File : core/lib/NominatimDataLoader.js

/*

Copyright - 2017 2023 - wwwouaiebe - Contact: https://www.ouaie.be/

This  program is free software;

you can redistribute it and/or modify it under the terms of the

GNU General Public License as published by the Free Software Foundation;

either version 3 of the License, or any later version.

This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

*/

/*

Changes:

    - v4.0.0:

        - created from v3.6.0

Doc reviewed 202208

 */

import theConfig from '../../data/Config.js';

import { ZERO, ONE, HTTP_STATUS_OK } from '../../main/Constants.js';

/* ------------------------------------------------------------------------------------------------------------------------- */

/**

This class search an address with Nominatim starting from a lat and lng

*/

/* ------------------------------------------------------------------------------------------------------------------------- */

class NominatimDataLoader {

    /** The status of the requests

    @type {Boolean}

    */

    #nominatimStatusOk = false;

    /**

    The name found by Nominatim

    @type {String}

    */

    #name = '';

    /**

    The street found by Nominatim

    @type {String}

    */

    #street = '';

    /**

    The city found by Nominatim

    @type {String}

    */

    #city = '';

    /**

    The country found by Nominatim

    @type {String}

    */

    #country = '';

    /**

    This method parse the data received from Nominatim

    @param {Object} nominatimDataZoom10 the data received from Nomination using the zoom factor 10

    @param {Object} nominatimDataZoom18 the data received from Nomination using the zoom factor 18

    */

    #parseNominatimData ( nominatimDataZoom10, nominatimDataZoom18 ) {

        if ( nominatimDataZoom10.error || nominatimDataZoom18.error ) {

            this.#nominatimStatusOk = false;

        }

        else {

            this.#name = nominatimDataZoom18.namedetails.name;

            if ( nominatimDataZoom18.address.house_number ) {

                this.#street = nominatimDataZoom18.address.house_number + ' ';

            }

            if ( nominatimDataZoom18.address.road ) {

                this.#street += nominatimDataZoom18.address.road + ' ';

            }

            else if ( nominatimDataZoom18.address.pedestrian ) {

                this.#street += nominatimDataZoom18.address.pedestrian + ' ';

            }

            this.#city =

                nominatimDataZoom10.address.city

                ||

                nominatimDataZoom10.address.town

                ||

                nominatimDataZoom10.address.municipality

                ||

                nominatimDataZoom10.address.village

                ||

                '';

            this.#country = nominatimDataZoom18.address.country;

            this.#nominatimStatusOk = true;

        }

    }

    /**

    The constructor

    */

    constructor ( ) {

        Object.freeze ( this );

    }

    /**

    This method call Nominatim

    @param {Array.<Number>} latLng The latitude and longitude of the point for witch the address is searched

    */

    async loadData ( latLng ) {

        this.#nominatimStatusOk = false;

        // url

        const nominatimUrl =

            theConfig.nominatim.url + 'reverse?format=json&lat=' +

            latLng [ ZERO ] + '&lon=' + latLng [ ONE ];

        // We do a request with zoom factor 10 for city

        let nominatimUrlZoom10 =

            nominatimUrl + '&zoom=10&addressdetails=1&namedetails=0';

        // We do a request with zoom factor 18 for others data

        let nominatimUrlZoom18 =

            nominatimUrl + '&zoom=18&addressdetails=1&namedetails=1';

        // language

        const nominatimLanguage = theConfig.nominatim.language;

        if ( nominatimLanguage && '*' !== nominatimLanguage ) {

            nominatimUrlZoom10 += '&accept-language=' + nominatimLanguage;

            nominatimUrlZoom18 += '&accept-language=' + nominatimLanguage;

        }

        const nominatimHeaders = new Headers ( );

        if ( nominatimLanguage && '*' === nominatimLanguage ) {

            nominatimHeaders.append ( 'accept-language', '' );

        }

        // call to Nominatim

        const nominatimResponseZoom10 = await fetch ( nominatimUrlZoom10, { headers : nominatimHeaders } );

        const nominatimResponseZoom18 = await fetch ( nominatimUrlZoom18, { headers : nominatimHeaders } );

        if (

            HTTP_STATUS_OK === nominatimResponseZoom10.status

            &&

            nominatimResponseZoom10.ok

            &&

            HTTP_STATUS_OK === nominatimResponseZoom18.status

            &&

            nominatimResponseZoom18.ok

        ) {

            this.#parseNominatimData (

                await nominatimResponseZoom10.json ( ),

                await nominatimResponseZoom18.json ( )

            );

        }

        else {

            this.#nominatimStatusOk = false;

        }

    }

    /**

    The name found by Nominatim. Null when an error occurs when calling Nomnatim

    @type {String}

    */

    get name ( ) { return this.#nominatimStatusOk ? this.#name : null; }

    /**

    The street found by Nominatim. Null when an error occurs when calling Nomnatim

    @type {String}

    */

    get street ( ) { return this.#nominatimStatusOk ? this.#street : null; }

    /**

    The city found by Nominatim. Null when an error occurs when calling Nomnatim

    @type {String}

    */

    get city ( ) { return this.#nominatimStatusOk ? this.#city : null; }

    /**

    The country found by Nominatim. Null when an error occurs when calling Nomnatim

    @type {String}

    */

    get country ( ) { return this.#nominatimStatusOk ? this.#country : null; }

}

export default NominatimDataLoader;

/* --- End of file --------------------------------------------------------------------------------------------------------- */