azuredatastudio/extensions-modules/src/models/logger.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
import * as os from 'os';
import { ILogger } from './interfaces';
import { Utils } from './utils';
import { IExtensionConstants } from './contracts/contracts';

/*
* Logger class handles logging messages using the Util functions.
*/
export class Logger implements ILogger {
	private _writer: (message: string) => void;
	private _prefix: string;
	private _extensionConstants: IExtensionConstants;

	private _indentLevel: number = 0;
	private _indentSize: number = 4;
	private _atLineStart: boolean = false;

	constructor(writer: (message: string) => void, extensionConstants: IExtensionConstants, prefix?: string) {
		this._writer = writer;
		this._prefix = prefix;
		this._extensionConstants = extensionConstants;
	}

	public logDebug(message: string): void {
		Utils.logDebug(message, this._extensionConstants.extensionConfigSectionName);
	}

	private _appendCore(message: string): void {
		if (this._atLineStart) {
			if (this._indentLevel > 0) {
				const indent = ' '.repeat(this._indentLevel * this._indentSize);
				this._writer(indent);
			}

			if (this._prefix) {
				this._writer(`[${this._prefix}] `);
			}

			this._atLineStart = false;
		}

		this._writer(message);
	}

	public increaseIndent(): void {
		this._indentLevel += 1;
	}

	public decreaseIndent(): void {
		if (this._indentLevel > 0) {
			this._indentLevel -= 1;
		}
	}

	public append(message?: string): void {
		message = message || '';
		this._appendCore(message);
	}

	public appendLine(message?: string): void {
		message = message || '';
		this._appendCore(message + os.EOL);
		this._atLineStart = true;
	}
}