/*
 *	aegis - project change supervisor
 *	Copyright (C) 1997, 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 manipulate logical trees
 */

#include <ac/stdio.h>

#include <aer/value/boolean.h>
#include <aer/value/error.h>
#include <str.h>
#include <sub.h>
#include <tree/constant.h>
#include <tree/diadic.h>
#include <tree/logical.h>
#include <tree/monadic.h>


static rpt_value_ty *and_evaluate _((tree_ty *, string_ty *, struct stat *));

static rpt_value_ty *
and_evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	tree_diadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v1b;
	rpt_value_ty	*v2;
	rpt_value_ty	*v2b;

	this = (tree_diadic_ty *)tp;

	v1 = tree_evaluate(this->left, path, st);
	if (v1->method->type == rpt_value_type_error)
		return v1;
	v1b = rpt_value_booleanize(v1);
	if (v1b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v1b);
		sub_var_set_charstar(scp, "Name", v1->method->name);
		rpt_value_free(v1);
		s =
			subst_intl
			(
				scp,
		i18n("boolean value required for logical and (was given $name)")
			);
		sub_context_delete(scp);
		v1b = rpt_value_error(0, s);
		str_free(s);
		return v1b;
	}
	rpt_value_free(v1);
	if (!rpt_value_boolean_query(v1b))
		return v1b;
	rpt_value_free(v1b);

	v2 = tree_evaluate(this->right, path, st);
	if (v2->method->type == rpt_value_type_error)
		return v2;
	v2b = rpt_value_booleanize(v2);
	if (v2b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v2b);
		sub_var_set_charstar(scp, "Name", v2->method->name);
		rpt_value_free(v2);
		s =
			subst_intl
			(
				scp,
		i18n("boolean value required for logical and (was given $name)")
			);
		sub_context_delete(scp);
		v2b = rpt_value_error(0, s);
		str_free(s);
		return v2b;
	}
	rpt_value_free(v2);
	return v2b;
}


static tree_method_ty and_method =
{
	sizeof(tree_diadic_ty),
	"&&",
	tree_diadic_destructor,
	tree_diadic_print,
	and_evaluate,
	tree_diadic_useful,
	tree_diadic_constant,
	tree_diadic_optimize,
};


tree_ty *
tree_and_new(left, right)
	tree_ty		*left;
	tree_ty		*right;
{
	return tree_diadic_new(&and_method, left, right);
}


static rpt_value_ty *or_evaluate _((tree_ty *, string_ty *, struct stat *));

static rpt_value_ty *
or_evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	tree_diadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v1b;
	rpt_value_ty	*v2;
	rpt_value_ty	*v2b;

	this = (tree_diadic_ty *)tp;

	v1 = tree_evaluate(this->left, path, st);
	if (v1->method->type == rpt_value_type_error)
		return v1;
	v1b = rpt_value_booleanize(v1);
	if (v1b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v1b);
		sub_var_set_charstar(scp, "Name", v1->method->name);
		rpt_value_free(v1);
		s =
			subst_intl
			(
				scp,
		 i18n("boolean value required for logical or (was given $name)")
			);
		sub_context_delete(scp);
		v1b = rpt_value_error(0, s);
		str_free(s);
		return v1b;
	}
	rpt_value_free(v1);
	if (rpt_value_boolean_query(v1b))
		return v1b;
	rpt_value_free(v1b);

	v2 = tree_evaluate(this->right, path, st);
	if (v2->method->type == rpt_value_type_error)
		return v2;
	v2b = rpt_value_booleanize(v2);
	if (v2b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v2b);
		sub_var_set_charstar(scp, "Name", v2->method->name);
		rpt_value_free(v2);
		s =
			subst_intl
			(
				scp,
		 i18n("boolean value required for logical or (was given $name)")
			);
		sub_context_delete(scp);
		v2b = rpt_value_error(0, s);
		str_free(s);
		return v2b;
	}
	rpt_value_free(v2);
	return v2b;
}


