break;
		}
		if (cubes[ty][tx]) {
			// Blocked by another cube
			// Can't move
			return;
		}
		nx = tx;
		ny = ty;
	}
	// If not moving, do nothing
	if (nx === gx && ny === gy) {
		return;
	}
	// Mark animating
	cube.isSliding = true;
	game.isAnimating = true;
	// Remove from grid
	cubes[gy][gx] = null;
	// Animate to out-of-grid position
	var endPos;
	if (inGrid(nx, ny)) {
		// Should not happen, but fallback
		endPos = gridToPos(nx, ny);
	} else {
		// Compute position just outside grid
		var outX = nx;
		var outY = ny;
		// If moving right, outX is GRID_SIZE, left: -1
		// If moving down, outY is GRID_SIZE, up: -1
		endPos = {
			x: GRID_ORIGIN_X + nx * CELL_SIZE,
			y: GRID_ORIGIN_Y + ny * CELL_SIZE
		};
	}
	// Animate slide
	tween(cube, {
		x: endPos.x,
		y: endPos.y
	}, {
		duration: 300,
		onFinish: function onFinish() {
			// Remove cube from scene and list
			cube.destroy();
			var idx = cubeList.indexOf(cube);
			if (idx !== -1) {
				cubeList.splice(idx, 1);
			}
			cube.isSliding = false;
			game.isAnimating = false;
			updateScore();
			// Check win
			var left = 0;
			for (var y = 0; y < GRID_SIZE; ++y) {
				for (var x = 0; x < GRID_SIZE; ++x) {
					if (cubes[y][x]) {
						left++;
					}
				}
			}
			if (left === 0) {
				if (currentLevel < LEVELS.length - 1) {
					buildLevel(currentLevel + 1);
				} else {
					LK.showYouWin();
				}
			}
		}
	});
};
// --- Level definitions ---
var LEVELS = [
// Level 1: Simple, 3 cubes
[{
	x: 0,
	y: 0,
	dir: 3
},
// right
{
	x: 1,
	y: 1,
	dir: 1
},
// down
{
	x: 2,
	y: 2,
	dir: 0
} // up
],
// Level 2: 4 cubes, corners (fixed directions to make passable)
[{
	x: 0,
	y: 0,
	dir: 4
},
// right
{
	x: 3,
	y: 0,
	dir: 1
},
// down
{
	x: 3,
	y: 3,
	dir: 2
},
// left
{
	x: 0,
	y: 3,
	dir: 1
} // down (changed from up to down)
],
// Level 3: 5 cubes, cross
[{
	x: 1,
	y: 0,
	dir: 1
},
// down
{
	x: 2,
	y: 1,
	dir: 2
},
// left
{
	x: 1,
	y: 2,
	dir: 3
},
// right
{
	x: 2,
	y: 3,
	dir: 0
},
// up
{
	x: 1,
	y: 1,
	dir: 1
} // down
],
// Level 4: 6 cubes, more complex
[{
	x: 0,
	y: 1,
	dir: 3
},
// right
{
	x: 1,
	y: 0,
	dir: 1
},
// down
{
	x: 2,
	y: 1,
	dir: 2
},
// left
{
	x: 3,
	y: 2,
	dir: 0
},
// up
{
	x: 2,
	y: 3,
	dir: 2
},
// left
{
	x: 1,
	y: 2,
	dir: 3
} // right
],
// Level 5: 7 cubes, challenge
[{
	x: 0,
	y: 0,
	dir: 3
},
// right
{
	x: 1,
	y: 0,
	dir: 1
},
// down
{
	x: 2,
	y: 0,
	dir: 1
},
// down
{
	x: 3,
	y: 1,
	dir: 2
},
// left
{
	x: 3,
	y: 2,
	dir: 0
},
// up
{
	x: 2,
	y: 3,
	dir: 2
},
// left
{
	x: 0,
	y: 2,
	dir: 0
} // up
]];
var currentLevel = 0;
// Level indicator text
var levelTxt = new Text2('Level 1', {
	size: 90,
	fill: 0xFFD700
});
levelTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(levelTxt);
// Build a level by index
function buildLevel(idx) {
	// Clamp level index
	if (idx < 0) {
		idx = 0;
	}
	if (idx >= LEVELS.length) {
		idx = LEVELS.length - 1;
	}
	currentLevel = idx;
	// Reset animation state
	game.isAnimating = false;
	// Clear previous
	for (var i = 0; i < cubeList.length; ++i) {
		cubeList[i].isSliding = false; // Reset sliding state in case any cube is still flagged
		cubeList[i].destroy();
	}
	cubeList = [];
	cubes = [];
	for (var y = 0; y < GRID_SIZE; ++y) {
		var row = [];
		for (var x = 0; x < GRID_SIZE; ++x) {
			row.push(null);
		}
		cubes.push(row);
	}
	// Place cubes for this level
	var levelCubes = LEVELS[idx];
	for (var i = 0; i < levelCubes.length; ++i) {
		var c = levelCubes[i];
		var cube = new Cube();
		cube.gridX = c.x;
		cube.gridY = c.y;
		cube.setDirection(c.dir);
		var pos = gridToPos(c.x, c.y);
		cube.x = pos.x;
		cube.y = pos.y;
		cubes[c.y][c.x] = cube;
		cubeList.push(cube);
		game.addChild(cube);
	}
	updateScore();
	levelTxt.setText("Level " + (currentLevel + 1));
	game.isAnimating = false;
}
// Prevent accidental drag
game.move = function (x, y, obj) {};
// No drag
game.down = function (x, y, obj) {};
game.up = function (x, y, obj) {};
// No per-tick logic needed
game.update = function () {};
// Start game at level 1
buildLevel(0);