/**
 * Copyright (c) 2013, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * 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.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @file logfile_sub_source.hh
 */

#include <stdio.h>
#include <string.h>
#include <sqlite3.h>

#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>

#include <algorithm>

extern "C" {
        #include "strnatcmp.h"
}

#define MAX_ADDR_LEN    128

static int strncmp2(int a_len, const char *a_str,
                    int b_len, const char *b_str)
{
    int retval = strncmp(a_str, b_str, std::min(a_len, b_len));

    if (retval == 0) {
        if (a_len < b_len) {
            retval = -1;
        }
        else {
            retval = 1;
        }
    }
    return retval;
}

static int try_inet_pton(int p_len, const char *p, char *n)
{
    static int family[] = { AF_INET6, AF_INET, AF_MAX };

    char buf[MAX_ADDR_LEN];
    int  retval = AF_MAX;

    strncpy(buf, p, p_len);
    buf[p_len] = '\0';
    for (int lpc = 0; family[lpc] != AF_MAX; lpc++) {
        if (inet_pton(family[lpc], buf, n) == 1) {
            retval = family[lpc];
            break;
        }
    }

    return retval;
}

static int convert_v6_to_v4(int family, char *n)
{
    struct in6_addr *ia = (struct in6_addr *)n;

    if (family == AF_INET6 &&
        (IN6_IS_ADDR_V4COMPAT(ia) ||
         IN6_IS_ADDR_V4MAPPED(ia))) {
        family = AF_INET;
        memmove(n, n + 12, sizeof(struct in_addr));
    }

    return family;
}

static
int ipaddress(void *ptr,
              int a_len, const void *a_in,
              int b_len, const void *b_in)
{
    char a_addr[sizeof(struct in6_addr)],
         b_addr[sizeof(struct in6_addr)];
    const char *a_str = (const char *)a_in, *b_str = (const char *)b_in;
    int         a_family, b_family, retval;

    if (a_len > MAX_ADDR_LEN || b_len > MAX_ADDR_LEN) {
        return strncmp2(a_len, a_str, b_len, b_str);
    }

    a_family = try_inet_pton(a_len, a_str, a_addr);
    b_family = try_inet_pton(b_len, b_str, b_addr);

    if (a_family == AF_MAX && b_family != AF_MAX) {
        retval = -1;
    }
    else if (a_family != AF_MAX && b_family == AF_MAX) {
        retval = 1;
    }
    else {
        a_family = convert_v6_to_v4(a_family, a_addr);
        b_family = convert_v6_to_v4(b_family, b_addr);
        if (a_family == b_family) {
            retval = memcmp(a_addr, b_addr,
                            a_family == AF_INET ?
                            sizeof(struct in_addr) :
                            sizeof(struct in6_addr));
        }
        else if (a_family == AF_INET) {
            retval = -1;
        }
        else {
            retval = 1;
        }
    }

    return retval;
}

static
int sql_strnatcmp(void *ptr,
                  int a_len, const void *a_in,
                  int b_len, const void *b_in)
{
    return strnatcmp(a_len, (char *)a_in, b_len, (char *)b_in);
}

static
int sql_strnatcasecmp(void *ptr,
                      int a_len, const void *a_in,
                      int b_len, const void *b_in)
{
    return strnatcasecmp(a_len, (char *)a_in, b_len, (char *)b_in);
}

int register_collation_functions(sqlite3 *db)
{
    sqlite3_create_collation(db, "ipaddress", SQLITE_UTF8, NULL, ipaddress);
    sqlite3_create_collation(db, "naturalcase", SQLITE_UTF8, NULL,
                             sql_strnatcmp);
    sqlite3_create_collation(db, "naturalnocase", SQLITE_UTF8, NULL,
                             sql_strnatcasecmp);

    return 0;
}