# Source: becca/entities/bnote.js

    "use strict";

    const protectedSessionService = require('../../services/protected_session');
    const log = require('../../services/log');
    const sql = require('../../services/sql');
    const utils = require('../../services/utils');
    const dateUtils = require('../../services/date_utils');
    const AbstractBeccaEntity = require("./abstract_becca_entity");
    const BRevision = require("./brevision");
    const BAttachment = require("./battachment");
    const TaskContext = require("../../services/task_context");
    const dayjs = require("dayjs");
    const utc = require('dayjs/plugin/utc');
    const eventService = require("../../services/events");
    dayjs.extend(utc);

    const LABEL = 'label';
    const RELATION = 'relation';

    /**
     * There are many different Note types, some of which are entirely opaque to the
     * end user. Those types should be used only for checking against, they are
     * not for direct use.
     * @typedef {"file" | "image" | "search" | "noteMap" | "launcher" | "doc" | "contentWidget" | "text" | "relationMap" | "render" | "canvas" | "mermaid" | "book" | "webView" | "code"} NoteType
     */

    /**
     * @typedef {Object} NotePathRecord
     * @property {boolean} isArchived
     * @property {boolean} isInHoistedSubTree
     * @property {Array<string>} notePath
     * @property {boolean} isHidden
     */

    /**
     * Trilium's main entity, which can represent text note, image, code note, file attachment etc.
     *
     * @extends AbstractBeccaEntity
     */
    class BNote extends AbstractBeccaEntity {
        static get entityName() { return "notes"; }
        static get primaryKeyName() { return "noteId"; }
        static get hashedProperties() { return ["noteId", "title", "isProtected", "type", "mime", "blobId"]; }

        constructor(row) {
            super();

            if (!row) {
                return;
            }

            this.updateFromRow(row);
            this.init();
        }

        updateFromRow(row) {
            this.update([
                row.noteId,
                row.title,
                row.type,
                row.mime,
                row.isProtected,
                row.blobId,
                row.dateCreated,
                row.dateModified,
                row.utcDateCreated,
                row.utcDateModified
            ]);
        }

        update([noteId, title, type, mime, isProtected, blobId, dateCreated, dateModified, utcDateCreated, utcDateModified]) {
            // ------ Database persisted attributes ------

            /** @type {string} */
            this.noteId = noteId;
            /** @type {string} */
            this.title = title;
            /** @type {NoteType} */
            this.type = type;
            /** @type {string} */
            this.mime = mime;
            /** @type {boolean} */
            this.isProtected = !!isProtected;
            /** @type {string} */
            this.blobId = blobId;
            /** @type {string} */
            this.dateCreated = dateCreated || dateUtils.localNowDateTime();
            /** @type {string} */
            this.dateModified = dateModified;
            /** @type {string} */
            this.utcDateCreated = utcDateCreated || dateUtils.utcNowDateTime();
            /** @type {string} */
            this.utcDateModified = utcDateModified;
            /**
             * set during the deletion operation, before it is completed (removed from becca completely)
             * @type {boolean}
             */
            this.isBeingDeleted = false;

            // ------ Derived attributes ------

            /** @type {boolean} */
            this.isDecrypted = !this.noteId || !this.isProtected;

            this.decrypt();

            /** @type {string|null} */
            this.__flatTextCache = null;

            return this;
        }

        init() {
            /** @type {BBranch[]}
             * @private */
            this.parentBranches = [];
            /** @type {BNote[]}
             * @private */
            this.parents = [];
            /** @type {BNote[]}
             * @private */
            this.children = [];
            /** @type {BAttribute[]}
             * @private */
            this.ownedAttributes = [];

            /** @type {BAttribute[]|null}
             * @private */
            this.__attributeCache = null;
            /** @type {BAttribute[]|null}
             * @private */
            this.__inheritableAttributeCache = null;

            /** @type {BAttribute[]}
             * @private */
            this.targetRelations = [];

            this.becca.addNote(this.noteId, this);

            /** @type {BNote[]|null}
             * @private */
            this.__ancestorCache = null;

            // following attributes are filled during searching in the database

            /**
             * size of the content in bytes
             * @type {int|null}
             * @private
             */
            this.contentSize = null;
            /**
             * size of the note content, attachment contents in bytes
             * @type {int|null}
             * @private
             */
            this.contentAndAttachmentsSize = null;
            /**
             * size of the note content, attachment contents and revision contents in bytes
             * @type {int|null}
             * @private
             */
            this.contentAndAttachmentsAndRevisionsSize = null;
            /**
             * number of note revisions for this note
             * @type {int|null}
             * @private
             */
            this.revisionCount = null;
        }

        isContentAvailable() {
            return !this.noteId // new note which was not encrypted yet
                || !this.isProtected
                || protectedSessionService.isProtectedSessionAvailable()
        }

        getTitleOrProtected() {
            return this.isContentAvailable() ? this.title : '[protected]';
        }

        /** @returns {BBranch[]} */
        getParentBranches() {
            return this.parentBranches;
        }

        /**
         * Returns <i>strong</i> (as opposed to <i>weak</i>) parent branches. See isWeak for details.
         *
         * @returns {BBranch[]}
         */
        getStrongParentBranches() {
            return this.getParentBranches().filter(branch => !branch.isWeak);
        }

        /**
         * @returns {BBranch[]}
         * @deprecated use getParentBranches() instead
         */
        getBranches() {
            return this.parentBranches;
        }

        /** @returns {BNote[]} */
        getParentNotes() {
            return this.parents;
        }

        /** @returns {BNote[]} */
        getChildNotes() {
            return this.children;
        }

        /** @returns {boolean} */
        hasChildren() {
            return this.children && this.children.length > 0;
        }

        /** @returns {BBranch[]} */
        getChildBranches() {
            return this.children.map(childNote => this.becca.getBranchFromChildAndParent(childNote.noteId, this.noteId));
        }

