import ARCS from '../build/arcs.js';

/**
 * @class GeoLocator
 * @classdesc Uses the location provider of the browser to 
 * determine the geolocation of the device.
 * This component relies on the 
 * {@link http://www.w3.org/TR/geolocation-API/|Geolocation API}.
 */
let GeoLocator = ARCS.Component.create(function() {
    var self = this;
    var geolocator = navigator.geolocation ;
    var watcher;
    var timeout = 1000;
    var enableHighAccuracy = false;

    var handlePosition = function(position) {
        self.emit("sendPosition",position.coords.longitude,position.coords.latitude);
        self.emit("sendCoordinates", position);
    };

    var handleError = function(positionError) {
        switch(positionError.code) {
            case positionError.TIMEOUT:
                console.error("Timeout while geolocalizing", positionError.message);
                break;
                
            case positionError.PERMISSION_DENIED:
                console.error("You must authorize geolocation", positionError.message);
                break;
                
            case positionError.POSITION_UNAVAILABLE:
                console.error("Position is unavailable", positionError.message);
                break;
        }
        self.emit("geolocationDisabled");
    };


    /**
        * Set the timeout (in milliseconds) between the call of 
        * {@link GeoLocator#getPosition|getPosition} or
        * {@link GeoLocator#watchPosition|watchPosition} and 
        * the sending of signal {@link GeoLocator#sendPosition|sendPosition}.
        * @param t {number} timeout duration in milliseconds
        * @function GeoLocator#setTimeout
        * @slot
        */
    this.setTimeout = function(t) {
        timeout = t;
    };

    this.enableHighAccuracy = function() {
        enableHighAccuracy = true;
    };

    this.disableHighAccuracy = function() {
        enableHighAccuracy = false;
    };
        
    /**
        * Retrieves the geolocation of the device. Use this function for a 
        * one shot retrieval. If it succeeds, signals {@link GeoLocator#sendPosition|sendPosition}
        * and {@link GeoLocator#sendCoordinates|sendCoordinates} are triggered.
        * Otherwise, signal {@link GeoLocator#geolocationDisabled|geolocationDisabled} is triggered.
        * @emits sendPosition
        * @emits sendCoordinates
        * @emits geolocationDisabled
        * @function GeoLocator#getPosition
        * @slot
        */
    this.getPosition = function() {
        if (geolocator) {
            geolocator.getCurrentPosition(handlePosition,handleError, 
                { timeout: timeout, enableHighAccuracy : enableHighAccuracy} );                
        } else {
            this.emit("geolocationDisabled");
        }
    };


    /**
        * Retrieves the geolocation of the device. Use this function if you
        * want to continuously obtain the geolocation of the device.
        * If it succeeds, signals {@link GeoLocator#sendPosition|sendPosition}
        * and {@link GeoLocator#sendCoordinates|sendCoordinates} are triggered.
        * Otherwise, signal {@link GeoLocator#geolocationDisabled|geoLocationDisabled} is triggered.
        * You can use {@link clearWatch} to stop watching the position.
        * @emits sendPosition
        * @emits sendCoordinates
        * @emits geolocationDisabled
        * @function GeoLocator#watchPosition
        * @slot
        */
    this.watchPosition= function() {
        if (geolocator) {
            if (watcher) {
                geolocator.clearWatch(watcher);                    
            }
            watcher = geolocator.watchPosition(handlePosition, handleError, 
                    { timeout: timeout, enableHighAccuracy : enableHighAccuracy} );                 
        } else {
            this.emit("geolocationDisabled");
        }
    };


    /**
        * Ends geolocation queries.
        * @see {@link GeoLocator#watchPosition|watchPosition} 
        * @function GeoLocator#clearWatch
        * @slot 
        */        
    this.clearWatch = function() {
        if (geolocator) {
            if (watcher) {
                geolocator.clearWatch(watcher);
            }
        }
    };

    /**
        * Sends the position of the device (longitude and latitude)
        * @param lon {number} longitude of the geolocation 
        * @param lat {number} latitude of the geolocation
        * @function GeoLocator#sendPosition
        * @signal
        */

    /**
        * Sends the coordinates of the device using the coordinates object
        * proposed in the specification of the geolocation API.
        * @param coords {object} coordinates of the device. 
        * @function GeoLocator#sendCoordinates
        * @signal
        */

    /**
        * Notifies that the geolocation service is disabled 
        * @function GeoLocator#geolocationDisabled
        * @signal
        */

    },
    [
        "getPosition","watchPosition","clearWatch","setTimeout",
        "enableHighAccuracy", "disableHighAccuracy"
    ], // liste slots
    ["sendPosition","sendCoordinates","geolocationDisabled"] // liste de signaux    
);

export default { GeoLocator:GeoLocator};

/*
ARCS.__lib__`
{
    "components": {
        "GeoLocator": {
            "description": "Uses the location provider of the browser to determine the geolocation of the device. This component relies on the Geolocation API.",
            "keywords": [
                "geolocation",
                "location"
            ]
        }
    }
}
`;
*/