//========================================================================

//

// DateInfo.cc

//

// Copyright (C) 2008, 2018, 2019, 2021, 2022, 2024, 2025 Albert Astals Cid <aacid@kde.org>

// Copyright (C) 2009 Carlos Garcia Campos <carlosgc@gnome.org>

// Copyright (C) 2015 André Guerreiro <aguerreiro1985@gmail.com>

// Copyright (C) 2015 André Esser <bepandre@hotmail.com>

// Copyright (C) 2016, 2018, 2021 Adrian Johnson <ajohnson@redneon.com>

// Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, <info@kdab.com>. Work sponsored by Technische Universität Dresden

// Copyright (C) 2024-2026 g10 Code GmbH, Author: Sune Stolborg Vuorela <sune@vuorela.dk>

// Copyright (C) 2024, 2025 Erich E. Hoover <erich.e.hoover@gmail.com>

//

// To see a description of the changes please see the Changelog file that

// came with your tarball or type make ChangeLog if you are building from git

//

//========================================================================

//========================================================================

//

// Based on code from pdfinfo.cc

//

// Copyright 1998-2003 Glyph & Cog, LLC

//

//========================================================================

#include <config.h>

#include "goo/glibc.h"

#include "DateInfo.h"

#include "UTF.h"

#include <cstdio>

#include <cstring>

/* See PDF Reference 1.3, Section 3.8.2 for PDF Date representation */

bool parseDateString(const std::string &date, int *year, int *month, int *day, int *hour, int *minute, int *second, char *tz, int *tzHour, int *tzMinute)

{

    std::vector<Unicode> u = TextStringToUCS4(date);

    std::string s;

    for (auto &c : u) {

        // Ignore any non ASCII characters

        if (c < 128) {

            s.push_back(c);

        }

    }

    const char *dateString = s.c_str();

    if (strlen(dateString) < 2) {

        return false;

    }

    if (dateString[0] == 'D' && dateString[1] == ':') {

        dateString += 2;

    }

    *month = 1;

    *day = 1;

    *hour = 0;

    *minute = 0;

    *second = 0;

    *tz = 0x00;

    *tzHour = 0;

    *tzMinute = 0;

    if (sscanf(dateString, "%4d%2d%2d%2d%2d%2d%c%2d%*c%2d", year, month, day, hour, minute, second, tz, tzHour, tzMinute) > 0) {

        /* Workaround for y2k bug in Distiller 3 stolen from gpdf, hoping that it won't

         * be used after y2.2k */

        if (*year < 1930 && strlen(dateString) > 14) {

            int century, years_since_1900;

            if (sscanf(dateString, "%2d%3d%2d%2d%2d%2d%2d", &century, &years_since_1900, month, day, hour, minute, second) == 7) {

                *year = century * 100 + years_since_1900;

            } else {

                return false;

            }

        }

        if (*year <= 0) {

            return false;

        }

        return true;

    }

    return false;

}

std::string timeToStringWithFormat(const time_t *timeA, const char *format)

{

    const time_t timet = timeA ? *timeA : time(nullptr);

    struct tm localtime_tm;

    localtime_r(&timet, &localtime_tm);

    char timeOffset[12];

    // strftime "%z" does not work on windows (it prints zone name, not offset)

    // calculate time zone offset by comparing local and gmtime time_t value for same

    // time.

    const time_t timeg = timegm(&localtime_tm);

    const int offset = static_cast<int>(difftime(timeg, timet)); // find time zone offset in seconds

    if (offset > 0) {

        snprintf(timeOffset, sizeof(timeOffset), "+%02d'%02d'", offset / 3600, (offset % 3600) / 60);

    } else if (offset < 0) {

        snprintf(timeOffset, sizeof(timeOffset), "-%02d'%02d'", -offset / 3600, (-offset % 3600) / 60);

    } else {

        snprintf(timeOffset, sizeof(timeOffset), "Z");

    }

    std::string fmt(format);

    const char timeOffsetPattern[] = "%z";

    size_t timeOffsetPosition = fmt.find(timeOffsetPattern);

    if (timeOffsetPosition != std::string::npos) {

        fmt.replace(timeOffsetPosition, sizeof(timeOffsetPattern) - 1, timeOffset);

    }

    if (fmt.empty()) {

        return "";

    }

    size_t bufLen = 50;

    std::string buf(bufLen, ' ');

    while (strftime(buf.data(), buf.size(), fmt.c_str(), &localtime_tm) == 0) {

        buf.resize(bufLen *= 2);

    }

    buf.resize(buf.find('\0'));

    return buf;

}

std::unique_ptr<GooString> timeToDateString(const time_t *timeA)

{

    return std::make_unique<GooString>(timeToStringWithFormat(timeA, "D:%Y%m%d%H%M%S%z"));

}

// Convert PDF date string to time. Returns -1 if conversion fails.

time_t dateStringToTime(const std::string &dateString)

{

    int year, mon, day, hour, min, sec, tz_hour, tz_minute;

    char tz;

    struct tm tm;

    time_t time;

    if (!parseDateString(dateString, &year, &mon, &day, &hour, &min, &sec, &tz, &tz_hour, &tz_minute)) {

        return -1;

    }

    tm.tm_year = year - 1900;

    tm.tm_mon = mon - 1;

    tm.tm_mday = day;

    tm.tm_hour = hour;

    tm.tm_min = min;

    tm.tm_sec = sec;

    tm.tm_wday = -1;

    tm.tm_yday = -1;

    tm.tm_isdst = -1; /* 0 = DST off, 1 = DST on, -1 = don't know */

    /* compute tm_wday and tm_yday and check date */

    time = timegm(&tm);

    if (time == static_cast<time_t>(-1)) {

        return time;

    }

    time_t offset = (tz_hour * 60 + tz_minute) * 60;

    if (tz == '-') {

        offset *= -1;

    }

    time -= offset;

    return time;

}