#include "cache.h"

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

/* Name of the dotfile kept inside each cloned repo. */
#define CACHE_FILENAME ".gbuild_cache"

/* ----------------------------------------------------------------- helpers */

static void cache_path(char *out, size_t n, const char *repo_path)
{
    snprintf(out, n, "%s/" CACHE_FILENAME, repo_path);
}

/* ----------------------------------------------------------------- public API */

int cache_read(const char *repo_path, char *out, size_t n)
{
    char path[1024];
    cache_path(path, sizeof(path), repo_path);

    out[0] = '\0';

    FILE *f = fopen(path, "r");
    if (!f)
        return -1;   /* file doesn't exist yet — not an error, just a cache miss */

    char buf[CACHE_HASH_LEN] = {0};
    int ok = (fgets(buf, sizeof(buf), f) != NULL);
    fclose(f);

    if (!ok || buf[0] == '\0')
        return -1;

    /* strip trailing newline */
    size_t l = strlen(buf);
    if (l > 0 && buf[l - 1] == '\n')
        buf[--l] = '\0';

    if (l == 0)
        return -1;

    strncpy(out, buf, n - 1);
    out[n - 1] = '\0';
    return 0;
}

int cache_write(const char *repo_path, const char *hash)
{
    char path[1024];
    cache_path(path, sizeof(path), repo_path);

    FILE *f = fopen(path, "w");
    if (!f) {
        fprintf(stderr, "[WARN ] cache_write: cannot open %s: %s\n",
                path, strerror(errno));
        return -1;
    }

    fprintf(f, "%s\n", hash);
    fclose(f);
    return 0;
}