#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<Windows.h>
#include<vector>
#include<string.h>
#include<time.h>
#include<cmath>

//(1,2,3,6,7,8)
using namespace std;

#define WIDTH	40
#define HEIGHT	20

#define SPACE	0
#define SNAKEHEAD	1
#define SNAKEBODY	2
#define EDGE	4
#define APPLE	5
#define POISON	6

#define UP		0
#define DOWN	1
#define LEFT	2
#define RIGHT	3


int area_left, area_right, area_top, area_bottom;

int score;
bool isLose;
bool isPause;
int canvas[HEIGHT + 1][WIDTH + 1] = {
    
     0 };
int snakeDir;

int sprint = 0;
int difficulty = 1;
int start = 0;
int exhabit = 0;
int start2 = 0;
int exhabit2 = 0;
int count = 0;
int edited = 0;

struct apple{
    
    
	int exit;
	int row;
	int col;
}apple;

struct POS {
    
    
	int row;
	int col;
	POS(int x, int y) :row(x), col(y) {
    
    }
};
struct POS lastBody = POS(1,1);
vector<POS> snake;

void gotoxy(int x, int y)
{
    
    
	HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);
	COORD pos;
	pos.X = x;
	pos.Y = y;
	SetConsoleCursorPosition(handle, pos);
}
void HideCursor()
{
    
    
	HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);
	CONSOLE_CURSOR_INFO cursor_info = {
    
     1,0 };
	SetConsoleCursorInfo(handle, &cursor_info);
}
void show()
{
    
    
	int i, j;
	gotoxy(0, 0);
	
	for (i = area_top; i <= area_bottom; i++)
	{
    
    
		for (j = area_left; j <= area_right; j++)
		{
    
    
			if (canvas[i][j] == SNAKEHEAD)
				printf("@");//head
			else if(canvas[i][j] == APPLE)
				printf("C");//food
			else if(canvas[i][j] == POISON)
				printf("X");
			else if (canvas[i][j] == EDGE)
				printf("#");//edge 
			else if (canvas[i][j] == SNAKEBODY)
				printf("*");//body			
			else printf(" ");//,SPACE
		}
		printf("\n");
	}
	
	printf("targrt:%d",(difficulty*difficulty)-difficulty+10);
	printf("score:%d\n", score);
	//printf("count:%d\n",count);
}


void startup()
{
    
    
	int i, j;
	area_left = 0;
	area_right = WIDTH;
	area_top = 0;
	area_bottom = HEIGHT;
	
	apple.exit = 1;
	apple.col = 3;
	apple.row = 3;
	
	snakeDir = DOWN;
	
	snake.push_back(POS(5, 5));
	snake.push_back(POS(5, 6));
	snake.push_back(POS(5, 7));
	snake.push_back(POS(5, 8));


	for(i=0;i<=HEIGHT;i++)
		for (j = 0; j <= WIDTH; j++)
		{
    
    
			if (j == area_left || j == area_right)
				canvas[i][j] = EDGE;
			else if (i == area_top || i == area_bottom)
				canvas[i][j] = EDGE;
			else canvas[i][j] = SPACE;
		}
		
	canvas[apple.row][apple.col] = APPLE;
	
	canvas[snake[0].row][snake[0].col] = SNAKEHEAD;
	for (i = 1; i < snake.size(); i++)
		canvas[snake[i].row][snake[i].col] = SNAKEBODY;
		
	srand(time(0));
}
void turnLeft()
{
    
    
	if(snakeDir != RIGHT && edited == 0){
    
    
		edited = 1;
		snakeDir = LEFT;
	}
}
void turnRight()
{
    
    
	if(snakeDir != LEFT && edited == 0){
    
    
		edited = 1;
		snakeDir = RIGHT;
	}
}
void turnUp()
{
    
    
	if(snakeDir != DOWN && edited == 0)
	{
    
    
		edited = 1;
		snakeDir = UP;
	}
}
void turnDown()
{
    
    
	if(snakeDir != UP && edited == 0){
    
    
		edited = 1;
		snakeDir = DOWN;
	}
}


int crack(){
    
    
	if(snake[0].row == 0 || snake[0].row == area_bottom || snake[0].col == 0 || snake[0].col == area_right || canvas[snake[0].row][snake[0].col] == SNAKEBODY)
		return 1;	
	return 0;
}

void snakeMove()
{
    
    
	int i;
	lastBody.row = snake[snake.size() - 1].row;
	lastBody.col = snake[snake.size() - 1].col;
	
	for (i = snake.size() - 1; i > 0; i--)
		snake[i] = snake[i - 1];

