import { nothing, TemplateResult } from 'lit';
import { BahtElement } from '../base.js';
/**
 * Shared chart vocabulary for the baht-*-chart primitives: series colors,
 * value formatters, scales, the floating tooltip and the table twin every
 * chart ships behind "View as table".
 *
 * Series colors come from the `--baht-chart-1 … --baht-chart-10` tokens so a
 * consumer can retheme every chart from CSS; `color` on a chart overrides the
 * first (or only) series.
 */
export interface ChartGroup {
    label: string;
    count: number;
}
/** One plotted series: a name, one value per category, optional fixed color. */
export interface ChartSeries {
    name: string;
    values: number[];
    color?: string;
}
/** A reference line (budget, target, daily average) drawn over the marks. */
export interface ChartMarker {
    /** Category the marker belongs to; omit for a chart-wide line. */
    category?: string;
    value: number;
    label?: string;
}
/** One dated observation for `<baht-heatmap>`. */
export interface ChartDatePoint {
    /** ISO `YYYY-MM-DD`. */
    date: string;
    value: number;
}
/** How a raw number is rendered as text. `percent` takes a fraction (0.18 → 18%). */
export type ChartFormat = 'number' | 'currency' | 'percent' | 'compact';
/** CSS color for series `i` — `override` wins for the first series only. */
export declare function chartColor(i: number, override?: string): string;
/** Sequential ramp step `i` (0-based, light → dark in light mode). */
export declare function chartSeqColor(i: number, steps?: number): string;
/**
 * Render a number as display text.
 *
 * - `number` — grouped integer (`4,200`)
 * - `currency` — narrow symbol, no decimals; THB renders `฿4,200`
 * - `percent` — the value is a fraction (`0.185` → `18.5%`)
 * - `compact` — `12.9K`, `4.2M`
 */
export declare function formatValue(value: number, format?: ChartFormat, currency?: string): string;
/**
 * Axis ticks rounded to clean numbers: `0 … max` in 1 / 2 / 2.5 / 5 × 10ⁿ steps,
 * always including 0 and a top step at or above `max` (marks-and-anatomy.md).
 */
export declare function niceTicks(max: number, count?: number): number[];
/** `v → px` over a linear domain. Degenerate domains map to the range start. */
export declare function linearScale(domain: readonly [number, number], range: readonly [number, number]): (value: number) => number;
/**
 * Fold the tail of a group list into a single grey "Other" bucket — never cycle
 * or generate a ninth hue (anti-patterns.md).
 */
export declare function foldOther(groups: ChartGroup[], max: number, label?: string): ChartGroup[];
/**
 * The table twin every chart ships: the same numbers as real text, behind a
 * `<details>` so it never competes with the marks. Cells are bound as text, so
 * untrusted series/category names can never inject markup.
 */
export declare function renderTableTwin(caption: string, columns: string[], rows: (string | number)[][], summary?: string): TemplateResult;
/**
 * Base for every chart element: the empty/loading contract, the value
 * formatter, the table twin toggle and one floating tooltip per chart.
 *
 * `loading` holds the previous render at reduced opacity instead of flashing a
 * skeleton (interaction.md): the data snapshot the chart draws is frozen while
 * the attribute is set, and picks up the new props when it clears.
 */
export declare abstract class BahtChartBase extends BahtElement {
    /** Shown instead of the marks when there is nothing to plot. */
    emptyMessage: string;
    /** Hold the previous render at reduced opacity while new data loads. */
    loading: boolean;
    /** Render the "View as table" twin under the chart. */
    showTable: boolean;
    /** How values are rendered in labels, ticks, tooltips and the table twin. */
    format: ChartFormat;
    /** ISO currency code for `format="currency"` (THB renders `฿`). */
    currency: string;
    private tipEl?;
    private held;
    /** Value → display text using this chart's `format` / `currency`. */
    protected fmt(value: number): string;
    /**
     * The snapshot to draw. While `loading` is set the previous one is returned,
     * so a refetch dims the chart instead of emptying it.
     */
    protected hold<T>(next: T): T;
    /** Root class list: `baht-chart` plus the loading modifier. */
    protected rootClass(extra: string): string;
    /** The single floating tooltip node; rendered by the template, never appended. */
    protected renderTooltip(): TemplateResult;
    /**
     * Show `text` near the pointer (or, on keyboard focus, near the mark).
     * Content is assigned with `textContent`: category and series names are
     * untrusted data (interaction.md).
     */
    protected showTip(event: Event, text: string): void;
    /** Hide the tooltip (pointerleave / blur). */
    protected hideTip(): void;
    /** The empty placeholder, or `nothing` when there is data. */
    protected renderEmpty(): TemplateResult;
    /** Legend rows — only ever rendered for 2+ series (marks-and-anatomy.md). */
    protected renderLegend(entries: {
        label: string;
        color: string;
        value?: string;
        share?: string;
    }[], kind?: 'rect' | 'line'): TemplateResult | typeof nothing;
}