const { createStore, applyMiddleware } = require('redux');
const { reducer, defaultState } = require('lib/reducer.js');
const { JoplinDatabase } = require('lib/joplin-database.js');
const { Database } = require('lib/database.js');
const { FoldersScreenUtils } = require('lib/folders-screen-utils.js');
const { DatabaseDriverNode } = require('lib/database-driver-node.js');
const { BaseModel } = require('lib/base-model.js');
const { Folder } = require('lib/models/folder.js');
const { BaseItem } = require('lib/models/base-item.js');
const { Note } = require('lib/models/note.js');
const { Tag } = require('lib/models/tag.js');
const { Setting } = require('lib/models/setting.js');
const { Logger } = require('lib/logger.js');
const { sprintf } = require('sprintf-js');
const { reg } = require('lib/registry.js');
const { fileExtension } = require('lib/path-utils.js');
const { _, setLocale, defaultLocale, closestSupportedLocale } = require('lib/locale.js');
const os = require('os');
const fs = require('fs-extra');
const { cliUtils } = require('./cli-utils.js');
const EventEmitter = require('events');

class Application {

	constructor() {
		this.showPromptString_ = true;
		this.logger_ = new Logger();
		this.dbLogger_ = new Logger();
		this.commands_ = {};
		this.commandMetadata_ = null;
		this.activeCommand_ = null;
		this.allCommandsLoaded_ = false;
		this.showStackTraces_ = false;
		this.gui_ = null;
		this.eventEmitter_ = new EventEmitter();

		// Note: this is basically a cache of state.selectedFolderId. It should *only* 
		// be derived from the state and not set directly since that would make the
		// state and UI out of sync.
		this.currentFolder_ = null; 
	}

	gui() {
		return this.gui_;
	}

	logger() {
		return this.logger_;
	}

	store() {
		return this.store_;
	}

	currentFolder() {
		return this.currentFolder_;
	}

	commandStdoutMaxWidth() {
		return this.gui().stdoutMaxWidth();
	}

	async refreshCurrentFolder() {
		let newFolder = null;
		
		if (this.currentFolder_) newFolder = await Folder.load(this.currentFolder_.id);
		if (!newFolder) newFolder = await Folder.defaultFolder();

		this.switchCurrentFolder(newFolder);
	}

	switchCurrentFolder(folder) {
		this.dispatch({
			type: 'FOLDERS_SELECT',
			id: folder ? folder.id : '',
		});
	}

	async guessTypeAndLoadItem(pattern, options = null) {
		let type = BaseModel.TYPE_NOTE;
		if (pattern.indexOf('/') === 0) {
			type = BaseModel.TYPE_FOLDER;
			pattern = pattern.substr(1);
		}
		return this.loadItem(type, pattern, options);
	}

	async loadItem(type, pattern, options = null) {
		let output = await this.loadItems(type, pattern, options);

		if (output.length > 1) {
			// output.sort((a, b) => { return a.user_updated_time < b.user_updated_time ? +1 : -1; });

			// let answers = { 0: _('[Cancel]') };
			// for (let i = 0; i < output.length; i++) {
			// 	answers[i + 1] = output[i].title;
			// }

			// Not really useful with new UI?
			throw new Error(_('More than one item match "%s". Please narrow down your query.', pattern));

			// let msg = _('More than one item match "%s". Please select one:', pattern);
			// const response = await cliUtils.promptMcq(msg, answers);
			// if (!response) return null;

			return output[response - 1];
		} else {
			return output.length ? output[0] : null;
		}
	}

	async loadItems(type, pattern, options = null) {
		if (type === 'folderOrNote') {
			const folders = await this.loadItems(BaseModel.TYPE_FOLDER, pattern, options);
			if (folders.length) return folders;
			return await this.loadItems(BaseModel.TYPE_NOTE, pattern, options);
		}

		pattern = pattern ? pattern.toString() : '';

		if (type == BaseModel.TYPE_FOLDER && (pattern == Folder.conflictFolderTitle() || pattern == Folder.conflictFolderId())) return [Folder.conflictFolder()];

		if (!options) options = {};

