/*
 * 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.
 */
#ifndef INCLUDE_git_blob_h__
#define INCLUDE_git_blob_h__

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

/**
 * @file git2/blob.h
 * @brief Git blob load and write routines
 * @defgroup git_blob Git blob load and write routines
 * @ingroup Git
 * @{
 */
GIT_BEGIN_DECL

/**
 * Lookup a blob object from a repository.
 *
 * @param blob pointer to the looked up blob
 * @param repo the repo to use when locating the blob.
 * @param id identity of the blob to locate.
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_lookup(git_blob **blob, git_repository *repo, const git_oid *id);

/**
 * Lookup a blob object from a repository,
 * given a prefix of its identifier (short id).
 *
 * @see git_object_lookup_prefix
 *
 * @param blob pointer to the looked up blob
 * @param repo the repo to use when locating the blob.
 * @param id identity of the blob to locate.
 * @param len the length of the short identifier
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_lookup_prefix(git_blob **blob, git_repository *repo, const git_oid *id, size_t len);

/**
 * Close an open blob
 *
 * This is a wrapper around git_object_free()
 *
 * IMPORTANT:
 * It *is* necessary to call this method when you stop
 * using a blob. Failure to do so will cause a memory leak.
 *
 * @param blob the blob to close
 */
GIT_EXTERN(void) git_blob_free(git_blob *blob);

/**
 * Get the id of a blob.
 *
 * @param blob a previously loaded blob.
 * @return SHA1 hash for this blob.
 */
GIT_EXTERN(const git_oid *) git_blob_id(const git_blob *blob);

/**
 * Get the repository that contains the blob.
 *
 * @param blob A previously loaded blob.
 * @return Repository that contains this blob.
 */
GIT_EXTERN(git_repository *) git_blob_owner(const git_blob *blob);

/**
 * Get a read-only buffer with the raw content of a blob.
 *
 * A pointer to the raw content of a blob is returned;
 * this pointer is owned internally by the object and shall
 * not be free'd. The pointer may be invalidated at a later
 * time.
 *
 * @param blob pointer to the blob
 * @return the pointer
 */
GIT_EXTERN(const void *) git_blob_rawcontent(const git_blob *blob);

/**
 * Get the size in bytes of the contents of a blob
 *
 * @param blob pointer to the blob
 * @return size on bytes
 */
GIT_EXTERN(git_off_t) git_blob_rawsize(const git_blob *blob);

/**
 * Flags to control the functionality of `git_blob_filter`.
 */
typedef enum {
	/** When set, filters will not be applied to binary files. */
	GIT_BLOB_FILTER_CHECK_FOR_BINARY = (1 << 0),

	/**
	 * When set, filters will not load configuration from the
	 * system-wide `gitattributes` in `/etc` (or system equivalent).
	 */
	GIT_BLOB_FILTER_NO_SYSTEM_ATTRIBUTES = (1 << 1),

	/**
	 * When set, filters will be loaded from a `.gitattributes` file
	 * in the HEAD commit.
	 */
	GIT_BLOB_FILTER_ATTTRIBUTES_FROM_HEAD = (1 << 2),
} git_blob_filter_flag_t;

/**
 * The options used when applying filter options to a file.
 */
typedef struct {
	int version;

	/** Flags to control the filtering process */
	git_blob_filter_flag_t flags;
} git_blob_filter_options;

#define GIT_BLOB_FILTER_OPTIONS_VERSION 1
#define GIT_BLOB_FILTER_OPTIONS_INIT {GIT_BLOB_FILTER_OPTIONS_VERSION, GIT_BLOB_FILTER_CHECK_FOR_BINARY}

