const path = require('path');
const fs = require('fs');
const { spawnSync } = require('child_process');
const { app, BrowserWindow, Menu, clipboard, dialog, ipcMain, nativeImage } = require('electron');

let currentWorkPath = process.cwd();
const startupOptions = parseStartupOptions(process.argv);
let quickStartWindow = null;

// Packaged builds retain the class expected by installed desktop launchers.
// A distinct development class prevents npm start from inheriting the icon
// cached for an older system installation of TrimSP.
app.setName(app.isPackaged ? 'TrimSP' : 'TrimSPDev');
if (process.platform === 'linux' && !app.isPackaged) {
    // KDE resolves taskbar icons through matching desktop entries and ignores
    // Electron's development-window icon. Keep a hidden per-user entry tied
    // to this checkout so npm start uses the current repository artwork.
    try {
	const dataHome = process.env.XDG_DATA_HOME || path.join(app.getPath('home'), '.local', 'share');
	const applicationsDir = path.join(dataHome, 'applications');
	const desktopFile = path.join(applicationsDir, 'trimsp-dev.desktop');
	const executable = process.execPath.replace(/"/g, '\\"');
	const projectPath = __dirname.replace(/"/g, '\\"');
	const iconPath = path.join(__dirname, 'icon.png');
	const desktopContent = [
	    '[Desktop Entry]',
	    'Type=Application',
	    'Name=TRIMSP-NL Workbench (Development)',
	    `Exec="${executable}" "${projectPath}"`,
	    `Icon=${iconPath}`,
	    `X-TrimSP-Icon-MTime=${fs.statSync(iconPath).mtimeMs}`,
	    'StartupWMClass=TrimSPDev',
	    'NoDisplay=true',
	    'Categories=Science;',
	    '',
	].join('\n');
	fs.mkdirSync(applicationsDir, {recursive: true});
	if (!fs.existsSync(desktopFile) || fs.readFileSync(desktopFile, 'utf8') !== desktopContent) {
	    fs.writeFileSync(desktopFile, desktopContent, 'utf8');
	    // KDE caches desktop identities and icons; refresh that user cache only
	    // when this entry changes. Other desktops safely ignore ENOENT here.
	    spawnSync('kbuildsycoca6', ['--noincremental'], {stdio: 'ignore'});
	}
	app.setDesktopName('trimsp-dev.desktop');
    } catch (error) {
	console.warn('Could not register the development desktop entry:', error);
    }
}

function parseStartupOptions(argv) {
    const options = {
	configPaths: [],
	autoRun: false,
    };

    for (const arg of argv.slice(2)) {
	if (arg === '--run') {
	    options.autoRun = true;
	} else if (!arg.startsWith('--')) {
	    let candidates = [path.resolve(arg)];
	    if (/[*?]/.test(arg)) {
		const resolvedPattern = path.resolve(arg);
		const parsed = path.parse(resolvedPattern);
		const relativePattern = resolvedPattern.slice(parsed.root.length);
		const segments = relativePattern.split(path.sep).filter(Boolean);
		candidates = [parsed.root || '.'];

		for (const segment of segments) {
		    const nextCandidates = [];
		    let matcher = null;
		    if (/[*?]/.test(segment)) {
			let pattern = '^';
			for (const char of segment) {
			    if (char === '*') {
				pattern += '.*';
			    } else if (char === '?') {
				pattern += '.';
			    } else {
				pattern += char.replace(/[|\\{}()[\]^$+?.]/g, '\\$&');
			    }
			}
			pattern += '$';
			matcher = new RegExp(pattern);
		    }

		    for (const candidate of candidates) {
			if (!matcher) {
			    const nextPath = path.join(candidate, segment);
			    if (typeof nextPath === 'string' && fs.existsSync(nextPath)) {
				nextCandidates.push(nextPath);
			    }
			    continue;
			}

			if (typeof candidate !== 'string' || !fs.existsSync(candidate) || !fs.statSync(candidate).isDirectory()) {
			    continue;
			}

			const entries = fs.readdirSync(candidate).sort();
			for (const entry of entries) {
			    if (matcher.test(entry)) {
				nextCandidates.push(path.join(candidate, entry));
			    }
			}
		    }

		    candidates = nextCandidates;
		    if (candidates.length === 0) {
			break;
		    }
		}

		candidates = candidates
		    .filter((candidate) => typeof candidate === 'string' && fs.existsSync(candidate) && fs.statSync(candidate).isFile())
		    .sort();
	    }