		const parent = options.parent ? options.parent : app().currentFolder();
		const ItemClass = BaseItem.itemClass(type);

		if (type == BaseModel.TYPE_NOTE && pattern.indexOf('*') >= 0) { // Handle it as pattern
			if (!parent) throw new Error(_('No notebook selected.'));
			return await Note.previews(parent.id, { titlePattern: pattern });
		} else { // Single item
			let item = null;
			if (type == BaseModel.TYPE_NOTE) {
				if (!parent) throw new Error(_('No notebook has been specified.'));
				item = await ItemClass.loadFolderNoteByField(parent.id, 'title', pattern);
			} else {
				item = await ItemClass.loadByTitle(pattern);
			}
			if (item) return [item];

			item = await ItemClass.load(pattern); // Load by id
			if (item) return [item];

			if (pattern.length >= 2) {
				return await ItemClass.loadByPartialId(pattern);
			}
		}

		return [];
	}

	// Handles the initial flags passed to main script and
	// returns the remaining args.
	async handleStartFlags_(argv) {
		let matched = {};
		argv = argv.slice(0);
		argv.splice(0, 2); // First arguments are the node executable, and the node JS file

		while (argv.length) {
			let arg = argv[0];
			let nextArg = argv.length >= 2 ? argv[1] : null;
			
			if (arg == '--profile') {
				if (!nextArg) throw new Error(_('Usage: %s', '--profile <dir-path>'));
				matched.profileDir = nextArg;
				argv.splice(0, 2);
				continue;
			}

			if (arg == '--env') {
				if (!nextArg) throw new Error(_('Usage: %s', '--env <dev|prod>'));
				matched.env = nextArg;
				argv.splice(0, 2);
				continue;
			}

			if (arg == '--is-demo') {
				Setting.setConstant('isDemo', true);
				argv.splice(0, 1);
				continue;
			}

			if (arg == '--update-geolocation-disabled') {
				Note.updateGeolocationEnabled_ = false;
				argv.splice(0, 1);
				continue;
			}

			if (arg == '--stack-trace-enabled') {
				this.showStackTraces_ = true;
				argv.splice(0, 1);
				continue;
			}

			if (arg == '--log-level') {
				if (!nextArg) throw new Error(_('Usage: %s', '--log-level <none|error|warn|info|debug>'));
				matched.logLevel = Logger.levelStringToId(nextArg);
				argv.splice(0, 2);
				continue;
			}

			if (arg.length && arg[0] == '-') {
				throw new Error(_('Unknown flag: %s', arg));
			} else {
				break;
			}
		}

		if (!matched.logLevel) matched.logLevel = Logger.LEVEL_INFO;
		if (!matched.env) matched.env = 'prod';

		return {
			matched: matched,
			argv: argv,
		};
	}

	escapeShellArg(arg) {
		if (arg.indexOf('"') >= 0 && arg.indexOf("'") >= 0) throw new Error(_('Command line argument "%s" contains both quotes and double-quotes - aborting.', arg)); // Hopeless case
		let quote = '"';
		if (arg.indexOf('"') >= 0) quote = "'";
		if (arg.indexOf(' ') >= 0 || arg.indexOf("\t") >= 0) return quote + arg + quote;
		return arg;
	}

	shellArgsToString(args) {
		let output = [];
		for (let i = 0; i < args.length; i++) {
			output.push(this.escapeShellArg(args[i]));
		}
		return output.join(' ');
	}

	onLocaleChanged() {
		return;

		let currentCommands = this.vorpal().commands;
		for (let i = 0; i < currentCommands.length; i++) {
			let cmd = currentCommands[i];
			if (cmd._name == 'help') {
				cmd.description(_('Provides help for a given command.'));
			} else if (cmd._name == 'exit') {
				cmd.description(_('Exits the application.'));
			} else if (cmd.__commandObject) {
				cmd.description(cmd.__commandObject.description());
			}
		}
	}

	baseModelListener(action) {
		this.eventEmitter_.emit('modelAction', { action: action });
	}

	on(eventName, callback) {
		return this.eventEmitter_.on(eventName, callback);
	}

