#include<stdio.h>
#include<Windows.h>
#include<conio.h>
#include<stdlib.h>
#include<time.h>
#define HEAD 1
#define TAIL 2
int score = 0;
bool lastwin = false;
unsigned long speed = 505;
typedef struct Snake
{
	int ch;
	COORD pos;
	Snake *next;
	Snake *last;
} *PriSna;
PriSna s;
PriSna tail = NULL;
int sx, sy;
void goto_x_y(int x, int y);
void Creatsnake(int len = 1);
void gamestart();
void Drawseed();
void goto_x_y(int x, int y)
{
	HANDLE hout = GetStdHandle(STD_OUTPUT_HANDLE);
	COORD pt;
	pt.X = x;
	pt.Y = y;
	SetConsoleCursorPosition(hout, pt);
	CONSOLE_CURSOR_INFO set = { 1,0 };
	SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE), &set); //隱藏游標
}
 
 
void Creatsnake(int len)  //蛇的身體
{
	if (s->next == NULL)
	{
		tail = s;
	}
	for (int i = 0; i < len; i++)
	{
		tail->next = new Snake[1];
		tail->next->last = tail;
		tail = tail->next;
		tail->ch = TAIL;
		tail->pos = tail->last->pos;
		tail->next = NULL;
	}
}
 
 
void DrawMap()
{
	for (int i = 0; i < 40; i++)
	{
		printf("□");
	}
	for (int i = 0; i < 22; i++)
	{
		goto_x_y(0, i + 1);
		printf("□");
		goto_x_y(78, i + 1);
		printf("□");
	}
	goto_x_y(0, 23);
	for (int i = 0; i < 40; i++)
	{
		printf("□");
	}
	goto_x_y(0, 24);
	printf("wasd控制反向，z暫停，自動變速; MADE BY TOUYI");
	goto_x_y(65, 24);
	printf("score:00");
	goto_x_y(0, 0);
}
 
 
bool judgegame()
{
	if (s->pos.X >= 79 || s->pos.X <= 2 || s->pos.Y>22 || s->pos.Y < 1)
		return true;
	else
	{
		PriSna t = s->next;
		while (t != NULL)
		{
			if (s->pos.X == t->pos.X&&s->pos.Y == t->pos.Y)
				return true;
			t = t->next;
		}
	}
	return false;
}
 
 
bool Drawsnake(char cha)
{
	if (cha == 't')
	{
		int two = 2;
		PriSna t = s;
		while (two--)
		{
			goto_x_y(t->pos.X - 2, t->pos.Y);
			if (t->ch == HEAD)
				printf("●");
			else
				printf("■");
			goto_x_y(0, 0);
			t = t->next;
		}
		return true;
	}
	if (cha == 'z' || cha == 'Z')
	{
		PriSna t = s;
		while (t != NULL)
		{
			goto_x_y(t->pos.X - 2, t->pos.Y);
			if (t->ch == HEAD)
				printf("●");
			else
				printf("■");
			goto_x_y(0, 0);
			t = t->next;
		}
	}
	else
	{
		PriSna t;
		if (cha == 'a' || cha == 'A')
		{
			goto_x_y(tail->pos.X, tail->pos.Y);
			t = tail;
			tail = tail->last;
			tail->next = NULL;
			printf("\b \b");
			goto_x_y(s->pos.X, s->pos.Y);
			(*t) = (*s);
			t->ch = TAIL;
			t->next->last = t;
			t->last = s;
			s->next = t;
			s->pos.X -= 2;
			printf("\b \b");
			Drawsnake('t');
		}
		else if (cha == 's' || cha == 'S')
		{
			goto_x_y(tail->pos.X, tail->pos.Y);
			t = tail;
			tail = tail->last;
			tail->next = NULL;
			printf("\b \b");
			goto_x_y(s->pos.X, s->pos.Y);
			(*t) = (*s);
			t->ch = TAIL;
			t->next->last = t;
			t->last = s;
			s->next = t;
			s->pos.Y++;
			printf("\b \b");
			Drawsnake('t');
		}
		else if (cha == 'd' || cha == 'D')
		{
			goto_x_y(tail->pos.X, tail->pos.Y);
			t = tail;
			tail = tail->last;
			tail->next = NULL;
			printf("\b \b");
			goto_x_y(s->pos.X, s->pos.Y);
			(*t) = (*s);
			t->ch = TAIL;
			t->next->last = t;
			t->last = s;
			s->next = t;
			s->pos.X += 2;
			printf("\b \b");
			Drawsnake('t');
		}
		else if (cha == 'w' || cha == 'W')
		{
			goto_x_y(tail->pos.X, tail->pos.Y);
			t = tail;
			tail = tail->last;
			tail->next = NULL;
			printf("\b \b");
			goto_x_y(s->pos.X, s->pos.Y);
			(*t) = (*s);
			t->ch = TAIL;
			t->next->last = t;
			t->last = s;
			s->next = t;
			s->pos.Y--;
			printf("\b \b");
			Drawsnake('t');
		}
	}
	if (s->pos.X == sx + 2 && s->pos.Y == sy)
	{
		Drawseed();
		Creatsnake();
		score += 10;
		goto_x_y(71, 24);
		speed -= 10;
		printf("%d", score);
		return true;
	}
	if (judgegame())
		return false;
	return true;
}
 
