#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <windows.h>
#include <time.h>
#include <string.h>

// * ============================
// * 定义按键
// * ============================
#define UP 'w'
//#define UP_2 38
#define DOWN 's'
//#define DOWN_2 40
#define LEFT 'a'
//#define LEFT_2 37
#define RIGHT 'd'
//#define RIGHT_2 40
#define CONFIG_ON 'x'
#define CONFIG_OFF 'c'
#define QUIT 'q'

// * ==========================
// * 基本功能函数
// * ==========================
int randint(int min, int max);
void HideCursor();
void gotoxy(int x, int y);
void gotoPrint(int x, int y, char *content);
void initGame();
void clearXY(int x, int y);
void clearConfigInfo();

// * ==========================
// * 游戏逻辑函数
// * ==========================
void getControl();
void gameLoop();
int ifGameEnd();
void createFood();
void snakeOverride();
void eatFood();
void changeBody();
void startMenu();
void gameOver();

void displayList();
void findMyInfo();

// * ==========================
// * 链表实现贪吃蛇身体
// * 定义蛇身体节点 结构体， 包含坐标（x, y), 和下一节点指针
// * ==========================
struct Snakes
{
	int x;
	int y;
	char type;
	struct Snakes *next;
};
typedef struct Snakes snake;


// * ==========================
// * 食物结构体， 包含坐标 (x, y) 和 每个食物所含分数（随机值）
// * ==========================
struct Food
{
	int x;
	int y;
	int score;
};

// * 蛇头和蛇尾节点
snake *head, *tail;
// * 声明食物结构体变量
struct Food food;

int score = 0;
int length = 1;
char cUserName[20];

// * 储存按键变量
char control = 0;

// * 游戏难度
int difficulty = 200;
int easy = 200;
int medium = 90;
int hard = 50;
int nightmare = 30;

// * 调试及相关变量
int paused = 0;
int endGame = 0;
int iQuit = 0;
unsigned int foodEaten = 0;
unsigned int configMode = 0;
unsigned int hitTimes = 0;

// * ==========================
// * main（）
int main(void)
{
	char cKey;

	srand((int)time(NULL));

	while (1)
	{
		system("cls");
		printf("输入用户名：");
		gets(cUserName);
		HideCursor();
		startMenu();
		initGame();
		gameLoop();
		fflush(stdin);
		
		printf("按 E 退出游戏.");
		cKey = _getch();
		if (cKey == 'e' || cKey == 'E')
		{
			break;
		}
		// 写入分数（）
		
	}
	
	gotoxy(0, 26);
	return 0;
}
// * ==========================
int randint(int min, int max)
{
	return rand() % (max - min + 1) + min;
}
// * ==========================
void HideCursor()
{
	CONSOLE_CURSOR_INFO cursor_info = { 1, 0 };
	SetConsoleCursorInfo(GetStdHandle(STD_OUTPUT_HANDLE), &cursor_info);
}
// * ==========================
void gotoxy(int x, int y)
{
	COORD pos = { x, y };
	HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
	SetConsoleCursorPosition(hOut, pos);
}

void gotoPrint(int x, int y, char *content)
{
	gotoxy(x, y);
	puts(content);
}
void clearXY(int x, int y)
{
	gotoxy(x, y);
	printf(" ");
}
// * ==========================
void initGame()
{
	int i;

	for (i = 0; i < 58; i++)
	{
		gotoPrint(i, 0, "#");
		gotoPrint(i, 25, "#");
	}
	for (i = 0; i < 26; i++)
	{
		gotoPrint(0, i, "#");
		gotoPrint(57, i, "#");
	}

	head = (snake*)malloc(sizeof(snake));
	head->x = 25;
	head->y = 10;
	head->next = NULL;
	tail = head;
	gotoPrint(head->x, head->y, "@");
	createFood();