	stdout(text) {
		return this.gui().stdout(text);
	}

	setupCommand(cmd) {
		cmd.setStdout((text) => {
			return this.stdout(text);
		});

		cmd.setDispatcher((action) => {
			if (this.store()) {
				return this.store().dispatch(action);
			} else {
				return (action) => {};
			}
		});

		cmd.setPrompt(async (message, options) => {
			if (!options) options = {};
			if (!options.type) options.type = 'boolean';
			if (!options.booleanAnswerDefault) options.booleanAnswerDefault = 'y';
			if (!options.answers) options.answers = options.booleanAnswerDefault === 'y' ? [_('Y'), _('n')] : [_('N'), _('y')];

			if (options.type == 'boolean') {
				message += ' (' + options.answers.join('/') + ')';
			}

			let answer = await this.gui().prompt('', message + ' ');

			if (options.type === 'boolean') {
				if (answer === null) return false; // Pressed ESCAPE
				if (!answer) answer = options.answers[0];
				let positiveIndex = options.booleanAnswerDefault == 'y' ? 0 : 1;
				return answer.toLowerCase() === options.answers[positiveIndex].toLowerCase();
			}
		});

		return cmd;
	}

	async exit(code = 0) {
		const doExit = async () => {
			await Setting.saveAll();
			this.gui().exit();
			process.exit(code);
		};

		// Give it a few seconds to cancel otherwise exit anyway
		setTimeout(async () => {
			await doExit();
		}, 5000);

		if (await reg.syncStarted()) {
			this.stdout(_('Cancelling background synchronisation... Please wait.'));
			const sync = await reg.synchronizer(Setting.value('sync.target'));
			await sync.cancel();
		}

		await doExit();
	}

	commands() {
		if (this.allCommandsLoaded_) return this.commands_;

		fs.readdirSync(__dirname).forEach((path) => {
			if (path.indexOf('command-') !== 0) return;
			const ext = fileExtension(path)
			if (ext != 'js') return;

			let CommandClass = require('./' + path);
			let cmd = new CommandClass();
			if (!cmd.enabled()) return;
			cmd = this.setupCommand(cmd);
			this.commands_[cmd.name()] = cmd;
		});

		this.allCommandsLoaded_ = true;

		return this.commands_;
	}

	async commandNames() {
		const metadata = await this.commandMetadata();
		let output = [];
		for (let n in metadata) {
			if (!metadata.hasOwnProperty(n)) continue;
			output.push(n);
		}
		return output;
	}

	async commandMetadata() {
		if (this.commandMetadata_) return this.commandMetadata_;

		const osTmpdir = require('os-tmpdir');
		const storage = require('node-persist');
		await storage.init({ dir: osTmpdir() + '/commandMetadata', ttl: 1000 * 60 * 60 * 24 });

		let output = await storage.getItem('metadata');
		if (Setting.value('env') != 'dev' && output) {
			this.commandMetadata_ = output;
			return Object.assign({}, this.commandMetadata_);
		}

		const commands = this.commands();

		output = {};
		for (let n in commands) {
			if (!commands.hasOwnProperty(n)) continue;
			const cmd = commands[n];
			output[n] = cmd.metadata();
		}

		await storage.setItem('metadata', output);

		this.commandMetadata_ = output;
		return Object.assign({}, this.commandMetadata_);
	}

	findCommandByName(name) {
		if (this.commands_[name]) return this.commands_[name];

		let CommandClass = null;
		try {
			CommandClass = require(__dirname + '/command-' + name + '.js');
		} catch (error) {
			let e = new Error('No such command: ' + name);
			e.type = 'notFound';
			throw e;
		}

		let cmd = new CommandClass();
		cmd = this.setupCommand(cmd);
		this.commands_[name] = cmd;
		return this.commands_[name];
	}

	dummyGui() {
		return {
			isDummy: () => { return true; },
			prompt: (initialText = '', promptString = '') => { return cliUtils.prompt(initialText, promptString); },
			showConsole: () => {},
			maximizeConsole: () => {},
			stdout: (text) => { console.info(text); },
			fullScreen: (b=true) => {},
			exit: () => {},
			showModalOverlay: (text) => {},
			hideModalOverlay: () => {},
			stdoutMaxWidth: () => { return 78; }
		};
	}

