#include "HaD_Badge.h"
#include <stdlib.h>

uint32_t tick = 150;
uint32_t nextTick = 0;
uint8_t started = 0;
uint8_t gameOverFlag = 0;

uint8_t snakeElementX[128];
uint8_t snakeElementY[128];
uint8_t snakeSize = 0;

uint8_t direction;
uint8_t newPositionX = 0;
uint8_t newPositionY = 0;

uint8_t eggX = 0;
uint8_t eggY = 0;

void newGame() {
	displayClear();

	snakeSize = 3;
	snakeElementX[0] = 5;
	snakeElementX[1] = 5;
	snakeElementX[2] = 5;
	snakeElementY[0] = 11;
	snakeElementY[1] = 12;
	snakeElementY[2] = 13;

	for (uint8_t i = 0; i < snakeSize; i++) {
		displayPixel(snakeElementX[i], snakeElementY[i], ON);
	}
	
	eggX = 3;
	eggY = 7;
	displayPixel(eggX, eggY, ON);

	displayLatch();

	nextTick = 0;
	started = 0;

	getControl();
}

void gameOver() {
	gameOverFlag = 1;
	
	for (uint8_t i = 0; i < 15; i++) {
		for (uint8_t j = 0; j < snakeSize; j++) {
			displayPixel(snakeElementX[j], snakeElementY[j], i % 2);
		}
		displayLatch();
		controlDelayMs(100);
	}

	gameOverFlag = 0;
}

void placeEgg() {
	//displayPixel(eggX, eggY, OFF);

	uint8_t tInt = 1;
	do {
		tInt = 0;
		srand ((int)getTime());
        eggX = rand() % 7;
		eggY = rand() % 15;

		for (uint8_t i = 0; i < snakeSize; i++) {
			if (snakeElementX[i] == eggX && snakeElementY[i] == eggY) {
				tInt = 1;		
				break;
			} 
		}
	} while (tInt == 1);

	displayPixel(eggX, eggY, ON);
	displayLatch();  
}

void moveSnake() {
	if (gameOverFlag) {
		return;
	}

	if (newPositionX < 0 || newPositionX > 7 || newPositionY < 0 || newPositionY > 15) {
		gameOver();
		newGame();
		return;
	}

	for (uint8_t i = 3; i < snakeSize; i++) {
		if (snakeElementX[i] == newPositionX && snakeElementY[i] == newPositionY) {
			gameOver();
			newGame();
			return;
		} 
	}
	
	if (newPositionX == eggX && newPositionY == eggY) {
		++snakeSize;

		for (uint8_t i = snakeSize - 1; i > 0; i--) {
			snakeElementX[i] = snakeElementX[i - 1];
			snakeElementY[i] = snakeElementY[i - 1];
		}
		
		snakeElementX[0] = newPositionX;
		snakeElementY[0] = newPositionY;

		placeEgg();
	} else {
		displayPixel(snakeElementX[snakeSize - 1], snakeElementY[snakeSize - 1], OFF);

		for (uint8_t i = snakeSize; i > 1; i--) {
			snakeElementX[i - 1] = snakeElementX[i - 2];
			snakeElementY[i - 1] = snakeElementY[i - 2];
		}

		snakeElementX[0] = newPositionX;
		snakeElementY[0] = newPositionY;

		displayPixel(snakeElementX[0], snakeElementY[0], ON);
		displayLatch();
	}

	nextTick = getTime() + tick;
}

uint8_t checkDirection(uint8_t tDirection) {
	if (gameOverFlag) {
		return 0;
	}	
	
	uint8_t tX = snakeElementX[0];	
	uint8_t tY = snakeElementY[0];	
	
	if (tDirection == UP) {
		--tY;
	} else if (tDirection == DOWN) {
		++tY;	
	} else if (tDirection == LEFT) {
		--tX;	
	} else if (tDirection == RIGHT) {
		++tX;	
	}	
	
	if (snakeElementX[1] != tX || snakeElementY[1] != tY) {
		newPositionX = tX;
		newPositionY = tY;
		direction = tDirection;
		return 1;
	}

	return 0;
}

void animateBadge(void) {	
	newGame();

	while(1) {
		switch (getControl()) {
        		case (ESCAPE):
		                displayClose();
                		return;
			case (UP):
				if (checkDirection(UP)) {
					started = 1;
				}
                		break;
		        case (DOWN):
				if (checkDirection(DOWN)) {
					started = 1;
				}
                		break;
            		case (LEFT):
				if (checkDirection(LEFT)) {
					started = 1;
				}
                		break;
			case (RIGHT):
				if (checkDirection(RIGHT)) {
					started = 1;
				}
				break;
		}
		
		if (started && nextTick < getTime()) {
			nextTick = getTime() + tick;
			checkDirection(direction);
			moveSnake();
		}					
	}
}