#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <conio.h> 	

#define MAX_NAME_LENGTH 24

//宣告函式原型 
void init_f();
void readStudentsFromFile(char* filename);
void insertStudent(char* name, int english, int math);
void printStudentList();
void sort(int mode , int target);
void modify_list();
void add_data(char* name, int english, int math);
void remove_data(char* name);
void choose_subject();

// 定義學生節點結構
typedef struct Student {
    char name[MAX_NAME_LENGTH];
    int english;
    int math;
    struct Student* llink;
    struct Student* rlink;
} Student;

Student *head, *tail, *current, *prev, *temp ,**arr;
FILE* file; 
int list_length ;

void init_f() {
    head = (Student *) malloc(sizeof(Student));
    tail = (Student *) malloc(sizeof(Student));
    
//    head->llink = head;    // 左鏈結指向自己
//    head->rlink = head;    // 右鏈結指向自己
//    tail = head;
    
//	head->llink = tail;
	head->rlink = tail;
//	tail->rlink = head;
	tail->llink = head;
}

// 在尾部插入新學生節點
void insertStudent(char* name, int english, int math) {

    Student* newNode = (Student*)malloc(sizeof(Student));
	
	strcpy(newNode->name, name);
    newNode->english = english;
    newNode->math = math;

//  插入尾部  
    newNode->llink = tail->llink;  
    newNode->rlink = tail;         
    tail->llink->rlink = newNode;  
    tail->llink = newNode;
}

//增加資料 
void add_data(char* name, int english, int math){
	Student* newNode = (Student*)malloc(sizeof(Student));
	
	strcpy(newNode->name, name);
    newNode->english = english;
    newNode->math = math;
    
    newNode->llink = tail->llink;  
    newNode->rlink = tail;         
    tail->llink->rlink = newNode;  
    tail->llink = newNode;
    printf("%s 已增加\n", name);
}

//減少資料 
void remove_data(char* name){

	prev = head;
    current = head->rlink;
    
	while(current!=tail &&strcmp(name,current->name)!=0){
		prev=current;
		current=current->rlink;
	}
	if(current != tail){
		
		current->rlink->llink = prev;
		prev->rlink = current->rlink;
		printf("%s 已刪除\n", name);
		free(current);
	}else  /* 找不到資料則顯示錯誤 */
        printf(" %s 不在串列中\n", name);
	
}

// 從文件讀取學生資料
void readStudentsFromFile(char* filename) {
    file = fopen(filename, "r");
    if (file == NULL) {
        printf("無法開啟檔案 %s\n", filename);
        exit(0);
    }

    char line[100];
    int lineCount = 0;

    // 跳過前四行
    while (lineCount < 4 && fgets(line, sizeof(line), file)) {
        lineCount++;
    }

    // 讀取學生資料
    char name[MAX_NAME_LENGTH];
    int english, math;
	// %[ ]表示要讀入一個字符集合  
	// %23[^\t]為「讀取最多23個字符，直到遇到\t為止」 ^為非 不是\t就讀  
	while(fgets(line, sizeof(line), file)!=NULL){
		if(isalpha(line[0])){
			sscanf(line, "%23[^\t]\t%d\t%d\n", name, &english, &math);
			insertStudent(name, english, math);
		}else if(line[0]=='*'){
			break;
		}
	}
//	此flocse為測試用 正常使用應在modify_list的尾端 
//	fclose(file);
}

// 執行***後的增加或減少資料 
void modify_list(){
	char name[MAX_NAME_LENGTH];
    int english, math;
	char line[100];
	
	while(fgets(line, sizeof(line), file)!=NULL){
		if(line[0]=='+'){
			sscanf(line, "%*[^ ] %[^\t]\t%d\t%d\n", name, &english, &math);
			printf("\n===============================\n");
	    	printf("增加一筆資料\n\n");
	    	add_data(name, english, math);
	    	printStudentList();
		}else if(line[0]=='-'){
			sscanf(line, "%*[^ ] %[^\t]\t%d\t%d\n", name, &english, &math);
			printf("\n===============================\n");
	    	printf("刪除一筆資料\n\n");
	    	remove_data(name);
	    	printStudentList();
	    }
	}
	fclose(file);
}

// 列印學生列表
void printStudentList() {
	
	current = head->rlink;
	
	printf("\n從頭開始\n");
    printf("\n姓名\t\t英文\t數學\n");
	printf("--------------------------------\n");
	
    while (current != tail) {
        printf("%-15s\t%d\t%d\n", current->name, current->english, current->math);
        current = current->rlink;
    }
    
    current = tail->llink;
    
    printf("\n從尾開始\n");
    printf("\n姓名\t\t英文\t數學\n");
    printf("--------------------------------\n");
    while (current != head) {
        printf("%-15s\t%d\t%d\n", current->name, current->english, current->math);
        current = current->llink;
    }
}

//依照mode進行排序 
void sort(int mode , int target){ 
	list_length =  0; 
	//若沒有資料或只有一筆資料 
	if (head->rlink == tail || head->rlink->rlink == tail) {
        return;
    }
    
    current = head->rlink;
    while(current!=tail){
    	list_length++;
    	current = current->rlink;
	}
    