	async execCommand(argv) {
		if (!argv.length) return this.execCommand(['help']);
		reg.logger().info('execCommand()', argv);
		const commandName = argv[0];
		this.activeCommand_ = this.findCommandByName(commandName);

		let outException = null;
		try {
			if (this.gui().isDummy() && !this.activeCommand_.supportsUi('cli')) throw new Error(_('The command "%s" is only available in GUI mode', this.activeCommand_.name()));			
			const cmdArgs = cliUtils.makeCommandArgs(this.activeCommand_, argv);
			await this.activeCommand_.action(cmdArgs);
		} catch (error) {
			outException = error;
		}
		this.activeCommand_ = null;
		if (outException) throw outException;
	}

	currentCommand() {
		return this.activeCommand_;
	}

	async refreshNotes(parentType, parentId) {
		this.logger().debug('Refreshing notes:', parentType, parentId);

		const state = this.store().getState();

		let options = {
			order: state.notesOrder,
			uncompletedTodosOnTop: Setting.value('uncompletedTodosOnTop'),
		};

		const source = JSON.stringify({
			options: options,
			parentId: parentId,
		});

		let notes = [];

		if (parentId) {
			if (parentType === Folder.modelType()) {
				notes = await Note.previews(parentId, options);
			} else if (parentType === Tag.modelType()) {
				notes = await Tag.notes(parentId);
			} else if (parentType === BaseModel.TYPE_SEARCH) {
				let fields = Note.previewFields();
				let search = BaseModel.byId(state.searches, parentId);
				notes = await Note.previews(null, {
					fields: fields,
					anywherePattern: '*' + search.query_pattern + '*',
				});
			}
		}

		this.store().dispatch({
			type: 'NOTES_UPDATE_ALL',
			notes: notes,
			notesSource: source,
		});

		this.store().dispatch({
			type: 'NOTES_SELECT',
			noteId: notes.length ? notes[0].id : null,
		});
	}

	reducerActionToString(action) {
		let o = [action.type];
		if (action.id) o.push(action.id);
		if (action.noteId) o.push(action.noteId);
		if (action.folderId) o.push(action.folderId);
		if (action.tagId) o.push(action.tagId);
		if (action.tag) o.push(action.tag.id);
		if (action.folder) o.push(action.folder.id);
		if (action.notesSource) o.push(JSON.stringify(action.notesSource));
		return o.join(', ');
	}

	generalMiddleware() {
		const middleware = store => next => async (action) => {
			this.logger().debug('Reducer action', this.reducerActionToString(action));

			const result = next(action);
			const newState = store.getState();

			if (action.type == 'FOLDERS_SELECT' || action.type === 'FOLDER_DELETE') {
				Setting.setValue('activeFolderId', newState.selectedFolderId);
				this.currentFolder_ = newState.selectedFolderId ? await Folder.load(newState.selectedFolderId) : null;
				await this.refreshNotes(Folder.modelType(), newState.selectedFolderId);
			}

			if (action.type == 'TAGS_SELECT') {
				await this.refreshNotes(Tag.modelType(), action.id);
			}

			if (action.type == 'SEARCH_SELECT') {
				await this.refreshNotes(BaseModel.TYPE_SEARCH, action.id);
			}

			if (this.gui() && action.type == 'SETTINGS_UPDATE_ONE' && action.key == 'sync.interval' || action.type == 'SETTINGS_UPDATE_ALL') {
				reg.setupRecurrentSync();
			}

		  	return result;
		}

		return middleware;
	}

	dispatch(action) {
		if (this.store()) return this.store().dispatch(action);
	}

	async start() {
		let argv = process.argv;
		let startFlags = await this.handleStartFlags_(argv);
		argv = startFlags.argv;
		let initArgs = startFlags.matched;
		if (argv.length) this.showPromptString_ = false;

		if (process.argv[1].indexOf('joplindev') >= 0) {
			if (!initArgs.profileDir) initArgs.profileDir = '/mnt/d/Temp/TestNotes2';
			initArgs.logLevel = Logger.LEVEL_DEBUG;
			initArgs.env = 'dev';
		}