 
bool judge(int x, int y)
{
	PriSna t = s;
	while (t != NULL)
	{
		if (t->pos.X == x && t->pos.Y == y)
			return false;
		t = t->next;
	}
	return true;
}
 
 
void Drawseed()  //畫食物
{
	srand((unsigned)time(NULL));
	while (1)
	{
		sx = ((rand() % 38) + 1) * 2;
		sy = (rand() % 22) + 1;
		if (judge(sx, sy))
		{
			break;
		}
	}
	goto_x_y(sx, sy);
	printf("▲");
	goto_x_y(0, 0);
}
 
 
void init()
{
	s = new Snake[1];
	PriSna p = s;
	s->pos.X = 16;
	s->pos.Y = 1;
	s->ch = HEAD;
	s->next = NULL;
	s->last = NULL;
	Creatsnake(3);
	p = p->next;
	for (int i = 1; i < 4; i++)
	{
		p->pos.X = (SHORT)(16 - i * 2);
		p->pos.Y = 1;
		p->ch = TAIL;
		p = p->next;
	}
	Drawsnake('z');
	Drawseed();
}
void gamestart()
{
	char ch = 'z', tch = 'd';
	//unsigned long speed = 1000;
	while (1)
	{
		if (_kbhit())
		{
			tch = ch;
			ch = _getch();
		}
		/*if (ch <= '5' && ch > '0')
		{
		speed = (unsigned long)((ch - '0') * 100);
		ch = tch;
		}
		else */
		if (ch == 'z' || ch == 'Z')  //暫停
		{
			_getch();
			ch = tch;
		}
		else if (ch == 'a' || ch == 'A' || ch == 'S' || ch == 's' || ch == 'd' || ch == 'D' || ch == 'W' || ch == 'w')
		{
			if (((ch == 'W' || ch == 'w') && (tch == 's' || tch == 'S')) || ((ch == 'd' || ch == 'D') && (tch == 'a' || tch == 'A')) || ((ch == 's' || ch == 'S') && (tch == 'w' || tch == 'W')) || ((ch == 'a' || ch == 'A') && (tch == 'd' || tch == 'D')))
			{
				ch = tch;
				continue;
			}
			tch = ch;
			if (Drawsnake(ch) == false && lastwin == false)
			{
				goto_x_y(35, 10);
				printf("game over!");
				break;
			}
			else if (lastwin == true)
				break;
		}
		else if (ch == 'q' || ch == 'Q')
			break;
		else
			ch = tch;
		Sleep(speed);
	}
	//此處結束
}
int main()
{
	init();
	DrawMap();
	gamestart();
	_getch();
	return 0;
}