import InteropService from '@joplinapp/lib/services/interop/InteropService';
import CommandService from '@joplinapp/lib/services/CommandService';
import shim from '@joplinapp/lib/shim';
import { ExportOptions, FileSystemItem, Module } from '@joplinapp/lib/services/interop/types';

import { _ } from '@joplinapp/lib/locale';
const bridge = require('electron').remote.require('./bridge').default;
const Setting = require('@joplinapp/lib/models/Setting').default;
const Note = require('@joplinapp/lib/models/Note.js');
const { friendlySafeFilename } = require('@joplinapp/lib/path-utils');
const time = require('@joplinapp/lib/time').default;
const md5 = require('md5');
const url = require('url');

interface ExportNoteOptions {
	customCss?: string,
	sourceNoteIds?: string[],
	sourceFolderIds?: string[],
	printBackground?: boolean,
	pageSize?: string,
	landscape?: boolean,
}

export default class InteropServiceHelper {

	private static async exportNoteToHtmlFile(noteId:string, exportOptions:ExportNoteOptions) {
		const tempFile = `${Setting.value('tempDir')}/${md5(Date.now() + Math.random())}.html`;

		const fullExportOptions:ExportOptions = Object.assign({}, {
			path: tempFile,
			format: 'html',
			target: FileSystemItem.File,
			sourceNoteIds: [noteId],
			customCss: '',
		}, exportOptions);

		const service = InteropService.instance();

		const result = await service.export(fullExportOptions);
		console.info('Export HTML result: ', result);
		return tempFile;
	}

	private static async exportNoteTo_(target:string, noteId:string, options:ExportNoteOptions = {}) {
		let win:any = null;
		let htmlFile:string = null;

		const cleanup = () => {
			if (win) win.destroy();
			if (htmlFile) shim.fsDriver().remove(htmlFile);
		};

		try {
			const exportOptions = {
				customCss: options.customCss ? options.customCss : '',
			};

			htmlFile = await this.exportNoteToHtmlFile(noteId, exportOptions);

			const windowOptions = {
				show: false,
			};

			win = bridge().newBrowserWindow(windowOptions);

			return new Promise((resolve, reject) => {
				win.webContents.on('did-finish-load', () => {

					// did-finish-load will trigger when most assets are done loading, probably
					// images, JavaScript and CSS. However it seems it might trigger *before*
					// all fonts are loaded, which will break for example Katex rendering.
					// So we need to add an additional timer to make sure fonts are loaded
					// as it doesn't seem there's any easy way to figure that out.
					shim.setTimeout(async () => {
						if (target === 'pdf') {
							try {
								const data = await win.webContents.printToPDF(options);
								resolve(data);
							} catch (error) {
								reject(error);
							} finally {
								cleanup();
							}
						} else {
							// TODO: it is crashing at this point :(
							// Appears to be a Chromium bug: https://github.com/electron/electron/issues/19946
							// Maybe can be fixed by doing everything from main process?
							// i.e. creating a function `print()` that takes the `htmlFile` variable as input.

							win.webContents.print(options, (success:boolean, reason:string) => {
								// TODO: This is correct but broken in Electron 4. Need to upgrade to 5+
								// It calls the callback right away with "false" even if the document hasn't be print yet.

								cleanup();
								if (!success && reason !== 'cancelled') reject(new Error(`Could not print: ${reason}`));
								resolve();
							});
						}
					}, 2000);

				});

				win.loadURL(url.format({
					pathname: htmlFile,
					protocol: 'file:',
					slashes: true,
				}));
			});
		} catch (error) {
			cleanup();
			throw error;
		}
	}

	public static async exportNoteToPdf(noteId:string, options:ExportNoteOptions = {}) {
		return this.exportNoteTo_('pdf', noteId, options);
	}

	public static async printNote(noteId:string, options:ExportNoteOptions = {}) {
		return this.exportNoteTo_('printer', noteId, options);
	}

	public static async defaultFilename(noteId:string, fileExtension:string) {
		// Default filename is just the date
		const date = time.formatMsToLocal(new Date().getTime(), time.dateFormat());
		let filename = friendlySafeFilename(`${date}`, 100);

		if (noteId) {
			const note = await Note.load(noteId);
			// In a rare case the passed note will be null, use the id for filename
			filename = friendlySafeFilename(note ? note.title : noteId, 100);
		}

		return `${filename}.${fileExtension}`;
	}

	public static async export(_dispatch:Function, module:Module, options:ExportNoteOptions = null) {
		if (!options) options = {};

		let path = null;

		if (module.target === 'file') {
			const noteId = options.sourceNoteIds && options.sourceNoteIds.length ? options.sourceNoteIds[0] : null;
			path = bridge().showSaveDialog({
				filters: [{ name: module.description, extensions: module.fileExtensions }],
				defaultPath: await this.defaultFilename(noteId, module.fileExtensions[0]),
			});
		} else {
			path = bridge().showOpenDialog({
				properties: ['openDirectory', 'createDirectory'],
			});
		}

		if (!path || (Array.isArray(path) && !path.length)) return;

		if (Array.isArray(path)) path = path[0];

		CommandService.instance().execute('showModalMessage', _('Exporting to "%s" as "%s" format. Please wait...', path, module.format));

		const exportOptions:ExportOptions = {};
		exportOptions.path = path;
		exportOptions.format = module.format;
		exportOptions.modulePath = module.path;
		exportOptions.target = module.target;
		if (options.sourceFolderIds) exportOptions.sourceFolderIds = options.sourceFolderIds;
		if (options.sourceNoteIds) exportOptions.sourceNoteIds = options.sourceNoteIds;

		const service = InteropService.instance();

		try {
			const result = await service.export(exportOptions);
			console.info('Export result: ', result);
		} catch (error) {
			console.error(error);
			bridge().showErrorMessageBox(_('Could not export notes: %s', error.message));
		}

		CommandService.instance().execute('hideModalMessage');
	}

}