/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/


'use strict';

import events = require('events');
import path = require('path');
import fs = require('fs');

import {ipcMain as ipc, app, screen, crashReporter, BrowserWindow, dialog} from 'electron';

import platform = require('vs/base/common/platform');
import env = require('vs/workbench/electron-main/env');
import window = require('vs/workbench/electron-main/window');
import lifecycle = require('vs/workbench/electron-main/lifecycle');
import nls = require('vs/nls');
import paths = require('vs/base/common/paths');
import json = require('vs/base/common/json');
import arrays = require('vs/base/common/arrays');
import objects = require('vs/base/common/objects');
import storage = require('vs/workbench/electron-main/storage');
import settings = require('vs/workbench/electron-main/settings');
import {Instance as UpdateManager, IUpdate} from 'vs/workbench/electron-main/update-manager';

const eventEmitter = new events.EventEmitter();

const EventTypes = {
	OPEN: 'open',
	CLOSE: 'close',
	READY: 'ready'
};

export function onOpen<T>(clb: (path: window.IPath) => void): () => void {
	eventEmitter.addListener(EventTypes.OPEN, clb);

	return () => eventEmitter.removeListener(EventTypes.OPEN, clb);
}

export function onReady<T>(clb: (win: window.VSCodeWindow) => void): () => void {
	eventEmitter.addListener(EventTypes.READY, clb);

	return () => eventEmitter.removeListener(EventTypes.READY, clb);
}

export function onClose<T>(clb: (remainingWindowCount: number) => void): () => void {
	eventEmitter.addListener(EventTypes.CLOSE, clb);

	return () => eventEmitter.removeListener(EventTypes.CLOSE, clb);
}

enum WindowError {
	UNRESPONSIVE,
	CRASHED
}

export interface IOpenConfiguration {
	cli: env.ICommandLineArguments;
	userEnv?: env.IProcessEnvironment;
	pathsToOpen?: string[];
	forceNewWindow?: boolean;
	forceEmpty?: boolean;
	windowToUse?: window.VSCodeWindow;
}

interface IWindowState {
	workspacePath?: string;
	uiState: window.IWindowState;
}

interface IWindowsState {
	lastActiveWindow?: IWindowState;
	lastPluginDevelopmentHostWindow?: IWindowState;
	openedFolders: IWindowState[];
}

export interface IOpenedPathsList {
	folders: string[];
	files: string[];
}

interface ILogEntry {
	severity: string;
	arguments: any;
}

export class WindowsManager {

	public static openedPathsListStorageKey = 'openedPathsList';

	private static workingDirPickerStorageKey = 'pickerWorkingDir';
	private static windowsStateStorageKey = 'windowsState';

	private static WINDOWS: window.VSCodeWindow[] = [];

	private initialUserEnv: env.IProcessEnvironment;
	private windowsState: IWindowsState;

	public ready(initialUserEnv: env.IProcessEnvironment): void {
		this.registerListeners();

		this.initialUserEnv = initialUserEnv;
		this.windowsState = storage.getItem<IWindowsState>(WindowsManager.windowsStateStorageKey) || { openedFolders: [] };
	}

	private registerListeners(): void {
		app.on('activate', (event: Event, hasVisibleWindows: boolean) => {
			env.log('App#activate');

			// Mac only event: reopen last window when we get activated
			if (!hasVisibleWindows) {

				// We want to open the previously opened folder, so we dont pass on the path argument
				let cliArgWithoutPath = objects.clone(env.cliArgs);
				cliArgWithoutPath.pathArguments = [];
				this.windowsState.openedFolders = []; // make sure we do not restore too much

				this.open({ cli: cliArgWithoutPath });
			}
		});

		let macOpenFiles: string[] = [];
		let runningTimeout: number = null;
		app.on('open-file', (event: Event, path: string) => {
			env.log('App#open-file: ', path);
			event.preventDefault();

			// Keep in array because more might come!
			macOpenFiles.push(path);

			// Clear previous handler if any
			if (runningTimeout !== null) {
				clearTimeout(runningTimeout);
				runningTimeout = null;
			}

			// Handle paths delayed in case more are coming!
			runningTimeout = setTimeout(() => {
				this.open({ cli: env.cliArgs, pathsToOpen: macOpenFiles, forceNewWindow: true /* dropping on the dock should force open in a new window */ });
				macOpenFiles = [];
				runningTimeout = null;
			}, 100);
		});

		settings.manager.onChange((newSettings) => {
			this.sendToAll('vscode:optionsChange', JSON.stringify({ globalSettings: newSettings }));
		}, this);

		ipc.on('vscode:startCrashReporter', (event: any, config: any) => {
			crashReporter.start(config);
		});

		ipc.on('vscode:windowOpen', (event, paths: string[], forceNewWindow?: boolean) => {
			env.log('IPC#vscode-windowOpen: ', paths);

			if (paths && paths.length) {
				this.open({ cli: env.cliArgs, pathsToOpen: paths, forceNewWindow: forceNewWindow });
			}
		});

		ipc.on('vscode:workbenchLoaded', (event, windowId: number) => {
			env.log('IPC#vscode-workbenchLoaded');

			let win = this.getWindowById(windowId);
			if (win) {
				win.setReady();

