/* $NetBSD: citrus_esdb.c,v 1.5 2008/02/09 14:56:20 junyoung Exp $ */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c)2003 Citrus Project,
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>

#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <paths.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "citrus_namespace.h"
#include "citrus_types.h"
#include "citrus_bcs.h"
#include "citrus_region.h"
#include "citrus_memstream.h"
#include "citrus_mmap.h"
#include "citrus_lookup.h"
#include "citrus_db.h"
#include "citrus_db_hash.h"
#include "citrus_esdb.h"
#include "citrus_esdb_file.h"

#define ESDB_DIR        "esdb.dir"
#define ESDB_ALIAS      "esdb.alias"

/*
 * _citrus_esdb_alias:
 *      resolve encoding scheme name aliases.
 */
const char *
_citrus_esdb_alias(const char *esname, char *buf, size_t bufsize)
{

        return (_lookup_alias(_PATH_ESDB "/" ESDB_ALIAS, esname, buf, bufsize,
            _LOOKUP_CASE_IGNORE));
}


/*
 * conv_esdb:
 *      external representation -> local structure.
 */
static int
conv_esdb(struct _citrus_esdb *esdb, struct _region *fr)
{
        struct _citrus_db *db;
        const char *str;
        char buf[100];
        uint32_t csid, i, num_charsets, tmp, version;
        int ret;

        /* open db */
        ret = _db_open(&db, fr, _CITRUS_ESDB_MAGIC, &_db_hash_std, NULL);
        if (ret)
                goto err0;

        /* check version */
        ret = _db_lookup32_by_s(db, _CITRUS_ESDB_SYM_VERSION, &version, NULL);
        if (ret)
                goto err1;
        switch (version) {
        case 0x00000001:
                /* current version */
                /* initial version */
                break;
        default:
                ret = EFTYPE;
                goto err1;
        }

        /* get encoding/variable */
        ret = _db_lookupstr_by_s(db, _CITRUS_ESDB_SYM_ENCODING, &str, NULL);
        if (ret)
                goto err1;
        esdb->db_encname = strdup(str);
        if (esdb->db_encname == NULL) {
                ret = errno;
                goto err1;
        }

        esdb->db_len_variable = 0;
        esdb->db_variable = NULL;
        ret = _db_lookupstr_by_s(db, _CITRUS_ESDB_SYM_VARIABLE, &str, NULL);
        if (ret == 0) {
                esdb->db_len_variable = strlen(str) + 1;
                esdb->db_variable = strdup(str);
                if (esdb->db_variable == NULL) {
                        ret = errno;
                        goto err2;
                }
        } else if (ret != ENOENT)
                goto err2;

        /* get number of charsets */
        ret = _db_lookup32_by_s(db, _CITRUS_ESDB_SYM_NUM_CHARSETS,
            &num_charsets, NULL);
        if (ret)
                goto err3;
        esdb->db_num_charsets = num_charsets;

        /* get invalid character */
        ret = _db_lookup32_by_s(db, _CITRUS_ESDB_SYM_INVALID, &tmp, NULL);
        if (ret == 0) {
                esdb->db_use_invalid = 1;
                esdb->db_invalid = tmp;
        } else if (ret == ENOENT)
                esdb->db_use_invalid = 0;
        else
                goto err3;

        /* get charsets */
        esdb->db_charsets = malloc(num_charsets * sizeof(*esdb->db_charsets));
        if (esdb->db_charsets == NULL) {
                ret = errno;
                goto err3;
        }
        for (i = 0; i < num_charsets; i++) {
                snprintf(buf, sizeof(buf),
                    _CITRUS_ESDB_SYM_CSID_PREFIX "%d", i);
                ret = _db_lookup32_by_s(db, buf, &csid, NULL);
                if (ret)
                        goto err4;
                esdb->db_charsets[i].ec_csid = csid;

                snprintf(buf, sizeof(buf),
                    _CITRUS_ESDB_SYM_CSNAME_PREFIX "%d", i);
                ret = _db_lookupstr_by_s(db, buf, &str, NULL);
                if (ret)
                        goto err4;
                esdb->db_charsets[i].ec_csname = strdup(str);
                if (esdb->db_charsets[i].ec_csname == NULL) {
                        ret = errno;
                        goto err4;
                }
        }

        _db_close(db);
        return (0);

err4:
        for (; i > 0; i--)
                free(esdb->db_charsets[i - 1].ec_csname);
        free(esdb->db_charsets);
err3:
        free(esdb->db_variable);
err2:
        free(esdb->db_encname);
err1:
        _db_close(db);
        if (ret == ENOENT)
                ret = EFTYPE;
err0:
        return (ret);
}

