/*-
 * Copyright (c) 2003 Citrus Project,
 * Copyright (c) 2009, 2010 Gabor Kovesdan <gabor@FreeBSD.org>,
 * 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 "dcmtk/oficonv/iconv.h"

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

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

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

#ifdef HAVE_LANGINFO_H
#include <langinfo.h>
#endif

#include <locale.h>

#include "citrus_types.h"
#include "citrus_module.h"
#include "citrus_esdb.h"
#include "citrus_hash.h"
#include "citrus_iconv.h"
#include "oficonv_strlcpy.h"
#include "oficonv_strcasestr.h"

#define ISBADF(_h_) (!(_h_) || (_h_) == (iconv_t)-1)

char *my_strndup(const char *str, size_t chars)
{
    char *buffer;
    size_t n;

    buffer = (char *) malloc(chars +1);
    if (buffer)
    {
        for (n = 0; ((n < chars) && (str[n] != 0)) ; n++) buffer[n] = str[n];
        buffer[n] = 0;
    }

    return buffer;
}

int _iconv_version = _ICONV_VERSION;

iconv_t      _iconv_open(const char *out, const char *in,
            struct _citrus_iconv *prealloc);

iconv_t
_iconv_open(const char *out, const char *in, struct _citrus_iconv *handle)
{
    const char *out_slashes;
    char *out_noslashes;
    int ret;

    /*
     * Remove anything following a //, as these are options (like
     * //ignore, //translate, etc) and we just don't handle them.
     * This is for compatibility with software that uses these
     * blindly.
     */
    out_slashes = strstr(out, "//");
    if (out_slashes != NULL) {
        out_noslashes = my_strndup(out, out_slashes - out);
        if (out_noslashes == NULL) {
            errno = ENOMEM;
            return ((iconv_t)-1);
        }
        ret = _citrus_iconv_open(&handle, in, out_noslashes);
        free(out_noslashes);
    } else {
        ret = _citrus_iconv_open(&handle, in, out);
    }

    if (ret) {
        errno = ret == ENOENT ? EINVAL : ret;
        return ((iconv_t)-1);
    }

    handle->cv_shared->ci_discard_ilseq = strcasestr(out, "//IGNORE");
    handle->cv_shared->ci_ilseq_invalid = false;
    handle->cv_shared->ci_hooks = NULL;

    return ((iconv_t)(void *)handle);
}

iconv_t
OFiconv_open(const char *out, const char *in)
{

    return (_iconv_open(out, in, NULL));
}

int
OFiconv_open_into(const char *out, const char *in, iconv_allocation_t *ptr)
{
    struct _citrus_iconv *handle;

    handle = (struct _citrus_iconv *)ptr;
    return ((_iconv_open(out, in, handle) == (iconv_t)-1) ? -1 : 0);
}

int
OFiconv_close_in(iconv_allocation_t *ptr)
{
    struct _citrus_iconv *handle;

    handle = (struct _citrus_iconv *)ptr;

    if (ISBADF((iconv_t)handle)) {
        errno = EBADF;
        return (-1);
    }

    _citrus_iconv_close_nofree(handle);

    return (0);
}

int
OFiconv_close(iconv_t handle)
{

    if (ISBADF(handle)) {
        errno = EBADF;
        return (-1);
    }

    _citrus_iconv_close((struct _citrus_iconv *)(void *)handle);

    return (0);
}

size_t
OFiconv(iconv_t handle, char ** in, size_t * szin, char ** out, size_t * szout)
{
    size_t ret;
    int err;

    if (ISBADF(handle)) {
        errno = EBADF;
        return ((size_t)-1);
    }

    err = _citrus_iconv_convert((struct _citrus_iconv *)(void *)handle,
        in, szin, out, szout, 0, &ret);
    if (err) {
        errno = err;
        ret = (size_t)-1;
    }

    return (ret);
}

size_t
OF__iconv(iconv_t handle, char **in, size_t *szin, char **out,
    size_t *szout, uint32_t flags, size_t *invalids)
{
    size_t ret;
    int err;

    if (ISBADF(handle)) {
        errno = EBADF;
        return ((size_t)-1);
    }

    err = _citrus_iconv_convert((struct _citrus_iconv *)(void *)handle,
        in, szin, out, szout, flags, &ret);
    if (invalids)
        *invalids = ret;
    if (err) {
        errno = err;
        ret = (size_t)-1;
    }

    return (ret);
}

int
OF__iconv_get_list(char ***rlist, size_t *rsz, __iconv_bool sorted)
{
    int ret;

