/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright 2017 Nexenta Systems, Inc.
 * Copyright (c) 2002 Tim J. Robbins
 * All rights reserved.
 *
 * Copyright (c) 2011 The FreeBSD Foundation
 *
 * Portions of this software were developed by David Chisnall
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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 <errno.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include "collate.h"

int
wcscoll_l(const wchar_t *ws1, const wchar_t *ws2, locale_t locale)
{
        int len1, len2, pri1, pri2;
        wchar_t *tr1 = NULL, *tr2 = NULL;
        int direc, pass;
        int ret = wcscmp(ws1, ws2);

        FIX_LOCALE(locale);
        struct xlocale_collate *table =
                (struct xlocale_collate*)locale->components[XLC_COLLATE];

        if (table->__collate_load_error || ret == 0)
                return (ret);

        if (*ws1 == 0 && *ws2 != 0)
                return (-1);
        if (*ws1 != 0 && *ws2 == 0)
                return (1);

        /*
         * Once upon a time we had code to try to optimize this, but
         * it turns out that you really can't make many assumptions
         * safely.  You absolutely have to run this pass by pass,
         * because some passes will be ignored for a given character,
         * while others will not.  Simpler locales will benefit from
         * having fewer passes, and most comparisons should resolve
         * during the primary pass anyway.
         *
         * Note that we do one final extra pass at the end to pick
         * up UNDEFINED elements.  There is special handling for them.
         */
        for (pass = 0; pass <= table->info->directive_count; pass++) {

                const int32_t *st1 = NULL;
                const int32_t *st2 = NULL;
                const wchar_t   *w1 = ws1;
                const wchar_t   *w2 = ws2;

                /* special pass for UNDEFINED */
                if (pass == table->info->directive_count) {
                        direc = DIRECTIVE_FORWARD;
                } else {
                        direc = table->info->directive[pass];
                }

                if (direc & DIRECTIVE_BACKWARD) {
                        wchar_t *bp, *fp, c;
                        free(tr1);
                        if ((tr1 = wcsdup(w1)) == NULL)
                                goto end;
                        bp = tr1;
                        fp = tr1 + wcslen(tr1) - 1;
                        while (bp < fp) {
                                c = *bp;
                                *bp++ = *fp;
                                *fp-- = c;
                        }
                        free(tr2);
                        if ((tr2 = wcsdup(w2)) == NULL)
                                goto end;
                        bp = tr2;
                        fp = tr2 + wcslen(tr2) - 1;
                        while (bp < fp) {
                                c = *bp;
                                *bp++ = *fp;
                                *fp-- = c;
                        }
                        w1 = tr1;
                        w2 = tr2;
                }

                if (direc & DIRECTIVE_POSITION) {
                        int check1, check2;
                        while (*w1 && *w2) {
                                pri1 = pri2 = 0;
                                check1 = check2 = 1;
                                while ((pri1 == pri2) && (check1 || check2)) {
                                        if (check1) {
                                                _collate_lookup(table, w1, &len1,
                                                    &pri1, pass, &st1);
                                                if (pri1 < 0) {
                                                        errno = EINVAL;
                                                        goto end;
                                                }
                                                if (!pri1) {
                                                        pri1 = COLLATE_MAX_PRIORITY;
                                                        st1 = NULL;
                                                }
                                                check1 = (st1 != NULL);
                                        }
                                        if (check2) {
                                                _collate_lookup(table, w2, &len2,
                                                    &pri2, pass, &st2);
                                                if (pri2 < 0) {
                                                        errno = EINVAL;
                                                        goto end;
                                                }
                                                if (!pri2) {
                                                        pri2 = COLLATE_MAX_PRIORITY;
                                                        st2 = NULL;
                                                }
                                                check2 = (st2 != NULL);
                                        }
                                }
                                if (pri1 != pri2) {
                                        ret = pri1 - pri2;
                                        goto end;
                                }
                                w1 += len1;
                                w2 += len2;
                        }
                        if (!*w1) {
                                if (*w2) {
                                        ret = -(int)*w2;
                                        goto end;
                                }
                        } else {
                                ret = *w1;
                                goto end;
                        }
                } else {
                        int vpri1 = 0, vpri2 = 0;
                        while (*w1 || *w2 || st1 || st2) {
                                pri1 = 1;
                                while (*w1 || st1) {
                                        _collate_lookup(table, w1, &len1, &pri1,
                                            pass, &st1);
                                        w1 += len1;
                                        if (pri1 > 0) {
                                                vpri1++;
                                                break;
                                        }

                                        if (pri1 < 0) {
                                                errno = EINVAL;
                                                goto end;
                                        }
                                        st1 = NULL;
                                }
                                pri2 = 1;
                                while (*w2 || st2) {
                                        _collate_lookup(table, w2, &len2, &pri2,
                                            pass, &st2);
                                        w2 += len2;
                                        if (pri2 > 0) {
                                                vpri2++;
                                                break;
                                        }
                                        if (pri2 < 0) {
                                                errno = EINVAL;
                                                goto end;
                                        }
                                        st2 = NULL;
                                }
                                if ((!pri1 || !pri2) && (vpri1 == vpri2))
                                        break;
                                if (pri1 != pri2) {
                                        ret = pri1 - pri2;
                                        goto end;
                                }
                        }
                        if (vpri1 && !vpri2) {
                                ret = 1;
                                goto end;
                        }
                        if (!vpri1 && vpri2) {
                                ret = -1;
                                goto end;
                        }
                }
        }
        ret = 0;

end:
        free(tr1);
        free(tr2);

        return (ret);
}

int
wcscoll(const wchar_t *ws1, const wchar_t *ws2)
{
        return wcscoll_l(ws1, ws2, __get_locale());
}