/*
 * _citrus_esdb_open:
 *      open an ESDB file.
 */
int
_citrus_esdb_open(struct _citrus_esdb *db, const char *esname)
{
        struct _region fr;
        const char *realname, *encfile;
        char buf1[PATH_MAX], buf2[PATH_MAX], path[PATH_MAX];
        int ret;

        snprintf(path, sizeof(path), "%s/%s", _PATH_ESDB, ESDB_ALIAS);
        realname = _lookup_alias(path, esname, buf1, sizeof(buf1),
            _LOOKUP_CASE_IGNORE);

        snprintf(path, sizeof(path), "%s/%s", _PATH_ESDB, ESDB_DIR);
        encfile = _lookup_simple(path, realname, buf2, sizeof(buf2),
            _LOOKUP_CASE_IGNORE);
        if (encfile == NULL)
                return (ENOENT);

        /* open file */
        snprintf(path, sizeof(path), "%s/%s", _PATH_ESDB, encfile);
        ret = _map_file(&fr, path);
        if (ret)
                return (ret);

        ret = conv_esdb(db, &fr);

        _unmap_file(&fr);

        return (ret);
}

/*
 * _citrus_esdb_close:
 *      free an ESDB.
 */
void
_citrus_esdb_close(struct _citrus_esdb *db)
{

        for (int i = 0; i < db->db_num_charsets; i++)
                free(db->db_charsets[i].ec_csname);
        db->db_num_charsets = 0;
        free(db->db_charsets); db->db_charsets = NULL;
        free(db->db_encname); db->db_encname = NULL;
        db->db_len_variable = 0;
        free(db->db_variable); db->db_variable = NULL;
}

/*
 * _citrus_esdb_free_list:
 *      free the list.
 */
void
_citrus_esdb_free_list(char **list, size_t num)
{

        for (size_t i = 0; i < num; i++)
                free(list[i]);
        free(list);
}

/*
 * _citrus_esdb_get_list:
 *      get esdb entries.
 */
int
_citrus_esdb_get_list(char ***rlist, size_t *rnum, bool sorted)
{
        struct _citrus_lookup *cla, *cld;
        struct _region key, data;
        char **list, **q;
        char buf[PATH_MAX];
        size_t num;
        int ret;

        ret = _lookup_seq_open(&cla, _PATH_ESDB "/" ESDB_ALIAS,
            _LOOKUP_CASE_IGNORE);
        if (ret)
                goto quit0;

        ret = _lookup_seq_open(&cld, _PATH_ESDB "/" ESDB_DIR,
            _LOOKUP_CASE_IGNORE);
        if (ret)
                goto quit1;

        /* count number of entries */
        num = _lookup_get_num_entries(cla) + _lookup_get_num_entries(cld);

        _lookup_seq_rewind(cla);
        _lookup_seq_rewind(cld);

        /* allocate list pointer space */
        list = malloc(num * sizeof(char *));
        num = 0;
        if (list == NULL) {
                ret = errno;
                goto quit3;
        }

        /* get alias entries */
        while ((ret = _lookup_seq_next(cla, &key, &data)) == 0) {
                /* XXX: sorted? */
                snprintf(buf, sizeof(buf), "%.*s/%.*s",
                    (int)_region_size(&data),
                    (const char *)_region_head(&data),
                    (int)_region_size(&key),
                    (const char *)_region_head(&key));
                _bcs_convert_to_upper(buf);
                list[num] = strdup(buf);
                if (list[num] == NULL) {
                        ret = errno;
                        goto quit3;
                }
                num++;
        }
        if (ret != ENOENT)
                goto quit3;
        /* get dir entries */
        while ((ret = _lookup_seq_next(cld, &key, &data)) == 0) {
                if (!sorted)
                        snprintf(buf, sizeof(buf), "%.*s",
                            (int)_region_size(&key),
                            (const char *)_region_head(&key));
                else {
                        /* check duplicated entry */
                        char *p;
                        char buf1[PATH_MAX];

                        snprintf(buf1, sizeof(buf1), "%.*s",
                            (int)_region_size(&data),
                            (const char *)_region_head(&data));
                        if ((p = strchr(buf1, '/')) != NULL)
                                memmove(buf1, p + 1, strlen(p) - 1);
                        if ((p = strstr(buf1, ".esdb")) != NULL)
                                *p = '\0';
                        snprintf(buf, sizeof(buf), "%s/%.*s", buf1,
                            (int)_region_size(&key),
                            (const char *)_region_head(&key));
                }
                _bcs_convert_to_upper(buf);
                ret = _lookup_seq_lookup(cla, buf, NULL);
                if (ret) {
                        if (ret != ENOENT)
                                goto quit3;
                        /* not duplicated */
                        list[num] = strdup(buf);
                        if (list[num] == NULL) {
                                ret = errno;
                                goto quit3;
                        }
                        num++;
                }
        }
        if (ret != ENOENT)
                goto quit3;

        ret = 0;
        /* XXX: why reallocing the list space posteriorly?
            shouldn't be done earlier? */
        q = reallocarray(list, num, sizeof(char *));
        if (!q) {
                ret = ENOMEM;
                goto quit3;
        }
        list = q;
        *rlist = list;
        *rnum = num;
quit3:
        if (ret)
                _citrus_esdb_free_list(list, num);
        _lookup_seq_close(cld);
quit1:
        _lookup_seq_close(cla);
quit0:
        return (ret);
}