/**
 * Which form a message uses. Also drives the `data-content` attribute, because
 * plain text is the one form whose whitespace has to survive.
 *
 * @param {Message} message
 * @returns {'text' | 'html' | 'template' | 'element' | 'component'}
 */
export function contentField(message: Message): "text" | "html" | "template" | "element" | "component";
/**
 * The value a message's content is built from. Used to decide whether a
 * message actually changed, so `chat-message-render` does not fire on every
 * unrelated update.
 *
 * @param {Message} message
 * @returns {unknown}
 */
export function contentKey(message: Message): unknown;
/**
 * Build (or reuse) an element for a component reference and write its props.
 *
 * The instance is kept across renders so the component keeps its own state; a
 * changed reference replaces it, and changed props are assigned one by one so
 * the component's own setters see each change.
 *
 * @param {ChitUI} host
 * @param {string} key                                       Cache key.
 * @param {(new () => HTMLElement) | string} source
 * @param {Record<string, unknown>} [props]
 * @returns {HTMLElement}
 */
export function resolveComponent(host: ChitUI, key: string, source: (new () => HTMLElement) | string, props?: Record<string, unknown>): HTMLElement;
/**
 * Drop cached instances for messages that are gone, so a long conversation
 * does not hold on to elements it will never show again. Non-message entries,
 * such as the launcher's, are left alone.
 *
 * @param {ChitUI} host
 * @param {Set<string>} liveIds
 */
export function pruneComponents(host: ChitUI, liveIds: Set<string>): void;
/**
 * The component instance backing a message, when it has one.
 *
 * @param {ChitUI} host
 * @param {string} id
 * @returns {HTMLElement | undefined}
 */
export function componentInstance(host: ChitUI, id: string): HTMLElement | undefined;
/**
 * Turn a message's content into something Lit can render as a child value.
 *
 * All four shapes collapse here: an HTML string becomes an `unsafeHTML`
 * directive, a Lit template passes straight through, and an element or a
 * component becomes a Node, which Lit inserts as-is.
 *
 * @param {ChitUI} host
 * @param {Message} message
 * @returns {unknown}
 */
export function renderContent(host: ChitUI, message: Message): unknown;
/** The cache key for the closed-state component. */
export const LAUNCHER_KEY: "launcher";
export type ComponentEntry = {
    /**
     * What `component` held when this was built.
     */
    source: (new () => HTMLElement) | string;
    element: HTMLElement;
    /**
     * Last props written to the element.
     */
    props: Record<string, unknown>;
};
import type { Message } from '../types.js';
import type { ChitUI } from '../chit-ui.js';