#ifndef CACHE_H
#define CACHE_H

/*
 * Build cache — per-project dirty detection.
 *
 * A small dotfile (.gbuild_cache) is kept inside each cloned repo dir.
 * It stores the git HEAD hash that was current at the last *successful*
 * build.  On the next run gbuild compares the live HEAD to the cached
 * one; if they match the build is skipped unless --force was passed.
 *
 * Format of .gbuild_cache (plain text, one line):
 *   <40-char sha1>\n
 */

#include <stddef.h>

/* Maximum length of a stored hash (SHA-1 hex + NUL). */
#define CACHE_HASH_LEN 64

/*
 * Read the cached hash for the repo at repo_path into out (>= CACHE_HASH_LEN
 * bytes).  Returns 0 on success, -1 if the file does not exist or is
 * unreadable (out is set to an empty string in that case).
 */
int cache_read(const char *repo_path, char *out, size_t n);

/*
 * Write hash as the new cached HEAD for the repo at repo_path.
 * Creates or overwrites .gbuild_cache inside repo_path.
 * Returns 0 on success, -1 on error.
 */
int cache_write(const char *repo_path, const char *hash);

#endif /* CACHE_H */