class Piece {
    static int lBorder, rBorder, uBorder, dBorder, st;
    field int x1, y1, x2, y2, x3, y3, x4, y4, piece, direction;
    field bool move;
    static Array st;

    constructor Piece new(int Ax1, int Ay1, int Ax2, int Ay2, int Ax3, int Ay3, int Ax4, int Ay4, int p) {
        let x1 = Ax1;
        let y1 = Ay1;
        let x2 = Ax2;
        let y2 = Ay2;
        let x3 = Ax3;
        let y3 = Ay3;
        let x4 = Ax4;
        let y4 = Ay4;
        let piece = p;
        let direction = 0;
        let move = true;
        return this;
    }
    
    function void init(){
        var int a;
        let lBorder = 0;
        let rBorder = 511;
        let uBorder = 0;
        let dBorder = 255;
        let st = Array.new(16);
        let st[0] = 1;
        while (a < 15){
            let a = a + 1;
            let st[a] = st[a - 1] + st[a - 1];
        }
        return;
    }

    method void dispose() {
        do Memory.deAlloc(this);
        return;
    }

    /** draws 2 rectangles also checks if there is a piece at the spawn which will indicate end of the game. */
    method bool draw() { 
        var bool finish;
        let finish = true;
        let finish = Piece.sample(x1,y1) & finish;
        let finish = Piece.sample(x2,y2) & finish;
        let finish = Piece.sample(x3,y3) & finish;
        let finish = Piece.sample(x4,y4) & finish;
        if (finish){
            do Screen.setColor(true);
            do Screen.drawRectangle(x1, y1, x2, y2);
            do Screen.drawRectangle(x3, y3, x4, y4);
            return true;
        }
        return false;
    }

    /** Erases the square from the screen. */
    method void erase() {
        do Screen.setColor(false);
        do Screen.drawRectangle(x1, y2, x2, y2);
        do Screen.drawRectangle(x3, y3, x4, y4);
        return;
    }
    /** checks if those coodinates hold any value > 0. */
    function bool sample(int x, int y){ 
        var int value, address, bit, memBlock;
        let memBlock = x / 16;
        let address = (32 * y) + memBlock + 16384;
        if (address > 24576){
            return false;
        }
        let value = Memory.peek(address);
        if (value = 0){
            return true;
            }
        return false;
    }
    
    method bool getMove(){
        return move;
    }
    
    /** Checks if the piece can move in the given direction(dir). */
    method bool fullSample(int dir){
        var int size1, size2, i, j;
        var bool result, flagUpon;     
        if (dir = 1){ //down
            let size1 = x2 - x1;
            let size2 = x4 - x3;
            let result = true;
            while (i < size1){ // for each block of the first rectangle
                let j = 0;
                let flagUpon = false;
                while (j < size2){ // for each block of the second rectangle
                    if ((x1 + i) = (x3 + j)){ // if this block of the first rectangle sits upon a block of the second rectangle
                        let flagUpon = true;
                    }
                    let result = result & Piece.sample(x3 + j, y4 + 1); // if there is a block under the second rectangle
                    let j = j + 16; // sets the coords for the next block of the second rectangle
                }
                if (~(flagUpon)){
                    let result = result & Piece.sample(x1 + i, y2 + 1); // if there is a block under the first rectangle
                }
                let i = i + 16; // sets the coords for the next block of the firs rectangle
            }    
            return result;
        }
        else{
            if (dir = 2){   //right
                let size1 = y2 - y1;
                let size2 = y4 - y3;
                let result = true;
                while (i < size1){
                    let j = 0;
                    let flagUpon = false;
                    while (j < size2){
                        if ((y1 + i) = (y3 + j)){
                            let flagUpon = true;
                        }
                        let result = result & Piece.sample(x4 + 1, (y3 + j));
                        let j = j + 16;  
                    }
                    if (~(flagUpon)){
                        let result = result & Piece.sample(x2 + 1, (y1 + i));
                    }
                    let i = i +16;
                }
                return result;
            }
            else{ // left
                let size1 = y2 - y1;
                let size2 = y4 - y3;
                let result = true;
                while (i < size2){
                    let j = 0;
                    let flagUpon = false;
                    while (j < size1){
                        if ((y3 + i) = (y1 + j)){
                            let flagUpon = true;
                        }
                        let result = result & Piece.sample(x1 - 1, (y1 + j));
                        let j = j + 16;
                    }
                    if (~(flagUpon)){
                        let result = result & Piece.sample(x3 - 1, (y3 + i));
                    }
                    let i = i + 16;
                }
                return result;
            } 
        }
    }
    
