/** A severity threshold, ordered from most to least verbose. */
export type LogLevel = "trace" | "debug" | "info" | "warn" | "error" | "silent";
export type LoggerEnvironment = "development" | "staging" | "production";
export type LogData = unknown | (() => unknown);

/** A structured event after its level policy has allowed it to be emitted. */
export interface LogEvent {
    level: Exclude<LogLevel, "silent">;
    namespace?: string;
    arguments: readonly unknown[];
    timestamp: Date;
}

/** A destination for enabled log events. */
export interface LogSink {
    emit(event: LogEvent): void;
}

export interface LoggerOptions {
    environment: LoggerEnvironment;
    namespace?: string | readonly string[];
    /** Runtime used for the default destination policy. It is inferred when omitted. */
    runtime?: "browser" | "node";
    /** Hard override. It takes precedence over runtime environment defaults. */
    level?: LogLevel;
    /** Browser-only session override source; defaults to global sessionStorage when available. */
    sessionStorage?: Pick<Storage, "getItem">;
    /** Node/container environment source; defaults to process.env when available. */
    env?: Record<string, string | undefined>;
    /** Production error destination. Browser errors go only here; Node errors also go to stderr. */
    sentry?: LogSink | false;
    /** Complete destination override. When provided, `sentry` and default console behavior are not used. */
    sinks?: readonly LogSink[];
}

export interface Logger {
    readonly namespace?: string;
    child(namespace: string): Logger;
    trace(...arguments_: readonly unknown[]): void;
    debug(...arguments_: readonly unknown[]): void;
    log(...arguments_: readonly unknown[]): void;
    info(...arguments_: readonly unknown[]): void;
    warn(...arguments_: readonly unknown[]): void;
    error(...arguments_: readonly unknown[]): void;
    assert(condition: unknown, ...arguments_: readonly unknown[]): void;
    group(...arguments_: readonly unknown[]): void;
    groupCollapsed(...arguments_: readonly unknown[]): void;
    groupEnd(): void;
    dir(item?: unknown, options?: unknown): void;
    dirxml(...arguments_: readonly unknown[]): void;
    table(tabularData?: unknown, properties?: readonly string[]): void;
    clear(): void;
    count(label?: string): void;
    countReset(label?: string): void;
    time(label?: string): void;
    timeLog(label?: string, ...arguments_: readonly unknown[]): void;
    timeEnd(label?: string): void;
    timeStamp(label?: string): void;
    profile(label?: string): void;
    profileEnd(label?: string): void;
}