	//gotoPrint(64, 8, "Welcome to play the Snake! ! !");
	//gotoPrint(64, 9, "---------Version: BETA--------");
	gotoPrint(64, 10, "按下 WASD 来控制");
	/*if (paused)
		gotoPrint(64, 11, "Press w a s d to continue.");
	else
		gotoPrint(64, 11, "Press p to pause game.");*/
	gotoPrint(64, 11, "按下 P 暂停游戏");
	gotoPrint(64, 12, "====================================");
	gotoxy(64, 14);
	printf("当前得分: %2d", score);
}

// * ==========================

void clearConfigInfo()
{
	int i, j;

	for (i = 20; i <= 26; i++)
	{
		for (j = 64; j <= 100; j++)
		{
			clearXY(j, i);
		}
	}
}

// * ==========================

void getControl()
{
	if (_kbhit())
	{
		hitTimes++;
		control = _getch();
	}
}

// * ==========================

int ifGameEnd()
{
	if (head->x == 57 || head->x == 0 || head->y == 25 || head->y == 0)
		return 1;

	snake *node = head->next;
	if (head != tail)
	{
		while (1)
		{
			if (node->x == head->x && node->y == head->y)
			{
				return 1;
				break;
			}
			if (node->next == NULL)
				break;
			node = node->next;
		}
	}
	return 0;
}

// * ==========================

void createFood()
{
	int x, y, score;

	score = randint(1, 3);

	snake *node = head;
	
LABLE:
	x = randint(1, 56);
	y = randint(1, 24);
	while (1)
	{
		if (node->x == x && node->y == y)
			goto LABLE;
		if (node->next == NULL)
			break;
		node = node->next;
	}

	food.x = x;
	food.y = y;
	food.score = score;
	gotoPrint(food.x, food.y, "*");
	foodEaten = 0;
}

// * ==========================

void snakeOverride()
{
	snake *node = head;

	while (1)
	{
		clearXY(node->x, node->y);
		if (node->next == NULL)
			break;
		node = node->next;
	}
	
	switch (control)
	{
	case UP:changeBody(); head->y--; paused = 0; break;
	case DOWN:changeBody(); head->y++; paused = 0; break;
	case LEFT:changeBody(); head->x--; paused = 0;  break;
	case RIGHT:changeBody(); head->x++; paused = 0; break;
	case QUIT:endGame = 1; break;
	default:paused = 1; break;
	}

	node = head;
	while (1)
	{
		gotoPrint(node->x, node->y, "O");
		if (node->next == NULL)
			break;
		node = node->next;
	}
	gotoPrint(head->x, head->y, "@");
}

// * ==========================

void eatFood()
{
	if (head->x == food.x && head->y == food.y)
	{
		foodEaten = 1;
		score += food.score;
		length += 1;
		tail->next = (snake*)malloc(sizeof(snake));
		tail->next->next = NULL;
		tail = tail->next;
	}
}

// * ==========================

void changeBody()
{
	snake *node = head->next;

	int x1 = head->x, y1 = head->y, x2, y2;

	if (tail != head)
	{
		while (1)
		{
			x2 = node->x;
			y2 = node->y;
			node->x = x1;
			node->y = y1;
			x1 = x2;
			y1 = y2;
			if (node->next == NULL)
				break;
			node = node->next;
		}
	}
}

// * ==========================

void displayList()
{
	FILE *fp;
	int iScore;
	char cUserName[20];
	char key;

	system("cls");
	gotoxy(0, 0);
	if ((fp = fopen("scoreBoard.txt", "r+")) == NULL)
	{
		printf(" 无法打开文件，请检查游戏完整性...");
		exit(0);
	}

	printf("\t\t\t\t排行榜\n\n");
	while (!feof(fp))
	{
		fscanf(fp, "%s%d\n", cUserName, &iScore);
		printf("\t\t%s:  %d\n\n", cUserName, iScore);
	}