        /*
         * Note content has quite special handling - it's not a separate entity, but a lazily loaded
         * part of Note entity with its own sync. Reasons behind this hybrid design has been:
         *
         * - content can be quite large, and it's not necessary to load it / fill memory for any note access even if we don't need a content, especially for bulk operations like search
         * - changes in the note metadata or title should not trigger note content sync (so we keep separate utcDateModified and entity changes records)
         * - but to the user note content and title changes are one and the same - single dateModified (so all changes must go through Note and content is not a separate entity)
         */

        /** @returns {string|Buffer}  */
        getContent() {
            return this._getContent();
        }

        /**
         * @returns {*}
         * @throws Error in case of invalid JSON */
        getJsonContent() {
            const content = this.getContent();

            if (!content || !content.trim()) {
                return null;
            }

            return JSON.parse(content);
        }

        /** @returns {*|null} valid object or null if the content cannot be parsed as JSON */
        getJsonContentSafely() {
            try {
                return this.getJsonContent();
            }
            catch (e) {
                return null;
            }
        }

        /**
         * @param content
         * @param {object} [opts]
         * @param {object} [opts.forceSave=false] - will also save this BNote entity
         * @param {object} [opts.forceFrontendReload=false] - override frontend heuristics on when to reload, instruct to reload
         */
        setContent(content, opts) {
            this._setContent(content, opts);

            eventService.emit(eventService.NOTE_CONTENT_CHANGE, { entity: this });
        }

        setJsonContent(content) {
            this.setContent(JSON.stringify(content, null, '\t'));
        }

        get dateCreatedObj() {
            return this.dateCreated === null ? null : dayjs(this.dateCreated);
        }

        get utcDateCreatedObj() {
            return this.utcDateCreated === null ? null : dayjs.utc(this.utcDateCreated);
        }

        get dateModifiedObj() {
            return this.dateModified === null ? null : dayjs(this.dateModified);
        }

        get utcDateModifiedObj() {
            return this.utcDateModified === null ? null : dayjs.utc(this.utcDateModified);
        }

        /** @returns {boolean} true if this note is the root of the note tree. Root note has "root" noteId */
        isRoot() {
            return this.noteId === 'root';
        }

        /** @returns {boolean} true if this note is of application/json content type */
        isJson() {
            return this.mime === "application/json";
        }

        /** @returns {boolean} true if this note is JavaScript (code or attachment) */
        isJavaScript() {
            return (this.type === "code" || this.type === "file" || this.type === 'launcher')
                && (this.mime.startsWith("application/javascript")
                    || this.mime === "application/x-javascript"
                    || this.mime === "text/javascript");
        }

        /** @returns {boolean} true if this note is HTML */
        isHtml() {
            return ["code", "file", "render"].includes(this.type)
                && this.mime === "text/html";
        }

        /** @returns {boolean} true if this note is an image */
        isImage() {
            return this.type === 'image'
                || (this.type === 'file' && this.mime?.startsWith('image/'));
        }

        /** @deprecated use hasStringContent() instead */
        isStringNote() {
            return this.hasStringContent();
        }

        /** @returns {boolean} true if the note has string content (not binary) */
        hasStringContent() {
            return utils.isStringNote(this.type, this.mime);
        }

        /** @returns {string|null} JS script environment - either "frontend" or "backend" */
        getScriptEnv() {
            if (this.isHtml() || (this.isJavaScript() && this.mime.endsWith('env=frontend'))) {
                return "frontend";
            }

            if (this.type === 'render') {
                return "frontend";
            }

            if (this.isJavaScript() && this.mime.endsWith('env=backend')) {
                return "backend";
            }

            return null;
        }

        /**
         * Beware that the method must not create a copy of the array, but actually returns its internal array
         * (for performance reasons)
         *
         * @param {string} [type] - (optional) attribute type to filter
         * @param {string} [name] - (optional) attribute name to filter
         * @returns {BAttribute[]} all note's attributes, including inherited ones
         */
        getAttributes(type, name) {
            this.__validateTypeName(type, name);
            this.__ensureAttributeCacheIsAvailable();

            if (type && name) {
                return this.__attributeCache.filter(attr => attr.name === name && attr.type === type);
            }
            else if (type) {
                return this.__attributeCache.filter(attr => attr.type === type);
            }
            else if (name) {
                return this.__attributeCache.filter(attr => attr.name === name);
            }
            else {
                return this.__attributeCache;
            }
        }

        /** @private */
        __ensureAttributeCacheIsAvailable() {
            if (!this.__attributeCache) {
                this.__getAttributes([]);
            }
        }

        /** @private */
        __getAttributes(path) {
            if (path.includes(this.noteId)) {
                return [];
            }

            if (!this.__attributeCache) {
                const parentAttributes = this.ownedAttributes.slice();
                const newPath = [...path, this.noteId];

                // inheritable attrs on root are typically not intended to be applied to hidden subtree #3537
                if (this.noteId !== 'root' && this.noteId !== '_hidden') {
                    for (const parentNote of this.parents) {
                        parentAttributes.push(...parentNote.__getInheritableAttributes(newPath));
                    }
                }

                const templateAttributes = [];

                for (const ownedAttr of parentAttributes) { // parentAttributes so we process also inherited templates
                    if (ownedAttr.type === 'relation' && ['template', 'inherit'].includes(ownedAttr.name)) {
                        const templateNote = this.becca.notes[ownedAttr.value];

                        if (templateNote) {
                            templateAttributes.push(
                                ...templateNote.__getAttributes(newPath)
                                    // template attr is used as a marker for templates, but it's not meant to be inherited
                                    .filter(attr => !(attr.type === 'label' && (attr.name === 'template' || attr.name === 'workspacetemplate')))
                            );
                        }
                    }
                }

                this.__attributeCache = [];

                const addedAttributeIds = new Set();

                for (const attr of parentAttributes.concat(templateAttributes)) {
                    if (!addedAttributeIds.has(attr.attributeId)) {
                        addedAttributeIds.add(attr.attributeId);

