import { Axis } from 'd3-axis';
import { NumberValue, ScaleLinear, ScaleOrdinal, ScaleTime } from 'd3-scale';
import { CurveFactory } from 'd3-shape';
import { ComputedRef, MaybeRefOrGetter } from '../../node_modules/vue';
/**
 * One rendered line series: its source key, the SVG path `d` attribute and the
 * stroke color resolved from the ordinal color scale.
 */
export interface LineChartSeries {
    key: string;
    path: string | null;
    color: string | null;
}
/**
 * A value formatter compatible with `useChart`'s `d3Formatter`: applies a d3
 * format string or a custom function, returning the value untouched otherwise.
 */
export type LineChartFormatter = (value: number | string, formatter?: ((v: number | string) => string) | string) => string | number;
/**
 * The chart's inner padding box, once the axis margins are subtracted.
 */
export interface LineChartPadded {
    width: number;
    height: number;
}
/**
 * Reactive inputs driving {@link useLineChart}. They mirror the `LineChart`
 * component's loaded data, its measured padding box and the geometry-affecting
 * props, accepted as plain values, refs or getters so the composable adapts to
 * how the caller wires its state.
 */
export interface UseLineChartOptions {
    /**
     * The chart's loaded data (inline array or fetched), as exposed by `useChart`.
     */
    loadedData: MaybeRefOrGetter<Record<string, unknown>[] | null>;
    /**
     * The measured inner padding box (width/height in pixels) the scales map onto.
     */
    padded: MaybeRefOrGetter<LineChartPadded>;
    /**
     * Field names for each series. When non-empty the chart is multi-line.
     */
    keys: MaybeRefOrGetter<string[]>;
    /**
     * Field name holding the y value in single-series mode (when `keys` is empty).
     */
    seriesName: MaybeRefOrGetter<string>;
    /**
     * Field name holding the x time/date value, parsed as a year (`%Y`).
     */
    timeseriesKey: MaybeRefOrGetter<string>;
    /**
     * Explicit stroke colors for each line; falls back to `schemeCategory10`.
     */
    lineColors: MaybeRefOrGetter<string[]>;
    /**
     * Optional d3 curve factory for line interpolation (defaults to linear).
     */
    curve: MaybeRefOrGetter<CurveFactory | undefined>;
    /**
     * The `d3Formatter` helper exposed by `useChart`, used to format y-axis ticks.
     */
    d3Formatter: LineChartFormatter;
    /**
     * Number of x-axis ticks or a d3 tick configuration.
     */
    xAxisTicks: MaybeRefOrGetter<object | number | ((d: any) => any) | null>;
    /**
     * Formatter function or d3 format string for y-axis tick labels.
     */
    yAxisTickFormat: MaybeRefOrGetter<((v: any) => string) | string>;
    /**
     * Number of y-axis ticks or a d3 tick configuration.
     */
    yAxisTicks: MaybeRefOrGetter<number | object>;
    /**
     * Formats an x-axis year, as exposed by `useChart` (`xAxisYearFormat`).
     */
    xAxisYearFormat: (year: number | string) => number | string;
}
/**
 * Reactive API returned by {@link useLineChart}.
 */
export interface UseLineChart {
    isMultiLine: ComputedRef<boolean>;
    activeKeys: ComputedRef<string[]>;
    colorScale: ComputedRef<ScaleOrdinal<string, string>>;
    formattedData: ComputedRef<Record<string, any>[]>;
    scaleX: ComputedRef<ScaleTime<number, number>>;
    scaleY: ComputedRef<ScaleLinear<number, number>>;
    lines: ComputedRef<LineChartSeries[]>;
    line: ComputedRef<string | null>;
    xAxis: ComputedRef<Axis<Date | NumberValue>>;
    yAxis: ComputedRef<Axis<NumberValue>>;
}
/**
 * Owns the pure d3 geometry of the `LineChart` component: it normalizes the data
 * (parsing the time field and casting series values), builds the time and linear
 * scales with their domains applied, derives every line path (single or
 * multi-series) and configures the x/y axes. It holds no DOM state — the measured
 * padding box is passed in, and the axis rendering stays in the component.
 *
 * @param options - Reactive geometry options (see {@link UseLineChartOptions}).
 * @returns The {@link UseLineChart} API of derived geometry and axis builders.
 * @remarks Internal building block of the `LineChart` component; not exported
 * from the package root.
 * @example
 * // Inside the `LineChart` component's `<script setup>` block:
 * import { toRef } from 'vue'
 * import { useLineChart } from '@/composables/useLineChart'
 *
 * const { lines, line, scaleX, xAxis } = useLineChart({
 *   loadedData,
 *   padded,
 *   d3Formatter,
 *   xAxisYearFormat,
 *   keys: toRef(() => props.keys),
 *   seriesName: toRef(() => props.seriesName),
 *   timeseriesKey: toRef(() => props.timeseriesKey)
 *   // ...remaining geometry props
 * })
 */
export declare function useLineChart(options: UseLineChartOptions): UseLineChart;
export default useLineChart;