/*
** Copyright 2011, Oliver Tappe, zooey@hirschkaefer.de. All rights reserved.
** Distributed under the terms of the MIT License.
*/

#include <errno.h>
#include <string.h>
#include <wchar.h>

#include <errno_private.h>
#include <LocaleBackend.h>
#include <wchar_private.h>


//#define TRACE_WCSRTOMBS
#ifdef TRACE_WCSRTOMBS
#       include <OS.h>
#       define TRACE(x) debug_printf x
#else
#       define TRACE(x) ;
#endif


using BPrivate::Libroot::GetCurrentLocaleBackend;
using BPrivate::Libroot::LocaleBackend;


extern "C" size_t
__wcsnrtombs(char* dst, const wchar_t** src, size_t nwc, size_t len,
        mbstate_t* ps)
{
        LocaleBackend* backend = GetCurrentLocaleBackend();

        TRACE(("wcsnrtombs(%p, %p, %lu, %lu) - lb:%p\n", dst, *src, nwc, len,
                backend));

        if (ps == NULL) {
                static mbstate_t internalMbState;
                ps = &internalMbState;
        }

        if (backend == NULL) {
                /*
                 * The POSIX locale is active. Since the POSIX locale only contains
                 * chars 0-127 and those ASCII chars are compatible with the UTF32
                 * values used in wint_t, we can just copy the codepoint values.
                 */
                size_t count = 0;
                const wchar_t* srcEnd = *src + nwc;
                if (dst == NULL) {
                        // only count number of required wide characters
                        const wchar_t* wcSrc = *src;
                        for (; wcSrc < srcEnd; ++wcSrc, ++count) {
                                if (*wcSrc < 0) {
                                        // char is non-ASCII
                                        __set_errno(EILSEQ);
                                        count = (size_t)-1;
                                        break;
                                }
                                if (*wcSrc == 0) {
                                        memset(ps, 0, sizeof(mbstate_t));
                                        break;
                                }
                        }
                } else {
                        // "convert" the characters
                        for (; *src < srcEnd && count < len; ++*src, ++count) {
                                if (**src < 0) {
                                        // char is non-ASCII
                                        __set_errno(EILSEQ);
                                        count = (size_t)-1;
                                        break;
                                }
                                *dst++ = (char)**src;
                                if (**src == 0) {
                                        memset(ps, 0, sizeof(mbstate_t));
                                        *src = NULL;
                                        break;
                                }
                        }
                }

                TRACE(("wcsnrtombs returns %lx and src %p\n", count, *src));

                return count;
        }

        size_t result = 0;
        status_t status = backend->WcharStringToMultibyte(dst, len, src, nwc,
                ps, result);

        if (status == B_BAD_DATA) {
                TRACE(("wcsnrtomb(): setting errno to EILSEQ\n"));
                __set_errno(EILSEQ);
                result = (size_t)-1;
        } else if (status != B_OK) {
                TRACE(("wcsnrtomb(): setting errno to EINVAL (status: %lx)\n", status));
                __set_errno(EINVAL);
                result = (size_t)-1;
        }

        TRACE(("wcsnrtombs returns %lx and src %p\n", result, *src));

        return result;
}


B_DEFINE_WEAK_ALIAS(__wcsnrtombs, wcsnrtombs);


extern "C" size_t
__wcsrtombs(char* dst, const wchar_t** src, size_t len, mbstate_t* ps)
{
        if (ps == NULL) {
                static mbstate_t internalMbState;
                ps = &internalMbState;
        }

        return __wcsnrtombs(dst, src, __wcslen(*src) + 1, len, ps);
}


B_DEFINE_WEAK_ALIAS(__wcsrtombs, wcsrtombs);