"use strict";

const Expression = require('./expression');
const NoteSet = require('../note_set');
const noteCache = require('../../note_cache/note_cache');

class NoteCacheFlatTextExp extends Expression {
    constructor(tokens) {
        super();

        this.tokens = tokens;
    }

    execute(inputNoteSet, executionContext) {
        // has deps on SQL which breaks unit test so needs to be dynamically required
        const noteCacheService = require('../../note_cache/note_cache_service');
        const resultNoteSet = new NoteSet();

        function searchDownThePath(note, tokens, path) {
            if (tokens.length === 0) {
                const retPath = noteCacheService.getSomePath(note, path);

                if (retPath) {
                    const noteId = retPath[retPath.length - 1];
                    executionContext.noteIdToNotePath[noteId] = retPath;

                    resultNoteSet.add(noteCache.notes[noteId]);
                }

                return;
            }

            if (!note.parents.length === 0 || note.noteId === 'root') {
                return;
            }

            const foundAttrTokens = [];

            for (const token of tokens) {
                if (note.type.includes(token) || note.mime.includes(token)) {
                    foundAttrTokens.push(token);
                }
            }

            for (const attribute of note.ownedAttributes) {
                for (const token of tokens) {
                    if (attribute.name.toLowerCase().includes(token)
                        || attribute.value.toLowerCase().includes(token)) {
                        foundAttrTokens.push(token);
                    }
                }
            }

            for (const parentNote of note.parents) {
                const title = noteCacheService.getNoteTitle(note.noteId, parentNote.noteId).toLowerCase();
                const foundTokens = foundAttrTokens.slice();

                for (const token of tokens) {
                    if (title.includes(token)) {
                        foundTokens.push(token);
                    }
                }

                if (foundTokens.length > 0) {
                    const remainingTokens = tokens.filter(token => !foundTokens.includes(token));

                    searchDownThePath(parentNote, remainingTokens, path.concat([note.noteId]));
                }
                else {
                    searchDownThePath(parentNote, tokens, path.concat([note.noteId]));
                }
            }
        }

        const candidateNotes = this.getCandidateNotes(inputNoteSet);

        for (const note of candidateNotes) {
            // autocomplete should be able to find notes by their noteIds as well (only leafs)
            if (this.tokens.length === 1 && note.noteId.toLowerCase() === this.tokens[0]) {
                searchDownThePath(note, [], []);
                continue;
            }

            const foundAttrTokens = [];

            for (const token of this.tokens) {
                if (note.type.includes(token) || note.mime.includes(token)) {
                    foundAttrTokens.push(token);
                }

                for (const attribute of note.ownedAttributes) {
                    if (attribute.name.includes(token) || attribute.value.includes(token)) {
                        foundAttrTokens.push(token);
                    }
                }
            }

            for (const parentNote of note.parents) {
                const title = noteCacheService.getNoteTitle(note.noteId, parentNote.noteId).toLowerCase();
                const foundTokens = foundAttrTokens.slice();

                for (const token of this.tokens) {
                    if (title.includes(token)) {
                        foundTokens.push(token);
                    }
                }

                if (foundTokens.length > 0) {
                    const remainingTokens = this.tokens.filter(token => !foundTokens.includes(token));

                    searchDownThePath(parentNote, remainingTokens, [note.noteId]);
                }
            }
        }

        return resultNoteSet;
    }

    /**
     * Returns noteIds which have at least one matching tokens
     *
     * @param {NoteSet} noteSet
     * @return {String[]}
     */
    getCandidateNotes(noteSet) {
        const candidateNotes = [];

        for (const note of noteSet.notes) {
            for (const token of this.tokens) {
                if (note.flatText.includes(token)) {
                    candidateNotes.push(note);
                    break;
                }
            }
        }

        return candidateNotes;
    }
}

module.exports = NoteCacheFlatTextExp;