				// Event
				eventEmitter.emit(EventTypes.READY, win);

				// TODO@Ben remove me in a couple of versions
				this.migrateAutoSave(win);
			}
		});

		ipc.on('vscode:openFilePicker', () => {
			env.log('IPC#vscode-openFilePicker');

			this.openFilePicker();
		});

		ipc.on('vscode:openFolderPicker', () => {
			env.log('IPC#vscode-openFolderPicker');

			this.openFolderPicker();
		});

		ipc.on('vscode:closeFolder', (event, windowId: number) => {
			env.log('IPC#vscode-closeFolder');

			let win = this.getWindowById(windowId);
			if (win) {
				this.open({ cli: env.cliArgs, forceEmpty: true, windowToUse: win });
			}
		});

		ipc.on('vscode:openNewWindow', () => {
			env.log('IPC#vscode-openNewWindow');

			this.openNewWindow();
		});

		ipc.on('vscode:openFileFolderPicker', () => {
			env.log('IPC#vscode-openFileFolderPicker');

			this.openFolderPicker();
		});

		ipc.on('vscode:reloadWindow', (event, windowId: number) => {
			env.log('IPC#vscode:reloadWindow');

			let vscodeWindow = this.getWindowById(windowId);
			if (vscodeWindow) {
				this.reload(vscodeWindow);
			}
		});

		ipc.on('vscode:toggleFullScreen', (event, windowId: number) => {
			env.log('IPC#vscode:toggleFullScreen');

			let vscodeWindow = this.getWindowById(windowId);
			if (vscodeWindow) {
				vscodeWindow.toggleFullScreen();
			}
		});

		ipc.on('vscode:toggleMenuBar', (event, windowId: number) => {
			env.log('IPC#vscode:toggleMenuBar');

			// Update in settings
			let menuBarHidden = storage.getItem(window.VSCodeWindow.menuBarHiddenKey, false);
			let newMenuBarHidden = !menuBarHidden;
			storage.setItem(window.VSCodeWindow.menuBarHiddenKey, newMenuBarHidden);

			// Update across windows
			WindowsManager.WINDOWS.forEach(w => w.setMenuBarVisibility(!newMenuBarHidden));
		});

		ipc.on('vscode:changeTheme', (event, theme: string) => {
			this.sendToAll('vscode:changeTheme', theme);
			storage.setItem(window.VSCodeWindow.themeStorageKey, theme);
		});

		ipc.on('vscode:broadcast', (event, windowId: number, target: string, broadcast: { channel: string; payload: any; }) => {
			if (broadcast.channel && broadcast.payload) {
				if (target) {
					const otherWindowsWithTarget = WindowsManager.WINDOWS.filter(w => w.id !== windowId && typeof w.openedWorkspacePath === 'string');
					const directTargetMatch = otherWindowsWithTarget.filter(w => this.isPathEqual(target, w.openedWorkspacePath));
					const parentTargetMatch = otherWindowsWithTarget.filter(w => paths.isEqualOrParent(target, w.openedWorkspacePath));

					const targetWindow = directTargetMatch.length ? directTargetMatch[0] : parentTargetMatch[0]; // prefer direct match over parent match
					if (targetWindow) {
						targetWindow.send('vscode:broadcast', broadcast);
					}
				} else {
					this.sendToAll('vscode:broadcast', broadcast, [windowId]);
				}
			}
		});

		ipc.on('vscode:log', (event, logEntry: ILogEntry) => {
			let args = [];
			try {
				let parsed = JSON.parse(logEntry.arguments);
				args.push(...Object.getOwnPropertyNames(parsed).map(o => parsed[o]));
			} catch (error) {
				args.push(logEntry.arguments);
			}

			console[logEntry.severity].apply(console, args);
		});

		ipc.on('vscode:exit', (event, code: number) => {
			process.exit(code);
		});

		UpdateManager.on('update-downloaded', (update: IUpdate) => {
			this.sendToFocused('vscode:telemetry', { eventName: 'update:downloaded', data: { version: update.version } });

			this.sendToAll('vscode:update-downloaded', JSON.stringify({
				releaseNotes: update.releaseNotes,
				version: update.version,
				date: update.date
			}));
		});

		ipc.on('vscode:update-apply', () => {
			env.log('IPC#vscode:update-apply');

			if (UpdateManager.availableUpdate) {
				UpdateManager.availableUpdate.quitAndUpdate();
			}
		});

