/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"
#include "commit.h"
#include "tree.h"
#include "builtin.h"
#include "utf8.h"

static const char commit_tree_usage[] = "git commit-tree <sha1> [(-p <sha1>)...] < changelog";

static void new_parent(struct commit *parent, struct commit_list **parents_p)
{
	unsigned char *sha1 = parent->object.sha1;
	struct commit_list *parents;
	for (parents = *parents_p; parents; parents = parents->next) {
		if (parents->item == parent) {
			error("duplicate parent %s ignored", sha1_to_hex(sha1));
			return;
		}
		parents_p = &parents->next;
	}
	commit_list_insert(parent, parents_p);
}

int cmd_commit_tree(int argc, const char **argv, const char *prefix)
{
	int i;
	struct commit_list *parents = NULL;
	unsigned char tree_sha1[20];
	unsigned char commit_sha1[20];
	struct strbuf buffer = STRBUF_INIT;

	git_config(git_default_config, NULL);

	if (argc < 2 || !strcmp(argv[1], "-h"))
		usage(commit_tree_usage);
	if (get_sha1(argv[1], tree_sha1))
		die("Not a valid object name %s", argv[1]);

	for (i = 2; i < argc; i += 2) {
		unsigned char sha1[20];
		const char *a, *b;
		a = argv[i]; b = argv[i+1];
		if (!b || strcmp(a, "-p"))
			usage(commit_tree_usage);

		if (get_sha1(b, sha1))
			die("Not a valid object name %s", b);
		assert_sha1_type(sha1, OBJ_COMMIT);
		new_parent(lookup_commit(sha1), &parents);
	}

	if (strbuf_read(&buffer, 0, 0) < 0)
		die_errno("git commit-tree: failed to read");

	if (commit_tree(&buffer, tree_sha1, parents, commit_sha1, NULL)) {
		strbuf_release(&buffer);
		return 1;
	}

	printf("%s\n", sha1_to_hex(commit_sha1));
	strbuf_release(&buffer);
	return 0;
}