/*

 * 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 "common.h"

#include "sysdir.h"

#include "global.h"

#include "buffer.h"

#include "path.h"

#include <ctype.h>

#if GIT_WIN32

#include "win32/findfile.h"

#endif

static int git_sysdir_guess_programdata_dirs(git_buf *out)

{

#ifdef GIT_WIN32

	return git_win32__find_programdata_dirs(out);

#else

	git_buf_clear(out);

	return 0;

#endif

}

static int git_sysdir_guess_system_dirs(git_buf *out)

{

#ifdef GIT_WIN32

	return git_win32__find_system_dirs(out, L"etc\\");

#else

	return git_buf_sets(out, "/etc");

#endif

}

static int git_sysdir_guess_global_dirs(git_buf *out)

{

#ifdef GIT_WIN32

	return git_win32__find_global_dirs(out);

#else

	int error = git__getenv(out, "HOME");

	if (error == GIT_ENOTFOUND) {

		giterr_clear();

		error = 0;

	}

	return error;

#endif

}

static int git_sysdir_guess_xdg_dirs(git_buf *out)

{

#ifdef GIT_WIN32

	return git_win32__find_xdg_dirs(out);

#else

	git_buf env = GIT_BUF_INIT;

	int error;

	if ((error = git__getenv(&env, "XDG_CONFIG_HOME")) == 0)

		error = git_buf_joinpath(out, env.ptr, "git");

	if (error == GIT_ENOTFOUND && (error = git__getenv(&env, "HOME")) == 0)

		error = git_buf_joinpath(out, env.ptr, ".config/git");

	if (error == GIT_ENOTFOUND) {

		giterr_clear();

		error = 0;

	}

	git_buf_free(&env;;

	return error;

#endif

}

static int git_sysdir_guess_template_dirs(git_buf *out)

{

#ifdef GIT_WIN32

	return git_win32__find_system_dirs(out, L"share\\git-core\\templates");

#else

	return git_buf_sets(out, "/usr/share/git-core/templates");

#endif

}

struct git_sysdir__dir {

	git_buf buf;

	int (*guess)(git_buf *out);

};

static struct git_sysdir__dir git_sysdir__dirs[] = {

	{ GIT_BUF_INIT, git_sysdir_guess_system_dirs },

	{ GIT_BUF_INIT, git_sysdir_guess_global_dirs },

	{ GIT_BUF_INIT, git_sysdir_guess_xdg_dirs },

	{ GIT_BUF_INIT, git_sysdir_guess_programdata_dirs },

	{ GIT_BUF_INIT, git_sysdir_guess_template_dirs },

};

static void git_sysdir_global_shutdown(void)

{

	size_t i;

	for (i = 0; i < ARRAY_SIZE(git_sysdir__dirs); ++i)

		git_buf_free(&git_sysdir__dirs[i].buf);

}

int git_sysdir_global_init(void)

{

	size_t i;

	int error = 0;

	for (i = 0; !error && i < ARRAY_SIZE(git_sysdir__dirs); i++)

		error = git_sysdir__dirs[i].guess(&git_sysdir__dirs[i].buf);

	git__on_shutdown(git_sysdir_global_shutdown);

	return error;

}

static int git_sysdir_check_selector(git_sysdir_t which)

{

	if (which < ARRAY_SIZE(git_sysdir__dirs))

		return 0;

	giterr_set(GITERR_INVALID, "config directory selector out of range");

	return -1;

}

int git_sysdir_get(const git_buf **out, git_sysdir_t which)

{

	assert(out);

	*out = NULL;

	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));

	*out = &git_sysdir__dirs[which].buf;

	return 0;

}

int git_sysdir_get_str(

	char *out,

	size_t outlen,

	git_sysdir_t which)

{

	const git_buf *path = NULL;

	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));

	GITERR_CHECK_ERROR(git_sysdir_get(&path, which));

	if (!out || path->size >= outlen) {

		giterr_set(GITERR_NOMEMORY, "buffer is too short for the path");

		return GIT_EBUFS;

