/// <summary>
/// A function to retrieve flight's quotes from multiple web services concurrently.
/// The search response is then joined from each individual flight services once the all search is completed.
/// </summary>
/// <param name="modelQuoteRequest">A model encapsulating a flight request</param>
/// <returns></returns>
public IEnumerable <IFlightResponse> BrowseQuotes(IFlightRequest modelQuoteRequest)
{
var responses = new List <IFlightResponse>(); //response place holder
var childTasks = new List <Task <List <IFlightResponse> > >(); //list of task running concurrently
try
{
LogRequest(modelQuoteRequest);
//parent task to hold response until all child task running are completed.
var parentTask = StartSearch(modelQuoteRequest, childTasks);
//wait for all child tasks to complete
parentTask.Wait();
//join search response form each collaborator
childTasks.ForEach(_ => responses.AddRange(_.Result));
}
catch (Exception ex)
{
LogErrors(ex, childTasks);
}
Logger.Info($"All search completed: responses found ({responses.Count})");
return(responses);
}
private static Uri ParseApiRequestUri(IFlightRequest modelQuoteRequest)
{
var browseQuotesUrl = $"{ApiServiceUrl}/browsequotes/v1.0/US/USD/en-US";
return(new Uri($"{browseQuotesUrl}/{modelQuoteRequest.Origin}/{modelQuoteRequest.Destination}" +
$"/{modelQuoteRequest.DepartDate}?inboundpartialdate={modelQuoteRequest.ReturnDate}"));
}
private static IFlightResponse ParseResponse(IFlightRequest modelQuoteRequest, SkyscannerBrowseQuoteResponse response,
Quote quote)
{
IFlightItinerary outboundItinerary = GetItinerary(response, quote.OutboundLeg);
IFlightItinerary inboundItinerary = GetItinerary(response, quote.InboundLeg);
var flightItineraries = new List <IFlightItinerary>();
if (inboundItinerary != null)
{
flightItineraries.Add(inboundItinerary);
}
if (outboundItinerary != null)
{
flightItineraries.Add(outboundItinerary);
}
IFlightResponse aFlightResponse = new FlightResponse()
{
QuoteSource = "Skyscanner",
TripTotalPrice = TryGetCost(quote.MinPrice) ?? quote.MinPrice,
BookingLink = GetBookingLink(modelQuoteRequest),
FlightItineraries = flightItineraries
};
return(aFlightResponse);
}
private static HttpRequestMessage GetHttpRequestMessage(IFlightRequest modelQuoteRequest)
{
var httpRequest = new HttpRequestMessage()
{
Method = HttpMethod.Get,
};
httpRequest.Headers.Add(RapidApiHostAppSettingName, SecretRapidApiHost);
httpRequest.Headers.Add(RapidApiKeyAppSettingName, SecretRapidApiKey);
httpRequest.RequestUri = ParseApiRequestUri(modelQuoteRequest);
return(httpRequest);
}
/// <summary>
/// The URI used to perform the query
/// </summary>
/// <param name="modelQuoteRequest">User request</param>
/// <returns>The Uri to perform flight request</returns>
public string GetKayakUriForSearch(IFlightRequest modelQuoteRequest)
{
if (KayakFlightsUrl == null)
{
throw new Exception($"AppSettings '{KayakFlightUrlKey}' found found.");
}
var tripQuoteUrl = $"{KayakFlightsUrl}/{modelQuoteRequest.Origin}-{modelQuoteRequest.Destination}/" +
$"{modelQuoteRequest.DepartDate}";
if (modelQuoteRequest.ReturnDate != null)
{
tripQuoteUrl = $"{tripQuoteUrl}/{modelQuoteRequest.ReturnDate}";
}
return($"{tripQuoteUrl}?sort=bestflight_a");
}
private void Validate(IFlightRequest flightRequest)
{
const int locationCodeLength = 3; //Find out the 3-letter code of a location (airport, city) or identify which airport or city uses a particular code
if (flightRequest.Origin.IsNullOrEmpty() || flightRequest.Origin.Length < locationCodeLength)
{
ModelState.AddModelError("originPlace", "REQUIRED The origin place, minimum a 3-letter code of a location (airport, city)");
}
if (flightRequest.Destination.IsNullOrEmpty() || flightRequest.Destination.Length < locationCodeLength)
{
ModelState.AddModelError("destinationPlace", "REQUIRED The destination place, minimum a 3-letter code of a location (airport, city)");
}
//make sure depart/return dates make sense
ValidateDates(flightRequest.DepartDate, flightRequest.ReturnDate);
}
/// <summary>
/// Perform the actual web api search for flights sync
/// </summary>
/// <param name="modelQuoteRequest">model wrapping the actual user request</param>
/// <returns></returns>
public async Task <SkyscannerBrowseQuoteResponse> BrowseQuotesAsync(IFlightRequest modelQuoteRequest)
{
if (!ValidateApiSetting())
{
throw new Exception("Require skyscanner secret api host, key and url");
}
using (var httpRequest = GetHttpRequestMessage(modelQuoteRequest))
using (var responseMessage = await LocalHttpClient.SendAsync(httpRequest)) {
if (!responseMessage.IsSuccessStatusCode)
{
throw new Exception($"Rapid Skyscanner-Flight search status code `{responseMessage.StatusCode}` Error:{responseMessage.ReasonPhrase}");
}
using (var readStream = new StreamReader(await responseMessage.Content.ReadAsStreamAsync(), Encoding.UTF8))
return(JsonConvert.DeserializeObject <SkyscannerBrowseQuoteResponse>(readStream.ReadToEnd()));
}
}
/// <summary>
/// Browse for real-time flight quotes
/// </summary>
/// <param name="request">the user flight request</param>
/// <returns></returns>
public async Task <List <IFlightResponse> > BrowseQuotesAsync(IFlightRequest request)
{
var realTimeFlights = new List <IFlightResponse>();
try
{
var numOfLodAttempts = 0;
do //run query until result is found but not exceeding the maximum number of tries.