static tree_method_ty or_method =
{
	sizeof(tree_diadic_ty),
	"||",
	tree_diadic_destructor,
	tree_diadic_print,
	or_evaluate,
	tree_diadic_useful,
	tree_diadic_constant,
	tree_diadic_optimize,
};


tree_ty *
tree_or_new(left, right)
	tree_ty		*left;
	tree_ty		*right;
{
	return tree_diadic_new(&or_method, left, right);
}


static rpt_value_ty *not_evaluate _((tree_ty *, string_ty *, struct stat *));

static rpt_value_ty *
not_evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	tree_monadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v2;
	rpt_value_ty	*v3;

	this = (tree_monadic_ty *)tp;
	v1 = tree_evaluate(this->arg, path, st);
	if (v1->method->type == rpt_value_type_error)
		return v1;
	v2 = rpt_value_booleanize(v1);
	if (v2->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		sub_var_set_charstar(scp, "Name", v1->method->name);
		s =
			subst_intl
			(
				scp,
				i18n("illegal logical not ($name)")
			);
		sub_context_delete(scp);
		v3 = rpt_value_error(0, s);
		str_free(s);
	}
	else
	{
		v3 = rpt_value_boolean(!rpt_value_boolean_query(v2));
	}
	rpt_value_free(v1);
	rpt_value_free(v2);
	return v3;
}


static tree_method_ty not_method =
{
	sizeof(tree_monadic_ty),
	"!",
	tree_monadic_destructor,
	tree_monadic_print,
	not_evaluate,
	tree_monadic_useful,
	tree_monadic_constant,
	tree_monadic_optimize,
};


tree_ty *
tree_not_new(arg)
	tree_ty		*arg;
{
	return tree_monadic_new(&not_method, arg);
}


static rpt_value_ty *comma_evaluate _((tree_ty *, string_ty *, struct stat *));

static rpt_value_ty *
comma_evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	tree_diadic_ty	*this;
	rpt_value_ty	*vp;

	this = (tree_diadic_ty *)tp;

	vp = tree_evaluate(this->left, path, st);
	if (vp->method->type == rpt_value_type_error)
		return vp;
	rpt_value_free(vp);

	return tree_evaluate(this->right, path, st);
}


static tree_method_ty comma_method =
{
	sizeof(tree_diadic_ty),
	",",
	tree_diadic_destructor,
	tree_diadic_print,
	comma_evaluate,
	tree_diadic_useful,
	tree_diadic_constant,
	tree_diadic_optimize,
};


tree_ty *
tree_comma_new(left, right)
	tree_ty		*left;
	tree_ty		*right;
{
	return tree_diadic_new(&comma_method, left, right);
}


typedef struct triadic_ty triadic_ty;
struct triadic_ty
{
	tree_ty		inherited;
	tree_ty		*arg1;
	tree_ty		*arg2;
	tree_ty		*arg3;
};


static void triadic_destructor _((tree_ty *));

static void
triadic_destructor(tp)
	tree_ty		*tp;
{
	triadic_ty	*this;

	this = (triadic_ty *)tp;
	tree_delete(this->arg1);
	tree_delete(this->arg2);
	tree_delete(this->arg3);
}


static void triadic_print _((tree_ty *));

static void
triadic_print(tp)
	tree_ty		*tp;
{
	triadic_ty	*this;

	this = (triadic_ty *)tp;
	printf("( ( ");
	tree_print(this->arg1);
	printf(" ) ? ( ");
	tree_print(this->arg2);
	printf(" ) : ( ");
	tree_print(this->arg3);
	printf(" ) )");
}


static rpt_value_ty *triadic_evaluate _((tree_ty *, string_ty *,
	struct stat *));

static rpt_value_ty *
triadic_evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	triadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v1b;
	int		which;

	this = (triadic_ty *)tp;

	v1 = tree_evaluate(this->arg1, path, st);
	if (v1->method->type == rpt_value_type_error)
		return v1;
	v1b = rpt_value_booleanize(v1);
	if (v1b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v1b);
		sub_var_set_charstar(scp, "Name", v1->method->name);
		rpt_value_free(v1);
		s =
			subst_intl
			(
				scp,
			 i18n("boolean value required for if (was given $name)")
			);
		sub_context_delete(scp);
		v1b = rpt_value_error(0, s);
		str_free(s);
		return v1b;
	}
	rpt_value_free(v1);
	which = rpt_value_boolean_query(v1b);
	rpt_value_free(v1b);

