import { DistinctLogger, LogLevel } from '../logging';
import LogManager from './logManager';
import { LogEntry } from './logEntry';
/**
 * Log filter function that can be used to filter log entries
 * when returning false the log entry will be ignored otherwise it will be written
 */
export type LogFilter = (ops: {
    logger: Logger;
    severity: LogLevel;
    args: any[];
}) => boolean;
export interface LogWriter {
    /**
     * Write a entry to the log
     * @param entry Entry to write
     */
    write(entry: LogEntry): void | Promise<void>;
    /**
     * Optionally focus the output/log channel to the forground (only for supported channels)
     */
    focus?(): void | Promise<void>;
}
export declare class Logger {
    private readonly manager;
    readonly name: string;
    private readonly writer?;
    /**
     * Null logger, logs straight to /dev/null
     */
    static readonly null: Logger;
    constructor(manager: LogManager | undefined, name: string, writer?: LogWriter | undefined);
    focus(): void;
    /**
     * {@link Logger.write}
     */
    log(...args: any[]): void;
    /**
     * {@link Logger.write}
     */
    info(...args: any[]): void;
    /**
     * {@link Logger.write}
     */
    verbose(...args: any[]): void;
    /**
     * {@link Logger.write}
     */
    warn(...args: any[]): void;
    /**
     * {@link Logger.write}
     */
    error(...args: any[]): void;
    /**
     * {@link Logger.write}
     */
    debug(...args: any[]): void;
    /**
     * Write a log entry to the log, this will be filtered by the log level and optional filters that are set.
     *
     * Messages are formatted using the following rules:
     * - If a single argument is passed it will be used as the message
     * - If a single argument is passed and it is an error it will be used as the message and the stack trace will be appended
     * - If a single argument is passed and it is an object it will be serialized to JSON
     * - If a single argument is passed and it is a function it will be executed and the result will be used as the message
     * - If multiple arguments are passed the first argument will be used as a format string and the remaining arguments will be used as format arguments
     * - If a format string is used it can contain the following format specifiers:
     *   - `%s` String
     *   - `%i` Integer (no decimals)
     *   - `%d` Decimal with 2 decimals
     *   - `%d:<X>` Decimal with X decimals
     *   - `%S` String in uppercase
     *   - `%<any other character>` The character will be ignored
     *
     * @example
     * ```typescript
     * logger.write(LogLevel.info, 'Hello', 'world'); // Hello world this is great
     * logger.write(LogLevel.info, 'Hello %s', 'world'); // Hello world
     * logger.write(LogLevel.info, 'Hello %S', 'world'); // Hello WORLD
     * logger.write(LogLevel.info, 'Hello %d', 1.234); // Hello 1.23
     * logger.write(LogLevel.info, 'Hello %d:3', 1.234); // Hello 1.234
     * logger.write(LogLevel.info, 'Hello %i', 1.234); // Hello 1
     * logger.write(LogLevel.info, 'Hello %i', 1234); // Hello 1234
     * logger.write(LogLevel.info, 'Hello %s', { foo: 'bar' }); // Hello {"foo":"bar"}
     * logger.write(LogLevel.info, 'Hello %s', () => 'world'); // Hello world
     * logger.write(LogLevel.info, 'Hello %s', 'world', 'this', 'is', 'great'); // Hello world this is great
     * logger.write(LogLevel.info, 'Hello', 'world %s %s %s', 'this', 'is', 'great'); // Hello world this is great
     * ```
     * @param level Log level of the entry to write
     * @param args Arguments to write to the log entr. If a single argument is
     * passed it will be used as the message, otherwise the first argument will be used
     * as a format string and the remaining arguments will be used as format arguments
     */
    write(level: LogLevel, ...args: any[]): void;
    writeEntry(entry: LogEntry): void;
    /**
     * Returns a new logger that wraps the current logger and filters out duplicate log messages.
     * @returns A new `DistinctLogger` instance.
     */
    distinct(): DistinctLogger;
}
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