/* This script file handles the game logic */

var maxColumn = 10;

var maxRow = 15;

var maxIndex = maxColumn * maxRow;

var board = new Array(maxIndex);

var component;

//Index function used instead of a 2D array

function index(column, row) {

    return column + (row * maxColumn);

}

function startNewGame() {

    //Calculate board size

    maxColumn = Math.floor(gameCanvas.width / gameCanvas.blockSize);

    maxRow = Math.floor(gameCanvas.height / gameCanvas.blockSize);

    maxIndex = maxRow * maxColumn;

    //Close dialogs

    dialog.hide();

    //Initialize Board

    board = new Array(maxIndex);

    gameCanvas.score = 0;

    for (var column = 0; column < maxColumn; column++) {

        for (var row = 0; row < maxRow; row++) {

            board[index(column, row)] = null;

            createBlock(column, row);

        }

    }

}

function createBlock(column, row) {

    if (component == null)

        component = Qt.createComponent("Block.qml");

    // Note that if Block.qml was not a local file, component.status would be

    // Loading and we should wait for the component's statusChanged() signal to

    // know when the file is downloaded and ready before calling createObject().

    if (component.status == Component.Ready) {

        var dynamicObject = component.createObject(gameCanvas);

        if (dynamicObject == null) {

            console.log("error creating block");

            console.log(component.errorString());

            return false;

        }

        dynamicObject.type = Math.floor(Math.random() * 3);

        dynamicObject.x = column * gameCanvas.blockSize;

        dynamicObject.y = row * gameCanvas.blockSize;

        dynamicObject.width = gameCanvas.blockSize;

        dynamicObject.height = gameCanvas.blockSize;

        board[index(column, row)] = dynamicObject;

    } else {

        console.log("error loading block component");

        console.log(component.errorString());

        return false;

    }

    return true;

}

var fillFound; //Set after a floodFill call to the number of blocks found

var floodBoard; //Set to 1 if the floodFill reaches off that node

//![1]

function handleClick(xPos, yPos) {

    var column = Math.floor(xPos / gameCanvas.blockSize);

    var row = Math.floor(yPos / gameCanvas.blockSize);

    if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)

        return;

    if (board[index(column, row)] == null)

        return;

    //If it's a valid block, remove it and all connected (does nothing if it's not connected)

    floodFill(column, row, -1);

    if (fillFound <= 0)

        return;

    gameCanvas.score += (fillFound - 1) * (fillFound - 1);

    shuffleDown();

    victoryCheck();

}

//![1]

function floodFill(column, row, type) {

    if (board[index(column, row)] == null)

        return;

    var first = false;

    if (type == -1) {

        first = true;

        type = board[index(column, row)].type;

        //Flood fill initialization

        fillFound = 0;

        floodBoard = new Array(maxIndex);

    }

    if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)

        return;

    if (floodBoard[index(column, row)] == 1 || (!first && type != board[index(column, row)].type))

        return;

    floodBoard[index(column, row)] = 1;

    floodFill(column + 1, row, type);

    floodFill(column - 1, row, type);

    floodFill(column, row + 1, type);

    floodFill(column, row - 1, type);

    if (first == true && fillFound == 0)

        return;     //Can't remove single blocks

    board[index(column, row)].opacity = 0;

    board[index(column, row)] = null;

    fillFound += 1;

}

function shuffleDown() {

    //Fall down

    for (var column = 0; column < maxColumn; column++) {

        var fallDist = 0;

        for (var row = maxRow - 1; row >= 0; row--) {

            if (board[index(column, row)] == null) {

                fallDist += 1;

            } else {

                if (fallDist > 0) {

                    var obj = board[index(column, row)];

                    obj.y += fallDist * gameCanvas.blockSize;

                    board[index(column, row + fallDist)] = obj;

                    board[index(column, row)] = null;

                }

            }

        }

    }

    //Fall to the left

    var fallDist = 0;

    for (var column = 0; column < maxColumn; column++) {

        if (board[index(column, maxRow - 1)] == null) {

            fallDist += 1;

        } else {

            if (fallDist > 0) {

                for (var row = 0; row < maxRow; row++) {

                    var obj = board[index(column, row)];

                    if (obj == null)

                        continue;

                    obj.x -= fallDist * gameCanvas.blockSize;

                    board[index(column - fallDist, row)] = obj;

                    board[index(column, row)] = null;

                }

            }

        }

    }

}

//![2]

function victoryCheck() {

    //Award bonus points if no blocks left

    var deservesBonus = true;

    for (var column = maxColumn - 1; column >= 0; column--)

        if (board[index(column, maxRow - 1)] != null)

        deservesBonus = false;

    if (deservesBonus)

        gameCanvas.score += 500;

    //Check whether game has finished

    if (deservesBonus || !(floodMoveCheck(0, maxRow - 1, -1)))

        dialog.show("Game Over. Your score is " + gameCanvas.score);

}

//![2]

//only floods up and right, to see if it can find adjacent same-typed blocks 

function floodMoveCheck(column, row, type) {

    if (column >= maxColumn || column < 0 || row >= maxRow || row < 0)

        return false;

    if (board[index(column, row)] == null)

        return false;

    var myType = board[index(column, row)].type;

    if (type == myType)

        return true;

    return floodMoveCheck(column + 1, row, myType) || floodMoveCheck(column, row - 1, board[index(column, row)].type);

}