BALL_SPEED = 3;
VERT_MARGIN = 60;
HORIZ_MARGIN = 40;
BLOCK_PADDING = 5;
MAX_DX = 4;

COLL_LEFT = 1;
COLL_RIGHT = 2;
COLL_TOP = 3;
COLL_BOTTOM = 4;

lastScore = 0;
highScore = 0;

ballImage = loadImage("ball.png");
blockImage = loadImage("block.png");
batImage = loadImage("bat.png");

ballSprite = toSprite(ballImage);
batSprite = toSprite(batImage);

blocksPerLine = (width() - 2 * HORIZ_MARGIN) / (width(blockImage) + BLOCK_PADDING);
firstBlockX = (width() - blocksPerLine * width(blockImage) - (blocksPerLine - 1) * BLOCK_PADDING) / 2;
index = 1;
for y = 1 to 6 do
    blockX = firstBlockX;
    blockY = height() - (VERT_MARGIN + (y - 1) * (height(blockImage) + BLOCK_PADDING));
    for x = 1 to blocksPerLine do
        blockSprite[index] = toSprite(blockImage);
        spriteMove(blockSprite[index], blockX, blockY);
        blockX = blockX + width(blockImage) + BLOCK_PADDING;
        index = index + 1;
    done;
done;

function setupNewWall()
    numVisible = 0;
    for q = 1 to maxIndex(blockSprite) do
        spriteVisible(blockSprite[q], TRUE);
        numVisible = numVisible + 1;
    done;
endfunc;

function showScore()
    cls();
    println("Score: ", score, "        Lives: ", lives);
endfunc;

function setupNewGame()
    score = 0;
    lives = 3;
    showScore();
    setupNewWall();
    batX = (width() - width(batSprite)) / 2;
    batY = 20;
    spriteMove(batSprite, batX, batY);
    spriteVisible(ballSprite, TRUE);
    spriteVisible(batSprite, TRUE);
endfunc;

function setupNewRound()
    ballX = (width() - width(ballSprite)) / 2;
    ballY = (height() - height(ballSprite)) / 2;
    spriteMove(ballSprite, ballX, ballY);
    ballDX = 1;
    ballDY = -2;
    showScore();
    showMessage("Get ready!");
    wait(3000);
    showScore();
endfunc;

function getOneCollidedBlockIndex()
    for q = 1 to maxIndex(blockSprite) do
        if spriteCollision(ballSprite, blockSprite[q]) then
            return q;
        endif;
    done;
    return -1;
endfunc;

function getCollisionSide(index)
    local ballBottom = spriteY(ballSprite);
    local ballTop = ballBottom + height(ballSprite);
    local ballLeft = spriteX(ballSprite);
    local ballRight = ballLeft + width(ballSprite);
    local blockBottom = spriteY(blockSprite[index]);
    local blockTop = blockBottom + height(blockSprite[index]);
    local blockLeft = spriteX(blockSprite[index]);
    local blockRight = blockLeft + width(blockSprite[index]);
    if ballRight >= blockLeft and ballRight < blockLeft + 3 then
        return COLL_LEFT;
    elseif ballLeft <= blockRight and ballLeft > blockRight - 3 then
        return COLL_RIGHT;
    elseif ballTop >= blockBottom and ballBottom < blockBottom then
        return COLL_BOTTOM;
    elseif ballBottom <= blockTop and ballTop > blockTop then
        return COLL_TOP;
    endif;
    return COLL_BOTTOM; // just in case
endfunc;

function updateBallPos()
    ballX = ballX + BALL_SPEED * ballDX;
    if ballX < 0 or ballX > width() - width(ballSprite) then
        ballDX = -ballDX;
        ballX = ballX + 2 * BALL_SPEED * ballDX;
    endif;
    ballY = ballY + BALL_SPEED * ballDY;
    if ballY > height() - height(ballSprite) then
        ballDY = -ballDY;
        ballY = ballY + 2 * BALL_SPEED * ballDY;
    endif;
    spriteMove(ballSprite, ballX, ballY);

    if spriteCollision(ballSprite, batSprite) then
        local ballCenterX = ballX + width(ballSprite) / 2;
        local batCenterX = batX + width(batSprite) / 2;
        local dx = (ballCenterX - batCenterX) / 7;
        ballDX = ballDX + dx;
        if ballDX > MAX_DX then
            ballDX = MAX_DX;
        elseif ballDX < -MAX_DX then
            ballDX = -MAX_DX;
        endif;
        ballDY = -ballDY;
        ballX = ballX + 2 * BALL_SPEED * ballDX;
        ballY = ballY + 2 * BALL_SPEED * ballDY;
        spriteMove(ballSprite, ballX, ballY);
    endif;

    local collidedBlockIndex = getOneCollidedBlockIndex();
    while collidedBlockIndex > 0 do
        local collisionSide = getCollisionSide(collidedBlockIndex);
        if collisionSide == COLL_LEFT or collisionSide == COLL_RIGHT then
            ballDX = -ballDX;
        elseif collisionSide == COLL_TOP or collisionSide == COLL_BOTTOM then
            ballDY = -ballDY;
        endif;
        spriteVisible(blockSprite[collidedBlockIndex], FALSE);
        score = score + 10;
        showScore();
        numVisible = numVisible - 1;
        collidedBlockIndex = getOneCollidedBlockIndex();
    done;
    spriteMove(ballSprite, ballX, ballY);

endfunc;

function showMessage(message)
    println("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"
          + "                                   ", message);
    flush();
endfunc;

function gameOver()
    lastScore = score;
    if score > highScore then
        highScore = score;
    endif;
    showMessage("Game over");
    wait(3000);
endfunc;

function playRound()
    setupNewRound();
    local finished = FALSE;
    while not finished do
        local t = time();
        batX = mouseX() - width(batSprite) / 2;
        spriteMove(batSprite, batX, batY);
        updateBallPos();
        if ballY < 0 then
            lives = lives - 1;
            showScore();
            if lives == 0 then
                gameOver();
                finished = TRUE;
            else
                setupNewRound();
            endif;
        elseif numVisible == 0 then
            setupNewWall();
            setupNewRound();
        endif;
        flush();
        t = time() - t;
        wait(30 - t);
    done;
endfunc;

function playGame()
    for q = 1 to maxIndex(blockSprite) do
        spriteVisible(blockSprite[q], FALSE);
    done;
    spriteVisible(batSprite, FALSE);
    spriteVisible(ballSprite, FALSE);
    cls();
    println("\n\n    --- BREAKOUT ---");
    println("\n\n    Last score: ", lastScore, "    Highscore: ", highScore);
    println("\n\n    Use the mouse to control the \"bat\"");
    println("    Press F12 to quit");
    println("\n\n    Press any key to start");
    flush();
    waitKey();
    setupNewGame();
    playRound();
endfunc;

autoFlush(FALSE);
while TRUE do
    playGame();
done;