import * as L from 'leaflet';

interface SingleArrowheadOptions {
	/**
	 * The angle of opening of the arrowheads in degrees.  Defaults to 60.
	 */
	yawn?: number;
	/**
	 * The size of the arrowheads, give as a string specifying pixels, %, or meters.
	 * Defaults to '15%'
	 */
	size?: `${number}px` | `${number}%` | `${number}m`;
}

interface ArrowheadOptions extends L.PolylineOptions, SingleArrowheadOptions {
	/**
	 * The number and spacing of arrowheads to draw along the polyline.
	 * Defaults to 'allvertices'
	 */
	frequency?: number | `${number}px` | `${number}m` | 'allvertices' | 'endonly' | 'startonly' | 'startAndEnd';
	/**
	 * If the size of the arrowheads, when given in percent, should be a percentage proportional
	 * to the total length of the polyline, rather than the average of all the segments.
	 * Defaults to false
	 */
	proportionalToTotal?: boolean;
	/**
	 * The offsets from start of end of where to begin/end drawing arrowheads.
	 * Deafult to undefined (no offets)
	 */
	offsets?: {
		start?: `${number}px` | `${number}m`;
		end?: `${number}px` | `${number}m`;
	};
	/**
	 * Callback function to customize arrowheads on a 1-by-1 basis
	 * Defaults to undefined
	 */
	perArrowheadOptions?: (
		i: number
	) => L.PolylineOptions & SingleArrowheadOptions;
}

declare module 'leaflet' {
	export interface Polyline {
		/**
		 * Adds arrowheads to an L.polyline.  See documentation at https://github.com/slutske22/leaflet-arrowheads
		 * @param {object} options The options for the arrowhead.  See documentation for details
		 * @returns The L.polyline instance that they arrowheads are attached to
		 */
		arrowheads: (options: ArrowheadOptions) => L.Polyline;
	}
}