json.hpp

/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

#include "3rdparty/json11/json11.hpp"

using namespace json11;
using namespace std;

/**
 * Parse a JSON file stored in _file_to_saveload.
 * @returns The file parsed as a json11:Json object.
 */
Json ParseJsonFromLoadedFile()
{
    string err; ///< Holds the error message generated by the json11 parser.

    /* Load the GeoJSON file as a string initially. We'll parse it soon.. */
    size_t filesize;
    char *text{};
    FILE *handle = FioFOpenFile(_file_to_saveload.name, "rb", GEODATA_DIR, &filesize);
    if (handle == nullptr) return false;

    text = ReallocT(text, filesize);
    size_t read = fread(text, 1, filesize, handle);
    fclose(handle);

    if (read != filesize) return false;

    /* Add a trailing \0 to mark the end of the string */
    text = ReallocT(text, filesize + 1);
    text[filesize] = '\0';

    /* The parser doesn't like tabs or various newline characters, so we'll replace them with a space. */
    for (char *p = text; *p != '\0'; p++) {
        if (*p == '\t' || *p == '\r' || *p == '\n' || *p == '\r\n') *p = ' ';
    }

    /* Finally time to parse the string. */
    // TODO: Show errors from invalid JSON load to the player.
    return Json::parse(text, err);
}