/*
 * Copyright 2004-2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <langinfo.h>
#include <iconv.h>

#include "utf.h"

/* Global variables */

/*
 * Initialize all utf processing.
 */
struct UtfInst *JNICALL
utfInitialize(char *options)
{
    struct UtfInst *ui;
    char           *codeset;

    ui = (struct UtfInst*)calloc(sizeof(struct UtfInst), 1);
    ui->iconvToPlatform         = (void *)-1;
    ui->iconvFromPlatform       = (void *)-1;

    /* Set the locale from the environment */
    (void)setlocale(LC_ALL, "");

    /* Get the codeset name */
    codeset = (char*)nl_langinfo(CODESET);
    if ( codeset == NULL || codeset[0] == 0 ) {
        return ui;
    }

    /* If we don't need this, skip it */
    if (strcmp(codeset, "UTF-8") == 0 || strcmp(codeset, "utf8") == 0 ) {
        return ui;
    }

    /* Open conversion descriptors */
    ui->iconvToPlatform   = iconv_open(codeset, "UTF-8");
    if ( ui->iconvToPlatform == (void *)-1 ) {
        UTF_ERROR("Failed to complete iconv_open() setup");
    }
    ui->iconvFromPlatform = iconv_open("UTF-8", codeset);
    if ( ui->iconvFromPlatform == (void *)-1 ) {
        UTF_ERROR("Failed to complete iconv_open() setup");
    }
    return ui;
}

/*
 * Terminate all utf processing
 */
void  JNICALL
utfTerminate(struct UtfInst *ui, char *options)
{
    if ( ui->iconvFromPlatform != (void *)-1 ) {
        (void)iconv_close(ui->iconvFromPlatform);
    }
    if ( ui->iconvToPlatform != (void *)-1 ) {
        (void)iconv_close(ui->iconvToPlatform);
    }
    ui->iconvToPlatform   = (void *)-1;
    ui->iconvFromPlatform = (void *)-1;
    (void)free(ui);
}

/*
 * Do iconv() conversion.
 *    Returns length or -1 if output overflows.
 */
static int
iconvConvert(iconv_t ic, char *bytes, int len, char *output, int outputMaxLen)
{
    int outputLen = 0;

    UTF_ASSERT(bytes);
    UTF_ASSERT(len>=0);
    UTF_ASSERT(output);
    UTF_ASSERT(outputMaxLen>len);

    output[0] = 0;
    outputLen = 0;

    if ( ic != (iconv_t)(void *)-1 ) {
        int          returnValue;
        size_t       inLeft;
        size_t       outLeft;
        char        *inbuf;
        char        *outbuf;

        inbuf        = bytes;
        outbuf       = output;
        inLeft       = len;
        outLeft      = outputMaxLen;
        returnValue  = iconv(ic, (void*)&inbuf, &inLeft, &outbuf, &outLeft);
        if ( returnValue >= 0 && inLeft==0 ) {
            outputLen = outputMaxLen-outLeft;
            output[outputLen] = 0;
            return outputLen;
        }

        /* Failed to do the conversion */
        return -1;
    }

    /* Just copy bytes */
    outputLen = len;
    (void)memcpy(output, bytes, len);
    output[len] = 0;
    return outputLen;
}

/*
 * Convert UTF-8 to Platform Encoding.
 *    Returns length or -1 if output overflows.
 */
int  JNICALL
utf8ToPlatform(struct UtfInst*ui, jbyte *utf8, int len, char *output, int outputMaxLen)
{
    /* Negative length is an error */
    if ( len < 0 ) {
        return -1;
    }

    /* Zero length is ok, but we don't need to do much */
    if ( len == 0 ) {
        output[0] = 0;
        return 0;
    }

    return iconvConvert(ui->iconvToPlatform, (char*)utf8, len, output, outputMaxLen);
}

/*
 * Convert Platform Encoding to UTF-8.
 *    Returns length or -1 if output overflows.
 */
int  JNICALL
utf8FromPlatform(struct UtfInst*ui, char *str, int len, jbyte *output, int outputMaxLen)
{
    /* Negative length is an error */
    if ( len < 0 ) {
        return -1;
    }

    /* Zero length is ok, but we don't need to do much */
    if ( len == 0 ) {
        output[0] = 0;
        return 0;
    }

    return iconvConvert(ui->iconvFromPlatform, str, len, (char*)output, outputMaxLen);
}