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

typedef struct {
    char tenHang[25];
    int donGia;
    int soLuong;
    float thanhTien;
}ThongKe;

typedef struct NODE {
    ThongKe SoLieu;
    struct NODE* next;
}NODE;

typedef struct {
    NODE* first;
    NODE* last;
}DS;

NODE* taoSoLieu()
{
    NODE* node = (NODE*)calloc(1 ,sizeof(NODE));
    fflush(stdin);
    printf("\t\tTen don hang: ");
    gets(node->SoLieu.tenHang);
    fflush(stdin);
    do
    {
        printf("\t\tDon gia: ");
        scanf("%d", &node->SoLieu.donGia);
    }while (node->SoLieu.donGia < 0);
    fflush(stdin);
    do
    {
        printf("\t\tSo luong: ");
        scanf("%d", &node->SoLieu.soLuong);
    }while (node->SoLieu.soLuong < 0);
    fflush(stdin);
    node->next = NULL;
    return node;
}

DS* taoDanhSach(int n)
{
    int i;
    DS* ds = (DS*)calloc(1, sizeof(DS));
    ds->first = NULL;
    ds->last = NULL;
    NODE* node = NULL;
    for (i=0; i<n; i++)
    {
        printf("\t\tDon hang thu %d\n", i+1);
        node = taoSoLieu();
        if (ds->first == NULL)
        {
            ds->first = node;
            ds->last = node;
        }
        else
        {
            ds->last->next = node;
            ds->last = node;
        }
    }
}

void inDanhSach(DS* ds)
{
    int i=1;
    NODE* tmp = ds->first;
    printf("\t\t\t SO LIEU BAN HANG\n");
    printf("\t\t_%5s_%25s_%10s_%10s_%15s_\n", "_____", "_________________________", "__________", "__________", "_______________");
    printf("\t\t|%5s|%25s|%10s|%10s|%15s|\n", "STT", "Ten Hang", "Don Gia", "So Luong", "Thanh Tien");
    printf("\t\t|%5s+%25s+%10s+%10s+%15s|\n", "-----", "-------------------------", "----------", "----------", "---------------");
    while (tmp != NULL)
    {
        printf("\t\t|%5d|%25s|%10d|%10d|%15.3f|\n", i++, tmp->SoLieu.tenHang, tmp->SoLieu.donGia, tmp->SoLieu.soLuong, (float)(tmp->SoLieu.donGia * tmp->SoLieu.soLuong));
        tmp = tmp->next;
    }
    printf("\t\t|%5s_%25s_%10s_%10s_%15s|\n", "_____", "_________________________", "__________", "__________", "_______________");
}

void giaiPhong(DS* ds)
{
    NODE* tmp = NULL;
    NODE* del = NULL;
    del = tmp = ds->first;
    while (tmp != NULL)
    {
        tmp = tmp->next;
        free(del);
        del = tmp;
    }
}

void themHang(DS* ds, NODE* node)
{
    ds->last->next = node;
    ds->last = node;
}

int main()
{
    int n, chon;
    char select;
    DS* ds = NULL;
    label:
    printf("\t\t\t Bang chon\n");
    printf("\t\t ______________________________ \n");
    printf("\t\t|1. Nhap so lieu ban hang      |\n");
    printf("\t\t|2. Bo sung so lieu ban hang   |\n");
    printf("\t\t|3. Hien thi so lieu ban hang  |\n");
    printf("\t\t|4. Ket thuc                   |\n");
    printf("\t\t|______________________________|\n");
    printf("\t\tMoi chon: ");
    scanf("%d", &chon);
    switch (chon)
    {
        case 1:
        {
            printf("\t\tNhap so luong hang: ");
            scanf("%d", &n);
            ds = taoDanhSach(n);
            goto label;
        }
        case 2:
        {
            NODE* node = NULL;
            do
            {
                node = taoSoLieu();
                printf("\n\t\tNhap nua khong (y/n):  ");
                scanf("%s", &select);
            }
            while (select != 'n');
            printf("\n");
            goto label;
        }
        case 3:
        {
            inDanhSach(ds);
            goto label;
        }
        case 4:
        {
            giaiPhong(ds);
            exit(0);
        }
        default:
        {
            printf("\t\tNhap sai, nhap lai\n");
            goto label;
        }
    }
    return 0;
}