/**
 * Get a buffer with the filtered content of a blob.
 *
 * This applies filters as if the blob was being checked out to the
 * working directory under the specified filename.  This may apply
 * CRLF filtering or other types of changes depending on the file
 * attributes set for the blob and the content detected in it.
 *
 * The output is written into a `git_buf` which the caller must free
 * when done (via `git_buf_dispose`).
 *
 * If no filters need to be applied, then the `out` buffer will just
 * be populated with a pointer to the raw content of the blob.  In
 * that case, be careful to *not* free the blob until done with the
 * buffer or copy it into memory you own.
 *
 * @param out The git_buf to be filled in
 * @param blob Pointer to the blob
 * @param as_path Path used for file attribute lookups, etc.
 * @param opts Options to use for filtering the blob
 * @return 0 on success or an error code
 */
GIT_EXTERN(int) git_blob_filter(
	git_buf *out,
	git_blob *blob,
	const char *as_path,
	git_blob_filter_options *opts);

/**
 * Read a file from the working folder of a repository
 * and write it to the Object Database as a loose blob
 *
 * @param id return the id of the written blob
 * @param repo repository where the blob will be written.
 *	this repository cannot be bare
 * @param relative_path file from which the blob will be created,
 *	relative to the repository's working dir
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_create_from_workdir(git_oid *id, git_repository *repo, const char *relative_path);

/**
 * Read a file from the filesystem and write its content
 * to the Object Database as a loose blob
 *
 * @param id return the id of the written blob
 * @param repo repository where the blob will be written.
 *	this repository can be bare or not
 * @param path file from which the blob will be created
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_create_from_disk(git_oid *id, git_repository *repo, const char *path);

/**
 * Create a stream to write a new blob into the object db
 *
 * This function may need to buffer the data on disk and will in
 * general not be the right choice if you know the size of the data
 * to write. If you have data in memory, use
 * `git_blob_create_from_buffer()`. If you do not, but know the size of
 * the contents (and don't want/need to perform filtering), use
 * `git_odb_open_wstream()`.
 *
 * Don't close this stream yourself but pass it to
 * `git_blob_create_from_stream_commit()` to commit the write to the
 * object db and get the object id.
 *
 * If the `hintpath` parameter is filled, it will be used to determine
 * what git filters should be applied to the object before it is written
 * to the object database.
 *
 * @param out the stream into which to write
 * @param repo Repository where the blob will be written.
 *        This repository can be bare or not.
 * @param hintpath If not NULL, will be used to select data filters
 *        to apply onto the content of the blob to be created.
 * @return 0 or error code
 */
GIT_EXTERN(int) git_blob_create_from_stream(
	git_writestream **out,
	git_repository *repo,
	const char *hintpath);

/**
 * Close the stream and write the blob to the object db
 *
 * The stream will be closed and freed.
 *
 * @param out the id of the new blob
 * @param stream the stream to close
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_create_from_stream_commit(
	git_oid *out,
	git_writestream *stream);

/**
 * Write an in-memory buffer to the ODB as a blob
 *
 * @param id return the id of the written blob
 * @param repo repository where to blob will be written
 * @param buffer data to be written into the blob
 * @param len length of the data
 * @return 0 or an error code
 */
GIT_EXTERN(int) git_blob_create_from_buffer(
	git_oid *id, git_repository *repo, const void *buffer, size_t len);

/**
 * Determine if the blob content is most certainly binary or not.
 *
 * The heuristic used to guess if a file is binary is taken from core git:
 * Searching for NUL bytes and looking for a reasonable ratio of printable
 * to non-printable characters among the first 8000 bytes.
 *
 * @param blob The blob which content should be analyzed
 * @return 1 if the content of the blob is detected
 * as binary; 0 otherwise.
 */
GIT_EXTERN(int) git_blob_is_binary(const git_blob *blob);

/**
 * Create an in-memory copy of a blob. The copy must be explicitly
 * free'd or it will leak.
 *
 * @param out Pointer to store the copy of the object
 * @param source Original object to copy
 */
GIT_EXTERN(int) git_blob_dup(git_blob **out, git_blob *source);

/** @} */
GIT_END_DECL
#endif
