#include "test-tool.h"
#include "cache.h"
#include "mergesort.h"

struct line {
        char *text;
        struct line *next;
};

static void *get_next(const void *a)
{
        return ((const struct line *)a)->next;
}

static void set_next(void *a, void *b)
{
        ((struct line *)a)->next = b;
}

static int compare_strings(const void *a, const void *b)
{
        const struct line *x = a, *y = b;
        return strcmp(x->text, y->text);
}

int cmd__mergesort(int argc, const char **argv)
{
        struct line *line, *p = NULL, *lines = NULL;
        struct strbuf sb = STRBUF_INIT;

        for (;;) {
                if (strbuf_getwholeline(&sb, stdin, '\n'))
                        break;
                line = xmalloc(sizeof(struct line));
                line->text = strbuf_detach(&sb, NULL);
                if (p) {
                        line->next = p->next;
                        p->next = line;
                } else {
                        line->next = NULL;
                        lines = line;
                }
                p = line;
        }

        lines = llist_mergesort(lines, get_next, set_next, compare_strings);

        while (lines) {
                printf("%s", lines->text);
                lines = lines->next;
        }
        return 0;
}