var map;
var overlays = [];
var places = [{
        "latitude": 13.7485809,
        "longitude": 100.5832588,
        "name_en": "Bangkok Hospital",
        "name_th": "โรงพยาบาล กรุงเทพ ซอยศูนย์วิจัย"
    }, {
        "latitude": 13.746166,
        "longitude": 100.552348,
        "name_en": "Bumrungrad International Hospital",
        "name_th": "โรงพยาบาล บำรุงราษฎร์"
    }, {
        "latitude": 13.7679658,
        "longitude": 100.5345264,
        "name_en": "Phramongkutklao Hospital",
        "name_th": "โรงพยาบาลพระมงกุฎเกล้า"
    },
    {
        "latitude": 13.7561676,
        "longitude": 100.5391023,
        "name_en": "Phyathai 1 Hospital",
        "name_th": "โรงพยาบาล พญาไท 1"
    }, {
        "latitude": 13.7698357,
        "longitude": 100.5404377,
        "name_en": "Phyathai 2 Hospital",
        "name_th": "โรงพยาบาล พญาไท 2 อินเตอร์เนชันแนล"
    },
    {
        "latitude": 13.769295,
        "longitude": 100.527455,
        "name_en": "Prasat Neurological Hospital and Institute",
        "name_th": "สถาบันประสาทวิทยา"
    }, {
        "latitude": 13.76188,
        "longitude": 100.526455,
        "name_en": "Priest Hospital",
        "name_th": "โรงพยาบาลสงฆ์"
    }, {
        "latitude": 13.7659465,
        "longitude": 100.5353223,
        "name_en": "Queen Sirikit National Institute of Child Health",
        "name_th": "สถาบันสุขภาพเด็กแห่งชาติมหาราชินี"
    }, {
        "latitude": 13.7642952,
        "longitude": 100.5367674,
        "name_en": "Rajavithi Hospital",
        "name_th": "โรงพยาบาล ราชวิถี"
    },
    {
        "latitude": 13.766015,
        "longitude": 100.5267864,
        "name_en": "Ramathibodi Hospital",
        "name_th": "โรงพยาบาลรามาธิบดี"
    },
    {
        "latitude": 13.7657804,
        "longitude": 100.5333703,
        "name_en": "TropMed Hospital for Tropical Diseases - Faculty of Tropical Medicine, Mahidol University",
        "name_th": "โรงพยาบาล เวชศาสตร์เขตร้อน ม.มหิดล"
    }, {
        "latitude": 13.7719828,
        "longitude": 100.5515745,
        "name_en": "Veterans General Hospital",
        "name_th": "โรงพยาบาล ทหารผ่านศึก"
    }, {
        "latitude": 13.7831277,
        "longitude": 100.5336353,
        "name_en": "Vichaiyut Hospital (North Building)",
        "name_th": "โรงพยาบาล วิชัยยุทธ"
    }, {
        "latitude": 13.7804061,
        "longitude": 100.5330211,
        "name_en": "Vichaiyut Medical Center",
        "name_th": "ศูนย์การแพทย์วิชัยยุทธ"
    }, {
        "latitude": 13.7600024,
        "longitude": 100.534462,
        "name_en": "Bhumirajanakarindra Kidney Institute Hospital",
        "name_th": "โรงพยาบาล สถาบันโรคไตภูมิราชนครินทร์"
    }
];

/* function createMaps */
function createMap(mapArea, position) {
    var latlng = new google.maps.LatLng(parseFloat(position.latitude), parseFloat(position.longitude));
    map = new google.maps.Map(document.getElementById(mapArea), {
        "zoom": 18
    });

    map.setCenter(latlng);

    var marker = new google.maps.Marker({
        "map": map,
        "position": latlng,
    });

    var infowindow = new google.maps.InfoWindow({
        "content": 'Latitude = ' + position.latitude + ', ' + ' longitude = ' + position.longitude,
        "position": latlng,
    }).open(map, marker);

}

function deleteOverlays() {
    var overlaysLength = overlays.length;
    if (overlaysLength > 1) {
        for (var a = 0; a <= overlays.length; a++) {
            if (typeof overlays[a] !== 'undefined') {
                overlays[a].setMap(null);
            }
        }
    }
    overlays = [];
}

function getCenter(map, places) {
    $X = 0.0;
    $Y = 0.0;
    $Z = 0.0;
    var placesLength = places.length;
    for (var a = 0; a < placesLength; a++) {
        place = places[a];

        $lat = place.latitude * Math.PI / 180;
        $lon = place.longitude * Math.PI / 180;
        $a = Math.cos($lat) * Math.cos($lon);
        $b = Math.cos($lat) * Math.sin($lon);
        $c = Math.sin($lat);
        $X += $a;
        $Y += $b;
        $Z += $c;
    }
    $X /= placesLength;
    $Y /= placesLength;
    $Z /= placesLength;
    $lon = Math.atan2($Y, $X);
    $hyp = Math.sqrt($X * $X + $Y * $Y);
    $lat = Math.atan2($Z, $hyp);

    var latitude = $lat * 180 / Math.PI;
    var longitude = $lon * 180 / Math.PI;

    var latlng = new google.maps.LatLng(latitude, longitude);
    map.setCenter(latlng);

    var marker = new google.maps.Marker({
        "map": map,
        "position": latlng,
    });

    var infowindow = new google.maps.InfoWindow({
        "content": "setCenter Latitude = " + latitude + ", " + " longitude = " + longitude,
        "position": latlng,
    }).open(map, marker);
}

function handleLocationError(browserHasGeolocation, infoWindow, pos) {
    infoWindow.setPosition(pos);
    infoWindow.setContent(browserHasGeolocation ?
        'Error: The Geolocation service failed.' :
        'Error: Your browser doesn\'t support geolocation.');
    infoWindow.open(map);
}

function initMap(defaultLatitude = 13.7651991, defaultLongitude = 100.5368694) {
    position = {
        "latitude": defaultLatitude,
        "longitude": defaultLongitude,
    };

    createMap('mapA', position);

    setMarkers(map)
}

function setMarkers(map) {
    var placesLength = places.length;
    for (var a = 0; a < placesLength; a++) {
        var place = places[a];
        var marker = new google.maps.Marker({
            "map": map,
            "position": {
                "lat": parseFloat(place.latitude),
                "lng": parseFloat(place.longitude)
            },
            "title": place.name_en + "\n" + place.name_th,
            "zIndex": a
        });

        overlays.push(marker);
    }

    getCenter(map, places);
}

$(function() {
    $('#deleteBtn').click(function() {
        deleteOverlays();
    });
});

initMap();