	}

	git_buf_copy_cstr(out, outlen, path);

	return 0;

}

#define PATH_MAGIC "$PATH"

int git_sysdir_set(git_sysdir_t which, const char *search_path)

{

	const char *expand_path = NULL;

	git_buf merge = GIT_BUF_INIT;

	GITERR_CHECK_ERROR(git_sysdir_check_selector(which));

	if (search_path != NULL)

		expand_path = strstr(search_path, PATH_MAGIC);

	/* reset the default if this path has been cleared */

	if (!search_path)

		git_sysdir__dirs[which].guess(&git_sysdir__dirs[which].buf);

	/* if $PATH is not referenced, then just set the path */

	if (!expand_path) {

		if (search_path)

			git_buf_sets(&git_sysdir__dirs[which].buf, search_path);

		goto done;

	}

	/* otherwise set to join(before $PATH, old value, after $PATH) */

	if (expand_path > search_path)

		git_buf_set(&merge, search_path, expand_path - search_path);

	if (git_buf_len(&git_sysdir__dirs[which].buf))

		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR,

			merge.ptr, git_sysdir__dirs[which].buf.ptr);

	expand_path += strlen(PATH_MAGIC);

	if (*expand_path)

		git_buf_join(&merge, GIT_PATH_LIST_SEPARATOR, merge.ptr, expand_path);

	git_buf_swap(&git_sysdir__dirs[which].buf, &merge);

	git_buf_free(&merge);

done:

	if (git_buf_oom(&git_sysdir__dirs[which].buf))

		return -1;

	return 0;

}

static int git_sysdir_find_in_dirlist(

	git_buf *path,

	const char *name,

	git_sysdir_t which,

	const char *label)

{

	size_t len;

	const char *scan, *next = NULL;

	const git_buf *syspath;

	GITERR_CHECK_ERROR(git_sysdir_get(&syspath, which));

	if (!syspath || !git_buf_len(syspath))

		goto done;

	for (scan = git_buf_cstr(syspath); scan; scan = next) {

		/* find unescaped separator or end of string */

		for (next = scan; *next; ++next) {

			if (*next == GIT_PATH_LIST_SEPARATOR &&

				(next <= scan || next[-1] != '\\'))

				break;

		}

		len = (size_t)(next - scan);

		next = (*next ? next + 1 : NULL);

		if (!len)

			continue;

		GITERR_CHECK_ERROR(git_buf_set(path, scan, len));

		if (name)

			GITERR_CHECK_ERROR(git_buf_joinpath(path, path->ptr, name));

		if (git_path_exists(path->ptr))

			return 0;

	}

done:

	git_buf_free(path);

	giterr_set(GITERR_OS, "the %s file '%s' doesn't exist", label, name);

	return GIT_ENOTFOUND;

}

int git_sysdir_find_system_file(git_buf *path, const char *filename)

{

	return git_sysdir_find_in_dirlist(

		path, filename, GIT_SYSDIR_SYSTEM, "system");

}

int git_sysdir_find_global_file(git_buf *path, const char *filename)

{

	return git_sysdir_find_in_dirlist(

		path, filename, GIT_SYSDIR_GLOBAL, "global");

}

int git_sysdir_find_xdg_file(git_buf *path, const char *filename)

{

	return git_sysdir_find_in_dirlist(

		path, filename, GIT_SYSDIR_XDG, "global/xdg");

}

int git_sysdir_find_programdata_file(git_buf *path, const char *filename)

{

	return git_sysdir_find_in_dirlist(

		path, filename, GIT_SYSDIR_PROGRAMDATA, "ProgramData");

}

int git_sysdir_find_template_dir(git_buf *path)

{

	return git_sysdir_find_in_dirlist(

		path, NULL, GIT_SYSDIR_TEMPLATE, "template");

}

int git_sysdir_expand_global_file(git_buf *path, const char *filename)

{

	int error;

	if ((error = git_sysdir_find_global_file(path, NULL)) == 0) {

		if (filename)

			error = git_buf_joinpath(path, path->ptr, filename);

	}

	return error;

}