#include "cache.h"
#include "dir.h"
#include "pathspec.h"

/*
 * Finds which of the given pathspecs match items in the index.
 *
 * For each pathspec, sets the corresponding entry in the seen[] array
 * (which should be specs items long, i.e. the same size as pathspec)
 * to the nature of the "closest" (i.e. most specific) match found for
 * that pathspec in the index, if it was a closer type of match than
 * the existing entry.  As an optimization, matching is skipped
 * altogether if seen[] already only contains non-zero entries.
 *
 * If seen[] has not already been written to, it may make sense
 * to use find_used_pathspec() instead.
 */
void fill_pathspec_matches(const char **pathspec, char *seen, int specs)
{
	int num_unmatched = 0, i;

	/*
	 * Since we are walking the index as if we were walking the directory,
	 * we have to mark the matched pathspec as seen; otherwise we will
	 * mistakenly think that the user gave a pathspec that did not match
	 * anything.
	 */
	for (i = 0; i < specs; i++)
		if (!seen[i])
			num_unmatched++;
	if (!num_unmatched)
		return;
	for (i = 0; i < active_nr; i++) {
		struct cache_entry *ce = active_cache[i];
		match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen);
	}
}

/*
 * Finds which of the given pathspecs match items in the index.
 *
 * This is a one-shot wrapper around fill_pathspec_matches() which
 * allocates, populates, and returns a seen[] array indicating the
 * nature of the "closest" (i.e. most specific) matches which each of
 * the given pathspecs achieves against all items in the index.
 */
char *find_used_pathspec(const char **pathspec)
{
	char *seen;
	int i;

	for (i = 0; pathspec[i];  i++)
		; /* just counting */
	seen = xcalloc(i, 1);
	fill_pathspec_matches(pathspec, seen, i);
	return seen;
}