                        this.__attributeCache.push(attr);
                    }
                }

                this.__inheritableAttributeCache = [];

                for (const attr of this.__attributeCache) {
                    if (attr.isInheritable) {
                        this.__inheritableAttributeCache.push(attr);
                    }
                }
            }

            return this.__attributeCache;
        }

        /**
         * @private
         * @returns {BAttribute[]}
         */
        __getInheritableAttributes(path) {
            if (path.includes(this.noteId)) {
                return [];
            }

            if (!this.__inheritableAttributeCache) {
                this.__getAttributes(path); // will refresh also this.__inheritableAttributeCache
            }

            return this.__inheritableAttributeCache;
        }

        __validateTypeName(type, name) {
            if (type && type !== 'label' && type !== 'relation') {
                throw new Error(`Unrecognized attribute type '${type}'. Only 'label' and 'relation' are possible values.`);
            }

            if (name) {
                const firstLetter = name.charAt(0);
                if (firstLetter === '#' || firstLetter === '~') {
                    throw new Error(`Detect '#' or '~' in the attribute's name. In the API, attribute names should be set without these characters.`);
                }
            }
        }

        /**
         * @param type
         * @param name
         * @param [value]
         * @returns {boolean}
         */
        hasAttribute(type, name, value = null) {
            return !!this.getAttributes().find(attr =>
                attr.name === name
                && (value === undefined || value === null || attr.value === value)
                && attr.type === type
            );
        }

        getAttributeCaseInsensitive(type, name, value) {
            name = name.toLowerCase();
            value = value ? value.toLowerCase() : null;

            return this.getAttributes().find(
                attr => attr.name.toLowerCase() === name
                && (!value || attr.value.toLowerCase() === value)
                && attr.type === type);
        }

        getRelationTarget(name) {
            const relation = this.getAttributes().find(attr => attr.name === name && attr.type === 'relation');

            return relation ? relation.targetNote : null;
        }

        /**
         * @param {string} name - label name
         * @param {string} [value] - label value
         * @returns {boolean} true if label exists (including inherited)
         */
        hasLabel(name, value) { return this.hasAttribute(LABEL, name, value); }

        /**
         * @param {string} name - label name
         * @returns {boolean} true if label exists (including inherited) and does not have "false" value.
         */
        isLabelTruthy(name) {
            const label = this.getLabel(name);

            if (!label) {
                return false;
            }

            return label && label.value !== 'false';
        }

        /**
         * @param {string} name - label name
         * @param {string} [value] - label value
         * @returns {boolean} true if label exists (excluding inherited)
         */
        hasOwnedLabel(name, value) { return this.hasOwnedAttribute(LABEL, name, value); }

        /**
         * @param {string} name - relation name
         * @param {string} [value] - relation value
         * @returns {boolean} true if relation exists (including inherited)
         */
        hasRelation(name, value) { return this.hasAttribute(RELATION, name, value); }

        /**
         * @param {string} name - relation name
         * @param {string} [value] - relation value
         * @returns {boolean} true if relation exists (excluding inherited)
         */
        hasOwnedRelation(name, value) { return this.hasOwnedAttribute(RELATION, name, value); }

        /**
         * @param {string} name - label name
         * @returns {BAttribute|null} label if it exists, null otherwise
         */
        getLabel(name) { return this.getAttribute(LABEL, name); }

        /**
         * @param {string} name - label name
         * @returns {BAttribute|null} label if it exists, null otherwise
         */
        getOwnedLabel(name) { return this.getOwnedAttribute(LABEL, name); }

        /**
         * @param {string} name - relation name
         * @returns {BAttribute|null} relation if it exists, null otherwise
         */
        getRelation(name) { return this.getAttribute(RELATION, name); }

        /**
         * @param {string} name - relation name
         * @returns {BAttribute|null} relation if it exists, null otherwise
         */
        getOwnedRelation(name) { return this.getOwnedAttribute(RELATION, name); }

        /**
         * @param {string} name - label name
         * @returns {string|null} label value if label exists, null otherwise
         */
        getLabelValue(name) { return this.getAttributeValue(LABEL, name); }

        /**
         * @param {string} name - label name
         * @returns {string|null} label value if label exists, null otherwise
         */
        getOwnedLabelValue(name) { return this.getOwnedAttributeValue(LABEL, name); }

        /**
         * @param {string} name - relation name
         * @returns {string|null} relation value if relation exists, null otherwise
         */
        getRelationValue(name) { return this.getAttributeValue(RELATION, name); }

        /**
         * @param {string} name - relation name
         * @returns {string|null} relation value if relation exists, null otherwise
         */
        getOwnedRelationValue(name) { return this.getOwnedAttributeValue(RELATION, name); }

        /**
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @param {string} [value] - attribute value
         * @returns {boolean} true if note has an attribute with given type and name (excluding inherited)
         */
        hasOwnedAttribute(type, name, value) {
            return !!this.getOwnedAttribute(type, name, value);
        }

        /**
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @returns {BAttribute} attribute of the given type and name. If there are more such attributes, first is returned.
         *                       Returns null if there's no such attribute belonging to this note.
         */
        getAttribute(type, name) {
            const attributes = this.getAttributes();

            return attributes.find(attr => attr.name === name && attr.type === type);
        }

        /**
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @returns {string|null} attribute value of given type and name or null if no such attribute exists.
         */
        getAttributeValue(type, name) {
            const attr = this.getAttribute(type, name);

            return attr ? attr.value : null;
        }

        /**
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @returns {string|null} attribute value of given type and name or null if no such attribute exists.
         */
        getOwnedAttributeValue(type, name) {
            const attr = this.getOwnedAttribute(type, name);

            return attr ? attr.value : null;
        }

        /**
         * @param {string} [name] - label name to filter
         * @returns {BAttribute[]} all note's labels (attributes with type label), including inherited ones
         */
        getLabels(name) {
            return this.getAttributes(LABEL, name);
        }

        /**
         * @param {string} [name] - label name to filter
         * @returns {string[]} all note's label values, including inherited ones
         */
        getLabelValues(name) {
            return this.getLabels(name).map(l => l.value);
        }

        /**
         * @param {string} [name] - label name to filter
         * @returns {BAttribute[]} all note's labels (attributes with type label), excluding inherited ones
         */
        getOwnedLabels(name) {
            return this.getOwnedAttributes(LABEL, name);
        }

        /**
         * @param {string} [name] - label name to filter
         * @returns {string[]} all note's label values, excluding inherited ones
         */
        getOwnedLabelValues(name) {
            return this.getOwnedAttributes(LABEL, name).map(l => l.value);
        }

