/** @file
 * @brief Extract text from Gnumeric spreadsheets
 */
/* Copyright (C) 2020,2025 Olly Betts
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see
 * <https://www.gnu.org/licenses/>.
 */

#include <config.h>

#include "gnumericparser.h"

#include "datetime.h"
#include "stringutils.h"

using namespace std;

// Dummy std::string to point target at, but we actually parse the value into
// the time_t created member variable.
static string created_dummy_string;

bool
GnumericParser::opening_tag(const string& tag)
{
    if (target != nullptr) return true;

    if (tag.size() < 8) return true;
    if (tag == "gnm:Cell") {
        string value;
        if (!get_attribute("ValueType", value)) return true;
        target = &dump;
    } else if (startswith(tag, "dc:")) {
        if (tag == "dc:subject") {
            // dc:subject is "Subject and Keywords":
            // "Typically, Subject will be expressed as keywords, key phrases
            // or classification codes that describe a topic of the resource."
            // Gnumeric uses meta:keyword for keywords - dc:subject
            // comes from a text field labelled "Subject".  Let's just treat
            // it as more keywords.
            target = &keywords;
        } else if (tag == "dc:title") {
            target = &title;
        } else if (tag == "dc:description") {
            // Gnumeric's field is labelled "Comments".
            target = &sample;
        } else if (tag == "dc:initial-creator") {
            target = &author;
        }
    } else if (tag == "gnm:SheetName") {
        // Treat sheet names as keywords so they don't appear at the start
        // of the sample.
        target = &keywords;
    } else if (tag == "meta:creation-date") {
        target = &created_dummy_string;
    }
    return true;
}

bool
GnumericParser::closing_tag(const string&)
{
    target = nullptr;
    return true;
}

void
GnumericParser::process_content(const string& content)
{
    if (!target) return;

    if (target == &created_dummy_string) {
        if (created != time_t(-1)) return;

        // E.g. 2025-03-31T18:40:06Z
        created = parse_datetime(content);
        return;
    }

    if (!target->empty()) *target += ' ';
    *target += content;
}