	Student **arr = (Student**)malloc(list_length*(sizeof(Student*)));
	current = head->rlink;
    for(int i = 0; i < list_length; i++) {
        arr[i] = current;
        current = current->rlink;
    }
    
	for(int i = 0; i < list_length-1; i++) {
        for(int j = 0; j < list_length-1-i; j++) {
        	if(mode==0) {
        		if(strcmp(arr[j]->name, arr[j+1]->name) > 0){
        			Student *temp = arr[j];
	                arr[j] = arr[j+1];
	                arr[j+1] = temp;
				}
			}else if(mode==1){
				if(arr[j]->english < arr[j+1]->english ){
					Student *temp = arr[j+1];
	                arr[j+1] = arr[j];
	                arr[j] = temp;
				}
			} else if(mode==2){
				if(arr[j]->math < arr[j+1]->math ){
					Student *temp = arr[j+1];
	                arr[j+1] = arr[j];
	                arr[j] = temp;
				}
			} 
        }
    }
    
    if(target != -1){
    	if(target != 0 && target<=list_length){
			printf("排名第%d的學生為\n\n"
			"姓名\t\t英文\t數學\n%-15s\t%d\t%d", target, arr[target-1]->name, arr[target-1]->english, arr[target-1]->math);
			printf("\n*****************************\n");
		}else if(target == 0 && target >= list_length){
			printf("\n*****************************\n");
			printf("資料不存在"); 
			printf("\n*****************************\n");
		}
	}
	

	// 顯示排序後的結果  
    printf("\n排名\t姓名\t\t英文\t數學\n");
    printf("---------------------------------------------\n");
    for(int i = 0; i < list_length; i++) {
        printf("%d\t%-15s\t%d\t%d\n", i+1, arr[i]->name, arr[i]->english, arr[i]->math);
    }
    printf("---------------------------------------------\n");

} 

//選擇科目及排名 
void choose_subject(){
	int subject ,number , i=1;
	
	printf("\n輸入選擇的科目\n"
	"1 數學 2 英文 ==> ");
	subject = getche();
	switch(subject){
			case '1':
				printf("\n輸入排名(輸入完畢請按Enter) ==> ");
				scanf("%d",&number);
				printf("\n數學");
				sort(1,number);
				break;
			case '2':
				printf("\n輸入排名(輸入完畢請按Enter) ==> ");
				scanf("%d",&number);
				printf("\n英文");
				sort(2,number);	
				break;
			default :
				printf("輸入錯誤");
				break;
		}	
}

//釋放所有節點 
void freeAllNodes() {
    current = head->rlink;
    while (current != tail) {
        temp = current;
        current = current->rlink;
        free(temp);
    }
    free(head);  // 釋放 head 節點
    free(tail);	 // 釋放 tail 節點
    free(arr);
}

int main() {
	char mode ,sort_mode , name[15];
	int english , math;
    init_f();
    readStudentsFromFile("YunTechStudents.txt");
    
    printStudentList();
    modify_list();
	
	while(1){
		printf("\n******* 選擇進行排序或是排名第n名的學生 *******\n"
			   "*--------------------------------------*\n"
			   "* 1 進行排序 2 選擇排名第n名的學生 3 結束 *\n"
			   "* 4 顯示原始串列 5 清除畫面 6 增加一筆資料 *\n"
			   "* 7 刪除一筆資料 *\n"
			   "\n請選擇功\能 ==> "); //不打成 功\能 在視窗中會變亂碼 
		mode = getche();
		switch(mode){
			case '1':
				printf("\n\n選擇排序方式\n"
			   	"*--------------------------------------*\n"
			   	"1 名字   2 英文成績   3 數學成績  \n"
			   	"\n請選擇排序方式 ==> "); 
				sort_mode = getche();
				switch(sort_mode){
					case '1':
						printf("\n\n以名字進行排序\n");
						sort(0 ,-1);
						break;
					case '2':
						printf("\n\n以英文成績進行排序\n");
						sort(1 ,-1);	
						break;
					case '3':
						printf("\n\n以數學成績進行排序\n");
						sort(2 ,-1);
						break;
					default:
						printf("\n輸入錯誤\n");
						break;
					} 
					break;
			case '2':
				choose_subject();
				break;
			case '3':
				printf("\n\n謝謝使用，Bye~\n");
				freeAllNodes();
				return 0;
			case '4':
				printStudentList();
				break;
			case '5':
				system("cls");
				break;
			case '6':
				printf("\n輸入名字 ==> ");
//				scanf("%[^\n]",name);
				
			    while(getchar() != '\n');  // 清除緩衝區
			    fgets(name, sizeof(name), stdin);
			    name[strcspn(name, "\n")] = '\0';  // 移除換行符
			    
				printf("\n輸入英文成績 ==> ");
				scanf("%d",&english);
				printf("\n輸入數學成績 ==> ");
				scanf("%d",&math);
				add_data(name,english,math);
				
				printStudentList();
				break;
			case '7':
				printf("\n欲刪除輸入名字 ==> ");
//				scanf("%[^\n]",name);
				
			    while(getchar() != '\n');  // 清除緩衝區
			    fgets(name, sizeof(name), stdin);
			    name[strcspn(name, "\n")] = '\0';  // 移除換行符
				remove_data(name);
				
				printStudentList();
				break;
			default:
				printf("\n輸入錯誤\n");
				break;
		} 
	}
}