        /**
         * @param {string} [name] - relation name to filter
         * @returns {BAttribute[]} all note's relations (attributes with type relation), including inherited ones
         */
        getRelations(name) {
            return this.getAttributes(RELATION, name);
        }

        /**
         * @param {string} [name] - relation name to filter
         * @returns {BAttribute[]} all note's relations (attributes with type relation), excluding inherited ones
         */
        getOwnedRelations(name) {
            return this.getOwnedAttributes(RELATION, name);
        }

        /**
         * Beware that the method must not create a copy of the array, but actually returns its internal array
         * (for performance reasons)
         *
         * @param {string|null} [type] - (optional) attribute type to filter
         * @param {string|null} [name] - (optional) attribute name to filter
         * @param {string|null} [value] - (optional) attribute value to filter
         * @returns {BAttribute[]} note's "owned" attributes - excluding inherited ones
         */
        getOwnedAttributes(type = null, name = null, value = null) {
            this.__validateTypeName(type, name);

            if (type && name && value !== undefined && value !== null) {
                return this.ownedAttributes.filter(attr => attr.name === name && attr.value === value && attr.type === type);
            }
            else if (type && name) {
                return this.ownedAttributes.filter(attr => attr.name === name && attr.type === type);
            }
            else if (type) {
                return this.ownedAttributes.filter(attr => attr.type === type);
            }
            else if (name) {
                return this.ownedAttributes.filter(attr => attr.name === name);
            }
            else {
                return this.ownedAttributes;
            }
        }

        /**
         * @returns {BAttribute} attribute belonging to this specific note (excludes inherited attributes)
         *
         * This method can be significantly faster than the getAttribute()
         */
        getOwnedAttribute(type, name, value = null) {
            const attrs = this.getOwnedAttributes(type, name, value);

            return attrs.length > 0 ? attrs[0] : null;
        }

        get isArchived() {
            return this.hasAttribute('label', 'archived');
        }

        areAllNotePathsArchived() {
            // there's a slight difference between note being itself archived and all its note paths being archived
            // - note is archived when it itself has an archived label or inherits it
            // - note does not have or inherit archived label, but each note path contains a note with (non-inheritable)
            //   archived label

            const bestNotePathRecord = this.getSortedNotePathRecords()[0];

            if (!bestNotePathRecord) {
                throw new Error(`No note path available for note '${this.noteId}'`);
            }

            return bestNotePathRecord.isArchived;
        }

        hasInheritableArchivedLabel() {
            for (const attr of this.getAttributes()) {
                if (attr.name === 'archived' && attr.type === LABEL && attr.isInheritable) {
                    return true;
                }
            }

            return false;
        }

        // will sort the parents so that the non-archived are first and archived at the end
        // this is done so that the non-archived paths are always explored as first when looking for note path
        sortParents() {
            this.parentBranches.sort((a, b) => {
                if (a.parentNote?.isArchived) {
                    return 1;
                } else if (a.parentNote?.isHiddenCompletely()) {
                    return 1;
                } else {
                    return 0;
                }
            });

            this.parents = this.parentBranches
                .map(branch => branch.parentNote)
                .filter(note => !!note);
        }

        sortChildren() {
            if (this.children.length === 0) {
                return;
            }

            const becca = this.becca;

            this.children.sort((a, b) => {
                const aBranch = becca.getBranchFromChildAndParent(a.noteId, this.noteId);
                const bBranch = becca.getBranchFromChildAndParent(b.noteId, this.noteId);

                return (aBranch?.notePosition - bBranch?.notePosition) || 0;
            });
        }

        /**
         * This is used for:
         * - fast searching
         * - note similarity evaluation
         *
         * @returns {string} - returns flattened textual representation of note, prefixes and attributes
         */
        getFlatText() {
            if (!this.__flatTextCache) {
                this.__flatTextCache = `${this.noteId} ${this.type} ${this.mime} `;

                for (const branch of this.parentBranches) {
                    if (branch.prefix) {
                        this.__flatTextCache += `${branch.prefix} `;
                    }
                }

                this.__flatTextCache += `${this.title} `;

                for (const attr of this.getAttributes()) {
                    // it's best to use space as separator since spaces are filtered from the search string by the tokenization into words
                    this.__flatTextCache += `${attr.type === 'label' ? '#' : '~'}${attr.name}`;

                    if (attr.value) {
                        this.__flatTextCache += `=${attr.value}`;
                    }

                    this.__flatTextCache += ' ';
                }

                this.__flatTextCache = utils.normalize(this.__flatTextCache);
            }

            return this.__flatTextCache;
        }

        invalidateThisCache() {
            this.__flatTextCache = null;

            this.__attributeCache = null;
            this.__inheritableAttributeCache = null;
            this.__ancestorCache = null;
        }

        invalidateSubTree(path = []) {
            if (path.includes(this.noteId)) {
                return;
            }

            this.invalidateThisCache();

            if (this.children.length || this.targetRelations.length) {
                path = [...path, this.noteId];
            }

            for (const childNote of this.children) {
                childNote.invalidateSubTree(path);
            }

            for (const targetRelation of this.targetRelations) {
                if (targetRelation.name === 'template' || targetRelation.name === 'inherit') {
                    const note = targetRelation.note;

                    if (note) {
                        note.invalidateSubTree(path);
                    }
                }
            }
        }

        getRelationDefinitions() {
            return this.getLabels()
                .filter(l => l.name.startsWith("relation:"));
        }

        getLabelDefinitions() {
            return this.getLabels()
                .filter(l => l.name.startsWith("relation:"));
        }

        isInherited() {
            return !!this.targetRelations.find(rel => rel.name === 'template' || rel.name === 'inherit');
        }

        /** @returns {BNote[]} */
        getSubtreeNotesIncludingTemplated() {
            const set = new Set();

            function inner(note) {
                // _hidden is not counted as subtree for the purpose of inheritance
                if (set.has(note) || note.noteId === '_hidden') {
                    return;
                }

                set.add(note);

                for (const childNote of note.children) {
                    inner(childNote);
                }

                for (const targetRelation of note.targetRelations) {
                    if (targetRelation.name === 'template' || targetRelation.name === 'inherit') {
                        const targetNote = targetRelation.note;