	    for (const candidate of candidates) {
		if (
		    typeof candidate === 'string' &&
		    path.extname(candidate).toLowerCase() === '.cfg' &&
		    fs.existsSync(candidate) &&
		    fs.statSync(candidate).isFile() &&
		    !options.configPaths.includes(candidate)
		) {
		    options.configPaths.push(candidate);
		}
	    }
	}
    }

    return options;
}

function showAboutDialog(parentWindow) {
    const detail = [
	'Graphical workbench for low-energy muon and ion implantation simulations.',
	`Workbench version: ${app.getVersion()}`,
	'License: GNU General Public License v3 or later (GPL-3.0-or-later).',
	'Maintained by the Low Energy Muons group at the Paul Scherrer Institute.',
	'Main contributor: Zaher Salman.',
	'',
	'TRIM.SP-NL is the generalized multilayer Fortran transport engine.',
	'TRIMSP-NL Workbench combines the engine with the GUI and scan workflow.',
	'',
	'If you use this software in published work, please cite the relevant',
	'TRIM.SP references and the TRIMSP-NL Workbench paper.',
	'',
	'Key references:',
	'Z. Salman, R. M. L. McFadden, and T. Prokscha, Modernization and',
	'Statistical Validation of a Multilayer TRIM.SP Code for Low-Energy Muon',
	'and Ion Implantation.',
	'J. P. Biersack and W. Eckstein, Appl. Phys. A 34, 73-94 (1984).',
	'W. Eckstein, Computer Simulation of Ion-Solid Interactions (1991).',
	'E. Morenzoni et al., NIM B 192, 245-266 (2002).',
	'',
	'Project repository:',
	'Gitea: gitea.psi.ch/LMU/TRIMSP',
	'Web application: musruser.psi.ch/TRIMSP-NL/'
    ].join('\n');

    dialog.showMessageBox(parentWindow, {
	type: 'info',
	title: 'About TRIMSP-NL Workbench',
	message: 'TRIMSP-NL Workbench',
	detail: detail,
	buttons: ['OK'],
	icon: parentWindow ? undefined : undefined
    });
}

// Some Linux/remote desktop setups expose a broken GPU context to Electron.
// Fall back to software rendering instead of crashing on startup.
app.disableHardwareAcceleration();

if (process.platform === 'linux') {
    // The XDG portal dialog backend ignores defaultPath on some systems and
    // may cancel folder selection entirely in X11/SSH sessions.
    app.commandLine.appendSwitch('xdg-portal-required-version', '999');
}

function getDefaultDialogPath() {
    return currentWorkPath || process.cwd();
}

// Remember the folder in which the last file dialog opened or saved, so the
// dialogs reopen where the user actually works rather than at an OS default
// (or always at process.cwd()). Shared by every dialog type, stored in the
// app's userData dir, and durable across restarts; falls back to the current
// work path.
const DIALOG_FOLDERS_FILE = path.join(app.getPath('userData'), 'dialog-folders.json');
let dialogFolders = null;

function loadDialogFolders() {
    if (dialogFolders === null) {
	try {
	    dialogFolders = JSON.parse(fs.readFileSync(DIALOG_FOLDERS_FILE, 'utf8'));
	} catch (err) {
	    dialogFolders = {};
	}
    }
    return dialogFolders;
}

function rememberLastDialogFolder(folder) {
    if (!folder) return;
    loadDialogFolders();
    dialogFolders.lastUsed = folder;
    try {
	fs.writeFileSync(DIALOG_FOLDERS_FILE, JSON.stringify(dialogFolders, null, 2));
    } catch (err) {
	console.log('could not save dialog folder memory:', err);
    }
}

function rememberLastDialogFolderFromFiles(filePaths) {
    if (!filePaths || filePaths.length === 0) return;
    rememberLastDialogFolder(path.dirname(filePaths[0]));
}

function lastDialogFolder() {
    const fallback = getDefaultDialogPath();
    const saved = loadDialogFolders().lastUsed;
    if (saved && fs.existsSync(saved)) return saved;
    return fallback;
}

function getWindowIconPath() {
    if (app.isPackaged) {
        return path.join(process.resourcesPath, 'app.asar', 'icon.png');
    }
    return path.join(__dirname, 'icon.png');
}

function showQuickStartWindow(sectionId = 'helpLayers') {
    if (quickStartWindow && !quickStartWindow.isDestroyed()) {
	quickStartWindow.show();
	quickStartWindow.focus();
	quickStartWindow.webContents.send('quickStartSection', { sectionId: sectionId, version: app.getVersion() });
	return;
    }

