Tetris.js

var audio_file = "Tetris.mp3";
if(audio_file != undefined){
	var audio = new Audio(audio_file);	

}
var mute = false;


var board_color = "grey";
var board_width = 9;
var board_height = 15;

var btob;
var speed = 1000;;
var interval_auto_move;
var blocks_color = ["blue", "red", "green", "purple", "yellow", "orange", "white"];

var blocks = [	
	[ 					
		[[1,1],[2,1],[3,1],[4,1]],
		[[1,1],[2,1],[2,2],[3,1]],
		[[1,1],[2,1],[1,2],[2,2]],
		[[1,1],[2,1],[2,2],[3,2]],
		[[2,1],[3,1],[1,2],[2,2]],
		[[1,1],[2,1],[3,1],[1,2]], 
		[[1,1],[2,1],[3,1],[3,2]] 
	],
	[					
		[[2,3],[2,2],[2,1],[2,0]], 
		[[2,0],[2,1],[1,1],[2,2]],
		[[1,1],[2,1],[1,2],[2,2]],
		[[1,1],[2,1],[1,2],[2,0]],
		[[1,0],[1,1],[2,1],[2,2]],
		[[1,0],[2,0],[2,1],[2,2]],
		[[2,0],[2,1],[2,2],[1,2]] 
	],
	[						
		[[1,1],[2,1],[3,1],[4,1]], 
		[[1,1],[2,1],[2,0],[3,1]],
		[[1,1],[2,1],[1,2],[2,2]], 
		[[1,1],[2,1],[2,2],[3,2]],
		[[2,1],[3,1],[1,2],[2,2]], 
		[[3,0],[3,1],[2,1],[1,1]], 
		[[1,0],[1,1],[2,1],[3,1]] 
	],
	[				
		[[2,3],[2,2],[2,1],[2,0]],
		[[2,0],[2,1],[2,2],[3,1]],
		[[1,1],[2,1],[1,2],[2,2]],
		[[1,1],[2,1],[1,2],[2,0]],
		[[1,0],[1,1],[2,1],[2,2]],
		[[2,0],[2,1],[2,2],[3,2]], 
		[[2,0],[3,0],[2,1],[2,2]]  
	]
];

var c_block = new Object();

function play_audio(state){
	if(state == "play"){
		audio.addEventListener("ended", function() {
    			this.currentTime = 0;
    			this.play();
		}, false);
		audio.play();
	} else if(state == "stop"){
		audio.pause();
		audio.addEventListener("pause", function() {
			this.currentTime = 0;
		}, false);
			
	}
}

function create_board(){ 
	for(let y = 1; y <= board_height; y++){
		document.getElementById("board").insertAdjacentHTML("beforeend", "<tr id=\"row" + y + "\">");				
		for(let x = 1; x <= board_width; x++){
			document.getElementById("row" + y).insertAdjacentHTML(
				"beforeend",
				"<td id=" + x + "," + y + " style=\"background-color:" + board_color + "\">"
			);
		}
	}
}

function new_block(){
	function draw_block_on_board(){
		let x,y;
		for(let i in c_block.coords){
			x = c_block.coords[i][0] + (Math.floor(board_width/2 - 1));
			y = c_block.coords[i][1];
			if(document.getElementById(x + ","+ y).style.backgroundColor != board_color){
				return false;
			}
		}
		animate(Math.floor(board_width/2) - 1 , 0);
		return true;
	}

	c_block.id = Math.floor(Math.random() * blocks[0].length);
	c_block.rotation = 0;
	c_block.coords = blocks[c_block.rotation][c_block.id];
	c_block.color = blocks_color[c_block.id];
	c_block.indexes_lower_coords = find_indexes("bottom");
	c_block.indexes_right_coords = find_indexes("right");
	c_block.indexes_left_coords = find_indexes("left");
	
	if(!draw_block_on_board()){
		clearInterval(interval_auto_move);
		end_game();
	}
}

function change_color(x,y,color){
	if(x > 0 && y > 0){
		document.getElementById(x+","+y).style.backgroundColor = color;
	}
}

function draw_block_on_board(){
	for(let i in c_block.coords){
		change_color(c_block.coords[i][0], c_block.coords[i][1], c_block.color);
	}
}

function animate(x_offset, y_offset, custom){
	if(custom == undefined){
		let t_coords = [];
		for(let i in c_block.coords){
			t_coords.push([c_block.coords[i][0] + x_offset, c_block.coords[i][1] + y_offset]);
		}
		for(let i in c_block.coords){
			change_color(c_block.coords[i][0], c_block.coords[i][1], board_color);
		}
		for(let i in t_coords){
			change_color(t_coords[i][0], t_coords[i][1], c_block.color);
		}
		c_block.coords = t_coords;
	} else {
		c_block.coords = custom;
	}
}

