// Local Imports
import constants = require('./constants');
import * as client_handler from "./client_handler"


// External Imports
import { workspace, ExtensionContext } from 'vscode';
import * as vscode from "vscode";
import { LanguageClient } from 'vscode-languageclient/node';
import { startClientsForFolder } from './client_handler';


// Common and Persistent variables
export const outputChannel = vscode.window.createOutputChannel(
	constants.DISPLAY_NAME, constants.LANGUAGE_ID
);

export const clients: Map<string, LanguageClient> = new Map();


/**
 * This function gets called when the extension is activated, 
 * depending on what is the trigger configuration on `package.json#activationEvents
 */
export function activate(context: ExtensionContext) {
	// Use the console to output diagnostic information (console.log) and errors (console.error)
	// This line of code will only be executed once when your extension is activated
	outputChannel.appendLine('[INFO] Extension is now active, good deving and have fun !');
	
	// Commands (these are defined in `package.json#contributes.configurations`)
	context.subscriptions.push(
		vscode.commands.registerCommand(`${constants.SETTINGS_NAMESPACE}.reload_server`, () => {
			// The code placed here will be executed every time this command is ran
			vscode.window.showInformationMessage(`[INFO] Reloading Language Server`);
		})
	);
	
	// Start Language Clients for each folder in the workspace
	for (const folder of workspace.workspaceFolders || []) {
		startClientsForFolder(folder, context);
	}
	
	// Client to Server synchronization
	context.subscriptions.push(
		workspace.onDidChangeWorkspaceFolders(client_handler.updateClients(context))
	);
	
	// Refresh client and server settings when changes happen
	context.subscriptions.push(workspace.onDidChangeConfiguration(
		(event) => refreshSettings(event, context))
	);
}


export async function deactivate(): Promise<void> {
	await Promise.all([...clients.values()].map(client_handler.stopClient));
}


/**
 * Checks what changes were made in workspace and user settings and acts
 * accordingly, like reconnecting/relaunching language servers
 */
async function refreshSettings(event: vscode.ConfigurationChangeEvent, context: ExtensionContext) {
	// Check if changes to language server paths were made
	if (event.affectsConfiguration(`${constants.SETTINGS_NAMESPACE}.serverPath`)) {
		for (const client of clients.values()) {
			const folder = client.clientOptions.workspaceFolder;
			await client_handler.stopClient(client);	
			
			if (folder) {
				await startClientsForFolder(folder, context);
			}
		}
	}
	// 
	else {
		for (const client of clients.values()) {
			client.sendNotification("workspace/didChangeConfiguration", {
				settings: {
					...workspace.getConfiguration(constants.SETTINGS_NAMESPACE),
					checkForUpdates: false,
				},
			});
		}
	}
}