#include <stdio.h>
#define LEN 10

typedef struct {
char title[31];
char artist[31];
long duration; } song_t;

void clearbuffer(void)
{
    while(getchar() != '\n');
    return;
}

void insertItem(song_t items[], long len)
{
    int i=0;
    while(items[i].duration && i++<LEN);
    if(i==LEN)
    {
        printf("KEIN PLATZ FREI!\n");
        return;
    }
    printf("TITEL: ");
    scanf("%s", items[i].title);
    clearbuffer();
    printf("INTERPRET: ");
    scanf("%s", items[i].artist);
    clearbuffer();
    printf("LAENGE: ");
    scanf("%ld", &items[i].duration);
    clearbuffer();
    return;
}


void printItem(song_t *item)
{
    printf("%s - %s - %ld\n",item->title, item->artist,
                item->duration);
}

void printList(song_t items[], long len)
{
    int i;
    for(i=0;i<len;i++)
        if(items[i].duration)
            printItem(&items[i]);
}

void swap(song_t *a, song_t *b)
{
    song_t t=*a;
    *a=*b;
    *b=t;
    return;
}


void sortListDsc(song_t items[], long len, long attr)
{
    int i, j;
    for(i=len-1;i>0;i--)
    {
        for(j=0;j<i;j++)
        {
            switch(attr)
            {
            case 0:
                if(items[j].title[0]<items[j+1].title[0])
                    swap(&items[j],&items[j+1]);
                break;
            case 1:
                if(items[j].artist[0]<items[j+1].artist[0])
                    swap(&items[j],&items[j+1]);
                break;
            case 2:
                if(items[j].duration<items[j+1].duration)
                    swap(&items[j],&items[j+1]);
                break;
            }
        }
    }
    return;
}

void sortListAsc(song_t items[], long len, long attr)
{
    int i, j;
    for(i=1;i<len-1;i++)
    {
        for(j=0;j<i;j++)
        {
            switch(attr)
            {
            case 0:
                if(items[j].title[0]>items[j+1].title[0])
                    swap(&items[j],&items[j+1]);
                break;
            case 1:
                if(items[j].artist[0]>items[j+1].artist[0])
                    swap(&items[j],&items[j+1]);
                break;
            case 2:
                if(items[j].duration>items[j+1].duration)
                    swap(&items[j],&items[j+1]);
                break;
            }
        }
    }
    return;
}


int main()
{
    char menusel;
    song_t tracklist[LEN]=
    {
        { "DEMOTITLE_1","DEMOARTIST_1", 10 },
        { "DEMOTITLE_2","DEMOARTIST_2", 20 },
        { "DEMOTITLE_3","DEMOARTIST_3", 30 },
        { "DEMOTITLE_4","DEMOARTIST_4", 40 },
        { "DEMOTITLE_5","DEMOARTIST_5", 500 }
    };

    while(1)
    {
        printf("\n\n\n");
        printf("-1- ALLE DATEN AUSGEBEN\n");
        printf("-2- EINTRAG HINZUFUEGEN\n\n");
        printf("SORTIEREN AUFSTEIGEND:\n");
        printf("-3- NACH TITEL\n");
        printf("-4- NACH INTEPRET\n");
        printf("-5- NACH LAENGE\n\n");
        printf("SORTIEREN ABSTEIGEND:\n");
        printf("-6- NACH TITEL\n");
        printf("-7- NACH INTEPRET\n");
        printf("-8- NACH LAENGE\n\n");
        printf("-9- ENDE \n");
        scanf("%c",&menusel);
        clearbuffer();
        switch(menusel)
        {
        case '1':
            printList(tracklist,LEN);
            break;
        case '2':
            insertItem(tracklist,LEN);
            break;
        case '3':
            sortListAsc(tracklist,LEN,0);
            break;
        case '4':
            sortListAsc(tracklist,LEN,1);
            break;
        case '5':
            sortListAsc(tracklist,LEN,2);
            break;
        case '6':
            sortListDsc(tracklist,LEN,0);
            break;
        case '7':
            sortListDsc(tracklist,LEN,1);
            break;
        case '8':
            sortListDsc(tracklist,LEN,2);
            break;
        case '9':
            return 0;
        default:
            continue;
        }
        printf("\n*** EINGABETASTE DRUECKEN ***\n");
        getchar();
    }
}