import { isNil, extend } from '../../core/util/common';
import Common, { type CommonProjectionType } from './Projection';
import Coordinate from '../Coordinate';
import { WGS84Sphere, type WGS84SphereType } from '../measurer';
import etmerc from './etmerc';

/* eslint-disable no-loss-of-precision */
// from proj_api.h
// eslint-disable-next-line @typescript-eslint/no-loss-of-precision
const RAD_TO_DEG = 57.295779513082321, DEG_TO_RAD = 0.017453292519943296;
/* eslint-enable no-loss-of-precision */

// from pj_transform.c
const SRS_WGS84_SEMIMAJOR = 6378137;
const SRS_WGS84_ESQUARED = 0.0066943799901413165;


const aliases = ['Traverse_Mercator'];

export interface EPSG9807ProjectionParams {
    falseEasting: number;
    falseNorthing: number;
    scaleFactor: number;
    centralMeridian: number;
    latitudeOfOrigin: number;
    startLongtitude: number;
    startLatitude: number;
}

const EPSG9807Projection = {
    code: 'EPSG:9807',
    aliases,
    centralMeridian: 0,
    create(params: Partial<EPSG9807ProjectionParams>) {
        const P: Record<string, any> = {
            a: SRS_WGS84_SEMIMAJOR,
            es: SRS_WGS84_ESQUARED,
            x0: isNil(params.falseEasting) ? 500000 : params.falseEasting,
            y0: isNil(params.falseNorthing) ? 0 : params.falseNorthing,
            k0: params.scaleFactor || 0.9996,
            lam0: (params.centralMeridian || 0) * DEG_TO_RAD,
            phi0: (params.latitudeOfOrigin || 0) * DEG_TO_RAD,
            originLam0: params.startLongtitude || 0,
            originPhi0: params.startLatitude || 0
        };
        etmerc(P);
        const lp = { lam: 0, phi: 0 };
        const xy: any = {};
        let originX = 0;
        let originY = 0;
        if (P.originLam0 || P.originPhi0) {
            lp.lam = P.originLam0 * DEG_TO_RAD - P.lam0;
            lp.phi = P.originPhi0 * DEG_TO_RAD;
            P.fwd(lp, xy);
            originX = P.a * xy.x + P.x0;
            originY = P.a * xy.y + P.y0;
        }

        const methods = {
            /**
             * "EPSG:9807", Code of the projection
             * @type {String}
             * @constant
             */
            code: 'EPSG:9807',
            aliases,
            centralMeridian: params.centralMeridian,
            project: function (p: Coordinate, out?: Coordinate): Coordinate {
                lp.lam = p.x * DEG_TO_RAD - P.lam0;
                lp.phi = p.y * DEG_TO_RAD;
                P.fwd(lp, xy);
                const x = P.a * xy.x + P.x0 - originX;
                const y = P.a * xy.y + P.y0 - originY;
                const z = p.z;
                if (out) {
                    out.x = x;
                    out.y = y;
                    out.z = z;
                    return out;
                }
                return new Coordinate(x, y, z);
            },
            unproject: function (p: Coordinate, out?: Coordinate): Coordinate {
                xy.x = (p.x - P.x0 + originX) / P.a;
                xy.y = (p.y - P.y0 + originY) / P.a;
                P.inv(xy, lp);
                const x = (lp.lam + P.lam0) * RAD_TO_DEG;
                const y = lp.phi * RAD_TO_DEG;
                const z = p.z;
                if (out) {
                    out.x = x;
                    out.y = y;
                    out.z = z;
                    return out;
                }
                return new Coordinate(x, y, z);
            }
        };

        return extend<CommonProjectionType & typeof methods & WGS84SphereType, CommonProjectionType, typeof methods, WGS84SphereType>({} as any, Common, methods, WGS84Sphere);
    }
};

export type EPSG9807ProjectionType = CommonProjectionType & typeof EPSG9807Projection;

/**
 * 横轴墨卡托投影
 *
 * @english
 * Traverse Mercator Projection
 *
 * @category geo
 * @protected
 * @group projection
 * @name EPSG9807
 * {@inheritDoc projection.Common}
 * {@inheritDoc measurer.WGS84Sphere}
 */
export default extend<EPSG9807ProjectionType, CommonProjectionType, typeof EPSG9807Projection>({} as EPSG9807ProjectionType, Common, EPSG9807Projection);