/******************************************************************************
 * Copyright 2021 TypeFox GmbH
 * This program and the accompanying materials are made available under the
 * terms of the MIT License, which is available in the project root.
 ******************************************************************************/

import type { LanguageClientOptions, ServerOptions } from 'vscode-languageclient/node';
import type * as vscode from 'vscode';
import * as path from 'node:path';
import { LanguageClient, TransportKind } from 'vscode-languageclient/node';

let client: LanguageClient;

// This function is called when the extension is activated.
export async function activate(context: vscode.ExtensionContext): Promise<void> {
    client = await startLanguageClient(context);
}

// This function is called when the extension is deactivated.
export function deactivate(): Thenable<void> | undefined {
    if (client) {
        return client.stop();
    }
    return undefined;
}

async function startLanguageClient(context: vscode.ExtensionContext): Promise<LanguageClient> {
    const serverModule = context.asAbsolutePath(path.join('out', 'language-server', 'main.cjs'));
    // The debug options for the server
    // --inspect=6009: runs the server in Node's Inspector mode so VS Code can attach to the server for debugging
    const debugOptions = { execArgv: ['--nolazy', '--inspect=6009'] };

    // If the extension is launched in debug mode then the debug server options are used
    // Otherwise the run options are used
    const serverOptions: ServerOptions = {
        run: { module: serverModule, transport: TransportKind.ipc },
        debug: { module: serverModule, transport: TransportKind.ipc, options: debugOptions }
    };

    // Options to control the language client
    const clientOptions: LanguageClientOptions = {
        documentSelector: [{ scheme: 'file', language: 'domain-model' }]
    };

    // Create the language client and start the client.
    const client = new LanguageClient(
        'domain-model',
        'DomainModel',
        serverOptions,
        clientOptions
    );

    // Start the client. This will also launch the server
    await client.start();
    return client;
}