/*	$NetBSD: alist.c,v 1.6.2.2 2024/02/25 15:47:30 martin Exp $	*/

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0 AND ISC
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*
 * Copyright (C) 2001 Nominum, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND NOMINUM DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*! \file */

#include <stdbool.h>
#include <stdlib.h>
#include <string.h>

#include <isc/assertions.h>
#include <isc/print.h>
#include <isc/result.h>

#include <isccc/alist.h>
#include <isccc/sexpr.h>
#include <isccc/util.h>

#define CAR(s) (s)->value.as_dottedpair.car
#define CDR(s) (s)->value.as_dottedpair.cdr

#define ALIST_TAG  "*alist*"
#define MAX_INDENT 64

static char spaces[MAX_INDENT + 1] = "                                         "
				     "                       ";

isccc_sexpr_t *
isccc_alist_create(void) {
	isccc_sexpr_t *alist, *tag;

	tag = isccc_sexpr_fromstring(ALIST_TAG);
	if (tag == NULL) {
		return (NULL);
	}
	alist = isccc_sexpr_cons(tag, NULL);
	if (alist == NULL) {
		isccc_sexpr_free(&tag);
		return (NULL);
	}

	return (alist);
}

bool
isccc_alist_alistp(isccc_sexpr_t *alist) {
	isccc_sexpr_t *car;

	if (alist == NULL || alist->type != ISCCC_SEXPRTYPE_DOTTEDPAIR) {
		return (false);
	}
	car = CAR(alist);
	if (car == NULL || car->type != ISCCC_SEXPRTYPE_STRING) {
		return (false);
	}
	if (strcmp(car->value.as_string, ALIST_TAG) != 0) {
		return (false);
	}
	return (true);
}

bool
isccc_alist_emptyp(isccc_sexpr_t *alist) {
	REQUIRE(isccc_alist_alistp(alist));

	if (CDR(alist) == NULL) {
		return (true);
	}
	return (false);
}

isccc_sexpr_t *
isccc_alist_first(isccc_sexpr_t *alist) {
	REQUIRE(isccc_alist_alistp(alist));

	return (CDR(alist));
}

isccc_sexpr_t *
isccc_alist_assq(isccc_sexpr_t *alist, const char *key) {
	isccc_sexpr_t *car, *caar;

	REQUIRE(isccc_alist_alistp(alist));

	/*
	 * Skip alist type tag.
	 */
	alist = CDR(alist);

	while (alist != NULL) {
		INSIST(alist->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
		car = CAR(alist);
		INSIST(car->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
		caar = CAR(car);
		if (caar->type == ISCCC_SEXPRTYPE_STRING &&
		    strcmp(caar->value.as_string, key) == 0)
		{
			return (car);
		}
		alist = CDR(alist);
	}

	return (NULL);
}

void
isccc_alist_delete(isccc_sexpr_t *alist, const char *key) {
	isccc_sexpr_t *car, *caar, *rest, *prev;

	REQUIRE(isccc_alist_alistp(alist));

	prev = alist;
	rest = CDR(alist);
	while (rest != NULL) {
		INSIST(rest->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
		car = CAR(rest);
		INSIST(car != NULL && car->type == ISCCC_SEXPRTYPE_DOTTEDPAIR);
		caar = CAR(car);
		if (caar->type == ISCCC_SEXPRTYPE_STRING &&
		    strcmp(caar->value.as_string, key) == 0)
		{
			CDR(prev) = CDR(rest);
			CDR(rest) = NULL;
			isccc_sexpr_free(&rest);
			break;
		}
		prev = rest;
		rest = CDR(rest);
	}
}

isccc_sexpr_t *
isccc_alist_define(isccc_sexpr_t *alist, const char *key,
		   isccc_sexpr_t *value) {
	isccc_sexpr_t *kv, *k, *elt;

	kv = isccc_alist_assq(alist, key);
	if (kv == NULL) {
		/*
		 * New association.
		 */
		k = isccc_sexpr_fromstring(key);
		if (k == NULL) {
			return (NULL);
		}
		kv = isccc_sexpr_cons(k, value);
		if (kv == NULL) {
			isccc_sexpr_free(&kv);
			return (NULL);
		}
		elt = isccc_sexpr_addtolist(&alist, kv);
		if (elt == NULL) {
			isccc_sexpr_free(&kv);
			return (NULL);
		}
	} else {
		/*
		 * We've already got an entry for this key.  Replace it.
		 */
		isccc_sexpr_free(&CDR(kv));
		CDR(kv) = value;
	}

