added CKeller parser

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.cal.importer/src/main/java/de/srsoftware/cal/importer/weimar/CKeller.java

@@ -1,4 +1,114 @@
+/* © SRSoftware 2024 */
 package de.srsoftware.cal.importer.weimar;
 
-public class CKeller {
+import static de.srsoftware.tools.Error.error;
+import static de.srsoftware.tools.Optionals.nullable;
+import static de.srsoftware.tools.Result.transform;
+import static de.srsoftware.tools.Tag.*;
+import static de.srsoftware.tools.TagFilter.*;
+import static java.util.Optional.empty;
+
+import de.srsoftware.cal.BaseAppointment;
+import de.srsoftware.cal.Util;
+import de.srsoftware.cal.api.Appointment;
+import de.srsoftware.cal.api.Attachment;
+import de.srsoftware.cal.api.Importer;
+import de.srsoftware.cal.api.Link;
+import de.srsoftware.tools.Payload;
+import de.srsoftware.tools.Result;
+import de.srsoftware.tools.Tag;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.regex.Pattern;
+import java.util.stream.Stream;
+
+public class CKeller implements Importer {
+	private static final String BASE_URL = "http://c-keller.de";
+	private static final Pattern YEAR_PATTERN = Pattern.compile("^(\\d{4}):?$");
+	private static final Pattern EVENT_PATTERN = Pattern.compile("\\D*(\\d\\d?).(\\d\\d?). *([^&]+)&[^;]+;(.*)");
+	private static final String LOCATION = "C-Keller, Markt 21, 99423 Weimar";
+	private static final LocalTime START_TIME = LocalTime.of(19,0);
+	private final Link link;
+
+	public CKeller() throws MalformedURLException {
+		link = new Link(URI.create(BASE_URL).toURL(),"Homepage");
+	}
+	@Override
+	public String description() {
+		return "Importer für Events des C-Keller in Weimar";
+	}
+
+	@Override
+	public Stream<Appointment> fetch() throws IOException {
+		return Payload.of(BASE_URL)
+				.map(Util::url)
+				.map(Util::open)
+				.map(Util::preload)
+				.map(Util::parseXML)
+				.map(this::extract)
+				.optional()
+				.orElseGet(List::of)
+				.stream();
+	}
+
+	private Result<List<Appointment>> extract(Result<Tag> tagResult) {
+		var list = new ArrayList<Appointment>();
+		if (tagResult.optional().isEmpty()) return transform(tagResult);
+		Util.dump(tagResult.optional().get());
+		var divs = tagResult.optional().get()
+				.find(attributeEquals(ID,"col2_content")).stream()
+				.flatMap(tag -> tag.children().stream())
+				.toList();
+		Tag last = null;
+		var now = LocalDate.now();
+		for (var div : divs){
+			if ("textumschluss".equals(div.get(ID))){
+				createEvent(last,div,now).ifPresent(list::add);
+			}
+			last = div;
+		}
+		return Payload.of(list);
+	}
+
+	private Optional<Appointment> createEvent(Tag cal, Tag text, LocalDate now) {
+		var day = cal.find(attributeEquals(CLASS, "calday")).stream()
+				.map(Tag::strip).map(Util::parseInt).findAny().orElseGet(() -> error("No date")).optional();
+		if (day.isEmpty()) return empty();
+
+		Stream<Result<Integer>> stream = cal.find(attributeEquals(CLASS, "calmonth")).stream().map(Tag::strip).flatMap(s -> Util.toNumericMonth(s).stream());
+		Optional<Integer> mon = stream.findAny().orElse(error("Error")).optional();
+		if (mon.isEmpty()) return empty();
+		var title = text.find(attributeEquals(CLASS,"fett")).stream().map(Tag::strip).findAny();
+		if (title.isEmpty()) return empty();
+		var desc = text.find(attributeEquals(CLASS,"kalenderi")).stream().map(Tag::strip).findAny();
+
+		var date = LocalDate.of(now.getYear(),mon.get(),day.get());
+		if (date.isBefore(now)) date = date.withYear(now.getYear()+1);
+		var start = LocalDateTime.of(date,START_TIME);
+		var app = new BaseAppointment(0,title.get(),desc.orElse(title.get()),start,null,LOCATION);
+
+		text.find(IS_IMAGE).stream().map(tag -> imageToAttachment(tag))
+				.map(Result::optional).flatMap(Optional::stream)
+						.forEach(app::add);
+		app.addLinks(link);
+		app.tags("C-Keller","Weimar");
+		return Optional.of(app);
+	}
+
+	private Result<Attachment> imageToAttachment(Tag img) {
+		var parent = img.parent();
+		String url = parent.map(tag -> tag.get(HREF)).orElseGet(() -> img.get("src"));
+		if (url == null) return error("No link found");
+		if (url.startsWith("./")) url = url.substring(2);
+		if (!url.contains("://")) url = BASE_URL + "/" + url;
+		return Payload.of(url).map(Util::url).map(Util::toAttachment);
+	}
 }