/*
 *	aegis - project change supervisor
 *	Copyright (C) 1999-2001 Peter Miller;
 *	All rights reserved.
 *
 *	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: functions to manipulate truncates
 *
 * This class of wide output is used to truncate lines to a specified
 * printing width.  Characters beyond on each line this limit are
 * discarded.
 */

#include <language.h>
#include <mem.h>
#include <str.h>
#include <wide_output.h>
#include <wide_output/private.h>
#include <wide_output/truncate.h>


typedef struct wide_output_truncate_ty wide_output_truncate_ty;
struct wide_output_truncate_ty
{
	wide_output_ty	inherited;
	wide_output_ty	*deeper;
	int		delete_on_close;
	int		width;

	wchar_t		*buf;
	size_t		buf_pos;
	size_t		buf_max;

	int		column;
};


static void wide_output_truncate_destructor _((wide_output_ty *));

static void
wide_output_truncate_destructor(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	if (this->buf_pos)
		wide_output_write(this->deeper, this->buf, this->buf_pos);
	if (this->buf)
		mem_free(this->buf);
	if (this->delete_on_close)
		wide_output_delete(this->deeper);
	this->deeper = 0;
}


static string_ty *wide_output_truncate_filename _((wide_output_ty *));

static string_ty *
wide_output_truncate_filename(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	return wide_output_filename(this->deeper);
}


static void wide_output_truncate_write _((wide_output_ty *, const wchar_t *,
	size_t));

static void
wide_output_truncate_write(fp, data, len)
	wide_output_ty	*fp;
	const wchar_t	*data;
	size_t		len;
{
	wide_output_truncate_ty *this;
	int		cwid;

	this = (wide_output_truncate_ty *)fp;
	language_human();
	while (len > 0)
	{
		wchar_t wc = *data++;
		--len;
	
		switch (wc)
		{
		case '\n':
		case '\f':
			language_C();
			if (this->buf_pos)
			{
				wide_output_write
				(
					this->deeper,
					this->buf,
					this->buf_pos
				);
			}
			wide_output_putwc(this->deeper, wc);
			language_human();
			this->buf_pos = 0;
			this->column = 0;
			break;
	
		default:
			/*
			 * If we have already become too wide, don't
			 * make the deeper unnecessary function calls. 
			 */
			if (this->column >= this->width)
				break;

			/*
			 * Only remember this character if all of it
			 * fits within the specified width.
			 */
			cwid = wcwidth(wc);
			if (this->column + cwid > this->width)
				break;

			/*
			 * Make room if necessary
			 */
			if (this->buf_pos >= this->buf_max)
			{
				size_t		nbytes;

				this->buf_max = 16 + 2 * this->buf_max;
				nbytes = this->buf_max * sizeof(this->buf[0]);
				this->buf = mem_change_size(this->buf, nbytes);
			}
			this->buf[this->buf_pos++] = wc;
			this->column += cwid;
			break;
		}
	}
	language_C();
}


static void wide_output_truncate_flush _((wide_output_ty *));

static void
wide_output_truncate_flush(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	wide_output_write(this->deeper, this->buf, this->buf_pos);
	this->buf_pos = 0;
	/* DO NOT reset this->column */
}


static int wide_output_truncate_page_width _((wide_output_ty *));

static int
wide_output_truncate_page_width(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	return this->width;
}


static int wide_output_truncate_page_length _((wide_output_ty *));

static int
wide_output_truncate_page_length(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	return wide_output_page_length(this->deeper);
}


static void wide_output_truncate_eoln _((wide_output_ty *));

static void
wide_output_truncate_eoln(fp)
	wide_output_ty	*fp;
{
	wide_output_truncate_ty *this;

	this = (wide_output_truncate_ty *)fp;
	if (this->column > 0)
		wide_output_putwc(fp, (wchar_t)'\n');
}


static wide_output_vtbl_ty vtbl =
{
	sizeof(wide_output_truncate_ty),
	wide_output_truncate_destructor,
	wide_output_truncate_filename,
	wide_output_truncate_write,
	wide_output_truncate_flush,
	wide_output_truncate_page_width,
	wide_output_truncate_page_length,
	wide_output_truncate_eoln,
	"truncate",
};


wide_output_ty *
wide_output_truncate_open(deeper, delete_on_close, width)
	wide_output_ty	*deeper;
	int		delete_on_close;
	int		width;
{
	wide_output_ty	*result;
	wide_output_truncate_ty *this;

	result = wide_output_new(&vtbl);
	this = (wide_output_truncate_ty *)result;
	this->deeper = deeper;
	this->delete_on_close = delete_on_close;
	this->width = (width <= 0 ? wide_output_page_width(deeper) : width);
	this->buf = 0;
	this->buf_pos = 0;
	this->buf_max = 0;
	this->column = 0;
	return result;
}