xnv/src/server/backend/tags.js

const path = require("path");
const fs = require("fs");

function loadTags(directoryPath) {
    return new Promise((a, r) =>
        fs.readFile(
            path.join(directoryPath, "meta.json"),
            "utf8",
            async (err, data) => {
                if (err) {
                    if (!err.message.includes("ENOENT")) return r(err);
                    await saveTags(directoryPath, {});
                }

                const tagCache = JSON.parse(data);
                a(tagCache);
            }
        )
    );
}

function saveTags(directoryPath, tags = {}) {
    return new Promise((a, r) =>
        fs.writeFile(
            path.join(directoryPath, "meta.json"),
            JSON.stringify(tags),
            "utf8",
            err => {
                if (err) return r(err);
                a({});
            }
        )
    );
}

async function updateTagsForNote(directoryPath, { title, tags = [] }) {
    if (!title || title === "") {
        return Promise.reject();
    }

    const allTags = await loadTags(directoryPath);
    allTags[title] = [...tags];
    await saveTags(directoryPath, allTags);
}

async function getTagsForNote(directoryPath, { title }) {
    if (!title || title === "") {
        return Promise.reject();
    }

    const allTags = await loadTags(directoryPath);
    return allTags[title];
}

module.exports = {
    loadTags,
    getTagsForNote,
    updateTagsForNote
};