/// <summary>
/// Retrieves latest info about a live waypoint, including new coordinates and
/// description.
/// </summary>
/// <param name="liveWaypointId">live waypoint ID</param>
/// <returns>query result for live waypoint</returns>
public async Task <LiveWaypointQueryResult> GetLiveWaypointDataAsync(string liveWaypointId)
{
LiveWaypointQueryResult result = await this.backendWebApi.GetLiveWaypointDataAsync(liveWaypointId);
result.Data.ID = System.Net.WebUtility.UrlDecode(result.Data.ID);
return(result);
}
/// <summary>
/// Called when page requests an update for a live waypoint
/// </summary>
/// <param name="data">update live waypoint data</param>
/// <returns>
/// JSON result of query, either a LiveWaypointQueryResult or an exception text
/// </returns>
public async Task <JsonResult> OnGetUpdateLiveWaypointAsync(UpdateLiveWaypointData data)
{
string liveWaypointId = data.Uri;
try
{
LiveWaypointQueryResult queryResult = await this.backendWebApi.GetLiveWaypointDataAsync(liveWaypointId);
return(new JsonResult(queryResult));
}
catch (Exception ex)
{
return(new JsonResult(ex.Message));
}
}
/// <summary>
/// Retrieves current live waypoint map location
/// </summary>
/// <param name="waypointName">waypoint name to use</param>
/// <param name="appResourceUri">app resource uri to use</param>
/// <returns>map location, or invalid location when it couldn't be retrieved</returns>
private static async Task <Location> GetLiveWaypointLocation(string waypointName, AppResourceUri appResourceUri)
{
var dataService = DependencyService.Get <IDataService>();
LiveWaypointQueryResult result = await dataService.GetLiveWaypointDataAsync(appResourceUri.ToString());
var mapPoint = new MapPoint(result.Data.Latitude, result.Data.Longitude, result.Data.Altitude);
return(new Location
{
Id = result.Data.ID,
Name = waypointName ?? result.Data.Name,
MapLocation = mapPoint,
Description = result.Data.Description.Replace("\n", "<br/>"),
Type = LocationType.LiveWaypoint,
InternetLink = appResourceUri.ToString()
});
}
/// <summary>
/// Updates live waypoint by getting live waypoint data and notify all event subjects.
/// </summary>
/// <param name="liveWaypointId">live waypoint ID to update</param>
/// <returns>task to wait on</returns>
private async Task UpdateLiveWaypointAsync(string liveWaypointId)
{
Debug.WriteLine($"LiveWaypointRefreshService: updating live waypoint for {liveWaypointId}");
LiveWaypointQueryResult data = null;
try
{
data = await this.DataService.GetLiveWaypointDataAsync(liveWaypointId);
}
catch (Exception ex)
{
// ignore exception
Debug.WriteLine($"LiveWaypointRefreshService: exception occured: {ex.ToString()}");
}
if (data == null)
{
// try again in a minute
lock (this.dataLock)
{
this.nextPossibleUpdateMap[liveWaypointId] = DateTimeOffset.Now + TimeSpan.FromMinutes(1.0);
}
return;
}
if (data.Data != null)
{
this.UpdateLiveWaypoint?.Invoke(
this,
new LiveWaypointUpdateEventArgs
{
Data = data.Data,
});
}
var nextUpdate = data.NextRequestDate;
lock (this.dataLock)
{
this.nextPossibleUpdateMap[liveWaypointId] = nextUpdate;
}
}
/// <summary>
/// Returns live waypoint data for given live waypoint ID. May throw an exception when the
/// data is not readily available and must be fetched.
/// </summary>
/// <param name="rawId">live waypoint ID (maybe urlencoded)</param>
/// <returns>live waypoint query result</returns>
public async Task <LiveWaypointQueryResult> GetLiveWaypointData(string rawId)
{
AppResourceUri uri = GetAndCheckLiveWaypointId(rawId);
LiveWaypointQueryResult result = this.CheckCache(uri);
if (result != null)
{
return(result);
}
result = await this.GetLiveWaypointQueryResult(uri);
if (result != null)
{
this.CacheLiveWaypointData(result.Data);
}
return(result);
}