    /** Moves the game piece 16 pixels down. */
    method void moveDown() { 
        var int i;
        if ((y2 < dBorder) & (y4 < dBorder) & (move) & fullSample(1)) {
            while (i < 16){
                do Screen.setColor(false);
                do Screen.drawRectangle(x1, y1, x2, y1);
                do Screen.drawRectangle(x3, y3, x4, y3);
                let y1 = y1 + 1;
                let y2 = y2 + 1;
                let y3 = y3 + 1;
                let y4 = y4 + 1;
                do Screen.setColor(true);
                do Screen.drawRectangle(x1, y2, x2, y2);
                do Screen.drawRectangle(x3, y4, x4, y4);
                let i = i + 1;
                do Sys.wait(10);
            }
        }
        else{
            let move = false;
            }
        return;
    }
    
    /** Moves the game piece 16 pixels to the left. */
    method void moveLeft() {
        var int i;
        if ((x1 + 15 > lBorder) & (move) & (x3 + 15 > lBorder)& fullSample(0)){
            while (i < 16){
                do Screen.setColor(false);
                do Screen.drawRectangle(x2, y1, x2, y2);
                do Screen.drawRectangle(x4, y3, x4, y4);
                let x1 = x1 - 1;
                let x2 = x2 - 1;
                let x3 = x3 - 1;
                let x4 = x4 - 1;
                do Screen.setColor(true);
                do Screen.drawRectangle(x1, y1, x2, y2);
                do Screen.drawRectangle(x3, y3, x4, y4);
                let i = i + 1;
                do Sys.wait(10);
                }
        }    
        return;
    }
    
    /** Moves the game piece 16 pixels to the right. */
    method void moveRight() {
        var int i;
        if ((x4 < rBorder) & (move) & (x2 < rBorder) & fullSample(2)){
            while (i < 16){
                do Screen.setColor(false);
                do Screen.drawRectangle(x1, y1, x1, y2);
                do Screen.drawRectangle(x3, y3, x3, y4);
                let x1 = x1 + 1;
                let x2 = x2 + 1;
                let x3 = x3 + 1;
                let x4 = x4 + 1;
                do Screen.setColor(true);
                do Screen.drawRectangle(x1, y1, x2, y2);
                do Screen.drawRectangle(x3, y3, x4, y4);
                let i = i + 1;
                do Sys.wait(10);    
                } 
        }
        return;
    }
    
    /** Deletes the piece and draws it at the new coodinates. */
    method void reDraw(int Ax1, int Ay1, int Ax2, int Ay2, int Ax3, int Ay3, int Ax4, int Ay4){
        var int absTmp;
        if((Ax1 < 175) | (Ax3 < 175) | (Ax2 > 336) | (Ax4 > 336)){
            return;
        }
        if((Ay2 > 255) | (Ay4 > 255) | (Ay1 < 0) | (Ay3 < 0)){
            return;
        }
        if((Ax1 > Ax2) | (Ax3 > Ax4) | (Ay1 > Ay2) | (Ay3 > Ay4)){
            return;
        }
        do Screen.setColor(false);
        do Screen.drawRectangle(x1, y1, x2, y2);
        do Screen.drawRectangle(x3, y3, x4, y4);
        do Screen.setColor(true);
        let x1 = Ax1;
        let y1 = Ay1;
        let x2 = Ax2;
        let y2 = Ay2;
        let x3 = Ax3;
        let y3 = Ay3;
        let x4 = Ax4;
        let y4 = Ay4; 
        do Screen.drawRectangle(x1, y1, x2, y2);
        do Screen.drawRectangle(x3, y3, x4, y4);
        return;
    }
    
