import { JsonSimplifierOptions } from './JsonSimplifier';
import { LogLevel, LogPipe } from './ConsoleOverrides';
/** Options for JsonPipe. */
export interface JsonPipeOptions extends JsonSimplifierOptions {
    /**
     * Top-level property name that includes a concatenated message of all strings and primitive types passed to console.log.
     * Default: 'message'.
     */
    messagePropertyName: string;
    /**
     * Log level property name.
     * If <null>, no log level info is added to the result JSON.
     * Default: 'level'.
     */
    levelPropertyName: string | null;
    /** Log level value formatter. User only if @levelPropertyName is not <null>. */
    levelPropertyFormatter: (level: LogLevel) => string;
    /**
     * Timestamp property name.
     * If <null>, no timestamp is added to the result JSON.
     * Default: 'timestamp'.
     */
    timestampPropertyName: string | null;
    /** Timestamp formatter. User only if @timestampPropertyName is not <null>. */
    timestampPropertyFormatter: (timeInMillis: number) => string;
    /**
     * Message id property name.
     * If <null>, no message id is added to the result JSON.
     * Default: 'message_id'.
     */
    messageIdPropertyName: string | null;
    /**
     * Message id property value provider.
     * Default: a uuid like value generated by *generateUuidSimple*.
     * When *undefined* is returned falls back to *generateUuidSimple* result.
     */
    messageIdPropertyProvider: (level: LogLevel, ...args: Array<unknown>) => string | undefined;
    /**
     *  Builds object token for the message.
     *  By default, uses '$N' as a pattern where 'N' is positional a number (@messageArgumentIndex + 1)
     *  of the console.log argument not inlined into the message.
     *  @originalArgumentIndex is the original index of the argument in console.log() call.
     *  Example:
     *      console.log('a', {f:0}, 'b', {f:0});
     *      @messageArgumentIndex = 0, 1.
     *      @originalArgumentIndex = 1, 3.
     */
    getObjectMessageToken: (messageArgumentIndex: number, argument: object, originalArgumentIndex: number) => string;
    /**
     * For a single top-level field objects uses field name as an argument name and includes only a field sub-objects into arguments.
     *
     * Example: console("Hello", {headers: {header1:'', header2: ''}});
     *
     * pickFieldNameAsObjectMessageTokenForSingleFieldObjects = true:
     *  {"message":"Hello $headers","$headers":{"header1":"","header2":""}}
     *
     * pickFieldNameAsObjectMessageTokenForSingleFieldObjects = false:
     *  {"message":"Hello $1","$1":{"headers":{"header1":"","header2":""}}}
     *
     * Default: false. Overrides 'getObjectMessageToken'.
     */
    pickFieldNameAsObjectMessageTokenForSingleFieldObjects: boolean;
    /**
     * Used to provide a default value to reveal present but undefined fields.
     * The default value is <undefined> which results the fields with undefined value be excluded from the log.
     */
    undefinedMessageValue: undefined | string;
}
/** Returns default properties used by 'createJsonPipe'. */
export declare function getDefaultJsonPipeOptions(): JsonPipeOptions & {
    levelPropertyName: string;
    timestampPropertyName: string;
    messageIdPropertyName: string;
    messageIdPropertyProvider: () => string;
};
export interface JsonPipe extends LogPipe<unknown[]> {
    /**
     * Returns the last message ID assigned by the pipe.
     * If no messages were emitted yet contains an empty string.
     * If 'messageIdPropertyName' is null on the JsonPipe configuration (no ID is assigned), the value stays empty.
     */
    getLastMessageId: () => string;
    /**
     * Sets next emitted message id.
     * When set the *messageIdPropertyProvider* won't be used to generate the next message id.
     */
    setNextMessageId: (messageId: string) => void;
}
/**
 * Creates a pipe that converts console arguments into a serializable JSON object.
 */
export declare function createJsonPipe(inputOptions?: Partial<JsonPipeOptions>): JsonPipe;
/**
 * Generates a random uuid-like string.
 * The method does not provide the same level of randomness like 'crypto' based UUID generators.
 * but it is good for most logging purposes were message id uniqueness is required only on some time-local period.
 */
export declare function generateUuidSimple(): string;