/*-
 * 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 "dcmtk/config/osconfig.h"
#include "citrus_db_factory.h"

#include <sys/types.h>
#ifdef HAVE_SYS_QUEUE_H
#include <sys/queue.h>
#else
#include "dcmtk/oficonv/queue.h"
#endif

#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "citrus_bcs.h"
#include "citrus_region.h"
#include "citrus_db_file.h"

struct _citrus_db_factory_entry {
    STAILQ_ENTRY(_citrus_db_factory_entry)   de_entry;
    struct _citrus_db_factory_entry     *de_next;
    uint32_t                 de_hashvalue;
    struct _citrus_region               de_key;
    int                  de_key_free;
    struct _citrus_region               de_data;
    int                  de_data_free;
    int                 de_idx;
};

struct _citrus_db_factory {
    size_t                   df_num_entries;
    STAILQ_HEAD(, _citrus_db_factory_entry)  df_entries;
    size_t                   df_total_key_size;
    size_t                   df_total_data_size;
    uint32_t (*df_hashfunc)(struct _citrus_region *);
    void                    *df_hashfunc_closure;
};

#define DB_ALIGN 16

int
_citrus_db_factory_create(struct _citrus_db_factory **rdf,
    _citrus_db_hash_func_t hashfunc, void *hashfunc_closure)
{
    struct _citrus_db_factory *df;

    df = malloc(sizeof(*df));
    if (df == NULL)
        return (errno);
    df->df_num_entries = 0;
    df->df_total_key_size = df->df_total_data_size = 0;
    STAILQ_INIT(&df->df_entries);
    df->df_hashfunc = hashfunc;
    df->df_hashfunc_closure = hashfunc_closure;

    *rdf = df;

    return (0);
}

void
_citrus_db_factory_free(struct _citrus_db_factory *df)
{
    struct _citrus_db_factory_entry *de;

    while ((de = STAILQ_FIRST(&df->df_entries)) != NULL) {
        STAILQ_REMOVE_HEAD(&df->df_entries, de_entry);
        if (de->de_key_free)
            free(_citrus_region_head(&de->de_key));
        if (de->de_data_free)
            free(_citrus_region_head(&de->de_data));
        free(de);
    }
    free(df);
}

static __inline size_t
ceilto(size_t sz)
{
    return ((sz + DB_ALIGN - 1) & ~(DB_ALIGN - 1));
}

int
_citrus_db_factory_add(struct _citrus_db_factory *df, struct _citrus_region *key,
    int keyfree, struct _citrus_region *data, int datafree)
{
    struct _citrus_db_factory_entry *de;

    de = malloc(sizeof(*de));
    if (de == NULL)
        return (-1);

    de->de_hashvalue = df->df_hashfunc(key);
    de->de_key = *key;
    de->de_key_free = keyfree;
    de->de_data = *data;
    de->de_data_free = datafree;
    de->de_idx = -1;

    STAILQ_INSERT_TAIL(&df->df_entries, de, de_entry);
    df->df_total_key_size += _citrus_region_size(key);
    df->df_total_data_size += ceilto(_citrus_region_size(data));
    df->df_num_entries++;

    return (0);

}

int
_citrus_db_factory_add_by_string(struct _citrus_db_factory *df,
    const char *key, struct _citrus_region *data, int datafree)
{
    struct _citrus_region r;
    char *tmp;

    tmp = strdup(key);
    if (tmp == NULL)
        return (errno);
    _citrus_region_init(&r, tmp, strlen(key));
    return _citrus_db_factory_add(df, &r, 1, data, datafree);
}

int
_citrus_db_factory_add8_by_string(struct _citrus_db_factory *df,
    const char *key, uint8_t val)
{
    struct _citrus_region r;
    uint8_t *p;

    p = malloc(sizeof(*p));
    if (p == NULL)
        return (errno);
    *p = val;
    _citrus_region_init(&r, p, 1);
    return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add16_by_string(struct _citrus_db_factory *df,
    const char *key, uint16_t val)
{
    struct _citrus_region r;
    uint16_t *p;

    p = malloc(sizeof(*p));
    if (p == NULL)
        return (errno);
    *p = htons(val);
    _citrus_region_init(&r, p, 2);
    return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add32_by_string(struct _citrus_db_factory *df,
    const char *key, uint32_t val)
{
    struct _citrus_region r;
    uint32_t *p;

    p = malloc(sizeof(*p));
    if (p == NULL)
        return (errno);
    *p = htonl(val);
    _citrus_region_init(&r, p, 4);
    return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

int
_citrus_db_factory_add_string_by_string(struct _citrus_db_factory *df,
    const char *key, const char *data)
{
    char *p;
    struct _citrus_region r;

