"use strict";

const repository = require('../../services/repository');
const enexImportService = require('../../services/import/enex');
const opmlImportService = require('../../services/import/opml');
const tarImportService = require('../../services/import/tar');
const singleImportService = require('../../services/import/single');
const messagingService = require('../../services/messaging');
const cls = require('../../services/cls');
const path = require('path');
const noteCacheService = require('../../services/note_cache');
const log = require('../../services/log');

class ImportContext {
    constructor(importId) {
        // importId is to distinguish between different import events - it is possible (though not recommended)
        // to have multiple imports going at the same time
        this.importId = importId;
        // // count is mean to represent count of exported notes where practical, otherwise it's just some measure of progress
        this.progressCount = 0;
        this.lastSentCountTs = Date.now();
    }

    async increaseProgressCount() {
        this.progressCount++;

        if (Date.now() - this.lastSentCountTs >= 500) {
            this.lastSentCountTs = Date.now();

            await messagingService.sendMessageToAllClients({
                importId: this.importId,
                type: 'import-progress-count',
                progressCount: this.progressCount
            });
        }
    }

    async importFinished(noteId) {
        await messagingService.sendMessageToAllClients({
            importId: this.importId,
            type: 'import-finished',
            noteId: noteId
        });
    }

    // must remaing static
    async reportError(message) {
        await messagingService.sendMessageToAllClients({
            type: 'import-error',
            message: message
        });
    }
}

async function importToBranch(req) {
    const {parentNoteId, importId} = req.params;
    const file = req.file;

    if (!file) {
        return [400, "No file has been uploaded"];
    }

    const parentNote = await repository.getNote(parentNoteId);

    if (!parentNote) {
        return [404, `Note ${parentNoteId} doesn't exist.`];
    }

    const extension = path.extname(file.originalname).toLowerCase();

    // running all the event handlers on imported notes (and attributes) is slow
    // and may produce unintended consequences
    cls.disableEntityEvents();

    let note; // typically root of the import - client can show it after finishing the import

    const importContext = new ImportContext(importId);

    try {
        if (extension === '.tar') {
            note = await tarImportService.importTar(importContext, file.buffer, parentNote);
        } else if (extension === '.opml') {
            note = await opmlImportService.importOpml(importContext, file.buffer, parentNote);
        } else if (extension === '.md') {
            note = await singleImportService.importMarkdown(importContext, file, parentNote);
        } else if (extension === '.html' || extension === '.htm') {
            note = await singleImportService.importHtml(importContext, file, parentNote);
        } else if (extension === '.enex') {
            note = await enexImportService.importEnex(importContext, file, parentNote);
        } else {
            return [400, `Unrecognized extension ${extension}, must be .tar or .opml`];
        }
    }
    catch (e) {
        const message = "Import failed with following error: '" + e.message + "'. More details might be in the logs.";
        importContext.reportError(message);

        log.error(message + e.stack);

        return [500, message];
    }

    // import has deactivated note events so note cache is not updated
    // instead we force it to reload (can be async)
    noteCacheService.load();

    return note;
}

module.exports = {
    importToBranch
};