    /** Rotates the piece clockwise. */
    method void rotate(){
        var bool samp;
        let samp = true;
        if (direction = 0){ // starting position
            if (piece = 0){ // arrow
                let samp = Piece.sample(x4, y1) & samp; // checks if the place at which the new piece will be drawn are free
                let samp = Piece.sample(x4, y1 - 1) & samp;
                if (samp){
                    do reDraw(x1, y1, x2, y2, x4 - 15, y4 - 47, x4, y4); // redraws it at the new location
                    let direction = 1;
                }
            }
            if (piece = 1){ 
                let samp = Piece.sample(x1 + 16, y1) & samp;
                let samp = Piece.sample(x1 + 16, y1 - 16) & samp;
                let samp = Piece.sample(x4, y1 - 16) & samp;
                if(samp){
                    do reDraw(x1 + 16, y1 - 16, x4 - 16, y4, x4 - 15, y1 - 16, x4, y1 - 1);
                    let direction = 1;
                    }
                }
            if (piece = 2){
                let samp = Piece.sample(x1 - 16, y1 - 16) & samp;
                let samp = Piece.sample(x1 - 16, y1) & samp;
                if (samp){
                    do reDraw(x1 - 16, y1 - 16, x2 - 16, y2 + 16, x3 + 32, y3, x4, y4);
                    let direction = 1;
                }
            }
            if (piece = 3){
                let samp = Piece.sample(x3 + 16, y3 - 32) & samp;
                let samp = Piece.sample(x4, y4 - 16) & samp;
                if (samp){
                    do reDraw(x1 + 16, y1, x2, y2 + 16, x3 + 16, y3 - 32, x4, y4 - 16);
                    let direction = 1;
                }
            }
            if (piece = 4){
                let samp = Piece.sample(x3 + 32, y3 - 32) & samp;
                if (samp){
                    do reDraw(x1, y1, x2 - 16, y2 + 16, x3 + 32, y3 - 32, x4 + 16, y4 - 16);
                    let direction = 1;
                }
            }
            if (piece = 5){
                let samp = Piece.sample(x1 + 32, y1 - 32) & samp;
                let samp = Piece.sample(x2 + 16, y2 - 16) & samp;
                let samp = Piece.sample(x4 - 16, y4 + 16) & samp;
                if (samp){
                    do reDraw(x1 + 32, y1 - 32, x2 + 16, y2 - 16, x3, y3, x4 - 16, y4 + 16);
                    let direction = 1;
                }
            }    
        }
        else{
            if (direction = 1){
                if (piece = 0){
                    let samp = Piece.sample(x1, y3) & samp;
                    let samp = Piece.sample(x1 - 1, y3) & samp;
                    if (samp){
                        do reDraw(x1 - 16, y3, x4, y3 + 15, x1, y1, x2, y2);
                        let direction = 2;
                    }
                }
                if (piece = 1){
                    let samp = Piece.sample(x1 - 16, y1 + 16) & samp;
                    let samp = Piece.sample(x3, y3 + 16) & samp;
                    let samp = Piece.sample(x3, y3 + 32) & samp;
                    if (samp){
                        do reDraw(x1 - 16, y1 + 16, x4, y4 + 16, x3, y3 + 32, x4, y2);
                        let direction = 2;
                    }
                }
                if (piece = 2){
                    let samp = Piece.sample(x1 - 16, y1 + 16) & samp;
                    let samp = Piece.sample(x2 + 16, y2 - 16) & samp;
                    let samp = Piece.sample(x3 - 32, y3) & samp;
                    if (samp){
                        do reDraw(x1 - 16, y1 + 16, x2 + 16, y2 - 16, x3 - 32, y3, x4 - 32, y4);
                        let direction = 2;
                    }
                }
                if (piece = 3){
                    let samp = Piece.sample(x1 - 16, y1) & samp;
                    let samp = Piece.sample(x4, y4 + 16) & samp;
                    if (samp){
                        do reDraw(x1 - 16, y1, x2, y2 - 16, x3 - 16, y3 +32, x4, y4 + 16);
                        let direction = 2;
                    }
                }
                if (piece = 4){
                    let samp = Piece.sample(x3 - 32, y3 + 32) & samp;
                    if (samp){
                        do reDraw(x1, y1, x2 + 16, y2 - 16, x3 - 32, y3 + 32, x4 - 16, y4 + 16);
                        let direction = 2;
                    }
                }
                if (piece = 5){
                    let samp = Piece.sample(x1 - 16, y1 + 16) & samp;
                    let samp = Piece.sample(x3 + 16, y3 - 16) & samp;
                    let samp = Piece.sample(x4 + 32, y4 - 32) & samp;
                    if (samp){
                        do reDraw(x1 - 32, y1 + 16, x2 - 16, y2, x3, y3 - 16, x4 + 16, y4 - 32);
                        let direction = 2;
                    }
                } 
            }    
            else{
                if (direction = 2){
                    if (piece = 0){
                        let samp = Piece.sample(x1, y1+16) & samp;
                        let samp = Piece.sample(x1, y1+32) & samp;
                        if (samp){