                        if (targetNote) {
                            inner(targetNote);
                        }
                    }
                }
            }

            inner(this);

            return Array.from(set);
        }

        /** @returns {BNote[]} */
        getSearchResultNotes() {
            if (this.type !== 'search') {
                return [];
            }

            try {
                const searchService = require("../../services/search/services/search");
                const {searchResultNoteIds} = searchService.searchFromNote(this);

                const becca = this.becca;
                return searchResultNoteIds
                    .map(resultNoteId => becca.notes[resultNoteId])
                    .filter(note => !!note);
            }
            catch (e) {
                log.error(`Could not resolve search note ${this.noteId}: ${e.message}`);
                return [];
            }
        }

        /**
         * @returns {{notes: BNote[], relationships: Array.<{parentNoteId: string, childNoteId: string}>}}
         */
        getSubtree({includeArchived = true, includeHidden = false, resolveSearch = false} = {}) {
            const noteSet = new Set();
            const relationships = []; // list of tuples parentNoteId -> childNoteId

            function resolveSearchNote(searchNote) {
                try {
                    for (const resultNote of searchNote.getSearchResultNotes()) {
                        addSubtreeNotesInner(resultNote, searchNote);
                    }
                }
                catch (e) {
                    log.error(`Could not resolve search note ${searchNote?.noteId}: ${e.message}`);
                }
            }

            function addSubtreeNotesInner(note, parentNote = null) {
                if (note.noteId === '_hidden' && !includeHidden) {
                    return;
                }

                if (parentNote) {
                    // this needs to happen first before noteSet check to include all clone relationships
                    relationships.push({
                        parentNoteId: parentNote.noteId,
                        childNoteId: note.noteId
                    });
                }

                if (noteSet.has(note)) {
                    return;
                }

                if (!includeArchived && note.isArchived) {
                    return;
                }

                noteSet.add(note);

                if (note.type === 'search') {
                    if (resolveSearch) {
                        resolveSearchNote(note);
                    }
                }
                else {
                    for (const childNote of note.children) {
                        addSubtreeNotesInner(childNote, note);
                    }
                }
            }

            addSubtreeNotesInner(this);

            return {
                notes: Array.from(noteSet),
                relationships
            };
        }

        /** @returns {string[]} - includes the subtree root note as well */
        getSubtreeNoteIds({includeArchived = true, includeHidden = false, resolveSearch = false} = {}) {
            return this.getSubtree({includeArchived, includeHidden, resolveSearch})
                .notes
                .map(note => note.noteId);
        }

        /** @deprecated use getSubtreeNoteIds() instead */
        getDescendantNoteIds() {
            return this.getSubtreeNoteIds();
        }

        get parentCount() {
            return this.parents.length;
        }

        get childrenCount() {
            return this.children.length;
        }

        get labelCount() {
            return this.getAttributes().filter(attr => attr.type === 'label').length;
        }

        get ownedLabelCount() {
            return this.ownedAttributes.filter(attr => attr.type === 'label').length;
        }

        get relationCount() {
            return this.getAttributes().filter(attr => attr.type === 'relation' && !attr.isAutoLink()).length;
        }

        get relationCountIncludingLinks() {
            return this.getAttributes().filter(attr => attr.type === 'relation').length;
        }

        get ownedRelationCount() {
            return this.ownedAttributes.filter(attr => attr.type === 'relation' && !attr.isAutoLink()).length;
        }

        get ownedRelationCountIncludingLinks() {
            return this.ownedAttributes.filter(attr => attr.type === 'relation').length;
        }

        get targetRelationCount() {
            return this.targetRelations.filter(attr => !attr.isAutoLink()).length;
        }

        get targetRelationCountIncludingLinks() {
            return this.targetRelations.length;
        }

        get attributeCount() {
            return this.getAttributes().length;
        }

        get ownedAttributeCount() {
            return this.getOwnedAttributes().length;
        }

        /** @returns {BNote[]} */
        getAncestors() {
            if (!this.__ancestorCache) {
                const noteIds = new Set();
                this.__ancestorCache = [];

                for (const parent of this.parents) {
                    if (noteIds.has(parent.noteId)) {
                        continue;
                    }

                    this.__ancestorCache.push(parent);
                    noteIds.add(parent.noteId);

                    for (const ancestorNote of parent.getAncestors()) {
                        if (!noteIds.has(ancestorNote.noteId)) {
                            this.__ancestorCache.push(ancestorNote);
                            noteIds.add(ancestorNote.noteId);
                        }
                    }
                }
            }

            return this.__ancestorCache;
        }

        /** @returns {string[]} */
        getAncestorNoteIds() {
            return this.getAncestors().map(note => note.noteId);
        }

        /** @returns {boolean} */
        hasAncestor(ancestorNoteId) {
            for (const ancestorNote of this.getAncestors()) {
                if (ancestorNote.noteId === ancestorNoteId) {
                    return true;
                }
            }

            return false;
        }

        isInHiddenSubtree() {
            return this.noteId === '_hidden' || this.hasAncestor('_hidden');
        }

        /** @returns {BAttribute[]} */
        getTargetRelations() {
            return this.targetRelations;
        }

        /** @returns {BNote[]} - returns only notes which are templated, does not include their subtrees
         *                     in effect returns notes which are influenced by note's non-inheritable attributes */
        getInheritingNotes() {
            const arr = [this];

            for (const targetRelation of this.targetRelations) {
                if (targetRelation.name === 'template' || targetRelation.name === 'inherit') {
                    const note = targetRelation.note;

                    if (note) {
                        arr.push(note);
                    }
                }
            }

            return arr;
        }

        getDistanceToAncestor(ancestorNoteId) {
            if (this.noteId === ancestorNoteId) {
                return 0;
            }

            let minDistance = 999999;

            for (const parent of this.parents) {
                minDistance = Math.min(minDistance, parent.getDistanceToAncestor(ancestorNoteId) + 1);
            }

            return minDistance;
        }

        /** @returns {BRevision[]} */
        getRevisions() {
            return sql.getRows("SELECT * FROM revisions WHERE noteId = ?", [this.noteId])
                .map(row => new BRevision(row));
        }