		UpdateManager.on('update-not-available', (explicit: boolean) => {
			this.sendToFocused('vscode:telemetry', { eventName: 'update:notAvailable', data: { explicit } });

			if (explicit) {
				this.sendToFocused('vscode:update-not-available', '');
			}
		});

		lifecycle.onBeforeQuit(() => {

			// 0-1 window open: Do not keep the list but just rely on the active window to be stored
			if (WindowsManager.WINDOWS.length < 2) {
				this.windowsState.openedFolders = [];
				return;
			}

			// 2-N windows open: Keep a list of windows that are opened on a specific folder to restore it in the next session as needed
			this.windowsState.openedFolders = WindowsManager.WINDOWS.filter(w => w.readyState === window.ReadyState.READY && !!w.openedWorkspacePath && !w.isPluginDevelopmentHost).map(w => {
				return <IWindowState>{
					workspacePath: w.openedWorkspacePath,
					uiState: w.serializeWindowState()
				};
			});
		});

		app.on('will-quit', () => {
			storage.setItem(WindowsManager.windowsStateStorageKey, this.windowsState);
		});

		let loggedStartupTimes = false;
		onReady(window => {
			if (loggedStartupTimes) {
				return; // only for the first window
			}

			loggedStartupTimes = true;

			window.send('vscode:telemetry', { eventName: 'startupTime', data: { ellapsed: Date.now() - global.vscodeStart } });
		});
	}

	private migrateAutoSave(win: window.VSCodeWindow): void {
		if (storage.getItem<number>('autoSaveDelay') === 1000) {
			storage.removeItem('autoSaveDelay');
			win.send('vscode:showAutoSaveInfo');

			try {

				// Initial settings file
				if (!fs.existsSync(env.appSettingsPath)) {
					fs.writeFileSync(env.appSettingsPath, JSON.stringify({ 'files.autoSave': 'afterDelay' }, null, '    '));
				}

				// Update existing settings file
				else {
					const settingsRaw = fs.readFileSync(env.appSettingsPath).toString();
					const lastClosing = settingsRaw.lastIndexOf('}');
					const errors = [];
					const res = json.parse(settingsRaw, errors);

					// We found a closing '}' and the JSON does not contain errors
					if (lastClosing > 0 && !errors.length) {
						const migratedSettings = settingsRaw.substring(0, lastClosing) + '\n    , // Migrated from previous "File | Auto Save" setting:\n    "files.autoSave": "afterDelay"\n}';

						fs.writeFileSync(env.appSettingsPath, migratedSettings);
					}

					// Otherwise inform user that we cannot migrate the settings
					else {
						win.send('vscode:showAutoSaveError');
					}
				}
			} catch (error) {
				env.log(error);
				win.send('vscode:showAutoSaveError');
			}
		}
	}

	public reload(win: window.VSCodeWindow, cli?: env.ICommandLineArguments): void {

		// Only reload when the window has not vetoed this
		lifecycle.manager.unload(win).done((veto) => {
			if (!veto) {
				win.reload(cli);
			}
		});
	}

	public open(openConfig: IOpenConfiguration): boolean {
		let iPathsToOpen: window.IPath[];

		// Find paths from provided paths if any
		if (openConfig.pathsToOpen && openConfig.pathsToOpen.length > 0) {
			iPathsToOpen = openConfig.pathsToOpen.map((pathToOpen) => {
				let iPath = this.toIPath(pathToOpen, false, openConfig.cli && openConfig.cli.gotoLineMode);

				// Warn if the requested path to open does not exist
				if (!iPath) {
					let options = {
						title: env.product.nameLong,
						type: 'info',
						buttons: [nls.localize('ok', "OK")],
						message: nls.localize('pathNotExistTitle', "Path does not exist"),
						detail: nls.localize('pathNotExistDetail', "The path '{0}' does not seem to exist anymore on disk.", pathToOpen),
						noLink: true
					};

					let activeWindow = BrowserWindow.getFocusedWindow();
					if (activeWindow) {
						dialog.showMessageBox(activeWindow, options);
					} else {
						dialog.showMessageBox(options);
					}
				}

				return iPath;
			});

			// get rid of nulls
			iPathsToOpen = arrays.coalesce(iPathsToOpen);

			if (iPathsToOpen.length === 0) {
				return false; // indicate to outside that open failed
			}
		}

		// Check for force empty
		else if (openConfig.forceEmpty) {
			iPathsToOpen = [Object.create(null)];
		}

		// Otherwise infer from command line arguments
		else {
			let ignoreFileNotFound = openConfig.cli.pathArguments.length > 0; // we assume the user wants to create this file from command line
			iPathsToOpen = this.cliToPaths(openConfig.cli, ignoreFileNotFound);
		}

		let filesToOpen = iPathsToOpen.filter((iPath) => !!iPath.filePath && !iPath.createFilePath && !iPath.installExtensionPath);
		let filesToCreate = iPathsToOpen.filter((iPath) => !!iPath.filePath && iPath.createFilePath && !iPath.installExtensionPath);
		let foldersToOpen = iPathsToOpen.filter((iPath) => iPath.workspacePath && !iPath.filePath && !iPath.installExtensionPath);
		let emptyToOpen = iPathsToOpen.filter((iPath) => !iPath.workspacePath && !iPath.filePath && !iPath.installExtensionPath);
		let extensionsToInstall = iPathsToOpen.filter((iPath) => iPath.installExtensionPath).map(ipath => ipath.filePath);

		let configuration: window.IWindowConfiguration;

