/*

 * Copyright (c) 2013-2017, Intel Corporation

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *  * Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 *  * Neither the name of Intel Corporation nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef FILE_H

#define FILE_H

#include <stddef.h>

/* Provides linewise access to a string.

 * Access to the lines is guarded by the text_line function.

 */

struct text {

	/* Number of lines.  */

	size_t n;

	/* Each line[0] to line[n-1] points to the start of the

	 * corresponding line.

	 */

	char **line;

};

/* Allocates new text.

 *

 * Note, if s is NULL or the empty string the text has zero lines.

 *

 * Returns a non-NULL text object on success; NULL otherwise.

 */

extern struct text *text_alloc(const char *s);

/* Deallocates @t.

 * If @t is the NULL pointer, nothing happens.

 */

extern void text_free(struct text *t);

/* Initializes @t with @s.  All "\n" or "\r\n" lineendings, will be

 * replaced with '\0'.

 *

 * Returns 0 on success; a negative enum errcode otherwise.

 * Returns -err_internal if @t is the NULL pointer.

 */

extern int text_parse(struct text *t, const char *s);

/* Copies at most @destlen characters of line @n from text @t to @dest.

 * The line counts start with 0.

 * If @dest is the NULL pointer just the line number is checked.

 *

 * Returns 0 on success; a negative enum errcode otherwise.

 * Returns -err_internal if @t is the NULL pointer or if @dest is the

 * NULL pointer, but @destlen is non-zero.

 * Returns -err_out_of_range if @n is not in the range.

 *

 * Note, the string is always null byte terminated on success.

 */

extern int text_line(const struct text *t, char *dest, size_t destlen,

		     size_t n);

/* Provides access to lines of files.  Access to all files is cached

 * after the first request.

 *

 * By convention, the first file_list element in the list is the head

 * and stores no file information.

 */

struct file_list {

	/* Name of the file.  */

	char *filename;

	/* The content of the file.  */

	struct text *text;

	/* Points to the next file list entry.  It's NULL if the

	 * current file_list is the last entry in the list.

	 */

	struct file_list *next;

};

/* Allocates a new file list.

 *

 * Returns a non-NULL file list object on succes; NULL otherwise.

 */

extern struct file_list *fl_alloc(void);

/* Deallocates @fl.

 * If @fl is the NULL pointer, nothing happens.

 */

extern void fl_free(struct file_list *fl);

/* Looks up line @n in a file @filename.  The line content is stored in

 * @dest, which should have a capacity of @destlen.

 * If @dest is the NULL pointer just the line number is checked.

 * See function text_line how the line is copied to @dest.

 * The file @filename is loaded implicitly.

 *

 * Returns 0 on success; a negative enum errcode otherwise.

 * Returns -err_internal if @fl or @filename is the NULL pointer or if

 * @dest is the NULL pointer, but @destlen is non-zero.

 * Returns -err_out_of_range if n is not a valid line number.

 * Returns -err_file_stat if @filename could not be found.

 * Returns -err_file_open if @filename could not be opened.

 * Returns -err_file_read if the content of @filename could not be fully

 * read.

 */

extern int fl_getline(struct file_list *fl, char *dest, size_t destlen,

		      const char *filename, size_t n);

/* Looks up the text for @filename and stores its contents in @t.

 * The file @filename is loaded implicitly.

 *

 * Returns 0 on success; a negative enum errcode otherwise.

 * Returns -err_internal if @fl or @t or @filename is the NULL pointer.

 * Returns -err_file_stat if @filename could not be found.

 * Returns -err_file_open if @filename could not be opened.

 * Returns -err_file_read if the content of @filename could not be fully

 * read.

 */

extern int fl_gettext(struct file_list *fl, const struct text **t,

		      const char *filename);

#endif /* FILE_H */