import type { MudletColor } from '../mapIO';
import type { LabelSnapshot } from './types';
/**
 * Drawing context handed to a {@link LabelStyle} hook. It exposes the live
 * 2D canvas context (already DPR-scaled, so draw in logical px), the label
 * rect, the label snapshot, the (possibly transformed) text, and helpers for
 * reusing the built-in rendering.
 */
export interface LabelDrawContext {
    /** DPR-scaled 2D context. Draw in logical pixels (0..width, 0..height). */
    ctx: CanvasRenderingContext2D;
    /** Logical width in px (label.size[0] × PX_PER_UNIT). */
    width: number;
    /** Logical height in px. */
    height: number;
    /** The label being rendered. */
    label: LabelSnapshot;
    /** Text after `transformText` has run (defaults to `label.text`). */
    text: string;
    /** Run the built-in centered multi-line text layout (font, outline, underline/strikeout). */
    defaultDrawText(): void;
    /** Convert a Mudlet color to a CSS `rgba()` string. */
    colorToCss(c: MudletColor): string;
}
/**
 * A registered label appearance. Plugins contribute these via the
 * `labelStyles()` plugin hook; the label stores the chosen style by `id`.
 *
 * Every hook is optional — omitted stages fall back to the default rendering,
 * so a style only overrides what it cares about. The draw order is:
 *   transformText → drawBackground → drawText → decorate
 */
export interface LabelStyle {
    /** Stable id persisted on the label and in area userData. */
    id: string;
    /** Human-readable name shown in the label panel's style dropdown. */
    name: string;
    /** Transform the raw text before layout (e.g. UPPERCASE). */
    transformText?(text: string, label: LabelSnapshot): string;
    /** Replace the default background fill. When omitted, the label bg color fills the rect. */
    drawBackground?(c: LabelDrawContext): void;
    /** Draw the text. Return `true` to fully replace the built-in layout; otherwise the default runs. */
    drawText?(c: LabelDrawContext): boolean | void;
    /** Final pass drawn on top of background + text — borders, glow, shadow, etc. */
    decorate?(c: LabelDrawContext): void;
}
/** The built-in default: plain text, no extra styling. Equivalent to no style. */
export declare const PLAIN_STYLE: LabelStyle;
/**
 * Replace the plugin-contributed styles. Built-ins always come first; plugin
 * styles are appended. A plugin may override a built-in by reusing its id —
 * lookup returns the last match.
 */
export declare function registerLabelStyles(styles: LabelStyle[]): void;
/** All registered styles (built-ins first), for populating UI. */
export declare function getLabelStyles(): LabelStyle[];
/** Resolve a style by id, falling back to {@link PLAIN_STYLE}. Last match wins so plugins can override built-ins. */
export declare function getLabelStyle(id: string | undefined): LabelStyle;