		// Handle files to open or to create when we dont open a folder
		if (!foldersToOpen.length && (filesToOpen.length > 0 || filesToCreate.length > 0 || extensionsToInstall.length > 0)) {

			// Let the user settings override how files are open in a new window or same window
			let openFilesInNewWindow = openConfig.forceNewWindow;
			if (openFilesInNewWindow && !openConfig.cli.pluginDevelopmentPath) { // can be overriden via settings (not for PDE though!)
				if (settings.manager.getValue('window.openInNewWindow', null) !== null) {
					openFilesInNewWindow = settings.manager.getValue('window.openInNewWindow', openFilesInNewWindow); // TODO@Ben remove legacy setting in a couple of versions
				} else {
					openFilesInNewWindow = settings.manager.getValue('window.openFilesInNewWindow', openFilesInNewWindow);
				}
			}

			// Open Files in last instance if any and flag tells us so
			let lastActiveWindow = this.getLastActiveWindow();
			if (!openFilesInNewWindow && lastActiveWindow) {
				lastActiveWindow.focus();
				lastActiveWindow.ready().then((readyWindow) => {
					readyWindow.send('vscode:openFiles', {
						filesToOpen: filesToOpen,
						filesToCreate: filesToCreate
					});

					if (extensionsToInstall.length) {
						readyWindow.send('vscode:installExtensions', { extensionsToInstall });
					}
				});
			}

			// Otherwise open instance with files
			else {
				configuration = this.toConfiguration(openConfig.userEnv || this.initialUserEnv, openConfig.cli, null, filesToOpen, filesToCreate, extensionsToInstall);
				this.openInBrowserWindow(configuration, true /* new window */);

				openConfig.forceNewWindow = true; // any other folders to open must open in new window then
			}
		}

		// Handle folders to open
		if (foldersToOpen.length > 0) {

			// Check for existing instances
			let windowsOnWorkspacePath = arrays.coalesce(foldersToOpen.map((iPath) => this.findWindow(iPath.workspacePath)));
			if (windowsOnWorkspacePath.length > 0) {
				windowsOnWorkspacePath[0].focus(); // just focus one of them
				windowsOnWorkspacePath[0].ready().then((readyWindow) => {
					readyWindow.send('vscode:openFiles', {
						filesToOpen: filesToOpen,
						filesToCreate: filesToCreate
					});

					if (extensionsToInstall.length) {
						readyWindow.send('vscode:installExtensions', { extensionsToInstall });
					}
				});

				// Reset these because we handled them
				filesToOpen = [];
				filesToCreate = [];
				extensionsToInstall = [];

				openConfig.forceNewWindow = true; // any other folders to open must open in new window then
			}

			// Open remaining ones
			foldersToOpen.forEach((folderToOpen) => {
				if (windowsOnWorkspacePath.some((win) => this.isPathEqual(win.openedWorkspacePath, folderToOpen.workspacePath))) {
					return; // ignore folders that are already open
				}

				configuration = this.toConfiguration(openConfig.userEnv || this.initialUserEnv, openConfig.cli, folderToOpen.workspacePath, filesToOpen, filesToCreate, extensionsToInstall);
				this.openInBrowserWindow(configuration, openConfig.forceNewWindow, openConfig.forceNewWindow ? void 0 : openConfig.windowToUse);

				// Reset these because we handled them
				filesToOpen = [];
				filesToCreate = [];
				extensionsToInstall = [];

				openConfig.forceNewWindow = true; // any other folders to open must open in new window then
			});
		}

		// Handle empty
		if (emptyToOpen.length > 0) {
			emptyToOpen.forEach(() => {
				let configuration = this.toConfiguration(openConfig.userEnv || this.initialUserEnv, openConfig.cli);
				this.openInBrowserWindow(configuration, openConfig.forceNewWindow, openConfig.forceNewWindow ? void 0 : openConfig.windowToUse);

				openConfig.forceNewWindow = true; // any other folders to open must open in new window then
			});
		}

		// Remember in recent document list
		iPathsToOpen.forEach((iPath) => {
			if (iPath.filePath || iPath.workspacePath) {
				app.addRecentDocument(iPath.filePath || iPath.workspacePath);
			}
		});

