interface ErrorCodes {
  CONFLICTING_SECRET_PATH_FIELD: {
    fieldName: string;
  };

  INVALID_REQUIRED_FIELDS: {
    messages: string[];
  };

  MISSING_INTERPOLATION_VARIABLE: {
    pathKey: string;
    variableName: string;
  };

  MISSING_SECRET_FILE: {
    pathKey: string;
    filePath: string;
  };
}

const translationsWithVars: {
  [K in keyof ErrorCodes]: (vars: ErrorCodes[K]) => string;
} = {
  CONFLICTING_SECRET_PATH_FIELD: ({ fieldName }) =>
    `Both "${fieldName}" and "${fieldName}_path" are set; please provide only one of these fields.`,
  INVALID_REQUIRED_FIELDS: ({ messages }) =>
    `The configuration is missing required fields or has invalid values:\n- ${messages.join("\n- ")}`,
  MISSING_INTERPOLATION_VARIABLE: ({ pathKey, variableName }) =>
    `Could not resolve environment variable "${variableName}" for configuration key "${pathKey}".`,

  MISSING_SECRET_FILE: ({ pathKey, filePath }) =>
    `The secret file specified in "${pathKey}" could not be accessed at path "${filePath}". Please ensure the file exists and is readable.`,
} as const;

/**
 * Custom error class for configuration-related errors.
 */
export class ConfigError extends Error {
  /**
   * The error code representing the type of configuration error.
   */
  code: keyof ErrorCodes;

  /**
   * Creates a new ConfigError instance.
   *
   * @param code The error code
   * @param vars The variables to interpolate into the error message
   */
  constructor(code: keyof ErrorCodes, vars: unknown) {
    super(
      translationsWithVars[code](
        vars as (typeof translationsWithVars)[typeof code] extends (vars: infer U) => string
          ? U
          : never,
      ),
    );
    this.code = code;
    this.name = "ConfigError";
  }

  /**
   * Factory method to create a ConfigError instance.
   *
   * @param code The error code
   * @param vars The variables to interpolate into the error message
   * @returns A new ConfigError instance
   */
  static from<K extends keyof ErrorCodes>(code: K, vars: ErrorCodes[K]) {
    return new ConfigError(code, vars);
  }
}