function auto_move(){
	if(interval_auto_move == undefined){
		interval_auto_move = setInterval(function(){
			if(check_under() == false){
				animate(0,1);
			} else if(interval_auto_move != undefined){
				check_rows();
				new_block();
			}
		}, speed);
	}
}

function find_indexes(find){
	let indexes_duplicate_coords = [];
	let coords_checked = [];
	let indexes_coords = [];
	let first_coord;
	let second_coord;

	if(find == undefined){
		return false;
	} else if(find == "bottom"){
		first_coord = 0;
		second_coord = 1;
	} else if(find == "left" || find == "right"){
		first_coord = 1;
		second_coord = 0;
	}

	function already_checked(coord){
		for(let i in coords_checked){
			if(coords_checked[i] == coord){
				return true;
			}
		}
		return false;
	}

	function check_coords_with_x(indexes_of_x_coords){
		let index_of_lowest_y_coord = indexes_of_x_coords[0];

		for(let i in indexes_of_x_coords){ 
			if(c_block.coords[indexes_of_x_coords[i]][second_coord] > c_block.coords[index_of_lowest_y_coord][second_coord]){
				index_of_lowest_y_coord = indexes_of_x_coords[i];
			}
		}
		indexes_coords.push(index_of_lowest_y_coord);
	}

	function check_coords_with_y(indexes_of_y_coords){
		let index_of_direction_x_coord = indexes_of_y_coords[0];
		for(let i in indexes_of_y_coords){
			if(find == "left"){
				if(c_block.coords[indexes_of_y_coords[i]][second_coord] < c_block.coords[index_of_direction_x_coord][second_coord]){
					index_of_direction_x_coord = indexes_of_y_coords[i];
				}
			} else if(find == "right"){
				if(c_block.coords[indexes_of_y_coords[i]][second_coord] > c_block.coords[index_of_direction_x_coord][second_coord]){
					index_of_direction_x_coord = indexes_of_y_coords[i];
				}
			}
		}
		indexes_coords.push(index_of_direction_x_coord);
	}

	function check_coords(){
		for(let i in c_block.coords){
			if(already_checked(c_block.coords[i][first_coord]) == false){
				coords_checked.push(c_block.coords[i][first_coord]);

				for(let j in c_block.coords){
					if(i != j){
						if(c_block.coords[i][first_coord] == c_block.coords[j][first_coord]){
							if(indexes_duplicate_coords.length == 0){
								indexes_duplicate_coords.push(i);
							}
							indexes_duplicate_coords.push(j);
						}
					}
				}

				if(indexes_duplicate_coords.length > 0){
					if(find == "bottom"){
						check_coords_with_x(indexes_duplicate_coords);
					} else {
						check_coords_with_y(indexes_duplicate_coords);
					}
					indexes_duplicate_coords = [];
				} else {
					indexes_coords.push(i);
				}
			}
		}
	}

	check_coords();
	return indexes_coords;
}

function check_under(){
	let x_coord;
	let y_coord;
	for(let i = 0; i < c_block.indexes_lower_coords.length; i++){
		x_coord = c_block.coords[c_block.indexes_lower_coords[i]][0];
		y_coord = c_block.coords[c_block.indexes_lower_coords[i]][1] + 1;
		if(y_coord > board_height || (document.getElementById(x_coord + "," + y_coord).style.backgroundColor != board_color)){
			return true;
		} else if(i == c_block.indexes_lower_coords.length - 1){
			return false;
		}
	}
}


function level_check(score){
	console.log((1000/(score/1000+1)) + 200);

	change_speed((1000/(score/1000+1))+ 200);
}

function check_rows(){
	let count = 0;
	let tetris_count = 0;

	function move_block_down(limit){
		let block_holder = [];
		for(let y = 1; y < limit; y++){
			for(let x = 1; x <= board_width; x++){
				if(document.getElementById(x+","+y).style.backgroundColor != board_color){
					let color = document.getElementById(x+","+y).style.backgroundColor;
					block_holder.push([[x,y],[color]]);
					document.getElementById(x + "," + y).style.backgroundColor = board_color;
				}
			}
		}
		for(let i in block_holder){
			change_color(block_holder[i][0][0], block_holder[i][0][1] + 1, block_holder[i][1]);
		}
	}

	function remove_row(y){
		for(let x = 1; x <= board_width; x++){
			change_color(x,y,board_color); 
		}
		tetris_count++;
	}

	function score_total(){
		let score = Number(document.getElementById("score").innerHTML);
		if(btob === true && tetris_count == 4){
			score += 1200;
		}
		else if(tetris_count == 4){
			score += 800;
			btob = true;
		} else {
		 score += (100*tetris_count);
			btob = false;
		}
		score = score.toString();
		if(score.length != 8){
			for(let i = score.length; i < 8; i++){
				score = "0" + score;
			}		
		}
		document.getElementById("score").innerHTML = score;
		level_check(score);
	}