		// Emit events
		iPathsToOpen.forEach((iPath) => eventEmitter.emit(EventTypes.OPEN, iPath));

		return true;
	}

	public openPluginDevelopmentHostWindow(openConfig: IOpenConfiguration): void {

		// Reload an existing plugin development host window on the same path
		// We currently do not allow more than one extension development window
		// on the same plugin path.
		let res = WindowsManager.WINDOWS.filter((w) => w.config && this.isPathEqual(w.config.pluginDevelopmentPath, openConfig.cli.pluginDevelopmentPath));
		if (res && res.length === 1) {
			this.reload(res[0], openConfig.cli);
			res[0].focus(); // make sure it gets focus and is restored

			return;
		}

		// Fill in previously opened workspace unless an explicit path is provided
		if (openConfig.cli.pathArguments.length === 0) {
			let workspaceToOpen = this.windowsState.lastPluginDevelopmentHostWindow && this.windowsState.lastPluginDevelopmentHostWindow.workspacePath;
			if (workspaceToOpen) {
				openConfig.cli.pathArguments = [workspaceToOpen];
			}
		}

		// Make sure we are not asked to open a path that is already opened
		if (openConfig.cli.pathArguments.length > 0) {
			res = WindowsManager.WINDOWS.filter((w) => w.openedWorkspacePath && openConfig.cli.pathArguments.indexOf(w.openedWorkspacePath) >= 0);
			if (res.length) {
				openConfig.cli.pathArguments = [];
			}
		}

		// Open it
		this.open({ cli: openConfig.cli, forceNewWindow: true, forceEmpty: openConfig.cli.pathArguments.length === 0 });
	}

	private toConfiguration(userEnv: env.IProcessEnvironment, cli: env.ICommandLineArguments, workspacePath?: string, filesToOpen?: window.IPath[], filesToCreate?: window.IPath[], extensionsToInstall?: string[]): window.IWindowConfiguration {
		let configuration: window.IWindowConfiguration = objects.mixin({}, cli); // inherit all properties from CLI
		configuration.execPath = process.execPath;
		configuration.workspacePath = workspacePath;
		configuration.filesToOpen = filesToOpen;
		configuration.filesToCreate = filesToCreate;
		configuration.extensionsToInstall = extensionsToInstall;
		configuration.appName = env.product.nameLong;
		configuration.appRoot = env.appRoot;
		configuration.version = env.version;
		configuration.commitHash = env.product.commit;
		configuration.appSettingsHome = env.appSettingsHome;
		configuration.appSettingsPath = env.appSettingsPath;
		configuration.appKeybindingsPath = env.appKeybindingsPath;
		configuration.userPluginsHome = env.userPluginsHome;
		configuration.sharedIPCHandle = env.sharedIPCHandle;
		configuration.isBuilt = env.isBuilt;
		configuration.crashReporter = env.product.crashReporter;
		configuration.extensionsGallery = env.product.extensionsGallery;
		configuration.welcomePage = env.product.welcomePage;
		configuration.productDownloadUrl = env.product.downloadUrl;
		configuration.releaseNotesUrl = env.product.releaseNotesUrl;
		configuration.updateFeedUrl = UpdateManager.feedUrl;
		configuration.updateChannel = UpdateManager.channel;
		configuration.recentPaths = this.getRecentlyOpenedPaths(workspacePath, filesToOpen);
		configuration.aiConfig = env.product.aiConfig;
		configuration.sendASmile = env.product.sendASmile;
		configuration.enableTelemetry = env.product.enableTelemetry;
		configuration.userEnv = userEnv;

		return configuration;
	}

	private getRecentlyOpenedPaths(workspacePath?: string, filesToOpen?: window.IPath[]): string[] {

		// Get from storage
		let openedPathsList = storage.getItem<IOpenedPathsList>(WindowsManager.openedPathsListStorageKey);
		if (!openedPathsList) {
			openedPathsList = { folders: [], files: [] };
		}

		let recentPaths = openedPathsList.folders.concat(openedPathsList.files);

		// Add currently files to open to the beginning if any
		if (filesToOpen) {
			recentPaths.unshift(...filesToOpen.map(f => f.filePath));
		}

		// Add current workspace path to beginning if set
		if (workspacePath) {
			recentPaths.unshift(workspacePath);
		}

		// Clear those dupes
		recentPaths = arrays.distinct(recentPaths);

		// Make sure it is bounded
		return recentPaths.slice(0, 10); // TODO@Ben remove in a couple of versions, it should  be ok then because we limited storage
	}

	private toIPath(anyPath: string, ignoreFileNotFound?: boolean, gotoLineMode?: boolean): window.IPath {
		if (!anyPath) {
			return null;
		}

		let parsedPath: env.IParsedPath;
		if (gotoLineMode) {
			parsedPath = env.parseLineAndColumnAware(anyPath);
			anyPath = parsedPath.path;
		}

		let candidate = path.normalize(anyPath);
		try {
			let candidateStat = fs.statSync(candidate);
			if (candidateStat) {
				return candidateStat.isFile() ?
					{
						filePath: candidate,
						lineNumber: gotoLineMode ? parsedPath.line : void 0,
						columnNumber: gotoLineMode ? parsedPath.column : void 0,
						installExtensionPath: /\.vsix$/i.test(candidate)
					} :
					{ workspacePath: candidate };
			}
		} catch (error) {
			if (ignoreFileNotFound) {
				return { filePath: candidate, createFilePath: true }; // assume this is a file that does not yet exist
			}
		}

		return null;
	}

	private cliToPaths(cli: env.ICommandLineArguments, ignoreFileNotFound?: boolean): window.IPath[] {

