/*
 * Copyright (c) 1980 Regents of the University of California. All rights
 * reserved.  The Berkeley software License Agreement specifies the terms and
 * conditions for redistribution. 
 */

#ifndef lint
static char     sccsid[] = "@(#)pr_comment.c	5.2 (Berkeley) 8/28/85";
#endif not lint

/*-
 *
 *			  Copyright (C) 1976
 *				by the
 *			  Board of Trustees
 *				of the
 *			University of Illinois
 *
 *			 All rights reserved
 *
 *
 * NAME:
 *	pr_comment
 *
 * FUNCTION:
 *	This routine takes care of scanning and printing comments.
 *
 * ALGORITHM:
 *	1) Decide where the comment should be aligned, and if lines should
 *	   be broken.
 *	2) If lines should not be broken and filled, just copy up to end of
 *	   comment.
 *	3) If lines should be filled, then scan thru input_buffer copying
 *	   characters to com_buf.  Remember where the last blank, tab, or
 *	   newline was.  When line is filled, print up to last blank and 
 *	   continue copying.
 *
 * HISTORY:
 *	November 1976	D A Willcox of CAC	Initial coding
 *	12/6/76		D A Willcox of CAC	Modification to handle 
 *						UNIX-style comments
 *
 */

/*
 * this routine processes comments.  It makes an attempt to keep comments
 * from going over the max line length.  If a line is too long, it moves
 * everything from the last blank to the next comment line.  Blanks and tabs
 * from the beginning of the input line are removed 
 */

#include "indent_globs.h";


pr_comment()
{
	int             now_col;/* column we are in now */
	int             adj_max_col;	/* Adjusted max_col for when we
					 * decide to spill comments over the
					 * right margin */
	int             col_1_com;	/* this comment should not be touched */
	char           *last_bl;/* points to the last blank in the output
				 * buffer */
	char            achar;
	char           *t_ptr;	/* used for moving string */
	int             unix_comment;	/* tri-state variable used to decide
					 * if it is a unix-style comment. 0
					 * means only blanks since /*, 1
					 * means regular style comment, 2
					 * means unix style comment */
	int             break_delim = comment_delimiter_on_blankline;
	int             l_just_saw_decl = ps.just_saw_decl;
	/*
	 * int         ps.last_nl = 0;	/* true iff the last significant
	 * thing weve seen is a newline 
	 */
	int             one_liner = 1;	/* true iff this comment is a
					 * one-liner */
	adj_max_col = max_col;
	ps.just_saw_decl = 0;
	last_bl = 0;		/* no blanks found so far */
	ps.box_com = col_1_com = false;	/* at first, assume that we are not
					 * in a boxed comment or some other
					 * comment that should not be touched */
	++ps.out_coms;		/* keep track of number of comments */
	unix_comment = 1;	/* set flag to let us figure out if there is
				 * a unix-style comment ** DISABLED: use 0 to
				 * reenable this hack! */

	/* Figure where to align and how to treat the comment */

	if (ps.col_1 && !format_col1_comments) {	/* if comment starts in
							 * column 1 it should
							 * not be touched */
		col_1_com = ps.box_com = true;
		ps.com_col = 1;
	} else {
		if (*buf_ptr == '-' || *buf_ptr == '*') {
			ps.box_com = true;	/* a comment with a '-' or
						 * '*' immediately after the
						 * /* is assumed to be a
						 * boxed comment */
			col_1_com = true;
			break_delim = 0;
		}
		if ( /* ps.bl_line && */ (s_lab == e_lab) && (s_code == e_code)) {
			/* klg: check only if this line is blank */
			/*
			 * If this (*and previous lines are*) blank, dont put
			 * comment way out at left 
			 */
			ps.com_col = (ps.ind_level - ps.unindent_displace) * ps.ind_size + 1;
			adj_max_col = block_comment_max_col;
			if (ps.com_col <= 1)
				ps.com_col = 1 + !format_col1_comments;
		} else {
			register        target_col;
			break_delim = 0;
			if (s_code != e_code)
				target_col = count_spaces(compute_code_target(), s_code);
			else {
				target_col = 1;
				if (s_lab != e_lab)
					target_col = count_spaces(compute_label_target(), s_lab);
			}
			ps.com_col = ps.decl_on_line || ps.ind_level == 0 ? ps.decl_com_ind : ps.com_ind;
			if (ps.com_col < target_col)
				ps.com_col = ((target_col + 7) & ~7) + 1;
			if (ps.com_col + 24 > adj_max_col)
				adj_max_col = ps.com_col + 24;
		}
	}
	if (ps.box_com) {
		buf_ptr[-2] = 0;
		ps.n_comment_delta = 1 - count_spaces(1, in_buffer);
		ps.comment_delta = 0;
		buf_ptr[-2] = '/';
	} else {
		ps.n_comment_delta = 0;
		ps.comment_delta = 0;
		while (*buf_ptr == ' ' || *buf_ptr == '\t')
			buf_ptr++;
	}
	ps.comment_delta = 0;
	*e_com++ = '/';		/* put '/*' into buffer */
	*e_com++ = '*';
	if (*buf_ptr != ' ' && !ps.box_com)
		*e_com++ = ' ';

