declare module '@ioc:Adonis/Core/Env' {
    /**
     * An interface meant to be extended in the user land that holds
     * types for environment variables extracted using env.validate
     * method.
     */
    export interface EnvTypes {
    }
    /**
     * The shape of the validate fn
     */
    export type ValidateFn<T extends unknown> = (key: string, value?: string) => T;
    /**
     * A standard set of options accepted by the schema validation
     * functions
     */
    export type SchemaFnOptions = {
        message?: string;
    };
    export type StringFnUrlOptions = SchemaFnOptions & {
        format: 'url';
        /**
         * Whether the URL must have a valid TLD in their domain.
         * Defaults to `true`.
         */
        tld?: boolean;
        /**
         * Whether the URL must start with a valid protocol.
         * Defaults to `true`.
         */
        protocol?: boolean;
    };
    /**
     * Options accepted by the string schema function
     */
    export type StringFnOptions = (SchemaFnOptions & {
        format?: 'host' | 'email';
    }) | StringFnUrlOptions;
    /**
     * Shape of the number validator
     */
    export interface NumberType {
        (options?: SchemaFnOptions): ValidateFn<number>;
        optional: (options?: SchemaFnOptions) => ValidateFn<number | undefined>;
    }
    /**
     * Shape of the string validator
     */
    export interface StringType {
        (options?: StringFnOptions): ValidateFn<string>;
        optional: (options?: StringFnOptions) => ValidateFn<string | undefined>;
    }
    /**
     * Shape of the boolean validator
     */
    export interface BooleanType {
        (options?: SchemaFnOptions): ValidateFn<boolean>;
        optional: (options?: SchemaFnOptions) => ValidateFn<boolean | undefined>;
    }
    /**
     * Shape of the enum validator
     */
    export interface EnumType {
        <K extends any>(choices: readonly K[], options?: SchemaFnOptions): ValidateFn<K>;
        optional: <K extends any>(choices: readonly K[], options?: SchemaFnOptions) => ValidateFn<K | undefined>;
    }
    /**
     * Available schema functions. The end user can also define their
     * own
     */
    export interface EnvSchema {
        /**
         * Number function to enforce value to be a strict number
         */
        number: NumberType;
        /**
         * String function to enforce value to be a string. Optionally
         * the format can also be defined
         */
        string: StringType;
        /**
         * Boolean function to enforce value to be a boolean value.
         */
        boolean: BooleanType;
        /**
         * Boolean function to enforce value to be one of the defined values.
         */
        enum: EnumType;
    }
    /**
     * Env contract
     */
    export interface EnvContract {
        /**
         * Get value for a given environment variable
         */
        get<K extends keyof EnvTypes>(key: K): EnvTypes[K];
        get<K extends keyof EnvTypes>(key: K, defaultValue: Exclude<EnvTypes[K], undefined>): Exclude<EnvTypes[K], undefined>;
        get(key: string, defaultValue?: any): any;
        /**
         * Update/set value for a given environment variable. Ideally one should
         * avoid updating values during runtime
         */
        set<K extends keyof EnvTypes>(key: K, value: EnvTypes[K]): void;
        set(key: string, value: any): void;
        /**
         * Validate environment variables
         */
        rules<T extends {
            [key: string]: ValidateFn<unknown>;
        }>(values: T): {
            [K in keyof T]: ReturnType<T[K]>;
        };
        /**
         * Processes environment variables and performs the registered
         * validations
         */
        process(): void;
        /**
         * Reference to the schema object for defining validation
         * rules
         */
        schema: EnvSchema;
    }
    const Env: EnvContract;
    export default Env;
}