    quickStartWindow = new BrowserWindow({
	title: 'TRIMSP-NL Quick Start',
	width: 720,
	height: 680,
	minWidth: 480,
	minHeight: 360,
	resizable: true,
	autoHideMenuBar: true,
	icon: nativeImage.createFromPath(getWindowIconPath()),
	webPreferences: {
	    contextIsolation: false,
	    nodeIntegration: true,
	}
    });
    quickStartWindow.webContents.once('did-finish-load', () => {
	quickStartWindow.webContents.send('quickStartSection', { sectionId: sectionId, version: app.getVersion() });
    });
    quickStartWindow.loadFile('quick-start.html');
    quickStartWindow.on('closed', () => {
	quickStartWindow = null;
    });
}

function createWindow () {
    const windowIcon = nativeImage.createFromPath(getWindowIconPath());
    const win = new BrowserWindow({
	width: 1000,
	height: 610,
	icon: windowIcon,
	webPreferences: {
	    contextIsolation: false,
	    nodeIntegration: true,
	    nativeWindowOpen: true,
	    enableRemoteModule: true,
	}
    })

    // Pass a native image explicitly for Linux panels that can use the window
    // icon directly. KDE resolves the development icon through the matching
    // desktop entry registered above.
    if (process.platform === 'linux' && !windowIcon.isEmpty()) {
	win.setIcon(windowIcon);
    }

    let template = [
	{
	    label: 'File',
	    submenu: [
		{
		    label: 'Open',
		    id : 'openItem',
		    accelerator: 'CmdOrCtrl+O',
		    click () {
			dialog.showOpenDialog(win,
					      { title : "Load configuration file", 
						defaultPath : lastDialogFolder(),
						//buttonLabel : "Custom button",
						filters :[
						    {name: 'Config file type', extensions: ['cfg']},
						],
						properties: ['openFile']}
					     ).then(result => {
						 console.log(result.canceled);
						 console.log(result.filePaths);
						 if (!result.canceled) {
						     rememberLastDialogFolderFromFiles(result.filePaths);
						     setImmediate(function() {
							 var focusedWindow = win;
							 focusedWindow.webContents.send('openFile',result.filePaths);
						     });
						 }
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		},
		{
		    label: 'Save Folder...',
		    accelerator: 'CmdOrCtrl+F',
		    click () {
			dialog.showOpenDialog(win,
					      { title: "Select folder",
						defaultPath : lastDialogFolder(),
						properties:["openDirectory"]}
					     ).then(result => {
						 setImmediate(function() {
						     console.log(result.filePaths)
						     if (!result.canceled) {
							 rememberLastDialogFolder(result.filePaths[0]);
						     }
						     var focusedWindow = win;
						     focusedWindow.webContents.send('selectFolder',result.filePaths);
						 });
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		},
		{
		    label: 'Save',
		    accelerator: 'CmdOrCtrl+S',
		    click () {
			setImmediate(function() {
			    var focusedWindow = win;
			    focusedWindow.webContents.send('saveFile','');
			});
		    }
		},
		{
		    label: 'Save As...',
		    accelerator: 'CmdOrCtrl+Shift+S',
		    click () {
			dialog.showSaveDialog(win,
					      { title : "Save configuration file", 
						defaultPath : path.join(lastDialogFolder(), 'TrimSP.cfg'),
						filters :[
						    {name: 'Config file type', extensions: ['cfg']},
						    {name: 'All Files', extensions: ['*']}
						],
						properties: ['showOverwriteConfirmation']}
					     ).then(result => {
						 if (result.canceled || !result.filePath) {
						     return;
						 }
						 rememberLastDialogFolder(path.dirname(result.filePath));
						 setImmediate(function() {
						     var focusedWindow = win;
						     focusedWindow.webContents.send('saveFile',result.filePath);
						 });
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		},
		{
		    label: 'Print',
		    accelerator: 'CmdOrCtrl+P',
		    click () {
			setImmediate(function() {
			    var focusedWindow = win;
			    const options = {};
			    focusedWindow.webContents.print(options, (success, errorType) => {
				if (!success) console.log(errorType)
			    });
			});
		    }
		},
		{
		    role: 'quit'
		}
	    ]
	},
	{
	    role: 'editMenu'
	},
	{
	    label: 'Plot',
	    submenu: [
		{
		    label: 'Plot Profiles',
		    //accelerator: 'CmdOrCtrl+P P',
		    click () {
			dialog.showOpenDialog(win,
					      { title : "Select rge files", 
						defaultPath : lastDialogFolder(),
						filters :[
						    {name: 'Profile file type', extensions: ['rge']},
						    {name: 'All Files', extensions: ['*']}
						],
						properties: ['openFile', 'multiSelections']}
					     ).then(result => {
						 console.log(result.canceled);
						 console.log(result.filePaths);
						 if (!result.canceled) {
						     rememberLastDialogFolderFromFiles(result.filePaths);
						     setImmediate(function() {
							 var focusedWindow = win;
							 focusedWindow.webContents.send('plotProf',result.filePaths);
						     });
						 }
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		},
		{
		    label: 'Plot Fractions',
		    //accelerator: 'CmdOrCtrl+P F',
		    click () {
			dialog.showOpenDialog(win,
					      { title : "Select sequence file", 
						defaultPath : lastDialogFolder(),
						filters :[
						    {name: 'Sequence file type', extensions: ['dat']},
						    {name: 'All Files', extensions: ['*']}
						],
						properties: ['openFile']}
					     ).then(result => {
						 console.log(result.canceled);
						 console.log(result.filePaths);
						 if (!result.canceled) {
						     rememberLastDialogFolderFromFiles(result.filePaths);
						     setImmediate(function() {
							 var focusedWindow = win;
							 focusedWindow.webContents.send('plotFrac',result.filePaths);
						     });
						 }
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		}, 
		{
		    label: 'Plot Mean',
		    //accelerator: 'CmdOrCtrl+P M',
		    click () {
			dialog.showOpenDialog(win,
					      { title : "Select sequence file", 
						defaultPath : lastDialogFolder(),
						filters :[
						    {name: 'Sequence file type', extensions: ['dat']},
						    {name: 'All Files', extensions: ['*']}
						],
						properties: ['openFile']}
					     ).then(result => {
						 console.log(result.canceled);
						 console.log(result.filePaths);
						 if (!result.canceled) {
						     rememberLastDialogFolderFromFiles(result.filePaths);
						     setImmediate(function() {
							 var focusedWindow = win;
							 focusedWindow.webContents.send('plotMean',result.filePaths);
						     });
						 }
					     }).catch(err => {
						 console.log(err);
					     })
		    }
		}
	    ]
	},
	{
	    role: 'viewMenu'
	},
	{
	    role: 'help',
	    submenu: [
		{
		    label: 'Quick Start',
		    accelerator: 'F1',
		    click () { showQuickStartWindow(); }
		},
		{
		    label: 'About TRIMSP-NL Workbench',
		    click () { showAboutDialog(win); }
		}
	    ]
	}
    ]
    let menu = Menu.buildFromTemplate(template)
    Menu.setApplicationMenu(menu)
    