	return (kv);
}

isccc_sexpr_t *
isccc_alist_definestring(isccc_sexpr_t *alist, const char *key,
			 const char *str) {
	isccc_sexpr_t *v, *kv;

	v = isccc_sexpr_fromstring(str);
	if (v == NULL) {
		return (NULL);
	}
	kv = isccc_alist_define(alist, key, v);
	if (kv == NULL) {
		isccc_sexpr_free(&v);
	}

	return (kv);
}

isccc_sexpr_t *
isccc_alist_definebinary(isccc_sexpr_t *alist, const char *key,
			 isccc_region_t *r) {
	isccc_sexpr_t *v, *kv;

	v = isccc_sexpr_frombinary(r);
	if (v == NULL) {
		return (NULL);
	}
	kv = isccc_alist_define(alist, key, v);
	if (kv == NULL) {
		isccc_sexpr_free(&v);
	}

	return (kv);
}

isccc_sexpr_t *
isccc_alist_lookup(isccc_sexpr_t *alist, const char *key) {
	isccc_sexpr_t *kv;

	kv = isccc_alist_assq(alist, key);
	if (kv != NULL) {
		return (CDR(kv));
	}
	return (NULL);
}

isc_result_t
isccc_alist_lookupstring(isccc_sexpr_t *alist, const char *key, char **strp) {
	isccc_sexpr_t *kv, *v;

	kv = isccc_alist_assq(alist, key);
	if (kv != NULL) {
		v = CDR(kv);
		if (isccc_sexpr_stringp(v)) {
			if (strp != NULL) {
				*strp = isccc_sexpr_tostring(v);
			}
			return (ISC_R_SUCCESS);
		} else {
			return (ISC_R_EXISTS);
		}
	}

	return (ISC_R_NOTFOUND);
}

isc_result_t
isccc_alist_lookupbinary(isccc_sexpr_t *alist, const char *key,
			 isccc_region_t **r) {
	isccc_sexpr_t *kv, *v;

	kv = isccc_alist_assq(alist, key);
	if (kv != NULL) {
		v = CDR(kv);
		if (isccc_sexpr_binaryp(v)) {
			if (r != NULL) {
				*r = isccc_sexpr_tobinary(v);
			}
			return (ISC_R_SUCCESS);
		} else {
			return (ISC_R_EXISTS);
		}
	}

	return (ISC_R_NOTFOUND);
}

void
isccc_alist_prettyprint(isccc_sexpr_t *sexpr, unsigned int indent,
			FILE *stream) {
	isccc_sexpr_t *elt, *kv, *k, *v;

	if (isccc_alist_alistp(sexpr)) {
		fprintf(stream, "{\n");
		indent += 4;
		for (elt = isccc_alist_first(sexpr); elt != NULL;
		     elt = CDR(elt))
		{
			kv = CAR(elt);
			INSIST(isccc_sexpr_listp(kv));
			k = CAR(kv);
			v = CDR(kv);
			INSIST(isccc_sexpr_stringp(k));
			fprintf(stream, "%.*s%s => ", (int)indent, spaces,
				isccc_sexpr_tostring(k));
			isccc_alist_prettyprint(v, indent, stream);
			if (CDR(elt) != NULL) {
				fprintf(stream, ",");
			}
			fprintf(stream, "\n");
		}
		indent -= 4;
		fprintf(stream, "%.*s}", (int)indent, spaces);
	} else if (isccc_sexpr_listp(sexpr)) {
		fprintf(stream, "(\n");
		indent += 4;
		for (elt = sexpr; elt != NULL; elt = CDR(elt)) {
			fprintf(stream, "%.*s", (int)indent, spaces);
			isccc_alist_prettyprint(CAR(elt), indent, stream);
			if (CDR(elt) != NULL) {
				fprintf(stream, ",");
			}
			fprintf(stream, "\n");
		}
		indent -= 4;
		fprintf(stream, "%.*s)", (int)indent, spaces);
	} else {
		isccc_sexpr_print(sexpr, stream);
	}
}