	for(let y = 1; y <= board_height; y++){
		for(let x = 1; x <= board_width; x++){
				if(document.getElementById(x + "," + y).style.backgroundColor != board_color){
				count++;
				if(count == board_width){
					remove_row(y);
					move_block_down(y);
				}
			}
		}
		count = 0;
	}
	score_total();
}


function change_speed(new_speed){
	speed = new_speed;
	console.log(speed);
	clearInterval(interval_auto_move);
	interval_auto_move = undefined;
	auto_move();
}


function move(key){
	function check(direction){
		let x_offset = 0;
		let y_offset = 0;
		let x_coord;
		let y_coord;
		let indexes_amount;
		if(direction == "left"){
			x_offset = -1
			indexes_amount = c_block.indexes_left_coords.length;
		} else if(direction == "right"){
			x_offset = 1
			indexes_amount = c_block.indexes_right_coords.length;
		} else if (direction == "down"){
			y_offset = 1;
			indexes_amount = c_block.indexes_lower_coords.length;
		}

		for(let i = 0; i < indexes_amount; i++){
			if(direction == "left"){
				x_coord = c_block.coords[c_block.indexes_left_coords[i]][0] + x_offset;
				y_coord = c_block.coords[c_block.indexes_left_coords[i]][1];
			} else if (direction == "right"){
				x_coord = c_block.coords[c_block.indexes_right_coords[i]][0] + x_offset;
				y_coord = c_block.coords[c_block.indexes_right_coords[i]][1];
			} else if(direction == "down"){
				x_coord = c_block.coords[c_block.indexes_lower_coords[i]][0];
				y_coord = c_block.coords[c_block.indexes_lower_coords[i]][1] + y_offset;
			}

			if((x_coord > board_width || x_coord < 1) && (direction == "left" || direction == "right")){
				return false;
			} else if(y_coord > board_height && direction == "down"){
				new_block();
				return false;
			} else if(document.getElementById(x_coord + "," + y_coord).style.backgroundColor != board_color){
				return false;
			}
		}
		return true;
	}


	function place_down(){
		while(check_under() == false){
			animate(0,1);
		}
		check_rows();
		new_block();
	}

	function rotate(){
		let t_coords = [];
		for(let i in c_block.coords){
			t_coords.push([c_block.coords[i][0], c_block.coords[i][1]]);
		}
		let block_to_remove = blocks[c_block.rotation][c_block.id];
		let block_to_add;
		if(c_block.rotation == 3){
			block_to_add = blocks[0][c_block.id];
		} else {
			block_to_add = blocks[c_block.rotation + 1][c_block.id];
		}

		for(let i in c_block.coords){
			change_color(c_block.coords[i][0], c_block.coords[i][1], board_color);
		}

		for(let i in t_coords){
			for(let j in t_coords[i]){
				let axis;
				let total = t_coords[i][j] -  block_to_remove[i][j] + block_to_add[i][j];
				if(j == 0){
					axis = board_width;
				} else {
					axis = board_height;
				}
				if(total > axis || total < 1){
					animate(0,0);
					return false;
				}
				t_coords[i][j] = total;
			}
			if(document.getElementById(t_coords[i][0] + "," + t_coords[i][1]).style.backgroundColor != board_color){
				animate(0,0);
				return false;
			}
		}
		c_block.coords = t_coords
		if(c_block.rotation == 3){
			c_block.rotation = 0;
		} else {
			c_block.rotation += 1;
		}
		c_block.indexes_lower_coords = find_indexes("bottom");
		c_block.indexes_right_coords = find_indexes("right");
		c_block.indexes_left_coords = find_indexes("left");
		animate(0,0);
	}

	key = key || window.event;
	if(key.keyCode == 38) {
		rotate();
	} else if(key.keyCode == 32) {
		place_down();
	} else if(key.keyCode == 37) {
		if(check("left") == true){
			animate(-1,0);
		}
	} else if(key.keyCode == 39) {
		if(check("right") == true){
			animate(1,0);
		}
	} else if(key.keyCode == 40) {
		if(check("down") == true){
			animate(0,1);
		}

	}
	else if(key.keyCode == 77){
		if (!mute){
			play_audio("stop");
			mute = true;

		} else {
			play_audio("play");
			mute = false;	
		}

	}
}

function start(){
	create_board();
	new_block();
	auto_move();
	play_audio("play");
}

function end_game(){
	play_audio("stop");
	clearInterval(interval_auto_move);
	interval_auto_move = undefined;
	game_reset();
}

function game_reset(){
	if(document.getElementById("board").children.length != 0){
		for(let y = 1; y <= board_height; y++){
			document.getElementById("row" + y).outerHTML="";
		}
	}
	document.getElementById("score").innerHTML = "00000000";
	btob = false;
	start();
}