        /** @returns {BAttachment[]} */
        getAttachments(opts = {}) {
            opts.includeContentLength = !!opts.includeContentLength;
            // from testing, it looks like calculating length does not make a difference in performance even on large-ish DB
            // given that we're always fetching attachments only for a specific note, we might just do it always

            const query = opts.includeContentLength
                ? `SELECT attachments.*, LENGTH(blobs.content) AS contentLength
                   FROM attachments
                   JOIN blobs USING (blobId)
                   WHERE ownerId = ? AND isDeleted = 0
                   ORDER BY position`
                : `SELECT * FROM attachments WHERE ownerId = ? AND isDeleted = 0 ORDER BY position`;

            return sql.getRows(query, [this.noteId])
                .map(row => new BAttachment(row));
        }

        /** @returns {BAttachment|null} */
        getAttachmentById(attachmentId, opts = {}) {
            opts.includeContentLength = !!opts.includeContentLength;

            const query = opts.includeContentLength
                ? `SELECT attachments.*, LENGTH(blobs.content) AS contentLength
                   FROM attachments
                   JOIN blobs USING (blobId)
                   WHERE ownerId = ? AND attachmentId = ? AND isDeleted = 0`
                : `SELECT * FROM attachments WHERE ownerId = ? AND attachmentId = ? AND isDeleted = 0`;

            return sql.getRows(query, [this.noteId, attachmentId])
                .map(row => new BAttachment(row))[0];
        }

        /** @returns {BAttachment[]} */
        getAttachmentsByRole(role) {
            return sql.getRows(`
                    SELECT attachments.*
                    FROM attachments
                    WHERE ownerId = ?
                      AND role = ?
                      AND isDeleted = 0
                    ORDER BY position`, [this.noteId, role])
                .map(row => new BAttachment(row));
        }

        /** @returns {BAttachment} */
        getAttachmentByTitle(title) {
            // cannot use SQL to filter by title since it can be encrypted
            return this.getAttachments().filter(attachment => attachment.title === title)[0];
        }

        /**
         * Gives all possible note paths leading to this note. Paths containing search note are ignored (could form cycles)
         *
         * @returns {string[][]} - array of notePaths (each represented by array of noteIds constituting the particular note path)
         */
        getAllNotePaths() {
            if (this.noteId === 'root') {
                return [['root']];
            }

            const parentNotes = this.getParentNotes();

            const notePaths = parentNotes.length === 1
                ? parentNotes[0].getAllNotePaths() // optimization for the most common case
                : parentNotes.flatMap(parentNote => parentNote.getAllNotePaths());

            for (const notePath of notePaths) {
                notePath.push(this.noteId);
            }

            return notePaths;
        }

        /**
         * @param {string} [hoistedNoteId='root']
         * @return {Array<NotePathRecord>}
         */
        getSortedNotePathRecords(hoistedNoteId = 'root') {
            const isHoistedRoot = hoistedNoteId === 'root';

            const notePaths = this.getAllNotePaths().map(path => ({
                notePath: path,
                isInHoistedSubTree: isHoistedRoot || path.includes(hoistedNoteId),
                isArchived: path.some(noteId => this.becca.notes[noteId].isArchived),
                isHidden: path.includes('_hidden')
            }));

            notePaths.sort((a, b) => {
                if (a.isInHoistedSubTree !== b.isInHoistedSubTree) {
                    return a.isInHoistedSubTree ? -1 : 1;
                } else if (a.isArchived !== b.isArchived) {
                    return a.isArchived ? 1 : -1;
                } else if (a.isHidden !== b.isHidden) {
                    return a.isHidden ? 1 : -1;
                } else {
                    return a.notePath.length - b.notePath.length;
                }
            });

            return notePaths;
        }

        /**
         * Returns a note path considered to be the "best"
         *
         * @param {string} [hoistedNoteId='root']
         * @return {string[]} array of noteIds constituting the particular note path
         */
        getBestNotePath(hoistedNoteId = 'root') {
            return this.getSortedNotePathRecords(hoistedNoteId)[0]?.notePath;
        }

        /**
         * Returns a note path considered to be the "best"
         *
         * @param {string} [hoistedNoteId='root']
         * @return {string} serialized note path (e.g. 'root/a1h315/js725h')
         */
        getBestNotePathString(hoistedNoteId = 'root') {
            const notePath = this.getBestNotePath(hoistedNoteId);

            return notePath?.join("/");
        }

        /**
         * @return boolean - true if there's no non-hidden path, note is not cloned to the visible tree
         */
        isHiddenCompletely() {
            if (this.noteId === 'root') {
                return false;
            }

            for (const parentNote of this.parents) {
                if (parentNote.noteId === 'root') {
                    return false;
                } else if (parentNote.noteId === '_hidden') {
                    continue;
                } else if (!parentNote.isHiddenCompletely()) {
                    return false;
                }
            }

            return true;
        }

        /**
         * @param ancestorNoteId
         * @returns {boolean} - true if ancestorNoteId occurs in at least one of the note's paths
         */
        isDescendantOfNote(ancestorNoteId) {
            const notePaths = this.getAllNotePaths();

            return notePaths.some(path => path.includes(ancestorNoteId));
        }

        /**
         * Update's given attribute's value or creates it if it doesn't exist
         *
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @param {string} [value] - attribute value (optional)
         */
        setAttribute(type, name, value) {
            const attributes = this.getOwnedAttributes();
            const attr = attributes.find(attr => attr.type === type && attr.name === name);

            value = value?.toString() || "";

            if (attr) {
                if (attr.value !== value) {
                    attr.value = value;
                    attr.save();
                }
            }
            else {
                const BAttribute = require("./battribute");

                new BAttribute({
                    noteId: this.noteId,
                    type: type,
                    name: name,
                    value: value
                }).save();
            }
        }

