/**
 * Module definition of {@link Context} property decorators.
 *
 * The {@link Context} decorators provides functions to read/write the context
 * shared among the binary objects during the reading phase.
 *
 * @module Context
 */
import { DecoratorType } from '../types.ts';
import { PropertyMetaDescriptor } from './common.ts';
export declare const CtxSymbol: unique symbol;
export type GlobalCtx = object;
export type CtxKeyFunction<This> = (targetInstance: This) => string;
/**
 * @category Options
 */
export declare enum CtxType {
    CtxGetter = 0,
    CtxSetter = 1
}
/**
 * @category Options
 */
export interface CtxOptions {
    /**
     * Ensures that a relation exists before defining the Transformer decorator.
     */
    base_type: 'array' | undefined;
}
/**
 * @category Options
 */
export declare const CtxOptionsDefault: {
    base_type: undefined;
};
/**
 * Ctx metadata type definition.
 *
 * @extends {PropertyMetaDescriptor}
 */
export interface Ctx<This, Value> extends PropertyMetaDescriptor<This> {
    options: CtxOptions;
    /**
     * Function that retrieve the key to access the context
     */
    keyGetter: CtxKeyFunction<This>;
    /**
     * Context type: retrieve a value or set a value
     */
    func_type: CtxType;
    /**
     * Context
     */
    default_value: Value | undefined;
}
/**
 * `@CtxGet` decorator retrieve a value based on the key passed as argument
 * from a 'context' shared during the reading phase.
 *
 * @example
 *
 * In the following example, a streaming protocol that receives records
 * of arbitrary length is defined.
 * Records have two different type a 'definition' or a 'data' both use an
 * 'id' to identify themself. The definition defines the size of the data
 * message they define by using `CtxSet` to store that size into the
 * context. The data message uses `CtxGet` to fetch its size defined
 * previously by the definition.
 *
 * ```typescript
 * class RecordDefinition {
 *     @Relation(PrimitiveSymbol.u8)
 *     id: number
 *
 *     @CtxSet(_ => `Definition.${_.id}`)
 *     @Relation(PrimitiveSymbol.u8)
 *     size: number
 * }
 *
 * class RecordMessage {
 *     @Relation(PrimitiveSymbol.u8)
 *     id: number
 *
 *     @CtxGet(_ => `Definition.${_.id}`)
 *     _size: number
 *
 *     @Count('_size')
 *     @Relation(PrimitiveSymbol.u8)
 *     data
 * }
 *
 * class Record {
 *     @Relation(PrimitiveSymbol.u8)
 *     type: number
 *
 *     @Choice('type', {
 *         0x00: RecordDefinition,
 *         0x01: RecordMessage,
 *     })
 *     message: RecordDefinition | RecordMessage
 * }
 *
 * class Protocol {
 *     @Until(EOF)
 *     records: Record[]
 * }
 * ```
 *
 * @param {CtxKeyFunction<This>} keyGetter Either a string formatted as
 * recursive key or a function that returns that string based on the
 * instance value.
 * @param {Value} [defaultValue] Default value to retrieve if no value was
 * found for the key passed as argument. If no default value is passed an
 * error will be thrown.
 * @param {Partial<CtxOptions>} [opt] Optional configuration.
 * @returns {DecoratorType<This, Value>} The property decorator function.
 *
 * @category Decorators
 */
export declare function CtxGet<This extends object, Value>(keyGetter: CtxKeyFunction<This> | string, defaultValue?: Value, opt?: Partial<CtxOptions>): DecoratorType<This, Value>;
/**
 * `@CtxSet` decorator set the value of the decorated property into a
 * shared 'context' during the reading phase.
 *
 * @example
 *
 * In the following example, a streaming protocol that receives records
 * of arbitrary length is defined.
 * Records have two different type a 'definition' or a 'data' both use an
 * 'id' to identify themself. The definition defines the size of the data
 * message they define by using `CtxSet` to store that size into the
 * context. The data message uses `CtxGet` to fetch its size defined
 * previously by the definition.
 *
 * ```typescript
 * class RecordDefinition {
 *     @Relation(PrimitiveSymbol.u8)
 *     id: number
 *
 *     @CtxSet(_ => `Definition.${_.id}`)
 *     @Relation(PrimitiveSymbol.u8)
 *     size: number
 * }
 *
 * class RecordMessage {
 *     @Relation(PrimitiveSymbol.u8)
 *     id: number
 *
 *     @CtxGet(_ => `Definition.${_.id}`)
 *     _size: number
 *
 *     @Count('_size')
 *     @Relation(PrimitiveSymbol.u8)
 *     data
 * }
 *
 * class Record {
 *     @Relation(PrimitiveSymbol.u8)
 *     type: number
 *
 *     @Choice('type', {
 *         0x00: RecordDefinition,
 *         0x01: RecordMessage,
 *     })
 *     message: RecordDefinition | RecordMessage
 * }
 *
 * class Protocol {
 *     @Until(EOF)
 *     records: Record[]
 * }
 * ```
 *
 * @param {CtxKeyFunction<This>} keyGetter Either a string formatted as
 * recursive key or a function that returns that string based on the
 * instance value.
 * @param {Partial<CtxOptions>} [opt] Optional configuration.
 * @returns {DecoratorType<This, Value>} The property decorator function.
 *
 * @category Decorators
 */
export declare function CtxSet<This extends object, Value>(keyGetter: CtxKeyFunction<This> | string, opt?: Partial<CtxOptions>): DecoratorType<This, Value>;
/**
 * `@CtxAppend` decorator append the value of the decorated property into a
 * shared 'context' during the reading phase.
 *
 * It works the same way as `@CtxSet` but will append the data to an array
 * instead of an object property.
 *
 * @example
 *
*
 * ```typescript
 * class Record {
 *   @CtxAppend('Content')
 *   @Relation(PrimitiveSymbol.u8)
 *   data: number
 * }
 *
 * class Protocol {
 *     @Until(EOF)
 *     records: Record[]
 * }
 * ```
 *
 * @param {CtxKeyFunction<This>} keyGetter Either a string formatted as
 * recursive key or a function that returns that string based on the
 * instance value.
 * @param {Partial<CtxOptions>} [opt] Optional configuration.
 * @returns {DecoratorType<This, Value>} The property decorator function.
 *
 * @category Decorators
 */
export declare function CtxAppend<This extends object, Value>(keyGetter: CtxKeyFunction<This> | string, opt?: Partial<CtxOptions>): DecoratorType<This, Value>;
/**
 * useContextGet execute an array of `Ctx` decorator metadata.
 *
 * @typeParam This The type of the class the decorator is applied to.
 *
 * @param {Array<Ctx<This>>} metaCtx An array of context function to apply.
 * @param {This} targetInstance The target class instance containing the property.
 * @param {GlobalCtx} ctx The shared context reference.
 * @returns {any} The context retrieved.
 *
 * @category Advanced Use
 */
export declare function useContextGet<This, Value>(metaCtx: Array<Ctx<This, Value>>, targetInstance: This, ctx: GlobalCtx): any;
/**
 * useContextSet execute an array of `Ctx` decorator metadata.
 *
 * @typeParam This The type of the class the decorator is applied to.
 *
 * @param {Array<Ctx<This>>} metaCtx An array of context function to apply.
 * @param {This} targetInstance The target class instance containing the property.
 * @param {GlobalCtx} ctx The shared context reference.
 * @returns {any} The context retrieved.
 *
 * @category Advanced Use
 */
export declare function useContextSet<This, Value>(metaCtx: Array<Ctx<This, Value>>, propertyValue: any, targetInstance: This, ctx: GlobalCtx): void;