// Square implementation

#include "grid.h"
#include "square.h"

Square::Square() {
}

// new square at grid position (x,y)
Square::Square(GP142Display *display, Grid *grid, int x, int y)  {
	squareInit(display,grid,x,y);
}


// copy constructor
Square::Square(const Square &source) {
	squareInit(source.display, source.grid, source.x, source.y);
}

// initialize or assign the square the values passed
void Square::squareInit(GP142Display *display, Grid *grid, int x, int y) {
	this->display = display;
	this->grid = grid;
	this->x = x;
	this->y = y;
	ableToMove = true;
}

// operator=  make square a copy of other
Square & Square::operator=(const Square &other) {
	if (this == &other)
		return *this;

	x = other.x;
	y = other.y;
	display = other.display;
	grid    = other.grid;
	return *this;
}

// draw rectangle of pixels corresponding to square at
// grid location (x,y)
void Square::Draw(GP142Color color) {
	display->drawRectangle(GRID_LEFT+x*SQUARE_WIDTH,GRID_BOTTOM+y*SQUARE_HEIGHT,
						  GRID_LEFT+(x+1)*SQUARE_WIDTH, GRID_BOTTOM+(y+1)*SQUARE_HEIGHT,
						  color,FILL);
}

// get x coordinate of square
int Square::getX() const {
	return x;
}

// get y coordinate of square
int Square::getY() const {
	return y;
}


// move square in direction d if possible
// if the square can move in direction d then change its coordinates
// to reflect the move
// if we try to move DOWN and can't then the block becomes frozen
void Square::Move(Direction d) {
	if (canMove(d)) {
		switch (d) {
		case DOWN:
			y = y - 1;
			break;
		// other cases needed

		case ERROR:
		default: // this shouldn't happen
			
			break;
		}
	}
	// freeze if we land on another block
	if (d == DOWN && !canMove(DOWN))
		ableToMove = false;
}



// return if the square can move in direction d 
// (we can't move below the grid or outside the boundaries)
bool Square::canMove(Direction d) const{
	if (!ableToMove)
		return false;

	bool move = true;
	switch(d) {
	case DOWN:
		if (y == 0 || grid->IsSet(x,y-1))
			move = false;
		break;
	case LEFT:
		if (x == 0 || grid->IsSet(x-1,y))
			move = false;
		break;
	case RIGHT:
		if (x == GRID_WIDTH-1 || grid->IsSet(x+1,y))
			move = false;
		break;
	case ERROR:
	default:
		move = false;
		break;
	}

	return move;
}