        /**
         * Removes given attribute name-value pair if it exists.
         *
         * @param {string} type - attribute type (label, relation, etc.)
         * @param {string} name - attribute name
         * @param {string} [value] - attribute value (optional)
         */
        removeAttribute(type, name, value) {
            const attributes = this.getOwnedAttributes();

            for (const attribute of attributes) {
                if (attribute.type === type && attribute.name === name && (value === undefined || value === attribute.value)) {
                    attribute.markAsDeleted();
                }
            }
        }

        /**
         * Adds a new attribute to this note. The attribute is saved and returned.
         * See addLabel, addRelation for more specific methods.
         *
         * @param {string} type - attribute type (label / relation)
         * @param {string} name - name of the attribute, not including the leading ~/#
         * @param {string} [value] - value of the attribute - text for labels, target note ID for relations; optional.
         * @param {boolean} [isInheritable=false]
         * @param {int|null} [position]
         * @returns {BAttribute}
         */
        addAttribute(type, name, value = "", isInheritable = false, position = null) {
            const BAttribute = require("./battribute");

            return new BAttribute({
                noteId: this.noteId,
                type: type,
                name: name,
                value: value,
                isInheritable: isInheritable,
                position: position
            }).save();
        }

        /**
         * Adds a new label to this note. The label attribute is saved and returned.
         *
         * @param {string} name - name of the label, not including the leading #
         * @param {string} [value] - text value of the label; optional
         * @param {boolean} [isInheritable=false]
         * @returns {BAttribute}
         */
        addLabel(name, value = "", isInheritable = false) {
            return this.addAttribute(LABEL, name, value, isInheritable);
        }

        /**
         * Adds a new relation to this note. The relation attribute is saved and
         * returned.
         *
         * @param {string} name - name of the relation, not including the leading ~
         * @param {string} targetNoteId
         * @param {boolean} [isInheritable=false]
         * @returns {BAttribute}
         */
        addRelation(name, targetNoteId, isInheritable = false) {
            return this.addAttribute(RELATION, name, targetNoteId, isInheritable);
        }

        /**
         * Based on enabled, the attribute is either set or removed.
         *
         * @param {string} type - attribute type ('relation', 'label' etc.)
         * @param {boolean} enabled - toggle On or Off
         * @param {string} name - attribute name
         * @param {string} [value] - attribute value (optional)
         */
        toggleAttribute(type, enabled, name, value) {
            if (enabled) {
                this.setAttribute(type, name, value);
            }
            else {
                this.removeAttribute(type, name, value);
            }
        }

        /**
         * Based on enabled, label is either set or removed.
         *
         * @param {boolean} enabled - toggle On or Off
         * @param {string} name - label name
         * @param {string} [value] - label value (optional)
         */
        toggleLabel(enabled, name, value) { return this.toggleAttribute(LABEL, enabled, name, value); }

        /**
         * Based on enabled, relation is either set or removed.
         *
         * @param {boolean} enabled - toggle On or Off
         * @param {string} name - relation name
         * @param {string} [value] - relation value (noteId)
         */
        toggleRelation(enabled, name, value) { return this.toggleAttribute(RELATION, enabled, name, value); }

        /**
         * Update's given label's value or creates it if it doesn't exist
         *
         * @param {string} name - label name
         * @param {string} [value] - label value
         */
        setLabel(name, value) { return this.setAttribute(LABEL, name, value); }

        /**
         * Update's given relation's value or creates it if it doesn't exist
         *
         * @param {string} name - relation name
         * @param {string} value - relation value (noteId)
         */
        setRelation(name, value) { return this.setAttribute(RELATION, name, value); }

        /**
         * Remove label name-value pair, if it exists.
         *
         * @param {string} name - label name
         * @param {string} [value] - label value
         */
        removeLabel(name, value) { return this.removeAttribute(LABEL, name, value); }

        /**
         * Remove the relation name-value pair, if it exists.
         *
         * @param {string} name - relation name
         * @param {string} [value] - relation value (noteId)
         */
        removeRelation(name, value) { return this.removeAttribute(RELATION, name, value); }

        searchNotesInSubtree(searchString) {
            const searchService = require("../../services/search/services/search");

            return searchService.searchNotes(searchString);
        }

        searchNoteInSubtree(searchString) {
            return this.searchNotesInSubtree(searchString)[0];
        }

        /**
         * @param parentNoteId
         * @returns {{success: boolean, message: string, branchId: string, notePath: string}}
         */
        cloneTo(parentNoteId) {
            const cloningService = require("../../services/cloning");

            const branch = this.becca.getNote(parentNoteId).getParentBranches()[0];

            return cloningService.cloneNoteToBranch(this.noteId, branch.branchId);
        }

        isEligibleForConversionToAttachment(opts = {autoConversion: false}) {
            if (this.type !== 'image' || !this.isContentAvailable() || this.hasChildren() || this.getParentBranches().length !== 1) {
                return false;
            }

            const targetRelations = this.getTargetRelations().filter(relation => relation.name === 'imageLink');

            if (opts.autoConversion && targetRelations.length === 0) {
                return false;
            } else if (targetRelations.length > 1) {
                return false;
            }

            const parentNote = this.getParentNotes()[0]; // at this point note can have only one parent
            const referencingNote = targetRelations[0]?.getNote();

            if (referencingNote && parentNote !== referencingNote) {
                return false;
            } else if (parentNote.type !== 'text' || !parentNote.isContentAvailable()) {
                return false;
            }

            return true;
        }

        /**
         * Some notes are eligible for conversion into an attachment of its parent, note must have these properties:
         * - it has exactly one target relation
         * - it has a relation from its parent note
         * - it has no children
         * - it has no clones
         * - the parent is of type text
         * - both notes are either unprotected or user is in protected session
         *
         * Currently, works only for image notes.
         *
         * In the future, this functionality might get more generic and some of the requirements relaxed.
         *
         * @params {Object} [opts]
         * @params {bolean} [opts.autoConversion=false} if true, the action is not triggered by user, but e.g. by migration,
         *                                              and only perfect candidates will be migrated
         *
         * @returns {BAttachment|null} - null if note is not eligible for conversion
         */
        convertToParentAttachment(opts = {autoConversion: false}) {
            if (!this.isEligibleForConversionToAttachment(opts)) {
                return null;
            }

            const content = this.getContent();

