/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1992-2009 Edwin Groothuis <edwin@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 <sys/cdefs.h>
#include <sys/time.h>
#include <err.h>
#include <langinfo.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef WITH_ICONV
#include <iconv.h>
#include <errno.h>

static iconv_t conv = (iconv_t)-1;
static char *currentEncoding = NULL;

#endif

#include "pathnames.h"
#include "calendar.h"

#ifdef WITH_ICONV
void
set_new_encoding(void)
{
        const char *newenc;

        newenc = nl_langinfo(CODESET);
        if (currentEncoding == NULL) {
                currentEncoding = strdup(newenc);
                if (currentEncoding == NULL)
                        errx(1, "set_new_encoding: cannot allocate memory");
                return;
        }
        if (strcmp(currentEncoding, newenc) == 0)
                return;
        free(currentEncoding);
        currentEncoding = strdup(newenc);
        if (currentEncoding == NULL)
                errx(1, "set_new_encoding: cannot allocate memory");
        if (conv != (iconv_t) -1) {
                iconv_close(conv);
                conv = (iconv_t) -1;
        }
}
#endif

static char *
convert(char *input)
{
        char *output;
#ifdef WITH_ICONV
        size_t inleft, outleft, converted = 0;
        char *outbuf, *tmp;
        char *inbuf;
        size_t outlen;

        if (currentEncoding == NULL) {
                output = strdup(input);
                if (output == NULL)
                        errx(1, "convert: cannot allocate memory");
                return (output);
        }
        if (conv == (iconv_t)-1) {
                conv = iconv_open(outputEncoding, currentEncoding);
                if (conv == (iconv_t)-1) {
                        if (errno == EINVAL)
                                errx(1, "Conversion is not supported");
                        else
                                err(1, "Initialization failure");
                }
        }

        inleft = strlen(input);
        inbuf = input;

        outlen = inleft;
        if ((output = malloc(outlen + 1)) == NULL)
                errx(1, "convert: cannot allocate memory");

        for (;;) {
                errno = 0;
                outbuf = output + converted;
                outleft = outlen - converted;

                converted = iconv(conv, (char **) &inbuf, &inleft, &outbuf, &outleft);
                if (converted != (size_t) -1 || errno == EINVAL) {
                        /* finished or invalid multibyte, so truncate and ignore */
                        break;
                }

                if (errno != E2BIG) {
                        free(output);
                        err(1, "convert");
                }

                converted = outbuf - output;
                outlen += inleft * 2;

                if ((tmp = realloc(output, outlen + 1)) == NULL) {
                        free(output);
                        errx(1, "convert: cannot allocate memory");
                }

                output = tmp;
                outbuf = output + converted;
        }

        /* flush the iconv conversion */
        iconv(conv, NULL, NULL, &outbuf, &outleft);

        /* null terminate the string */
        *outbuf = '\0';
#else
        output = strdup(input);
        if (output == NULL)
                errx(1, "convert: cannot allocate memory");
#endif

        return (output);
}

struct event *
event_add(int year, int month, int day, int var, char *txt, char *extra)
{
        struct event *e;

        /*
         * Creating a new event:
         * - Create a new event
         * - Copy the machine readable day and month
         * - Copy the text of the event
         */
        e = (struct event *)calloc(1, sizeof(struct event));
        if (e == NULL)
                errx(1, "event_add: cannot allocate memory");
        e->year = year;
        e->month = month;
        e->day = day;
        e->var = var;
        e->text = convert(txt);
        if (e->text == NULL)
                errx(1, "event_add: cannot allocate memory");
        e->extra = NULL;
        if (extra != NULL && extra[0] != '\0')
                e->extra = convert(extra);
        addtodate(e);
        return (e);
}

void
event_continue(struct event *e, char *txt)
{
        char *oldtext, *text;

        text = convert(txt);
        oldtext = e->text;
        if (oldtext == NULL)
                errx(1, "event_continue: cannot allocate memory");

        asprintf(&e->text, "%s\n%s", oldtext, text);
        if (e->text == NULL)
                errx(1, "event_continue: cannot allocate memory");
        free(oldtext);
        free(text);

        return;
}

void
event_print_all(FILE *fp)
{
        struct event *e;
        struct tm tm;
        char dbuf[80];
        static int d_first;

        d_first = (*nl_langinfo(D_MD_ORDER) == 'd');

        while (walkthrough_dates(&e) != 0) {
                if (e) {
#ifdef DEBUG
                        fprintf(stderr, "event_print_all month: %d, day: %d\n",
                            e->month, e->day);
#endif
                        memset(&tm, 0, sizeof(struct tm));
                        tm.tm_mday = e->day;
                        tm.tm_mon = e->month - 1;
                        tm.tm_year = e->year - 1900;
                        (void)strftime(dbuf, sizeof(dbuf), d_first ? "%e %b" : "%b %e", &tm);
                }

                /*
                 * Go through all events and print the text of the matching
                 * dates
                 */
                while (e != NULL) {
                        (void)fprintf(fp, "%s%c%s%s%s%s\n", dbuf,
                            e->var ? '*' : ' ', e->text,
                            e->extra != NULL ? " (" : "",
                            e->extra != NULL ? e->extra : "",
                            e->extra != NULL ? ")" : ""
                        );

                        e = e->next;
                }
        }
}