	switch (snakeDir)
	{
    
    
		case UP:	snake[0].row--; break;
		case DOWN:	snake[0].row++; break;
		case LEFT:	snake[0].col--; break;
		case RIGHT:	snake[0].col++; break;
	}
}

void refreshApple(){
    
    
	while(1){
    
    
		if(apple.exit == 0){
    
    
			apple.exit = 1;
			apple.row = rand()%(HEIGHT-1)+1;
			apple.col = rand()%(WIDTH-1)+1;
		}
		int flag = 0;
		for(int i = 0;i < snake.size();i++)
			if(apple.row == snake[i].row && apple.col == snake[i].col)
				flag = 1;
		if(flag == 0)
			break;
	}
	canvas[apple.row][apple.col] = APPLE;
}
int IsEat(){
    
    
	if(apple.exit==1 && snake[0].row == apple.row && snake[0].col == apple.col)
		return 1;
	return 0;
}
void updateWithInput()
{
    
    
	int i;
	for (i = 0; i < snake.size(); i++)
		canvas[snake[i].row][snake[i].col] = SPACE;
	char input;
	if (kbhit()) {
    
    
		input = getch();
		switch (input)
		{
    
    
		case 'a':
			turnLeft();
			if(sprint == 1)
				snakeMove();
			break;
		case 'w': 
			turnUp();
			if(sprint == 1)
				snakeMove();
			break;
		case 'd': 
			turnRight();
			if(sprint == 1)
				snakeMove();
			break;
		case 's': 
			turnDown();
			if(sprint == 1)
				snakeMove();
			break;
		case ' ':isPause = !isPause; break;
		default:
			break;
		}
	} 
	canvas[snake[0].row][snake[0].col] = SNAKEHEAD;
	for (i = 1; i < snake.size(); i++)
		canvas[snake[i].row][snake[i].col] = SNAKEBODY;
	if(apple.exit == 1 && IsEat()){
    
    
		apple.exit = 0;
		canvas[apple.row][apple.col] = SPACE;
		score++;
		snake.push_back(POS(lastBody.row,lastBody.col));//lastBody
		refreshApple();
	}
}
void updateWithoutInput()
{
    
    
	int i;
	for (i = 0; i < snake.size(); i++)
		canvas[snake[i].row][snake[i].col] = SPACE;
	//static int count = 0;
	count ++;
	if(difficulty <= 6){
    
    
		if(count >= (30 - difficulty - score/2)){
    
    
			count = 0;
			edited = 0;
			snakeMove();
		}
	}
	else if(difficulty >= 7){
    
    
		if(count >= (30-(pow((difficulty-4),2) - score/20))){
    
    
			count = 0;
			edited = 0;
			snakeMove();
		}
	}
	canvas[snake[0].row][snake[0].col] = SNAKEHEAD;
	for (i = 1; i < snake.size(); i++)
		canvas[snake[i].row][snake[i].col] = SNAKEBODY;
		if(apple.exit == 1 && IsEat()){
    
    
			apple.exit = 0;
			canvas[apple.row][apple.col] = SPACE;
			score++;
			snake.push_back(POS(lastBody.row,lastBody.col));
			refreshApple();
		}
}
void choose(){
    
    
	if(exhabit == 0){
    
    
		exhabit = 1;
		printf("Please choose speed\n\n"); 
		printf("1 ->very easy	2 -> easy	3 -> normal\n4 -> hard	5 -> very hard	6 -> crazy\n7 -> very crazy	8 -> hell	9 -> unbelievable");
	}
	
	if(kbhit()){
    
    
		start = 1;
		difficulty = getch() - '0';
		system("cls");
	}
	
	//scanf("%c",difficulty);
}
void choose2(){
    
    
	if(exhabit2 == 0){
    
    
		exhabit2 = 1;
		printf("Do you need sprint?\n\n"); 
		printf("enter y or n.\n");
	}
	
	if(kbhit()){
    
    
		start2 = 1;
		char tmp = getch();
		if(tmp == 'y')
			sprint = 1;
		if(tmp == 'n')
			sprint = 0;
		system("cls");
	}
	
}

int main()
{
    
    
	HideCursor();
	while(start == 0)
		choose();
	while(start2 == 0)
		choose2();
	
	startup();
	while (1)
	{
    
    
		show();
		updateWithInput();
		if (!isPause)
			updateWithoutInput();
		if (score == ((difficulty*difficulty)-difficulty+10)) 
		{
    
    
			//system("cls");
			printf("^V^\n*congratulations!!!\n");
			break;
		}
		if(crack() == 1){
    
    
			//system("cls");
			printf("T_T\nyou have lost!!!\n");
			break;
		}
		
		//_sleep(500);//faster than before
	}
	system("pause");
	return 0;
}