	printf("\t\t\t\t按任意键继续");
	key = _getch();
	fclose(fp);
}

void findMyInfo(char myName[20])
{
	FILE *fp;
	char cUserName[20];
	int iScore;
	int iFound = 0;
	char key;

	system("cls");
	gotoxy(0, 0);
	if ((fp = fopen("scoreBoard.txt", "r+")) == NULL)
	{
		printf(" 无法打开文件，请检查游戏完整性...");
		exit(0);
	}

	while (!feof(fp))
	{
		fscanf(fp, "%s%d\n", cUserName, &iScore);
		if (strcmp(cUserName, myName) == 0)
		{
			iFound = 1;
			printf("\t\t\t\t查找情况：\n\n");
			printf("\t\t玩家：     %s\n\n", myName);
			printf("\t\t总分：     %d\n", iScore);
			break;
		}
	}
	if (iFound == 0)
	{
		printf("\t\t未找到你的信息\n");
	}
	printf("\t\t\t\t按任意键继续");
	key = _getch();
	fclose(fp);
}

void startMenu()
{
	int select;
	int i;

	system("cls");
	for (i = 0; i < 58; i++)
	{
		gotoPrint(i, 0, "#");
		gotoPrint(i, 25, "#");
	}
	for (i = 0; i < 26; i++)
	{
		gotoPrint(0, i, "#");
		gotoPrint(57, i, "#");
	}
	gotoPrint(1, 10, "=================Welcome to play the snake==============");
	gotoPrint(1, 12, "                                                        ");
	gotoPrint(1, 14, "                      请选择难度:                  ");
	gotoPrint(1, 16, "      1. 简单; 2. 普通; 3. 困难; 4. 噩梦; 5. 退出游戏");
	gotoPrint(1, 17, "      6. 显示排行榜; 7. 查看我的分数; ");
	gotoPrint(1, 19, "                    选项:");
	gotoxy(28, 19);
	scanf("%d", &select);
	switch (select)
	{
	case 1:difficulty = easy; break;
	case 2:difficulty = medium; break;
	case 3:difficulty = hard; break;
	case 4:difficulty = nightmare; break;
	case 5:system("cls"); exit(1); break;
	case 6: displayList(); system("cls"); startMenu(); break;
	case 7: findMyInfo(cUserName); system("cls"); startMenu(); break;
	default:break;
	}
	gotoPrint(1, 20, "                     Good Luck ! ! !                    ");
	Sleep(2000);
	system("cls");
}

// * ==========================

void gameOver()
{
	system("cls");
	int i;

	for (i = 0; i < 58; i++)
	{
		gotoPrint(i, 0, "#");
		gotoPrint(i, 25, "#");
	}
	for (i = 0; i < 26; i++)
	{
		gotoPrint(0, i, "#");
		gotoPrint(57, i, "#");
	}

	gotoPrint(1, 15, "=======================GAME OVER========================");
	gotoxy(1, 17);
	printf("                       最终得分: %d", score);
	
	Sleep(6000);
	gotoPrint(1, 19, "                    按任意键回到主菜单");
	while (1)
	{
		if (_kbhit())
			break;
	}
}

// * ==========================

void gameLoop()
{
	FILE *fp;

	system("cls");
	gotoxy(0, 0);
	if ((fp = fopen("scoreBoard.txt", "r+")) == NULL)
	{
		printf(" 无法打开文件，请检查游戏完整性...");
		exit(0);
	}
	while (!ifGameEnd() && !endGame)
	{
		if (foodEaten)
			createFood();
		getControl();
		eatFood();
		snakeOverride();

		gotoxy(64, 14);
		printf("当前得分: %2d", score);
		gotoxy(64, 15);
		printf("蛇身长度: %2d", length);
		
		Sleep(difficulty);
	}
	gameOver();
	fseek(fp, 0, SEEK_END);
	fprintf(fp, "\n%s %d\n", cUserName, score);
	fputc(EOF, fp);
	score = 0;
	fclose(fp);
}