	return tree_evaluate((which ? this->arg2 : this->arg3), path, st);
}


static int triadic_useful _((tree_ty *));

static int
triadic_useful(tp)
	tree_ty		*tp;
{
	triadic_ty	*this;

	this = (triadic_ty *)tp;
	return
	(
		tree_useful(this->arg1)
	||
		tree_useful(this->arg2)
	||
		tree_useful(this->arg3)
	);
}


static int triadic_constant _((tree_ty *));

static int
triadic_constant(tp)
	tree_ty		*tp;
{
	triadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v1b;
	int		which;

	this = (triadic_ty *)tp;

	if (!tree_constant(this->arg1))
		return 0;
	v1 = tree_evaluate_constant(this->arg1);
	if (v1->method->type == rpt_value_type_error)
	{
		rpt_value_free(v1);
		return 0;
	}
	v1b = rpt_value_booleanize(v1);
	rpt_value_free(v1);
	if (v1b->method->type != rpt_value_type_boolean)
	{
		rpt_value_free(v1b);
		return 0;
	}
	which = rpt_value_boolean_query(v1b);
	rpt_value_free(v1b);

	return tree_constant(which ? this->arg2 : this->arg3);
}


static tree_ty *triadic_optimize _((tree_ty *));

static tree_ty *
triadic_optimize(tp)
	tree_ty		*tp;
{
	triadic_ty	*this;
	rpt_value_ty	*v1;
	rpt_value_ty	*v1b;
	int		which;
	tree_ty		*result;

	this = (triadic_ty *)tp;

	if (!tree_constant(this->arg1))
	{
		tree_ty		*arg1;
		tree_ty		*arg2;
		tree_ty		*arg3;

		arg1 = tree_optimize(this->arg1);
		arg2 = tree_optimize(this->arg2);
		arg3 = tree_optimize(this->arg3);
		result = tree_triadic_new(arg1, arg2, arg3);
		tree_delete(arg1);
		tree_delete(arg2);
		tree_delete(arg3);
		return result;
	}
	v1 = tree_evaluate_constant(this->arg1);
	if (v1->method->type == rpt_value_type_error)
	{
		result = tree_constant_new(v1);
		rpt_value_free(v1);
		return result;
	}
	v1b = rpt_value_booleanize(v1);
	if (v1b->method->type != rpt_value_type_boolean)
	{
		sub_context_ty	*scp;
		string_ty	*s;

		scp = sub_context_new();
		rpt_value_free(v1b);
		sub_var_set_charstar(scp, "Name", v1->method->name);
		rpt_value_free(v1);
		s =
			subst_intl
			(
				scp,
			 i18n("boolean value required for if (was given $name)")
			);
		sub_context_delete(scp);
		v1 = rpt_value_error(0, s);
		str_free(s);
		result = tree_constant_new(v1);
		rpt_value_free(v1);
		return result;
	}
	rpt_value_free(v1);
	which = rpt_value_boolean_query(v1b);
	rpt_value_free(v1b);

	return tree_optimize(which ? this->arg2 : this->arg3);
}


static tree_method_ty triadic_method =
{
	sizeof(tree_diadic_ty),
	"?:",
	triadic_destructor,
	triadic_print,
	triadic_evaluate,
	triadic_useful,
	triadic_constant,
	triadic_optimize,
};


tree_ty *
tree_triadic_new(arg1, arg2, arg3)
	tree_ty		*arg1;
	tree_ty		*arg2;
	tree_ty		*arg3;
{
	tree_ty		*tp;
	triadic_ty	*this;

	tp = tree_new(&triadic_method);
	this = (triadic_ty *)tp;
	this->arg1 = tree_copy(arg1);
	this->arg2 = tree_copy(arg2);
	this->arg3 = tree_copy(arg3);
	return tp;
}