            const parentNote = this.getParentNotes()[0];
            const attachment = parentNote.saveAttachment({
                role: 'image',
                mime: this.mime,
                title: this.title,
                content: content
            });

            let parentContent = parentNote.getContent();

            const oldNoteUrl = `api/images/${this.noteId}/`;
            const newAttachmentUrl = `api/attachments/${attachment.attachmentId}/image/`;

            const fixedContent = utils.replaceAll(parentContent, oldNoteUrl, newAttachmentUrl);

            parentNote.setContent(fixedContent);

            const noteService = require("../../services/notes");
            noteService.asyncPostProcessContent(parentNote, fixedContent); // to mark an unused attachment for deletion

            this.deleteNote();

            return attachment;
        }

        /**
         * (Soft) delete a note and all its descendants.
         *
         * @param {string} [deleteId=null] - optional delete identified
         * @param {TaskContext} [taskContext]
         */
        deleteNote(deleteId = null, taskContext = null) {
            if (this.isDeleted) {
                return;
            }

            if (!deleteId) {
                deleteId = utils.randomString(10);
            }

            if (!taskContext) {
                taskContext = new TaskContext('no-progress-reporting');
            }

            // needs to be run before branches and attributes are deleted and thus attached relations disappear
            const handlers = require("../../services/handlers");
            handlers.runAttachedRelations(this, 'runOnNoteDeletion', this);
            taskContext.noteDeletionHandlerTriggered = true;

            for (const branch of this.getParentBranches()) {
                branch.deleteBranch(deleteId, taskContext);
            }
        }

        decrypt() {
            if (this.isProtected && !this.isDecrypted && protectedSessionService.isProtectedSessionAvailable()) {
                try {
                    this.title = protectedSessionService.decryptString(this.title);
                    this.__flatTextCache = null;

                    this.isDecrypted = true;
                }
                catch (e) {
                    log.error(`Could not decrypt note ${this.noteId}: ${e.message} ${e.stack}`);
                }
            }
        }

        isLaunchBarConfig() {
            return this.type === 'launcher' || ['_lbRoot', '_lbAvailableLaunchers', '_lbVisibleLaunchers'].includes(this.noteId);
        }

        isOptions() {
            return this.noteId.startsWith("_options");
        }

        get isDeleted() {
            // isBeingDeleted is relevant only in the transition period when the deletion process has begun, but not yet
            // finished (note is still in becca)
            return !(this.noteId in this.becca.notes) || this.isBeingDeleted;
        }

        /**
         * @returns {BRevision|null}
         */
        saveRevision() {
            return sql.transactional(() => {
                let noteContent = this.getContent();

                const revision = new BRevision({
                    noteId: this.noteId,
                    // title and text should be decrypted now
                    title: this.title,
                    type: this.type,
                    mime: this.mime,
                    isProtected: this.isProtected,
                    utcDateLastEdited: this.utcDateModified,
                    utcDateCreated: dateUtils.utcNowDateTime(),
                    utcDateModified: dateUtils.utcNowDateTime(),
                    dateLastEdited: this.dateModified,
                    dateCreated: dateUtils.localNowDateTime()
                }, true);

                revision.save(); // to generate revisionId, which is then used to save attachments

                for (const noteAttachment of this.getAttachments()) {
                    const revisionAttachment = noteAttachment.copy();
                    revisionAttachment.ownerId = revision.revisionId;
                    revisionAttachment.setContent(noteAttachment.getContent(), {forceSave: true});

                    if (this.type === 'text') {
                        // content is rewritten to point to the revision attachments
                        noteContent = noteContent.replaceAll(`attachments/${noteAttachment.attachmentId}`,
                            `attachments/${revisionAttachment.attachmentId}`);

                        noteContent = noteContent.replaceAll(new RegExp(`href="[^"]*attachmentId=${noteAttachment.attachmentId}[^"]*"`, 'gi'),
                            `href="api/attachments/${revisionAttachment.attachmentId}/download"`);
                    }
                }

                revision.setContent(noteContent);

                return revision;
            });
        }

        /**
         * @param {string} matchBy - choose by which property we detect if to update an existing attachment.
     *                               Supported values are either 'attachmentId' (default) or 'title'
         * @returns {BAttachment}
         */
        saveAttachment({attachmentId, role, mime, title, content, position}, matchBy = 'attachmentId') {
            if (!['attachmentId', 'title'].includes(matchBy)) {
                throw new Error(`Unsupported value '${matchBy}' for matchBy param, has to be either 'attachmentId' or 'title'.`);
            }

            let attachment;

            if (matchBy === 'title') {
                attachment = this.getAttachmentByTitle(title);
            } else if (matchBy === 'attachmentId' && attachmentId) {
                attachment = this.becca.getAttachmentOrThrow(attachmentId);
            }

            attachment = attachment || new BAttachment({
                ownerId: this.noteId,
                title,
                role,
                mime,
                isProtected: this.isProtected,
                position
            });

            content = content || "";
            attachment.setContent(content, {forceSave: true});

            return attachment;
        }

        getFileName() {
            return utils.formatDownloadTitle(this.title, this.type, this.mime);
        }

        beforeSaving() {
            super.beforeSaving();

            this.becca.addNote(this.noteId, this);

            this.dateModified = dateUtils.localNowDateTime();
            this.utcDateModified = dateUtils.utcNowDateTime();
        }

        getPojo() {
            return {
                noteId: this.noteId,
                title: this.title,
                isProtected: this.isProtected,
                type: this.type,
                mime: this.mime,
                blobId: this.blobId,
                isDeleted: false,
                dateCreated: this.dateCreated,
                dateModified: this.dateModified,
                utcDateCreated: this.utcDateCreated,
                utcDateModified: this.utcDateModified
            };
        }

        getPojoToSave() {
            const pojo = this.getPojo();

            if (pojo.isProtected) {
                if (this.isDecrypted) {
                    pojo.title = protectedSessionService.encrypt(pojo.title);
                }
                else {
                    // updating protected note outside of protected session means we will keep original ciphertexts
                    delete pojo.title;
                }
            }

            return pojo;
        }
    }

    module.exports = BNote;