		// Check for pass in candidate or last opened path
		let candidates: string[] = [];
		if (cli.pathArguments.length > 0) {
			candidates = cli.pathArguments;
		}

		// No path argument, check settings for what to do now
		else {
			let reopenFolders = settings.manager.getValue('window.reopenFolders', 'one');
			let lastActiveFolder = this.windowsState.lastActiveWindow && this.windowsState.lastActiveWindow.workspacePath;

			// Restore all
			if (reopenFolders === 'all') {
				let lastOpenedFolders = this.windowsState.openedFolders.map(o => o.workspacePath);

				// If we have a last active folder, move it to the end
				if (lastActiveFolder) {
					lastOpenedFolders.splice(lastOpenedFolders.indexOf(lastActiveFolder), 1);
					lastOpenedFolders.push(lastActiveFolder);
				}

				candidates.push(...lastOpenedFolders);
			}

			// Restore last active
			else if (lastActiveFolder && (reopenFolders === 'one' || reopenFolders !== 'none')) {
				candidates.push(lastActiveFolder);
			}
		}

		let iPaths = candidates.map((candidate) => this.toIPath(candidate, ignoreFileNotFound, cli.gotoLineMode)).filter((path) => !!path);
		if (iPaths.length > 0) {
			return iPaths;
		}

		// No path provided, return empty to open empty
		return [Object.create(null)];
	}

	private openInBrowserWindow(configuration: window.IWindowConfiguration, forceNewWindow?: boolean, windowToUse?: window.VSCodeWindow): void {
		let vscodeWindow: window.VSCodeWindow;

		if (!forceNewWindow) {
			vscodeWindow = windowToUse || this.getLastActiveWindow();

			if (vscodeWindow) {
				vscodeWindow.focus();
			}
		}

		// New window
		if (!vscodeWindow) {
			vscodeWindow = new window.VSCodeWindow({
				state: this.getNewWindowState(configuration),
				isPluginDevelopmentHost: !!configuration.pluginDevelopmentPath
			});

			WindowsManager.WINDOWS.push(vscodeWindow);

			// Window Events
			vscodeWindow.win.webContents.on('crashed', () => this.onWindowError(vscodeWindow.win, WindowError.CRASHED));
			vscodeWindow.win.on('unresponsive', () => this.onWindowError(vscodeWindow.win, WindowError.UNRESPONSIVE));
			vscodeWindow.win.on('close', () => this.onBeforeWindowClose(vscodeWindow));
			vscodeWindow.win.on('closed', () => this.onWindowClosed(vscodeWindow));

			// Lifecycle
			lifecycle.manager.registerWindow(vscodeWindow);
		}

		// Existing window
		else {

			// Some configuration things get inherited if the window is being reused and we are
			// in plugin development host mode. These options are all development related.
			let currentWindowConfig = vscodeWindow.config;
			if (!configuration.pluginDevelopmentPath && currentWindowConfig && !!currentWindowConfig.pluginDevelopmentPath) {
				configuration.pluginDevelopmentPath = currentWindowConfig.pluginDevelopmentPath;
				configuration.verboseLogging = currentWindowConfig.verboseLogging;
				configuration.logPluginHostCommunication = currentWindowConfig.logPluginHostCommunication;
				configuration.debugBrkPluginHost = currentWindowConfig.debugBrkPluginHost;
				configuration.debugPluginHostPort = currentWindowConfig.debugPluginHostPort;
				configuration.pluginHomePath = currentWindowConfig.pluginHomePath;
			}
		}

		// Only load when the window has not vetoed this
		lifecycle.manager.unload(vscodeWindow).done((veto) => {
			if (!veto) {

				// Load it
				vscodeWindow.load(configuration);
			}
		});
	}

	private getNewWindowState(configuration: window.IWindowConfiguration): window.IWindowState {

		// plugin development host Window - load from stored settings if any
		if (!!configuration.pluginDevelopmentPath && this.windowsState.lastPluginDevelopmentHostWindow) {
			return this.windowsState.lastPluginDevelopmentHostWindow.uiState;
		}

		// Known Folder - load from stored settings if any
		if (configuration.workspacePath) {
			let stateForWorkspace = this.windowsState.openedFolders.filter(o => this.isPathEqual(o.workspacePath, configuration.workspacePath)).map(o => o.uiState);
			if (stateForWorkspace.length) {
				return stateForWorkspace[0];
			}
		}