                            do reDraw(x1, y1, x1 + 15, y1 + 47, x3, y3, x4, y4);
                            let direction = 3;
                        }
                    }
                    if (piece = 1){
                        let samp = Piece.sample(x1 - 16, y1 + 16) & samp;
                        let samp = Piece.sample(x3, y3 + 16) & samp;
                        let samp = Piece.sample(x3, y3 + 32) & samp;
                        if (samp){
                            do reDraw(x1, y1 + 16, x1 + 15, y1 + 31, x1 + 16, y1 - 16, x4 - 16, y4);
                            let direction = 3;    
                        }
                    }
                    if (piece = 2){
                        let samp = Piece.sample(x1, y1 - 16) & samp;
                        let samp = Piece.sample(x2 + 32, y2 + 16) & samp;
                        let samp = Piece.sample(x4 + 16, y4) & samp;
                        if (samp){
                            do reDraw(x1, y1 - 16, x2 - 32, y2 - 16, x3 + 16, y3 - 32, x4 + 16, y4);
                            let direction = 3;
                        }
                    }
                    if (piece = 3){
                        let samp = Piece.sample(x2 - 16, y2 + 16) & samp;
                        let samp = Piece.sample(x3, y3 - 32) & samp;
                        if (samp){
                            do reDraw(x1, y1, x2 - 16, y2 + 16, x3, y3 - 32, x4 - 16, y4 - 16);
                            let direction = 3;
                        }
                    }
                    if (piece = 4){
                        let samp = Piece.sample(x1 - 16, y1 - 16) & samp;
                        let samp = Piece.sample(x2 - 32, y2) & samp;
                        if (samp){
                            do reDraw(x1 - 16, y1 - 16, x2 - 32, y2, x3 + 16, y3 - 16, x4, y4);
                            let direction = 3;
                        }    
                    }
                    if (piece = 5){
                        let samp = Piece.sample(x1 + 16, y1 - 16) & samp;
                        let samp = Piece.sample(x3 - 16, y3 - 16) & samp;
                        let samp = Piece.sample(x4 - 32, y4 + 32) & samp;
                        if (samp){
                            do reDraw(x1 + 16, y1 - 16, x2, y2, x3 - 16, y3 + 16, x4 - 32, y4 + 32);
                            let direction = 3;
                        }
                    } 
                }
                else{
                    if (piece = 0){
                        let samp = Piece.sample(x4 + 16, y4) & samp;
                        let samp = Piece.sample(x4 + 32, y4) & samp;
                        if (samp){
                            do reDraw(x3, y3, x4, y4, x1, y1 + 32, x1 + 47, y1 + 47);
                            let direction = 0;
                        }
                    }
                    if (piece = 1){
                        let samp = Piece.sample(x1, y1 - 16) & samp;
                        let samp = Piece.sample(x4 + 16, y4) & samp;
                        if (samp){
                            do reDraw(x1, y1 - 16, x2, y2 -16, x1, y1, x4 + 16, y4);
                            let direction = 0;    
                        }
                    }
                    if (piece = 2){
                        let samp = Piece.sample(x1 + 32, y1 + 16) & samp;
                        let samp = Piece.sample(x3 - 16, y3 + 32) & samp;
                        let samp = Piece.sample(x4 + 16, y4) & samp;
                        if (samp){
                            do reDraw(x1 + 32, y1 + 16, x2 + 32, y2 + 16, x3 - 16, y3 + 32, x4 + 16, y4);
                            let direction = 0;    
                        }
                    }
                    if (piece = 3){
                        let samp = Piece.sample(x3, y3 + 32) & samp;
                        let samp = Piece.sample(x4 + 16, y4 + 16) & samp;
                        if (samp){
                            do reDraw(x1, y1, x2 + 16, y2 - 16, x3, y3 + 32, x4 + 16, y4 + 16);
                            let direction = 0;
                        }
                    }
                    if (piece = 4){
                        let samp = Piece.sample(x3 - 16, y3 + 16) & samp;
                        let samp = Piece.sample(x2 + 32, y2) & samp;
                        if (samp){
                            do reDraw(x1 + 16, y1 + 16, x2 + 32, y2, x3 - 16, y3 + 16, x4, y4);
                            let direction = 0;
                        }    
                    }
                    if (piece = 5){
                        let samp = Piece.sample(x1 - 16, y1 + 32) & samp;
                        let samp = Piece.sample(x3 + 16, y3) & samp;
                        let samp = Piece.sample(x4 + 32, y4 - 16) & samp;
                        if (samp){
                            do reDraw(x1 - 16, y1 + 32, x2, y2 + 16, x3 + 16, y3, x4 + 32, y4 - 16);
                            let direction = 0;
                        }
                    } 
                }
            }   
        }
        return;
    }
}