	*e_com = '\0';
	now_col = count_spaces(ps.com_col, s_com);	/* figure what column we
							 * would be in if we
							 * printed the comment
							 * now */

	/* Start to copy the comment */

	while (1) {		/* this loop will go until the comment is
				 * copied */
		if (*buf_ptr > 040 && *buf_ptr != '*')
			ps.last_nl = 0;
		switch (*buf_ptr) {	/* this checks for various spcl cases */
		case 014:	/* check for a form feed */
			if (!ps.box_com) {	/* in a text comment, break
						 * the line here */
				ps.use_ff = true;
				/* fix so dump_line uses a form feed */
				dump_line();
				last_bl = 0;
				*e_com++ = ' ';
				*e_com++ = '*';
				*e_com++ = ' ';
				while (*++buf_ptr == ' ' || *buf_ptr == '\t');
			} else {
				if (++buf_ptr >= buf_end)
					fill_buffer();
				*e_com++ = 014;
			}
			break;

		case '\n':
			if (had_eof) {	/* check for unexpected eof */
				printf("Unterminated comment\n");
				*e_com = '\0';
				dump_line();
				return;
			}
			one_liner = 0;
			if (ps.box_com || ps.last_nl) {	/* if this is a boxed
							 * comment, we dont
							 * ignore the newline */
				if (s_com == e_com) {
					*e_com++ = ' ';
					*e_com++ = ' ';
				}
				*e_com = '\0';
				if (!ps.box_com && e_com - s_com > 3) {
					if (break_delim == 1 && s_com[0] == '/'
					    && s_com[1] == '*' && s_com[2] == ' ') {
						char           *t = e_com;
						break_delim = 2;
						e_com = s_com + 2;
						*e_com = 0;
						if (blanklines_before_blockcomments)
							prefix_blankline_requested = 1;
						dump_line();
						e_com = t;
						s_com[0] = s_com[1] = s_com[2] = ' ';
					}
					dump_line();
					*e_com++ = ' ';
					*e_com++ = ' ';
				}
				dump_line();
				now_col = ps.com_col;
			} else {
				ps.last_nl = 1;
				if (unix_comment != 1) {	/* we not are in
								 * unix_style comment */
					if (unix_comment == 0 && s_code == e_code) {
						/*
						 * if it is a UNIX-style
						 * comment, ignore the
						 * requirement that previous
						 * line be blank for
						 * unindention 
						 */
						ps.com_col = (ps.ind_level - ps.unindent_displace) * ps.ind_size + 1;
						if (ps.com_col <= 1)
							ps.com_col = 2;
					}
					unix_comment = 2;	/* permanently remember
								 * that we are in this
								 * type of comment */
					dump_line();
					++line_no;
					now_col = ps.com_col;
					*e_com++ = ' ';
					/*
					 * fix so that the star at the start
					 * of the line will line up 
					 */
					do	/* flush leading white space */
						if (++buf_ptr >= buf_end)
							fill_buffer();
					while (*buf_ptr == ' ' || *buf_ptr == '\t');
					break;
				}
				if (*(e_com - 1) == ' ' || *(e_com - 1) == '\t')
					last_bl = e_com - 1;
				/*
				 * if there was a space at the end of the
				 * last line, remember where it was 
				 */
				else {	/* otherwise, insert one */
					last_bl = e_com;
					*e_com++ = ' ';
					++now_col;
				}
			}
			++line_no;	/* keep track of input line number */
			if (!ps.box_com) {
				int             nstar = 1;
				do {	/* flush any blanks and/or tabs at
					 * start of next line */
					if (++buf_ptr >= buf_end)
						fill_buffer();
					if (*buf_ptr == '*' && --nstar >= 0) {
						if (++buf_ptr >= buf_end)
							fill_buffer();
						if (*buf_ptr == '/')
							goto end_of_comment;
					}
				} while (*buf_ptr == ' ' || *buf_ptr == '\t');
			} else if (++buf_ptr >= buf_end)
				fill_buffer();
			break;	/* end of case for newline */

