var geocoder;
var map;
var marker;

// initialise the google maps objects, and add listeners
function gmaps_init(){

    // center of the universe
    var latlng = new google.maps.LatLng(45.03478270000001,10.744630599999937);

    var options = {
        zoom: 7,
        center: latlng,
        scrollwheel: false,
        mapTypeId: google.maps.MapTypeId.ROADMAP
    };

    // create our map object
    map = new google.maps.Map(document.getElementById("gmaps-canvas"), options);

    // the geocoder object allows us to do latlng lookup based on address
    geocoder = new google.maps.Geocoder();

    // the marker shows us the position of the latest address
    marker = new google.maps.Marker({
        map: map,
        position: new google.maps.LatLng(45.03478270000001,10.744630599999937),
        draggable: true
    });

    // event triggered when marker is dragged and dropped
    google.maps.event.addListener(marker, 'dragend', function() {
        geocode_lookup( 'latLng', marker.getPosition());
    });

    // event triggered when map is clicked
    google.maps.event.addListener(map, 'click', function(event) {
        marker.setPosition(event.latLng)
        geocode_lookup( 'latLng', event.latLng);
    });

    $('#gmaps-error').hide();
}

// move the marker to a new position, and center the map on it
function update_map( geometry ) {
    map.fitBounds( geometry.viewport );
    marker.setPosition( geometry.location );
    geocode_lookup( 'latLng', marker.getPosition() );
    $('#coordinate').html(geometry.location.toString());
}

// fill in the UI elements with new position data
function update_ui( address, latLng ) {
    $('#gmaps-input-address').autocomplete("close");
    $('#gmaps-input-address').val(address);
}

// Query the Google geocode object
//
// type: 'address' for search by address
//       'latLng'  for search by latLng (reverse lookup)
//
// value: search query
//
// update: should we update the map (center map and position marker)?
function geocode_lookup( type, value, update ) {
    // default value: update = false
    update = typeof update !== 'undefined' ? update : false;

    request = {};
    request[type] = value;

    geocoder.geocode(request, function(results, status) {
        var message = {
            results: results,
            status: status
        };

        var stringMessage = JSON.stringify(message);
        sendMessage(stringMessage);

        $('#coordinate').html(value.toString());

        if (status == google.maps.GeocoderStatus.OK) {
            // Only update the map (position marker and center map) if requested
            if( update ) { update_map( results[0].geometry ) }
        }
    });
};

// initialise the jqueryUI autocomplete element
function autocomplete_init() {
    $("#gmaps-input-address").autocomplete({

        // source is the list of input options shown in the autocomplete dropdown.
        // see documentation: http://jqueryui.com/demos/autocomplete/
        source: function(request,response) {

            // the geocode method takes an address or LatLng to search for
            // and a callback function which should process the results into
            // a format accepted by jqueryUI autocomplete
            geocoder.geocode( {'address': request.term }, function(results, status) {
                response($.map(results, function(item) {
                    return {
                        label: item.formatted_address, // appears in dropdown box
                        value: item.formatted_address, // inserted into input element when selected
                        geocode: item                  // all geocode data: used in select callback event
                    }
                }));
            })
        },

        // event triggered when drop-down option selected
        select: function(event,ui){
            update_ui(  ui.item.value, ui.item.geocode.geometry.location )
            update_map( ui.item.geocode.geometry )

        }
    });

    // triggered when user presses a key in the address box
    $("#gmaps-input-address").bind('keydown', function(event) {
        if(event.keyCode == 13) {
            geocode_lookup( 'address', $('#gmaps-input-address').val(), true );

            // ensures dropdown disappears when enter is pressed
            $('#gmaps-input-address').autocomplete("disable")
        } else {
            // re-enable if previously disabled above
            $('#gmaps-input-address').autocomplete("enable")
        }
    });
}; // autocomplete_init

// Send a message to the parent
var sendMessage = function (msg) {
    // Make sure you are sending a string, and to stringify JSON
    window.parent.postMessage(msg, '*');
};

$(document).ready(function() {
    if( $('#gmaps-canvas').length  ) {
        gmaps_init();
        autocomplete_init();
    };

    $("#moveMarker").click(function() {
        var lat = parseFloat(document.getElementById("latitudine").value);
        var lng = parseFloat(document.getElementById("longitudine").value);
        var newLatLng = new google.maps.LatLng(lat, lng);
        marker.setPosition(newLatLng);
        map.setCenter(newLatLng);
        geocode_lookup( 'latLng', newLatLng);
    });

});