    p = strdup(data);
    if (p == NULL)
        return (errno);
    _citrus_region_init(&r, p, strlen(p) + 1);
    return (_citrus_db_factory_add_by_string(df, key, &r, 1));
}

size_t
_citrus_db_factory_calc_size(struct _citrus_db_factory *df)
{
    size_t sz;

    sz = ceilto(_CITRUS_DB_HEADER_SIZE);
    sz += ceilto(_CITRUS_DB_ENTRY_SIZE * df->df_num_entries);
    sz += ceilto(df->df_total_key_size);
    sz += df->df_total_data_size;

    return (sz);
}

static __inline void
put8(struct _citrus_region *r, size_t *rofs, uint8_t val)
{

    *(uint8_t *)_citrus_region_offset(r, *rofs) = val;
    *rofs += 1;
}

static __inline void
put32(struct _citrus_region *r, size_t *rofs, uint32_t val)
{

    val = htonl(val);
    memcpy(_citrus_region_offset(r, *rofs), &val, 4);
    *rofs += 4;
}

static __inline void
putpad(struct _citrus_region *r, size_t *rofs)
{
    size_t i;

    for (i = ceilto(*rofs) - *rofs; i > 0; i--)
        put8(r, rofs, 0);
}

static __inline void
dump_header(struct _citrus_region *r, const char *magic, size_t *rofs,
    size_t num_entries)
{

    while (*rofs<_CITRUS_DB_MAGIC_SIZE)
        put8(r, rofs, *magic++);
    put32(r, rofs, (uint32_t) num_entries);
    put32(r, rofs, _CITRUS_DB_HEADER_SIZE);
}

int
_citrus_db_factory_serialize(struct _citrus_db_factory *df, const char *magic,
    struct _citrus_region *r)
{
    struct _citrus_db_factory_entry *de, **depp, *det;
    size_t dataofs, i, keyofs, nextofs, ofs;

    ofs = 0;
    /* check whether more than 0 entries exist */
    if (df->df_num_entries == 0) {
        dump_header(r, magic, &ofs, 0);
        return (0);
    }
    /* allocate hash table */
    depp = calloc(df->df_num_entries, sizeof(*depp));
    if (depp == NULL)
        return (-1);

    /* step1: store the entries which are not conflicting */
    STAILQ_FOREACH(de, &df->df_entries, de_entry) {
        de->de_hashvalue %= df->df_num_entries;
        de->de_idx = -1;
        de->de_next = NULL;
        if (depp[de->de_hashvalue] == NULL) {
            depp[de->de_hashvalue] = de;
            de->de_idx = (int)de->de_hashvalue;
        }
    }

    /* step2: resolve conflicts */
    i = 0;
    STAILQ_FOREACH(de, &df->df_entries, de_entry) {
        if (de->de_idx == -1) {
            det = depp[de->de_hashvalue];
            while (det->de_next != NULL)
                det = det->de_next;
            det->de_next = de;
            while (depp[i] != NULL)
                i++;
            depp[i] = de;
            de->de_idx = (int)i;
        }
    }

    keyofs = _CITRUS_DB_HEADER_SIZE +
        ceilto(df->df_num_entries*_CITRUS_DB_ENTRY_SIZE);
    dataofs = keyofs + ceilto(df->df_total_key_size);

    /* dump header */
    dump_header(r, magic, &ofs, df->df_num_entries);

    /* dump entries */
    for (i = 0; i < df->df_num_entries; i++) {
        de = depp[i];
        nextofs = 0;
        if (de->de_next) {
            nextofs = _CITRUS_DB_HEADER_SIZE +
                de->de_next->de_idx * _CITRUS_DB_ENTRY_SIZE;
        }
        put32(r, &ofs, de->de_hashvalue);
        put32(r, &ofs, (uint32_t) nextofs);
        put32(r, &ofs, (uint32_t) keyofs);
        put32(r, &ofs, (uint32_t) _citrus_region_size(&de->de_key));
        put32(r, &ofs, (uint32_t) dataofs);
        put32(r, &ofs, (uint32_t) _citrus_region_size(&de->de_data));
        memcpy(_citrus_region_offset(r, keyofs),
            _citrus_region_head(&de->de_key), _citrus_region_size(&de->de_key));
        keyofs += _citrus_region_size(&de->de_key);
        memcpy(_citrus_region_offset(r, dataofs),
            _citrus_region_head(&de->de_data), _citrus_region_size(&de->de_data));
        dataofs += _citrus_region_size(&de->de_data);
        putpad(r, &dataofs);
    }
    putpad(r, &ofs);
    putpad(r, &keyofs);
    free(depp);

    return (0);
}