		case '*':	/* must check for possibility of being at end
				 * of comment */
			if (++buf_ptr >= buf_end)	/* get to next char
							 * after * */
				fill_buffer();

			if (unix_comment == 0)	/* set flag to show we are
						 * not in unix-style comment */
				unix_comment = 1;

			if (*buf_ptr == '/') {	/* it is the end!!! */
		end_of_comment:
				if (++buf_ptr >= buf_end)
					fill_buffer();

				if (*(e_com - 1) != ' ' && !ps.box_com) {	/* insure blank before
										 * end */
					*e_com++ = ' ';
					++now_col;
				}
				if (break_delim == 1 && !one_liner && s_com[0] == '/'
				    && s_com[1] == '*' && s_com[2] == ' ') {
					char           *t = e_com;
					break_delim = 2;
					e_com = s_com + 2;
					*e_com = 0;
					if (blanklines_before_blockcomments)
						prefix_blankline_requested = 1;
					dump_line();
					e_com = t;
					s_com[0] = s_com[1] = s_com[2] = ' ';
				}
				if (break_delim == 2 && e_com > s_com + 3
				     /* now_col > adj_max_col - 2 && !ps.box_com */ ) {
					*e_com = '\0';
					dump_line();
					now_col = ps.com_col;
				}
				*e_com++ = '*';
				*e_com++ = '/';
				*e_com = '\0';
				ps.just_saw_decl = l_just_saw_decl;
				return;
			} else {/* handle isolated '*' */
				*e_com++ = '*';
				++now_col;
			}
			break;
		default:	/* we have a random char */
			if (unix_comment == 0 && *buf_ptr != ' ' && *buf_ptr != '\t')
				unix_comment = 1;	/* we are not in
							 * unix-style comment */

			*e_com = *buf_ptr++;
			if (buf_ptr >= buf_end)
				fill_buffer();

			if (*e_com == '\t')	/* keep track of column */
				now_col = ((now_col - 1) & tabmask) + tabsize + 1;
			else if (*e_com == '\b')	/* this is a backspace */
				--now_col;
			else
				++now_col;

			if (*e_com == ' ' || *e_com == '\t')
				last_bl = e_com;
			/* remember we saw a blank */

			++e_com;
			if (now_col > adj_max_col && !ps.box_com && unix_comment == 1 && e_com[-1] > ' ') {
				/*
				 * the comment is too long, it must be broken
				 * up 
				 */
				if (break_delim == 1 && s_com[0] == '/'
				    && s_com[1] == '*' && s_com[2] == ' ') {
					char           *t = e_com;
					break_delim = 2;
					e_com = s_com + 2;
					*e_com = 0;
					if (blanklines_before_blockcomments)
						prefix_blankline_requested = 1;
					dump_line();
					e_com = t;
					s_com[0] = s_com[1] = s_com[2] = ' ';
				}
				if (last_bl == 0) {	/* we have seen no
							 * blanks */
					last_bl = e_com;	/* fake it */
					*e_com++ = ' ';
				}
				*e_com = '\0';	/* print what we have */
				*last_bl = '\0';
				while (last_bl > s_com && last_bl[-1] < 040)
					*--last_bl = 0;
				e_com = last_bl;
				dump_line();

				*e_com++ = ' ';	/* add blanks for
						 * continuation */
				*e_com++ = ' ';
				*e_com++ = ' ';

				t_ptr = last_bl + 1;
				last_bl = 0;
				if (t_ptr >= e_com) {
					while (*t_ptr == ' ' || *t_ptr == '\t')
						t_ptr++;
					while (*t_ptr != '\0') {	/* move unprinted part
									 * of comment down in
									 * buffer */
						if (*t_ptr == ' ' || *t_ptr == '\t')
							last_bl = e_com;
						*e_com++ = *t_ptr++;
					}
				}
				*e_com = '\0';
				now_col = count_spaces(ps.com_col, s_com);	/* recompute current
										 * position */
			}
			break;
		}
	}
}