    win.loadFile('TrimSP.html');
    // Comment the following line to start without Dev 
    // win.openDevTools();
}

app.whenReady().then(createWindow)
global.path = app.getAppPath();
//console.log("From main: ",global.path);

app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', () => {
  if (BrowserWindow.getAllWindows().length === 0) {
    createWindow()
  }
})

// Reply to calls from browser button
ipcMain.on('browseFolder', (event, args) => {
    console.log('received a message: '+args);
    const senderWindow = BrowserWindow.fromWebContents(event.sender);
    dialog.showOpenDialog(senderWindow, { title: "Select folder",
					  defaultPath : lastDialogFolder(),
					  properties:["openDirectory"]}
			       ).then(result => {
				     console.log(result)
				     if (result.canceled || result.filePaths.length === 0) {
					 event.reply('browseFolderFallback');
					 return;
				     }
				     rememberLastDialogFolder(result.filePaths[0]);
				     event.reply('browseFolder', result.filePaths);
				     app.setPath('temp',result.filePaths[0]);
				 }).catch(err => {
				     console.log(err);
				 })
});

ipcMain.on('updateWorkPath', (event, folder) => {
    if (folder) {
	currentWorkPath = folder;
    }
});

ipcMain.handle('getStartupOptions', async () => {
    return startupOptions;
});

ipcMain.on('openQuickStartWindow', (event, options) => {
    const sectionId = options && options.sectionId ? options.sectionId : 'helpLayers';
    showQuickStartWindow(sectionId);
});

ipcMain.handle('copyConfigurationLink', async (event, url) => {
    if (typeof url !== 'string' || url.length > 500000
	|| !url.startsWith('http://musruser.psi.ch/TRIMSP-NL/')) {
	throw new Error('Invalid configuration link');
    }
    clipboard.writeText(url);
    return true;
});

//ipcMain.on('browseFolder-send', (event, args) => {
//    dialog.showOpenDialog(null, args).then(filePaths => {
//	event.sender.dend('browseFolder', filePaths);
//    }).catch(err => {
//	console.log(err);
//    })
//});


//menuItem = menu.getMenuItemById('openItem');
//console.log(menuItem);