/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#include "reflog.h"

#include "repository.h"

#include "filebuf.h"

#include "signature.h"

#include "refdb.h"

#include <git2/sys/refdb_backend.h>

git_reflog_entry *git_reflog_entry__alloc(void)

{

	return git__calloc(1, sizeof(git_reflog_entry));

}

void git_reflog_entry__free(git_reflog_entry *entry)

{

	git_signature_free(entry->committer);

	git__free(entry->msg);

	git__free(entry);

}

void git_reflog_free(git_reflog *reflog)

{

	size_t i;

	git_reflog_entry *entry;

	if (reflog == NULL)

		return;

	if (reflog->db)

		GIT_REFCOUNT_DEC(reflog->db, git_refdb__free);

	for (i=0; i < reflog->entries.length; i++) {

		entry = git_vector_get(&reflog->entries, i);

		git_reflog_entry__free(entry);

	}

	git_vector_free(&reflog->entries);

	git__free(reflog->ref_name);

	git__free(reflog);

}

int git_reflog_read(git_reflog **reflog, git_repository *repo,  const char *name)

{

	git_refdb *refdb;

	int error;

	assert(reflog && repo && name);

	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)

		return error;

	return git_refdb_reflog_read(reflog, refdb, name);

}

int git_reflog_write(git_reflog *reflog)

{

	git_refdb *db;

	assert(reflog && reflog->db);

	db = reflog->db;

	return db->backend->reflog_write(db->backend, reflog);

}

int git_reflog_append(git_reflog *reflog, const git_oid *new_oid, const git_signature *committer, const char *msg)

{

	git_reflog_entry *entry;

	const git_reflog_entry *previous;

	const char *newline;

	assert(reflog && new_oid && committer);

	entry = git__calloc(1, sizeof(git_reflog_entry));

	GITERR_CHECK_ALLOC(entry);

	if ((git_signature_dup(&entry->committer, committer)) < 0)

		goto cleanup;

	if (msg != NULL) {

		if ((entry->msg = git__strdup(msg)) == NULL)

			goto cleanup;

		newline = strchr(msg, '\n');

		if (newline) {

			if (newline[1] != '\0') {

				giterr_set(GITERR_INVALID, "reflog message cannot contain newline");

				goto cleanup;

			}

			entry->msg[newline - msg] = '\0';

		}

	}

	previous = git_reflog_entry_byindex(reflog, 0);

	if (previous == NULL)

		git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO);

	else

		git_oid_cpy(&entry->oid_old, &previous->oid_cur);

	git_oid_cpy(&entry->oid_cur, new_oid);

	if (git_vector_insert(&reflog->entries, entry) < 0)

		goto cleanup;

	return 0;

cleanup:

	git_reflog_entry__free(entry);

	return -1;

}

int git_reflog_rename(git_repository *repo, const char *old_name, const char *new_name)

{

	git_refdb *refdb;

	int error;

	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)

		return -1;

	return refdb->backend->reflog_rename(refdb->backend, old_name, new_name);

}

int git_reflog_delete(git_repository *repo, const char *name)

{

	git_refdb *refdb;

	int error;

	if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)

		return -1;

	return refdb->backend->reflog_delete(refdb->backend, name);

}

size_t git_reflog_entrycount(git_reflog *reflog)

{

	assert(reflog);

	return reflog->entries.length;

}

const git_reflog_entry * git_reflog_entry_byindex(const git_reflog *reflog, size_t idx)

{

	assert(reflog);

	if (idx >= reflog->entries.length)

		return NULL;

	return git_vector_get(

		&reflog->entries, reflog_inverse_index(idx, reflog->entries.length));

}

const git_oid * git_reflog_entry_id_old(const git_reflog_entry *entry)

{

	assert(entry);

	return &entry->oid_old;

}

const git_oid * git_reflog_entry_id_new(const git_reflog_entry *entry)

{

	assert(entry);

	return &entry->oid_cur;

}

const git_signature * git_reflog_entry_committer(const git_reflog_entry *entry)

{

	assert(entry);

	return entry->committer;

}

const char * git_reflog_entry_message(const git_reflog_entry *entry)

{

	assert(entry);

	return entry->msg;

}

int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)

{

	size_t entrycount;

	git_reflog_entry *entry, *previous;

	entrycount = git_reflog_entrycount(reflog);

	entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);

	if (entry == NULL) {

		giterr_set(GITERR_REFERENCE, "no reflog entry at index %"PRIuZ, idx);

		return GIT_ENOTFOUND;

	}

	git_reflog_entry__free(entry);

	if (git_vector_remove(

			&reflog->entries, reflog_inverse_index(idx, entrycount)) < 0)

		return -1;

	if (!rewrite_previous_entry)

		return 0;

	/* No need to rewrite anything when removing the most recent entry */

	if (idx == 0)

		return 0;

	/* Have the latest entry just been dropped? */

	if (entrycount == 1)

		return 0;

	entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx - 1);

	/* If the oldest entry has just been removed... */

	if (idx == entrycount - 1) {

		/* ...clear the oid_old member of the "new" oldest entry */

		if (git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO) < 0)

			return -1;

		return 0;

	}

	previous = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);

	git_oid_cpy(&entry->oid_old, &previous->oid_cur);

	return 0;

}