"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var bearing_1 = __importDefault(require("@turf/bearing"));
var distance_1 = __importDefault(require("@turf/distance"));
var destination_1 = __importDefault(require("@turf/destination"));
var line_intersect_1 = __importDefault(require("@turf/line-intersect"));
var meta_1 = require("@turf/meta");
var helpers_1 = require("@turf/helpers");
var invariant_1 = require("@turf/invariant");
/**
 * Takes a {@link Point} and a {@link LineString} and calculates the closest Point on the (Multi)LineString.
 *
 * @name nearestPointOnLine
 * @param {Geometry|Feature<LineString|MultiLineString>} lines lines to snap to
 * @param {Geometry|Feature<Point>|number[]} pt point to snap from
 * @param {Object} [options={}] Optional parameters
 * @param {string} [options.units='kilometers'] can be degrees, radians, miles, or kilometers
 * @returns {Feature<Point>} closest point on the `line` to `point`. The properties object will contain three values: `index`: closest point was found on nth line part, `dist`: distance between pt and the closest point, `location`: distance along the line between start and the closest point.
 * @example
 * var line = turf.lineString([
 *     [-77.031669, 38.878605],
 *     [-77.029609, 38.881946],
 *     [-77.020339, 38.884084],
 *     [-77.025661, 38.885821],
 *     [-77.021884, 38.889563],
 *     [-77.019824, 38.892368]
 * ]);
 * var pt = turf.point([-77.037076, 38.884017]);
 *
 * var snapped = turf.nearestPointOnLine(line, pt, {units: 'miles'});
 *
 * //addToMap
 * var addToMap = [line, pt, snapped];
 * snapped.properties['marker-color'] = '#00f';
 */
function nearestPointOnLine(lines, pt, options) {
    if (options === void 0) { options = {}; }
    var closestPt = helpers_1.point([Infinity, Infinity], {
        dist: Infinity,
    });
    var length = 0.0;
    meta_1.flattenEach(lines, function (line) {
        var coords = invariant_1.getCoords(line);
        for (var i = 0; i < coords.length - 1; i++) {
            //start
            var start = helpers_1.point(coords[i]);
            start.properties.dist = distance_1.default(pt, start, options);
            //stop
            var stop_1 = helpers_1.point(coords[i + 1]);
            stop_1.properties.dist = distance_1.default(pt, stop_1, options);
            // sectionLength
            var sectionLength = distance_1.default(start, stop_1, options);
            //perpendicular
            var heightDistance = Math.max(start.properties.dist, stop_1.properties.dist);
            var direction = bearing_1.default(start, stop_1);
            var perpendicularPt1 = destination_1.default(pt, heightDistance, direction + 90, options);
            var perpendicularPt2 = destination_1.default(pt, heightDistance, direction - 90, options);
            var intersect = line_intersect_1.default(helpers_1.lineString([
                perpendicularPt1.geometry.coordinates,
                perpendicularPt2.geometry.coordinates,
            ]), helpers_1.lineString([start.geometry.coordinates, stop_1.geometry.coordinates]));
            var intersectPt = null;
            if (intersect.features.length > 0) {
                intersectPt = intersect.features[0];
                intersectPt.properties.dist = distance_1.default(pt, intersectPt, options);
                intersectPt.properties.location =
                    length + distance_1.default(start, intersectPt, options);
            }
            if (start.properties.dist < closestPt.properties.dist) {
                closestPt = start;
                closestPt.properties.index = i;
                closestPt.properties.location = length;
            }
            if (stop_1.properties.dist < closestPt.properties.dist) {
                closestPt = stop_1;
                closestPt.properties.index = i + 1;
                closestPt.properties.location = length + sectionLength;
            }
            if (intersectPt &&
                intersectPt.properties.dist < closestPt.properties.dist) {
                closestPt = intersectPt;
                closestPt.properties.index = i;
            }
            // update length
            length += sectionLength;
        }
    });
    return closestPt;
}
exports.default = nearestPointOnLine;