src/main/java/ohm/softa/a11/App.java

@@ -4,6 +4,7 @@ import ohm.softa.a11.openmensa.OpenMensaAPI;
 import ohm.softa.a11.openmensa.OpenMensaAPIService;
 import ohm.softa.a11.openmensa.model.Canteen;
 import ohm.softa.a11.openmensa.model.PageInfo;
+import retrofit2.HttpException;
 
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
@@ -53,27 +54,52 @@ public class App {
 	}
 
 	private static void printCanteens() {
-		System.out.print("Fetching canteens [");
-		/* TODO fetch all canteens and print them to STDOUT
+		/* fetch all canteens and print them to STDOUT
 		 * at first get a page without an index to be able to extract the required pagination information
 		 * afterwards you can iterate the remaining pages
 		 * keep in mind that you should await the process as the user has to select canteen with a specific id */
-		OpenMensaAPI api = OpenMensaAPIService.getInstance().getOpenMensaAPI();
-		var response = api.getCanteens();
+		var response = openMensaAPI.getCanteens();
 
 		try {
 			var pageInfo = PageInfo.extractFromResponse(response.get());
-			var firstCanteenPage = response.get().body();
+			var firstPage = response.get().body();
 			var N = pageInfo.getTotalCountOfPages();
-			var canteens = IntStream.range(2, N).parallel()
+			/*var canteens = IntStream.range(2, N).parallel()
 				.mapToObj((n) -> api.getCanteens(n).join())
 				.flatMap(Collection::stream)
-				.collect(Collectors.toList());
-			canteens.addAll(0, firstCanteenPage);
-			canteens.sort(Comparator.comparingInt(Canteen::getId));
-				//canteens = canteens.thenCombine(api.getCanteens(Integer.parseInt(pageN.get())), (l1, l2) -> Stream.concat(l1.parallelStream(), l2.parallelStream()))
-			canteens.forEach((c) -> System.out.println(c.toString()));
+				.collect(Collectors.toList());*/
 
+			final var id = CompletableFuture.completedFuture(firstPage);
+			var request = IntStream
+				.range(2, N + 1) // one-indexed
+				.mapToObj(openMensaAPI::getCanteens)
+				.reduce(
+					id,
+					(f1, f2) -> f1.thenCombine(
+						f2,
+						// lambda combining two lists
+						// cannot move to variable, because no templating and no type inference for lambdas
+						// fuck java
+						(l1, l2) -> Stream
+							.concat(l1.stream(), l2.stream())
+							.collect(Collectors.toList()))
+				)
+				.thenAccept(canteens -> {
+					canteens.stream()
+						.sorted(Comparator.comparingInt(Canteen::getId))
+						.forEach(System.out::println);
+					System.out.println(pageInfo.getTotalCountOfItems() + " <- Header | actual -> " + canteens.size());
+				})
+				.exceptionally(e -> {
+					do {
+						System.out.println(e.getMessage());
+						e = e.getCause();
+					} while (e != null);
+					return null;
+				});
+
+			// lazy -> eager
+			request.join();
 		} catch (InterruptedException | ExecutionException | NumberFormatException e) {
 			e.printStackTrace();
 			System.out.println("WHYYYYYYYYYYy!!!!");
@@ -84,6 +110,21 @@ public class App {
 		/* TODO fetch all meals for the currently selected canteen
 		 * to avoid errors retrieve at first the state of the canteen and check if the canteen is opened at the selected day
 		 * don't forget to check if a canteen was selected previously! */
+		if (currentCanteenId == -1) {
+			System.out.println("Error: no canteen selected");
+			return;
+		}
+
+		openMensaAPI
+			.getMeals(currentCanteenId, dateFormat.format(currentDate.getTime()))
+			.exceptionally((e) -> {
+				System.out.println(e.getMessage());
+				if (e instanceof HttpException) System.out.println(((HttpException) e).response());
+				return List.of();
+			})
+			.thenAccept(meals -> meals.forEach(System.out::println))
+			.join();
+
 	}
 
 	/**