/*
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2,
 * as published by the Free Software Foundation.
 *
 * In addition to the permissions in the GNU General Public License,
 * the authors give you unlimited permission to link the compiled
 * version of this file into combinations with other programs,
 * and to distribute those combinations without any restriction
 * coming from the use of this file.  (The General Public License
 * restrictions do apply in other respects; for example, they cover
 * modification of the file, and distribution when not linked into
 * a combined executable.)
 *
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */
#ifndef INCLUDE_git_index_h__
#define INCLUDE_git_index_h__

#include "common.h"
#include "types.h"
#include "oid.h"

/**
 * @file git2/index.h
 * @brief Git index parsing and manipulation routines
 * @defgroup git_index Git index parsing and manipulation routines
 * @ingroup Git
 * @{
 */
GIT_BEGIN_DECL

#define GIT_IDXENTRY_NAMEMASK  (0x0fff)
#define GIT_IDXENTRY_STAGEMASK (0x3000)
#define GIT_IDXENTRY_EXTENDED  (0x4000)
#define GIT_IDXENTRY_VALID     (0x8000)
#define GIT_IDXENTRY_STAGESHIFT 12

/** Time used in a git index entry */
typedef struct {
	git_time_t seconds;
	/* nsec should not be stored as time_t compatible */
	unsigned int nanoseconds;
} git_index_time;

/** Memory representation of a file entry in the index. */
typedef struct git_index_entry {
	git_index_time ctime;
	git_index_time mtime;

	unsigned int dev;
	unsigned int ino;
	unsigned int mode;
	unsigned int uid;
	unsigned int gid;
	git_off_t file_size;

	git_oid oid;

	unsigned short flags;
	unsigned short flags_extended;

	char *path;
} git_index_entry;


/**
 * Create a new Git index object as a memory representation
 * of the Git index file in 'index_path', without a repository
 * to back it.
 *
 * Since there is no ODB behind this index, any Index methods
 * which rely on the ODB (e.g. index_add) will fail with the
 * GIT_EBAREINDEX error code.
 *
 * @param index the pointer for the new index
 * @param index_path the path to the index file in disk
 * @return 0 on success; error code otherwise
 */
GIT_EXTERN(int) git_index_open_bare(git_index **index, const char *index_path);

/**
 * Open the Index inside the git repository pointed
 * by 'repo'.
 *
 * @param repo the git repo which owns the index
 * @param index_path the path to the index file in disk
 * @return 0 on success; error code otherwise
 */
GIT_EXTERN(int) git_index_open_inrepo(git_index **index, git_repository *repo);

/**
 * Clear the contents (all the entries) of an index object.
 * This clears the index object in memory; changes must be manually
 * written to disk for them to take effect.
 *
 * @param index an existing index object
 */
GIT_EXTERN(void) git_index_clear(git_index *index);

/**
 * Free an existing index object.
 *
 * @param index an existing index object
 */
GIT_EXTERN(void) git_index_free(git_index *index);

/**
 * Update the contents of an existing index object in memory
 * by reading from the hard disk.
 *
 * @param index an existing index object
 * @return 0 on success, otherwise an error code
 */
GIT_EXTERN(int) git_index_read(git_index *index);

/**
 * Write an existing index object from memory back to disk
 * using an atomic file lock.
 *
 * @param index an existing index object
 * @return 0 on success, otherwise an error code
 */
GIT_EXTERN(int) git_index_write(git_index *index);

/**
 * Find the first index of any entires which point to given
 * path in the Git index.
 *
 * @param index an existing index object
 * @param path path to search
 * @return an index >= 0 if found, -1 otherwise
 */
GIT_EXTERN(int) git_index_find(git_index *index, const char *path);

/**
 * Add or update an index entry from a file in disk.
 *
 * @param index an existing index object
 * @param path filename to add
 * @param stage stage for the entry
 * @return 0 on success, otherwise an error code
 */
GIT_EXTERN(int) git_index_add(git_index *index, const char *path, int stage);

/**
 * Remove an entry from the index 
 *
 * @param index an existing index object
 * @param position position of the entry to remove
 * @return 0 on success, otherwise an error code
 */
GIT_EXTERN(int) git_index_remove(git_index *index, int position);

/**
 * Insert an entry into the index.
 * A full copy (including the 'path' string) of the given
 * 'source_entry' will be inserted on the index; if the index
 * already contains an entry for the same path, the entry
 * will be updated.
 *
 * @param index an existing index object
 * @param source_entry new entry object
 * @return 0 on success, otherwise an error code
 */
GIT_EXTERN(int) git_index_insert(git_index *index, const git_index_entry *source_entry);

/**
 * Get a pointer to one of the entries in the index
 *
 * This entry can be modified, and the changes will be written
 * back to disk on the next write() call.
 *
 * @param index an existing index object
 * @param n the position of the entry
 * @return a pointer to the entry; NULL if out of bounds
 */
GIT_EXTERN(git_index_entry *) git_index_get(git_index *index, int n);

/**
 * Get the count of entries currently in the index
 *
 * @param index an existing index object
 * @return integer of count of current entries
 */
GIT_EXTERN(unsigned int) git_index_entrycount(git_index *index);


/** @} */
GIT_END_DECL
#endif