    ret = _citrus_esdb_get_list(rlist, rsz, sorted);
    if (ret) {
        errno = ret;
        return (-1);
    }

    return (0);
}

void
OF__iconv_free_list(char **list, size_t sz)
{

    _citrus_esdb_free_list(list, sz);
}

/*
 * GNU-compatibile non-standard interfaces.
 */
static int
qsort_helper(const void *first, const void *second)
{
    const char * const *s1;
    const char * const *s2;

    s1 = first;
    s2 = second;
    return (strcmp(*s1, *s2));
}

void
OFiconvlist(int (*do_one) (unsigned int, const char * const *,
    void *), void *data)
{
    char **list, **names;
    const char * const *np;
    char *curitem, *curkey, *slashpos;
    size_t sz;
    unsigned int i, j, n;

    i = 0;
    j = 0;
    names = NULL;

    if (OF__iconv_get_list(&list, &sz, true)) {
        list = NULL;
        goto out;
    }
    qsort((void *)list, sz, sizeof(char *), qsort_helper);
    while (i < sz) {
        j = 0;
        slashpos = strchr(list[i], '/');
        names = malloc(sz * sizeof(char *));
        if (names == NULL)
            goto out;
        curkey = my_strndup(list[i], slashpos - list[i]);
        if (curkey == NULL)
            goto out;
        names[j++] = curkey;
        for (; (i < sz) && (memcmp(curkey, list[i], strlen(curkey)) == 0); i++) {
            slashpos = strchr(list[i], '/');
            if (strcmp(curkey, &slashpos[1]) == 0)
                continue;
            curitem = strdup(&slashpos[1]);
            if (curitem == NULL)
                goto out;
            names[j++] = curitem;
        }
        np = (const char * const *)names;
        do_one(j, np, data);
        for (n = 0; n < j; n++)
            free(names[n]);
        free(names);
        names = NULL;
    }

out:
    if (names != NULL) {
        for (n = 0; n < j; n++)
            free(names[n]);
        free(names);
    }
    if (list != NULL)
        OF__iconv_free_list(list, sz);
}

const char
*OFiconv_canonicalize(const char *name)
{

    return (_citrus_iconv_canonicalize(name));
}

int
OFiconvctl(iconv_t cd, int request, void *argument)
{
    struct _citrus_iconv *cv;
    struct iconv_hooks *hooks;
    const char *convname;
    char *dst;
    int *i;
    size_t srclen;

    cv = (struct _citrus_iconv *)(void *)cd;
    hooks = (struct iconv_hooks *)argument;
    i = (int *)argument;

    if (ISBADF(cd)) {
        errno = EBADF;
        return (-1);
    }

    switch (request) {
    case ICONV_TRIVIALP:
        convname = cv->cv_shared->ci_convname;
        dst = strchr(convname, '/');
        srclen = dst - convname;
        dst++;
        *i = (srclen == strlen(dst)) && !memcmp(convname, dst, srclen);
        return (0);
    case ICONV_GET_TRANSLITERATE:
        *i = 1;
        return (0);
    case ICONV_SET_TRANSLITERATE:
        return  ((*i == 1) ? 0 : -1);
    case ICONV_GET_DISCARD_ILSEQ:
        *i = cv->cv_shared->ci_discard_ilseq ? 1 : 0;
        return (0);
    case ICONV_SET_DISCARD_ILSEQ:
        cv->cv_shared->ci_discard_ilseq = *i;
        return (0);
    case ICONV_SET_HOOKS:
        cv->cv_shared->ci_hooks = hooks;
        return (0);
    case ICONV_SET_FALLBACKS:
        errno = EOPNOTSUPP;
        return (-1);
    case ICONV_GET_ILSEQ_INVALID:
        *i = cv->cv_shared->ci_ilseq_invalid ? 1 : 0;
        return (0);
    case ICONV_SET_ILSEQ_INVALID:
        cv->cv_shared->ci_ilseq_invalid = *i;
        return (0);
    default:
        errno = EINVAL;
        return (-1);
    }
}

const char *OFlocale_charset(iconv_locale_allocation_t *buf)
{
#ifdef HAVE_WINDOWS_H
  snprintf((char *)buf, sizeof(iconv_locale_allocation_t), "%lu", (unsigned long) GetConsoleOutputCP());
  return (const char *)buf;
#elif defined(__ANDROID__)
  /* Android does not provide an implementation of nl_langinfo() and internally always uses UTF-8 */
  (void) buf;
  return "UTF-8";
#else
  (void) buf;
  return nl_langinfo(CODESET);
#endif
}