/* myLoc.js */

var map = null;
var ourCoords =
    {
        latitude : 47.624851,
        longitude : -122.52099
    };

var options =
    {
        enableHighaccuracy : true,
        timeout : 100,
        maximumage : 0
    };

window.onload = getMyLocation;

function getMyLocation()
{
    if (navigator.geolocation)
    {
        navigator.geolocation.getCurrentPosition(
            displayLocation,
            displayError,
            options
        );
    }
    else
    {
        alert("Oops, no geolocation support");
    }
}

function displayLocation(position)
{
    var latitude = position.coords.latitude;
    var longitude = position.coords.longitude;

    var div = document.getElementById("location");
    div.innerHTML = "You are at Latitude: " + latitude + ", Longitude: " + longitude;

    var km = computeDistance(position.coords, ourCoords);
    var distance = document.getElementById("distance");
    distance.innerHTML = "You are " + km + " km from HQ";

    showMap(position.coords);
}


// --------------------- Ready Bake ------------------
//
// Uses the Spherical Law of Cosines to find the distance
// between two lat/long points
//

function computeDistance(startCoords, destCoords)
{
    var startLatRads = degreesToRadians(startCoords.latitude);
    var startLongRads = degreesToRadians(startCoords.longitude);
    var destLatRads = degreesToRadians(destCoords.latitude);
    var destLongRads = degreesToRadians(destCoords.longitude);

    var Radius = 6371; // radius of the Earth in km
    var distance = Math.acos(Math.sin(startLatRads) * Math.sin(destLatRads) +
        Math.cos(startLatRads) * Math.cos(destLatRads) *
            Math.cos(startLongRads - destLongRads)) * Radius;

    return distance;
}

function degreesToRadians(degrees)
{
    radians = (degrees * Math.PI) / 180;
    return radians;
}

// ------------------ End Ready Bake -----------------

function showMap(coords)
{
    var googleLatAndLong = new google.maps.LatLng(coords.latitude, coords.longitude);
    var mapOptions =
        {
            zoom : 10,
            center : googleLatAndLong,
            mapTypeId : google.maps.MapTypeId.ROADMAP
        };
    
    var mapDiv = document.getElementById("map");
    map = new google.maps.Map(mapDiv, mapOptions);

    var title = "Your Location";
    var content = "You are here: " + coords.latitude + ", " + coords.longitude;
    addMarker(map, googleLatAndLong, title, content);
}

function displayError(error)
{
    var errorTypes = 
    {
        0 : "Unknown error",
        1 : "Permission denied",
        2 : "Position is not available",
        3 : "Request timeout"
    };
    
    var errorMessage = errorTypes[error.code];
    if (error.code == 0 || error.code == 2)
    {
        errorMessage = errorMessage + " " + error.message;
    }
    var div = document.getElementById("location");
    div.innerHTML = errorMessage;
}

function addMarker(map, latlong, title, content)
{
    var markerOptions = {
        position : latlong,
        map : map,
        title : title,
        clickable : true
    };
    var marker = new google.maps.Marker(markerOptions);
}