/**
 * The ErrorHandler class implements the Singleton pattern for error handling and logging.
 * Provides methods for creating a single instance and handling errors with context.
 * 
 *  Usage example:
 * ```js
 * try {
 *   // Code that may throw an error
 * } catch (error) {
 *   const errorHandler = ErrorHandler.getInstance();
 *   const message = errorHandler.wrapError(error, "Creating new merchant");
 *   ui.notifications.error(message);
 * }
 * ```
 */
export class ErrorHandler  {
    static #instance = null; // Private static field for storing the single instance

    /**
     * Class constructor. Implements the Singleton pattern.
     * If an instance already exists, returns it.
     * Otherwise creates a new instance.
     */
    constructor() {
        if (ErrorHandler.#instance) {
            return ErrorHandler.#instance;
        }
        ErrorHandler.#instance = this;
    }

    /**
     * Static method to get the class instance.
     * If the instance doesn't exist, creates a new one.
     * @returns {ErrorHandler} The single instance of ErrorHandler class
     */
    static getInstance() {
        if (!ErrorHandler.#instance) {
            ErrorHandler.#instance = new ErrorHandler();
        }
        return ErrorHandler.#instance;
    }

    /**
     * Method for handling errors with added context.
     * Forms a detailed error message with version information and call stack.
     * @param {Error} error - Error object
     * @param {string} context - Context in which the error occurred
     * @returns {string} Formatted error message
     */
    wrapError(error, context) {
        const moduleInfo = game.modules.get('test_tube_merchant');
        const systemInfo = game.system;
        
        const errorMessage = `
        Торговец из пробирки / Test Tube Merchant
        
        Версия Foundry: ${game.version}
        Версия системы: ${systemInfo.version}
        Версия модуля: ${moduleInfo.version}
        
        Контекст ошибки: ${context}
        Ошибка: ${error.message}
        Стек вызовов: ${error.stack}
        
        Пожалуйста, отправьте эту информацию на Discord:
        https://discord.gg/CwxwDHZAGy
        `;

        console.error(errorMessage);
        return errorMessage;
    }
}