{
await LoadQuotes(request, realTimeFlights);
numOfLodAttempts++;
}while (ContinueSearch(realTimeFlights, numOfLodAttempts));
}
catch (Exception ex)
{
Logger.Error($"{ex.Message}|{ex.InnerException}");
}
return(realTimeFlights);
}
/// <summary>
/// Browse for flights quotes from skyscanner Api
/// </summary>
/// <param name="request">An user flight request</param>
/// <returns></returns>
public async Task <List <IFlightResponse> > BrowseQuotesAsync(IFlightRequest request)
{
var flightResponses = new List <IFlightResponse>();
try
{
//load flights from skyscanner api
SkyscannerBrowseQuoteResponse response = await Loader.BrowseQuotesAsync(request);
//parse flight response to the model shown to the user
flightResponses.AddRange(response.Quotes.Select(quote => ParseResponse(request, response, quote)));
}
catch (Exception ex)
{
//log exception
Logger.Error($"{ex.Message}|{ex.InnerException}");
}
//return flight response for one-was or round trip.
return(flightResponses);
}
/// <summary>
/// Load real-time flights prices
/// </summary>
/// <param name="modelQuoteRequest">model representing the users flight request</param>
/// <param name="flights">list of flight to append results to the end</param>
/// <returns></returns>
private async Task LoadQuotes(IFlightRequest modelQuoteRequest, List <IFlightResponse> flights)
{
var kayakLoader = new KayakLoader(modelQuoteRequest);
IHtmlCollection <IElement> searchResults = await kayakLoader.GetFlightCollection();
if (searchResults == null)
{
return;
}
foreach (IElement searchResult in searchResults)
{
var flight = new FlightResponse
{
QuoteSource = "Kayak",
TripTotalPrice = KayakLoader.GetFlightCost(searchResult),
BookingLink = kayakLoader.RequestUrl,
FlightItineraries = KayakLoader.GetFlightItineraries(searchResult)
};
flights.Add(flight);
}
}
private Task StartSearch(IFlightRequest modelQuoteRequest, ICollection <Task <List <IFlightResponse> > > childTasks)
{
return(Task.Factory.StartNew(() =>
{
var childFactory = new TaskFactory(TaskCreationOptions.AttachedToParent, TaskContinuationOptions.None);
foreach (var service in _flightQuoteServiceCollaborators)
{
var serviceName = service.GetType().Name;
Logger.Info($"{serviceName} initiate service quote search.");
childFactory.StartNew(() =>
{
//search for flights
var aTask = Task.Run(async() => await service.BrowseQuotesAsync(modelQuoteRequest));
//on search complete log search result count
aTask.GetAwaiter().OnCompleted(() =>
Logger.Info($"{serviceName} search completed. responses ({aTask.Result.Count})"));
//track child task
childTasks.Add(aTask);
});
}
}));
}
private static void LogRequest(IFlightRequest modelQuoteRequest)
{
Logger.Info($"Initiating flight search from {modelQuoteRequest.Origin} to " +
$"{modelQuoteRequest.Destination} depart on {modelQuoteRequest.DepartDate} " +
$"return {modelQuoteRequest.ReturnDate}");
}
/// <summary>
/// Initialize url request using user search detail.
/// </summary>
/// <param name="modelQuoteRequest"></param>
public KayakLoader(IFlightRequest modelQuoteRequest)
{
RequestUrl = GetKayakUriForSearch(modelQuoteRequest);
}
private static string GetBookingLink(IFlightRequest modelQuoteRequest)
{
return($"{Loader.GetBaseBookingUrl()}/{modelQuoteRequest.Origin}/{modelQuoteRequest.Destination}" +
$"/{modelQuoteRequest.DepartDate}/{modelQuoteRequest.ReturnDate}");
}
