import { PluginAPI } from '../../entities/api/PluginAPI';
import { Plugin } from '../../entities/interfaces/Plugin';
/**
 * A Simple Bento Variable Loader. Automatically looks to the enviorment for values.
 * If you `VariableLoader.addVariable('HELLO_WORLD')` this Plugin will automatically
 * search `process.env.HELLO_WORLD`
 */
export declare class VariableLoader implements Plugin {
    name: string;
    api: PluginAPI;
    /**
     * Variables that this Loader is handling
     */
    protected readonly variables: Set<string>;
    /**
     * Variable defaults if exist
     */
    protected readonly defaults: Map<string, unknown>;
    /**
     * A cache of pending Variable Keys and Values
     * The only purpose is a place to put values if we don't have Bento API access yet
     */
    private readonly pending;
    onLoad(): Promise<void>;
    onUnload(): Promise<void>;
    private handlePending;
    /**
     * Add multiple Variables
     * @param kv String Array or Key/Value Object
     */
    addVariables(kv: Array<string> | {
        [key: string]: unknown;
    }): void;
    /**
     * Add Variable
     * @param key Key
     * @param value Value
     */
    addVariable<T = unknown>(key: string, value?: T): void;
    /**
     * Add multiple default values
     * @param kv Key/Default Object
     */
    addDefaults(kv: {
        [key: string]: unknown;
    }): void;
    /**
     * Add Default Value for Variable
     * @param key Key
     * @param def Default
     */
    addDefault<T = unknown>(key: string, def: T): void;
    /**
     * Remove Variable
     * @param key Key
     */
    removeVariable(key: string): void;
    /**
     * Get variable value, from underlying eniroment
     *
     * Note: This function will look on `process.env` and `window`
     * @param key Key
     */
    protected getVariableValue(key: string): string;
    /**
     * Process Variable Key
     * @param key Variable Key
     */
    protected processVariable<T = unknown>(key: string, override?: T): void;
    /**
     * Load Variable into Bento
     * @param key Key
     * @param value Value
     */
    protected loadVariable<T = unknown>(key: string, value: T): void;
    /**
     * Unload Variable from Bento
     * @param key Key
     */
    protected unloadVariable(key: string): void;
}