		// First Window
		let lastActive = this.getLastActiveWindow();
		if (!lastActive && this.windowsState.lastActiveWindow) {
			return this.windowsState.lastActiveWindow.uiState;
		}

		//
		// In any other case, we do not have any stored settings for the window state, so we come up with something smart
		//

		// We want the new window to open on the same display that the last active one is in
		let displayToUse: Electron.Display;
		let displays = screen.getAllDisplays();

		// Single Display
		if (displays.length === 1) {
			displayToUse = displays[0];
		}

		// Multi Display
		else {

			// on mac there is 1 menu per window so we need to use the monitor where the cursor currently is
			if (platform.isMacintosh) {
				let cursorPoint = screen.getCursorScreenPoint();
				displayToUse = screen.getDisplayNearestPoint(cursorPoint);
			}

			// if we have a last active window, use that display for the new window
			if (!displayToUse && lastActive) {
				displayToUse = screen.getDisplayMatching(lastActive.getBounds());
			}

			// fallback to first display
			if (!displayToUse) {
				displayToUse = displays[0];
			}
		}

		let defaultState = window.defaultWindowState();
		defaultState.x = displayToUse.bounds.x + (displayToUse.bounds.width / 2) - (defaultState.width / 2);
		defaultState.y = displayToUse.bounds.y + (displayToUse.bounds.height / 2) - (defaultState.height / 2);

		return this.ensureNoOverlap(defaultState);
	}

	private ensureNoOverlap(state: window.IWindowState): window.IWindowState {
		if (WindowsManager.WINDOWS.length === 0) {
			return state;
		}

		let existingWindowBounds = WindowsManager.WINDOWS.map((win) => win.getBounds());
		while (existingWindowBounds.some((b) => b.x === state.x || b.y === state.y)) {
			state.x += 30;
			state.y += 30;
		}

		return state;
	}

	public openFilePicker(): void {
		this.getFileOrFolderPaths(false, (paths: string[]) => {
			if (paths && paths.length) {
				this.open({ cli: env.cliArgs, pathsToOpen: paths });
			}
		});
	}

	public openFolderPicker(): void {
		this.getFileOrFolderPaths(true, (paths: string[]) => {
			if (paths && paths.length) {
				this.open({ cli: env.cliArgs, pathsToOpen: paths });
			}
		});
	}

	private getFileOrFolderPaths(isFolder: boolean, clb: (paths: string[]) => void): void {
		let workingDir = storage.getItem<string>(WindowsManager.workingDirPickerStorageKey);
		let focussedWindow = this.getFocusedWindow();

		let pickerProperties: string[];
		if (platform.isMacintosh) {
			pickerProperties = ['multiSelections', 'openDirectory', 'openFile', 'createDirectory'];
		} else {
			pickerProperties = ['multiSelections', isFolder ? 'openDirectory' : 'openFile', 'createDirectory'];
		}

		dialog.showOpenDialog(focussedWindow && focussedWindow.win, {
			defaultPath: workingDir,
			properties: pickerProperties
		}, (paths) => {
			if (paths && paths.length > 0) {

				// Remember path in storage for next time
				storage.setItem(WindowsManager.workingDirPickerStorageKey, path.dirname(paths[0]));

				// Return
				clb(paths);
			} else {
				clb(void (0));
			}
		});
	}

	public focusLastActive(cli: env.ICommandLineArguments): void {
		let lastActive = this.getLastActiveWindow();
		if (lastActive) {
			lastActive.focus();
		}

		// No window - open new one
		else {
			this.windowsState.openedFolders = []; // make sure we do not open too much
			this.open({ cli: cli });
		}
	}

	public getLastActiveWindow(): window.VSCodeWindow {
		if (WindowsManager.WINDOWS.length) {
			let lastFocussedDate = Math.max.apply(Math, WindowsManager.WINDOWS.map((w) => w.lastFocusTime));
			let res = WindowsManager.WINDOWS.filter((w) => w.lastFocusTime === lastFocussedDate);
			if (res && res.length) {
				return res[0];
			}
		}

		return null;
	}

	public findWindow(workspacePath: string, filePath?: string): window.VSCodeWindow {
		if (WindowsManager.WINDOWS.length) {

			// Sort the last active window to the front of the array of windows to test
			let windowsToTest = WindowsManager.WINDOWS.slice(0);
			let lastActiveWindow = this.getLastActiveWindow();
			if (lastActiveWindow) {
				windowsToTest.splice(windowsToTest.indexOf(lastActiveWindow), 1);
				windowsToTest.unshift(lastActiveWindow);
			}

			// Find it
			let res = windowsToTest.filter((w) => {

				// match on workspace
				if (typeof w.openedWorkspacePath === 'string' && (this.isPathEqual(w.openedWorkspacePath, workspacePath))) {
					return true;
				}