		Setting.setConstant('appName', initArgs.env == 'dev' ? 'joplindev' : 'joplin');

		const profileDir = initArgs.profileDir ? initArgs.profileDir : os.homedir() + '/.config/' + Setting.value('appName');
		const resourceDir = profileDir + '/resources';
		const tempDir = profileDir + '/tmp';

		Setting.setConstant('env', initArgs.env);
		Setting.setConstant('profileDir', profileDir);
		Setting.setConstant('resourceDir', resourceDir);
		Setting.setConstant('tempDir', tempDir);

		await fs.mkdirp(profileDir, 0o755);
		await fs.mkdirp(resourceDir, 0o755);
		await fs.mkdirp(tempDir, 0o755);

		this.logger_.addTarget('file', { path: profileDir + '/log.txt' });
		this.logger_.setLevel(initArgs.logLevel);

		reg.setLogger(this.logger_);
		reg.dispatch = (o) => {};

		this.dbLogger_.addTarget('file', { path: profileDir + '/log-database.txt' });
		this.dbLogger_.setLevel(initArgs.logLevel);

		if (Setting.value('env') === 'dev') {
			this.dbLogger_.setLevel(Logger.LEVEL_WARN);
		}

		const packageJson = require('./package.json');
		this.logger_.info(sprintf('Starting %s %s (%s)...', packageJson.name, packageJson.version, Setting.value('env')));
		this.logger_.info('Profile directory: ' + profileDir);

		this.database_ = new JoplinDatabase(new DatabaseDriverNode());
		//this.database_.setLogExcludedQueryTypes(['SELECT']);
		this.database_.setLogger(this.dbLogger_);
		await this.database_.open({ name: profileDir + '/database.sqlite' });

		reg.setDb(this.database_);
		BaseModel.db_ = this.database_;

		cliUtils.setStdout((object) => {
			return this.stdout(object);
		});

		await Setting.load();

		if (Setting.value('firstStart')) {
			let locale = process.env.LANG;
			if (!locale) locale = defaultLocale();
			locale = locale.split('.');
			locale = locale[0];
			reg.logger().info('First start: detected locale as ' + locale);
			Setting.setValue('locale', closestSupportedLocale(locale));
			Setting.setValue('firstStart', 0)
		}

		setLocale(Setting.value('locale'));

		let currentFolderId = Setting.value('activeFolderId');
		let currentFolder = null;
		if (currentFolderId) currentFolder = await Folder.load(currentFolderId);
		if (!currentFolder) currentFolder = await Folder.defaultFolder();
		Setting.setValue('activeFolderId', currentFolder ? currentFolder.id : '');

		// If we have some arguments left at this point, it's a command
		// so execute it.
		if (argv.length) {
			this.gui_ = this.dummyGui();

			try {
				await this.execCommand(argv);
			} catch (error) {
				if (this.showStackTraces_) {
					console.info(error);
				} else {
					console.info(error.message);
				}
			}
		} else { // Otherwise open the GUI
			this.store_ = createStore(reducer, applyMiddleware(this.generalMiddleware()));
			BaseModel.dispatch = this.store().dispatch;
			FoldersScreenUtils.dispatch = this.store().dispatch;

			const AppGui = require('./app-gui.js');
			this.gui_ = new AppGui(this, this.store());
			this.gui_.setLogger(this.logger_);
			await this.gui_.start();

			// Since the settings need to be loaded before the store is created, it will never
			// receive the SETTINGS_UPDATE_ALL even, which mean state.settings will not be
			// initialised. So we manually call dispatchUpdateAll() to force an update.
			Setting.dispatchUpdateAll();

			await FoldersScreenUtils.refreshFolders();

			const tags = await Tag.allWithNotes();

			this.dispatch({
				type: 'TAGS_UPDATE_ALL',
				tags: tags,
			});

			this.store().dispatch({
				type: 'FOLDERS_SELECT',
				id: Setting.value('activeFolderId'),
			});
		}
	}

}

let application_ = null;

function app() {
	if (application_) return application_;
	application_ = new Application();
	return application_;
}

module.exports = { app };