const entries = [
    [1000000, 1380326400], // 2013
    [2768409, 1383264000],
    [7679610, 1388448000],
    [11538514, 1391212000], // 2014
    [6925870357, 1701192327], // 2024
].sort((a, b) => a[0] - b[0]); // Sort by user ID

function parseRegistrationTime(prefix, reg_time) {
    return { prefix, date: new Date(reg_time * 1000).toISOString() };
}

function predictCreationDate(userId) {
    for (let i = 1; i < entries.length; i++) {
        if (userId >= entries[i - 1][0] && userId <= entries[i][0]) {
            const t = (userId - entries[i - 1][0]) / (entries[i][0] - entries[i - 1][0]);
            const reg_time = Math.floor(entries[i - 1][1] + t * (entries[i][1] - entries[i - 1][1]));
            return parseRegistrationTime("~", reg_time);
        }
    }
    return userId <= 1000000
        ? parseRegistrationTime("<", 1380326400)
        : parseRegistrationTime(">", 1701192327);
}

export { predictCreationDate };