				// match on file
				if (typeof w.openedFilePath === 'string' && this.isPathEqual(w.openedFilePath, filePath)) {
					return true;
				}

				// match on file path
				if (typeof w.openedWorkspacePath === 'string' && filePath && paths.isEqualOrParent(filePath, w.openedWorkspacePath)) {
					return true;
				}

				return false;
			});

			if (res && res.length) {
				return res[0];
			}
		}

		return null;
	}

	public openNewWindow(): void {
		this.open({ cli: env.cliArgs, forceNewWindow: true, forceEmpty: true });
	}

	public sendToFocused(channel: string, ...args: any[]): void {
		const focusedWindow = this.getFocusedWindow() || this.getLastActiveWindow();

		if (focusedWindow) {
			focusedWindow.sendWhenReady(channel, ...args);
		}
	}

	public sendToAll(channel: string, payload: any, windowIdsToIgnore?: number[]): void {
		WindowsManager.WINDOWS.forEach((w) => {
			if (windowIdsToIgnore && windowIdsToIgnore.indexOf(w.id) >= 0) {
				return; // do not send if we are instructed to ignore it
			}

			w.sendWhenReady(channel, payload);
		});
	}

	public getFocusedWindow(): window.VSCodeWindow {
		let win = BrowserWindow.getFocusedWindow();
		if (win) {
			return this.getWindowById(win.id);
		}

		return null;
	}

	public getWindowById(windowId: number): window.VSCodeWindow {
		let res = WindowsManager.WINDOWS.filter((w) => w.id === windowId);
		if (res && res.length === 1) {
			return res[0];
		}

		return null;
	}

	public getWindows(): window.VSCodeWindow[] {
		return WindowsManager.WINDOWS;
	}

	public getWindowCount(): number {
		return WindowsManager.WINDOWS.length;
	}

	private onWindowError(win: Electron.BrowserWindow, error: WindowError): void {
		console.error(error === WindowError.CRASHED ? '[VS Code]: render process crashed!' : '[VS Code]: detected unresponsive');

		// Unresponsive
		if (error === WindowError.UNRESPONSIVE) {
			dialog.showMessageBox(win, {
				title: env.product.nameLong,
				type: 'warning',
				buttons: [nls.localize('exit', "Exit"), nls.localize('wait', "Keep Waiting")],
				message: nls.localize('appStalled', "{0} is no longer responding", env.product.nameLong),
				detail: nls.localize('appStalledDetail', "Would you like to exit {0} or just keep waiting?", env.product.nameLong),
				noLink: true
			}, (result) => {
				if (result === 0) {
					win.destroy(); // make sure to destroy the window as otherwise quit will just not do anything
					app.quit();
				}
			});
		}

		// Crashed
		else {
			dialog.showMessageBox(win, {
				title: env.product.nameLong,
				type: 'warning',
				buttons: [nls.localize('exit', "Exit")],
				message: nls.localize('appCrashed', "{0} has crashed", env.product.nameLong),
				detail: nls.localize('appCrashedDetail', "We are sorry for the inconvenience! Please restart {0}.", env.product.nameLong),
				noLink: true
			}, (result) => {
				win.destroy(); // make sure to destroy the window as otherwise quit will just not do anything
				app.quit();
			});
		}
	}

	private onBeforeWindowClose(win: window.VSCodeWindow): void {
		if (win.readyState !== window.ReadyState.READY) {
			return; // only persist windows that are fully loaded
		}

		// On Window close, update our stored state of this window
		let state: IWindowState = { workspacePath: win.openedWorkspacePath, uiState: win.serializeWindowState() };
		if (win.isPluginDevelopmentHost) {
			this.windowsState.lastPluginDevelopmentHostWindow = state;
		} else {
			this.windowsState.lastActiveWindow = state;

			this.windowsState.openedFolders.forEach(o => {
				if (this.isPathEqual(o.workspacePath, win.openedWorkspacePath)) {
					o.uiState = state.uiState;
				}
			});
		}
	}

	private onWindowClosed(win: window.VSCodeWindow): void {

		// Tell window
		win.dispose();

		// Remove from our list so that Electron can clean it up
		let index = WindowsManager.WINDOWS.indexOf(win);
		WindowsManager.WINDOWS.splice(index, 1);

		// Emit
		eventEmitter.emit(EventTypes.CLOSE, WindowsManager.WINDOWS.length);
	}

	private isPathEqual(pathA: string, pathB: string): boolean {
		if (pathA === pathB) {
			return true;
		}

		if (!pathA || !pathB) {
			return false;
		}

		pathA = path.normalize(pathA);
		pathB = path.normalize(pathB);

		if (pathA === pathB) {
			return true;
		}

		if (!platform.isLinux) {
			pathA = pathA.toLowerCase();
			pathB = pathB.toLowerCase();
		}

		return pathA === pathB;
	}
}

export const manager = new WindowsManager();