/*
 *	aegis - project change supervisor
 *	Copyright (C) 1995, 1996, 1998, 1999 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 implement the builtin wrap function
 */

#include <ac/ctype.h>

#include <aer/expr.h>
#include <aer/func/wrap.h>
#include <aer/value/error.h>
#include <aer/value/integer.h>
#include <aer/value/list.h>
#include <aer/value/string.h>
#include <mem.h>
#include <sub.h>


static int wrap_verify _((rpt_expr_ty *));

static int
wrap_verify(ep)
	rpt_expr_ty	*ep;
{
	return (ep->nchild == 2);
}


static string_ty *trim _((string_ty *));

static string_ty *
trim(s)
	string_ty	*s;
{
	static size_t	buflen;
	static char	*buf;
	char		*bp;
	char		*sp;

	if (buflen < s->str_length)
	{
		buflen = s->str_length;
		buf = mem_change_size(buf, buflen);
	}
	bp = buf;
	sp = s->str_text;
	while (*sp && *sp != '\n' && isspace((unsigned char)*sp))
		++sp;
	while (*sp)
	{
		if (!*sp)
			break;
		if (*sp == '\n')
		{
			*bp++ = *sp++;
			while (*sp && *sp != '\n' && isspace((unsigned char)*sp))
				++sp;
		}
		else if (isspace((unsigned char)*sp))
		{
			*bp++ = ' ';
			do
				++sp;
			while
				(*sp && *sp != '\n' && isspace((unsigned char)*sp));
			if (!*sp || *sp == '\n')
				--bp;
		}
		else
			*bp++ = *sp++;
	}
	return str_n_from_c(buf, bp - buf);
}


static rpt_value_ty *wrap_run _((rpt_expr_ty *, size_t, rpt_value_ty **));

static rpt_value_ty *
wrap_run(ep, argc, argv)
	rpt_expr_ty	*ep;
	size_t		argc;
	rpt_value_ty	**argv;
{
	rpt_value_ty	*a1;
	rpt_value_ty	*a2;
	rpt_value_ty	*result;
	rpt_value_ty	*tmp;
	string_ty	*subject;
	string_ty	*s;
	long		width;
	char		*sp;

	a1 = rpt_value_stringize(argv[0]);
	if (a1->method->type != rpt_value_type_string)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		rpt_value_free(a1);
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "1");
		sub_var_set_charstar(scp, "Name", argv[0]->method->name);
		s =
			subst_intl
			(
				scp,
    i18n("$function: argument $number: string value required (was given $name)")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}
	subject = trim(rpt_value_string_query(a1));
	rpt_value_free(a1);

	a2 = rpt_value_integerize(argv[1]);
	if (a2->method->type != rpt_value_type_integer)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		rpt_value_free(a2);
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "2");
		sub_var_set_charstar(scp, "Name", argv[1]->method->name);
		s =
			subst_intl
			(
				scp,
   i18n("$function: argument $number: integer value required (was given $name)")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}
	width = rpt_value_integer_query(a2);
	rpt_value_free(a2);
	if (width < 1)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "2");
		sub_var_set_long(scp, "Value", width);
		s =
			subst_intl
			(
				scp,
		  i18n("$function: argument $number: width $value out of range")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}

	/*
	 * the result is a list
	 * create an empty one se we can start filling it
	 */
	result = rpt_value_list();

	sp = subject->str_text;
	while (*sp)
	{
		char		*end_p;
		string_ty	*os;

		/*
		 * find where the line ends
		 */
		end_p = sp;
		while (end_p - sp < width && *end_p && *end_p != '\n')
			++end_p;
		if (*end_p && *end_p != '\n')
		{
			char		*w;

			/*
			 * see if there is a better place to wrap
			 */
			w = end_p;
			while (w > sp && !isspace((unsigned char)(w[-1])))
				--w;
			if (w > sp + 1)
				end_p = w - 1;
			else
			{
				w = end_p;
				while (w > sp && !ispunct((unsigned char)(w[-1])))
					--w;
				if (w > sp + 1)
					end_p = w - 1;
			}
		}

		/*
		 * append the line to the result
		 */
		os = str_n_from_c(sp, end_p - sp);
		tmp = rpt_value_string(os);
		str_free(os);
		rpt_value_list_append(result, tmp);
		rpt_value_free(tmp);

		/*
		 * skip line terminator and spaces
		 */
		sp = end_p;
		if (*sp == '\n')
			++sp;
		while (isspace((unsigned char)*sp) && *sp != '\n')
			++sp;
	}

