/*
 *	fhist - file history and comparison tools
 *	Copyright (C) 1991-1994, 1998-2002 Peter Miller;
 *	All rights reserved.
 *
 *	Derived from a work
 *	Copyright (C) 1990 David I. Bell.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program 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; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: interface definition for common/compare.c
 *
 * Common definitions for talking to the fcomp module.
 * These are the variables which control its actions.
 */

#ifndef COMPARE_H
#define COMPARE_H

#include <main.h>

#define INFINITY (long)(~(unsigned long)0 >> 1)	/* maximum number */

#define VERBOSE_NONE 0		/* least verbosity level */
#define VERBOSE_DEFAULT 1	/* default verbosity level */
#define VERBOSE_FULL 2		/* full verbosity level */


/*
 * Structure which traces an optimal D-path through the edit path
 * for the two files.  The linked list of these structures lists the
 * snakes which define the path, where a snake is a region of multiple
 * line matchings.
 */
typedef struct snake SNAKE;
struct snake
{
	SNAKE	*next;		/* next snake in path */
	long	line1;		/* line number in file1 */
	long	line2;		/* line number in file2 */
	long	count;		/* number of matching lines */
};


/*
 * Data about a line.
 * Each line is placed on an appropriate hash chain.
 * For any two entries, the two l_hash values match if and only if
 * the two lines match, so that the data never needs to be examined
 * once the original comparisons are complete.  In the extremely rare
 * cases where the hash would incorrectly match, it is modified.
 */
typedef struct line LINE;
struct line
{
	LINE	*l_next;	/* next line on same hash chain */
	long	l_hash;		/* hash value for line */
	char	*l_canon;
	char	l_data[4];	/* chars (variable length, MUST BE LAST) */
};
#define LINE_SIZE(chars) (sizeof(LINE) + (chars) - 2)


/*
 * Data about the files being compared.
 */
typedef	struct FILEINFO FILEINFO;
struct FILEINFO
{
	LINE	**f_lines;	/* pointer to data lines */
	long	*f_lnums;	/* line number of each saved line */
	long	f_linecount;	/* number of saved lines in file */
	long	f_linestotal;	/* total number of lines in file */
	char	*f_name;	/* file name */
	struct input_ty *f_file; /* file structure for input */
	char	f_tag;		/* tag character for file */
	int	is_binary;
};


/*
 * Global data for file comparisons.
 */
typedef struct FCOMP_DATA FCOMP_DATA;
struct FCOMP_DATA
{
	/*
	 * Input arguments
	 */
	long	maxjoin;	/* maximum number of lines to join */
	long	maxchanges;	/* maximum changes to allow */
	long	maxlines;	/* maximum number of lines */
	long	context;	/* lines of context in output */
	long	fileAskip;	/* lines to skip for first file */
	long	fileBskip;	/* lines to skip for second file */
	long	fileAmodify;	/* lines to be modified for first file */
	long	fileBmodify;	/* lines to be modified for second file */
	long	verbosity;	/* verbosity level */
	short	numflag;	/* show line numbers */
	short	spaceflag;	/* ignore extra spaces in lines */
	short	blankflag;	/* ignore blank lines in files */
	short   hexify_flag;	/* turn binary files into byte-per-line text */
	short	upcaseflag;	/* ignore case differences in lines */
	short	quickflag;	/* only show quick summary */
	short	whatflag;	/* show both files showing what changed */
	short	editscriptflag;	/* output an edit script */
	short	matchflag;	/* output lines which match */
	short	debugflag;	/* tell some debugging info */
	/*
	 * Output arguments
	 */
	long	inserts;	/* number of lines inserted into first file */
	long	deletes;	/* number of lines deleted from first file */
	long	matches;	/* number of lines unchanged between files */
	SNAKE	*snakelist;	/* snake list describing matching lines */
	FILEINFO fileA;		/* first file being compared */
	FILEINFO fileB;		/* second file being compared */
	int	binary;		/* -binary cmd line option */
	int     cant_do_binary; /* -no-binary cmd line option */
};

extern FCOMP_DATA fc;		/* all data defined in here */

/*
 * for prototypes
 */
struct INFO;

/*
 * Function prototypes
 */
void *allocstr(long);
void fcomp(char *fileA, char *fileB);
void dumpmatch(char *outfile);
void dumpnormal(char *outfile);
void dumpwhat(char *outfile);
void dumplines(char *outfile);
void fcompreset(void);
void binary_warning(const char *);
void binary_fatal(const char *);

/*
 * the modifyline calls are used to alter line between reading them
 * and comparing them.
 */
typedef char *(*modifyline_type)(char *, long *, struct INFO *);
void modifyline_register(modifyline_type);

#endif /* COMPARE_H */