import { LitElement, PropertyValues } from "lit";
export type SkyAlertClosedEventDetail = {
    title: string;
    message: string;
};
export type SkyAlertStrip = "start" | "end" | "both" | "none";
export type SkyAlertVariant = "flat" | "bordered" | "light" | "faded" | "solid";
export type SkyAlertRoleType = "alert" | "alertdialog";
/**
 * @element sky-alert
 *
 * @summary Status alert banner with variants, optional icon, strip accents, actions, dismiss behavior, and loading state.
 *
 * @status stable
 * @since 1.0.0
 *
 * @documentation https://sky-ui.com/components/alert
 * @dependency sky-icon
 *
 * @slot - Custom message content (used when `message` is empty).
 * @slot actions - Action buttons or links displayed on the trailing side.
 *
 * @property {string} title - Title text shown above the message.
 * @property {string} message - Message text rendered inside the alert.
 * @property {boolean} removable - Shows a dismiss button when enabled.
 * @property {string} color - Base color token or CSS color used by the alert.
 * @property {string} size - Preset size token (`xs | sm | md | lg | xl`) or CSS length.
 * @property {string} radius - Radius token or CSS length.
 * @property {string | null} icon - Optional leading icon name for `<sky-icon>`.
 * @property {SkyAlertStrip} strip - Strip accent placement.
 * @property {string} stripColor - Strip accent color token or CSS color.
 * @property {SkyAlertVariant} variant - Visual style variant.
 * @property {boolean} loading - Shows a loading overlay.
 * @property {SkyAlertRoleType} roleType - ARIA role for the alert container.
 * @property {string} preset - Named prop preset from nearest `sky-config-provider`. Default: `""`.
 * @method close Dispatches `alert-closed` and removes the alert from the DOM.
 *
 * @fires {CustomEvent<SkyAlertClosedEventDetail>} alert-closed - Fired when the alert is dismissed via the close button; bubbles and is composed.
 *
 * @csspart alert - The outer alert container.
 * @csspart icon - The optional leading icon.
 * @csspart content - The content container (title + message/slot).
 * @csspart title - The title text element.
 * @csspart message - The message text element (when `message` is provided).
 * @csspart actions - The trailing actions container.
 * @csspart close-button - The dismiss button (when `removable`).
 * @csspart loading-overlay - Overlay shown when `loading` is true.
 * @csspart loading-spinner - Spinner element shown inside the loading overlay.
 *
 * @Behavior
 * - `message` content takes priority over default-slot message content.
 * - Dismissing a removable alert dispatches `alert-closed` and removes the element.
 * - `strip` controls accent placement (`start`, `end`, `both`, `none`).
 * - `role-type="alert"` maps to `aria-live="assertive"`; `alertdialog` maps to `aria-live="polite"`.
 * - Respects reduced motion preferences for entry, button hover rotation, and spinner animation.
 *
 * @example
 * ```html
 * <sky-alert title="Upload Complete" message="Your file is now available." variant="bordered" strip="start" removable>
 *   <button slot="actions">View</button>
 * </sky-alert>
 * ```
 * ```vue
 * <template>
 *   <sky-alert title="Upload Complete" message="Your file is now available." variant="bordered" strip="start" removable>
 *     <button slot="actions">View</button>
 *   </sky-alert>
 * </template>
 * ```
 * ```jsx
 * export default function Demo() {
 *   return (
 *     <sky-alert title="Upload Complete" message="Your file is now available." variant="bordered" strip="start" removable>
 *       <button slot="actions">View</button>
 *     </sky-alert>
 *   );
 * }
 * ```
 */
export declare class SkyAlert extends LitElement {
    static dependencies: Record<string, CustomElementConstructor>;
    /** Title text displayed above the message. @default "" */
    title: string;
    /** Message text displayed inside the alert. @default "" */
    message: string;
    /** Shows a close button that dismisses the alert. @default false */
    removable: boolean;
    /** Base color token or CSS color. @default "primary" */
    color: string;
    /** Size token (`xs | sm | md | lg | xl`) or CSS length. @default "md" */
    size: string;
    /** Radius token or CSS length. @default "md" */
    radius: string;
    /** Optional leading icon name for `<sky-icon>`. @default null */
    icon: string | null;
    /** Strip accent position. @default "none" */
    strip: SkyAlertStrip;
    /** Strip accent color. @default "currentColor" */
    stripColor: string;
    /** Visual style variant. @default "solid" */
    variant: SkyAlertVariant;
    /** Shows a loading overlay. @default false */
    loading: boolean;
    /** ARIA role applied to the alert container. @default "alert" */
    roleType: SkyAlertRoleType;
    /** Internal style variables */
    private _styleVars;
    /** Cached result of _resolveSize for the last `size` value (avoids recomputing when only color/variant change). */
    private _sizeCache;
    /** True when the actions slot has assigned content (used to show separator only when needed). */
    private _hasActionsSlotContent;
    /** Named prop preset from nearest `sky-config-provider`. */
    preset: string;
    private _presets;
    static styles: import("lit").CSSResult[];
    /**
     * Resolves size to get padding, font sizes, and other metrics.
     * Result is memoized by `size` to avoid recomputing when only color/variant/radius change.
     */
    private _resolveSize;
    /**
     * Lit order: willUpdate → controllers hostUpdate (presets) → update/render.
     * Rebuild CSS vars here so preset-applied color/variant are visible.
     */
    update(changedProperties: PropertyValues): void;
    private _lastPresetRevision;
    /** Initializes actions-slot presence state after first render. */
    firstUpdated(): void;
    /** Computes CSS custom properties from current variant, size, and color inputs. */
    private _updateStyleVars;
    /**
     * Dispatches `alert-closed` and removes the alert from the DOM.
     *
     * @returns {void}
     */
    close(): void;
    /** Returns the ARIA role applied to the alert container. */
    private getAriaRole;
    /** Checks whether the actions slot currently has meaningful assigned content. */
    private _checkActionsSlot;
    /** Updates action-slot state when the slot assignment changes. */
    private _onActionsSlotChange;
    render(): import("lit-html").TemplateResult<1>;
}