	/*
	 * clean up and go home
	 */
	str_free(subject);
	return result;
}


rpt_func_ty rpt_func_wrap =
{
	"wrap",
	1, /* optimizable */
	wrap_verify,
	wrap_run
};


static int wrap_html_verify _((rpt_expr_ty *));

static int
wrap_html_verify(ep)
	rpt_expr_ty	*ep;
{
	return (ep->nchild == 2);
}


static rpt_value_ty *wrap_html_run _((rpt_expr_ty *, size_t, rpt_value_ty **));

static rpt_value_ty *
wrap_html_run(ep, argc, argv)
	rpt_expr_ty	*ep;
	size_t		argc;
	rpt_value_ty	**argv;
{
	rpt_value_ty	*a1;
	rpt_value_ty	*a2;
	rpt_value_ty	*result;
	rpt_value_ty	*tmp;
	string_ty	*subject;
	string_ty	*s;
	long		width;
	char		*sp;

	a1 = rpt_value_stringize(argv[0]);
	if (a1->method->type != rpt_value_type_string)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		rpt_value_free(a1);
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "1");
		sub_var_set_charstar(scp, "Name", argv[0]->method->name);
		s =
			subst_intl
			(
				scp,
    i18n("$function: argument $number: string value required (was given $name)")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}
	subject = trim(rpt_value_string_query(a1));
	rpt_value_free(a1);

	a2 = rpt_value_integerize(argv[1]);
	if (a2->method->type != rpt_value_type_integer)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		rpt_value_free(a2);
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "2");
		sub_var_set_charstar(scp, "Name", argv[1]->method->name);
		s =
			subst_intl
			(
				scp,
   i18n("$function: argument $number: integer value required (was given $name)")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}
	width = rpt_value_integer_query(a2);
	rpt_value_free(a2);
	if (width < 1)
	{
		sub_context_ty	*scp;

		scp = sub_context_new();
		sub_var_set_charstar(scp, "Function", "wrap");
		sub_var_set_charstar(scp, "Number", "2");
		sub_var_set_long(scp, "Value", width);
		s =
			subst_intl
			(
				scp,
		  i18n("$function: argument $number: width $value out of range")
			);
		sub_context_delete(scp);
		tmp = rpt_value_error(ep->pos, s);
		str_free(s);
		return tmp;
	}

	/*
	 * the result is a list
	 * create an empty one se we can start filling it
	 */
	result = rpt_value_list();

	sp = subject->str_text;
	while (*sp)
	{
		char		*end_p;
		string_ty	*os;

		/*
		 * find where the line ends
		 */
		end_p = sp;
		while (end_p - sp < width && *end_p && *end_p != '\n')
			++end_p;
		if (*end_p && *end_p != '\n')
		{
			char		*w;

			/*
			 * see if there is a better place to wrap
			 */
			w = end_p;
			while (w > sp && !isspace((unsigned char)(w[-1])))
				--w;
			if (w > sp + 1)
				end_p = w - 1;
			else
			{
				w = end_p;
				while (w > sp && !ispunct((unsigned char)(w[-1])))
					--w;
				if (w > sp + 1)
					end_p = w - 1;
			}
		}

		/*
		 * append the line to the result
		 */
		os = str_n_from_c(sp, end_p - sp);
		tmp = rpt_value_string(os);
		str_free(os);
		rpt_value_list_append(result, tmp);
		rpt_value_free(tmp);

		/*
		 * skip line terminator and spaces
		 *
		 * Insert HTML paragraph breaks or line breaks
		 * if appropriate.
		 */
		sp = end_p;
		while (*sp && *sp != '\n' && isspace((unsigned char)*sp))
			++sp;
		if (*sp == '\n')
		{
			++sp;
			if (*sp && isspace((unsigned char)*sp))
			{
				os = str_from_c("<p>");
				tmp = rpt_value_string(os);
				str_free(os);
				rpt_value_list_append(result, tmp);
				rpt_value_free(tmp);
			}
			else
			{
				os = str_from_c("<br>");
				tmp = rpt_value_string(os);
				str_free(os);
				rpt_value_list_append(result, tmp);
				rpt_value_free(tmp);
			}
		}
		while (*sp && isspace((unsigned char)*sp))
			++sp;
	}

	/*
	 * clean up and go home
	 */
	str_free(subject);
	return result;
}


rpt_func_ty rpt_func_wrap_html =
{
	"wrap_html",
	1, /* optimizable */
	wrap_html_verify,
	wrap_html_run
};